services: complete ChannelTrace in channelz.proto

6 files changed, 2622 insertions, 147 deletions

diff --git a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTrace.java b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTrace.java
index 97710fc8d..37e5b131c 100644
--- a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTrace.java
+++ b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTrace.java
@@ -20,6 +20,8 @@ private static final long serialVersionUID = 0L;
     super(builder);
   }
   private ChannelTrace() {
+    numEventsLogged_ = 0L;
+    events_ = java.util.Collections.emptyList();
   }
 
   @java.lang.Override
@@ -35,6 +37,7 @@ private static final long serialVersionUID = 0L;
     if (extensionRegistry == null) {
       throw new java.lang.NullPointerException();
     }
+    int mutable_bitField0_ = 0;
     com.google.protobuf.UnknownFieldSet.Builder unknownFields =
         com.google.protobuf.UnknownFieldSet.newBuilder();
     try {
@@ -52,6 +55,33 @@ private static final long serialVersionUID = 0L;
             }
             break;
           }
+          case 8: {
+
+            numEventsLogged_ = input.readInt64();
+            break;
+          }
+          case 18: {
+            com.google.protobuf.Timestamp.Builder subBuilder = null;
+            if (creationTimestamp_ != null) {
+              subBuilder = creationTimestamp_.toBuilder();
+            }
+            creationTimestamp_ = input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(creationTimestamp_);
+              creationTimestamp_ = subBuilder.buildPartial();
+            }
+
+            break;
+          }
+          case 26: {
+            if (!((mutable_bitField0_ & 0x00000004) == 0x00000004)) {
+              events_ = new java.util.ArrayList<io.grpc.channelz.v1.ChannelTraceEvent>();
+              mutable_bitField0_ |= 0x00000004;
+            }
+            events_.add(
+                input.readMessage(io.grpc.channelz.v1.ChannelTraceEvent.parser(), extensionRegistry));
+            break;
+          }
         }
       }
     } catch (com.google.protobuf.InvalidProtocolBufferException e) {
@@ -60,6 +90,9 @@ private static final long serialVersionUID = 0L;
       throw new com.google.protobuf.InvalidProtocolBufferException(
           e).setUnfinishedMessage(this);
     } finally {
+      if (((mutable_bitField0_ & 0x00000004) == 0x00000004)) {
+        events_ = java.util.Collections.unmodifiableList(events_);
+      }
       this.unknownFields = unknownFields.build();
       makeExtensionsImmutable();
     }
@@ -76,6 +109,110 @@ private static final long serialVersionUID = 0L;
             io.grpc.channelz.v1.ChannelTrace.class, io.grpc.channelz.v1.ChannelTrace.Builder.class);
   }
 
+  private int bitField0_;
+  public static final int NUM_EVENTS_LOGGED_FIELD_NUMBER = 1;
+  private long numEventsLogged_;
+  /**
+   * <pre>
+   * Number of events ever logged in this tracing object. This can differ from
+   * events.size() because events can be overwritten or garbage collected by
+   * implementations.
+   * </pre>
+   *
+   * <code>int64 num_events_logged = 1;</code>
+   */
+  public long getNumEventsLogged() {
+    return numEventsLogged_;
+  }
+
+  public static final int CREATION_TIMESTAMP_FIELD_NUMBER = 2;
+  private com.google.protobuf.Timestamp creationTimestamp_;
+  /**
+   * <pre>
+   * Time that this channel was created.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+   */
+  public boolean hasCreationTimestamp() {
+    return creationTimestamp_ != null;
+  }
+  /**
+   * <pre>
+   * Time that this channel was created.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+   */
+  public com.google.protobuf.Timestamp getCreationTimestamp() {
+    return creationTimestamp_ == null ? com.google.protobuf.Timestamp.getDefaultInstance() : creationTimestamp_;
+  }
+  /**
+   * <pre>
+   * Time that this channel was created.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+   */
+  public com.google.protobuf.TimestampOrBuilder getCreationTimestampOrBuilder() {
+    return getCreationTimestamp();
+  }
+
+  public static final int EVENTS_FIELD_NUMBER = 3;
+  private java.util.List<io.grpc.channelz.v1.ChannelTraceEvent> events_;
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  public java.util.List<io.grpc.channelz.v1.ChannelTraceEvent> getEventsList() {
+    return events_;
+  }
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  public java.util.List<? extends io.grpc.channelz.v1.ChannelTraceEventOrBuilder> 
+      getEventsOrBuilderList() {
+    return events_;
+  }
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  public int getEventsCount() {
+    return events_.size();
+  }
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  public io.grpc.channelz.v1.ChannelTraceEvent getEvents(int index) {
+    return events_.get(index);
+  }
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  public io.grpc.channelz.v1.ChannelTraceEventOrBuilder getEventsOrBuilder(
+      int index) {
+    return events_.get(index);
+  }
+
   private byte memoizedIsInitialized = -1;
   public final boolean isInitialized() {
     byte isInitialized = memoizedIsInitialized;
@@ -88,6 +225,15 @@ private static final long serialVersionUID = 0L;
 
   public void writeTo(com.google.protobuf.CodedOutputStream output)
                       throws java.io.IOException {
+    if (numEventsLogged_ != 0L) {
+      output.writeInt64(1, numEventsLogged_);
+    }
+    if (creationTimestamp_ != null) {
+      output.writeMessage(2, getCreationTimestamp());
+    }
+    for (int i = 0; i < events_.size(); i++) {
+      output.writeMessage(3, events_.get(i));
+    }
     unknownFields.writeTo(output);
   }
 
@@ -96,6 +242,18 @@ private static final long serialVersionUID = 0L;
     if (size != -1) return size;
 
     size = 0;
+    if (numEventsLogged_ != 0L) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeInt64Size(1, numEventsLogged_);
+    }
+    if (creationTimestamp_ != null) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeMessageSize(2, getCreationTimestamp());
+    }
+    for (int i = 0; i < events_.size(); i++) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeMessageSize(3, events_.get(i));
+    }
     size += unknownFields.getSerializedSize();
     memoizedSize = size;
     return size;
@@ -112,6 +270,15 @@ private static final long serialVersionUID = 0L;
     io.grpc.channelz.v1.ChannelTrace other = (io.grpc.channelz.v1.ChannelTrace) obj;
 
     boolean result = true;
+    result = result && (getNumEventsLogged()
+        == other.getNumEventsLogged());
+    result = result && (hasCreationTimestamp() == other.hasCreationTimestamp());
+    if (hasCreationTimestamp()) {
+      result = result && getCreationTimestamp()
+          .equals(other.getCreationTimestamp());
+    }
+    result = result && getEventsList()
+        .equals(other.getEventsList());
     result = result && unknownFields.equals(other.unknownFields);
     return result;
   }
@@ -123,6 +290,17 @@ private static final long serialVersionUID = 0L;
     }
     int hash = 41;
     hash = (19 * hash) + getDescriptor().hashCode();
+    hash = (37 * hash) + NUM_EVENTS_LOGGED_FIELD_NUMBER;
+    hash = (53 * hash) + com.google.protobuf.Internal.hashLong(
+        getNumEventsLogged());
+    if (hasCreationTimestamp()) {
+      hash = (37 * hash) + CREATION_TIMESTAMP_FIELD_NUMBER;
+      hash = (53 * hash) + getCreationTimestamp().hashCode();
+    }
+    if (getEventsCount() > 0) {
+      hash = (37 * hash) + EVENTS_FIELD_NUMBER;
+      hash = (53 * hash) + getEventsList().hashCode();
+    }
     hash = (29 * hash) + unknownFields.hashCode();
     memoizedHashCode = hash;
     return hash;
@@ -252,10 +430,25 @@ private static final long serialVersionUID = 0L;
     private void maybeForceBuilderInitialization() {
       if (com.google.protobuf.GeneratedMessageV3
               .alwaysUseFieldBuilders) {
+        getEventsFieldBuilder();
       }
     }
     public Builder clear() {
       super.clear();
+      numEventsLogged_ = 0L;
+
+      if (creationTimestampBuilder_ == null) {
+        creationTimestamp_ = null;
+      } else {
+        creationTimestamp_ = null;
+        creationTimestampBuilder_ = null;
+      }
+      if (eventsBuilder_ == null) {
+        events_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000004);
+      } else {
+        eventsBuilder_.clear();
+      }
       return this;
     }
 
@@ -278,6 +471,24 @@ private static final long serialVersionUID = 0L;
 
     public io.grpc.channelz.v1.ChannelTrace buildPartial() {
       io.grpc.channelz.v1.ChannelTrace result = new io.grpc.channelz.v1.ChannelTrace(this);
+      int from_bitField0_ = bitField0_;
+      int to_bitField0_ = 0;
+      result.numEventsLogged_ = numEventsLogged_;
+      if (creationTimestampBuilder_ == null) {
+        result.creationTimestamp_ = creationTimestamp_;
+      } else {
+        result.creationTimestamp_ = creationTimestampBuilder_.build();
+      }
+      if (eventsBuilder_ == null) {
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          events_ = java.util.Collections.unmodifiableList(events_);
+          bitField0_ = (bitField0_ & ~0x00000004);
+        }
+        result.events_ = events_;
+      } else {
+        result.events_ = eventsBuilder_.build();
+      }
+      result.bitField0_ = to_bitField0_;
       onBuilt();
       return result;
     }
@@ -319,6 +530,38 @@ private static final long serialVersionUID = 0L;
 
     public Builder mergeFrom(io.grpc.channelz.v1.ChannelTrace other) {
       if (other == io.grpc.channelz.v1.ChannelTrace.getDefaultInstance()) return this;
+      if (other.getNumEventsLogged() != 0L) {
+        setNumEventsLogged(other.getNumEventsLogged());
+      }
+      if (other.hasCreationTimestamp()) {
+        mergeCreationTimestamp(other.getCreationTimestamp());
+      }
+      if (eventsBuilder_ == null) {
+        if (!other.events_.isEmpty()) {
+          if (events_.isEmpty()) {
+            events_ = other.events_;
+            bitField0_ = (bitField0_ & ~0x00000004);
+          } else {
+            ensureEventsIsMutable();
+            events_.addAll(other.events_);
+          }
+          onChanged();
+        }
+      } else {
+        if (!other.events_.isEmpty()) {
+          if (eventsBuilder_.isEmpty()) {
+            eventsBuilder_.dispose();
+            eventsBuilder_ = null;
+            events_ = other.events_;
+            bitField0_ = (bitField0_ & ~0x00000004);
+            eventsBuilder_ = 
+              com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders ?
+                 getEventsFieldBuilder() : null;
+          } else {
+            eventsBuilder_.addAllMessages(other.events_);
+          }
+        }
+      }
       this.mergeUnknownFields(other.unknownFields);
       onChanged();
       return this;
@@ -345,6 +588,516 @@ private static final long serialVersionUID = 0L;
       }
       return this;
     }
+    private int bitField0_;
+
+    private long numEventsLogged_ ;
+    /**
+     * <pre>
+     * Number of events ever logged in this tracing object. This can differ from
+     * events.size() because events can be overwritten or garbage collected by
+     * implementations.
+     * </pre>
+     *
+     * <code>int64 num_events_logged = 1;</code>
+     */
+    public long getNumEventsLogged() {
+      return numEventsLogged_;
+    }
+    /**
+     * <pre>
+     * Number of events ever logged in this tracing object. This can differ from
+     * events.size() because events can be overwritten or garbage collected by
+     * implementations.
+     * </pre>
+     *
+     * <code>int64 num_events_logged = 1;</code>
+     */
+    public Builder setNumEventsLogged(long value) {
+      
+      numEventsLogged_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <pre>
+     * Number of events ever logged in this tracing object. This can differ from
+     * events.size() because events can be overwritten or garbage collected by
+     * implementations.
+     * </pre>
+     *
+     * <code>int64 num_events_logged = 1;</code>
+     */
+    public Builder clearNumEventsLogged() {
+      
+      numEventsLogged_ = 0L;
+      onChanged();
+      return this;
+    }
+
+    private com.google.protobuf.Timestamp creationTimestamp_ = null;
+    private com.google.protobuf.SingleFieldBuilderV3<
+        com.google.protobuf.Timestamp, com.google.protobuf.Timestamp.Builder, com.google.protobuf.TimestampOrBuilder> creationTimestampBuilder_;
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public boolean hasCreationTimestamp() {
+      return creationTimestampBuilder_ != null || creationTimestamp_ != null;
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public com.google.protobuf.Timestamp getCreationTimestamp() {
+      if (creationTimestampBuilder_ == null) {
+        return creationTimestamp_ == null ? com.google.protobuf.Timestamp.getDefaultInstance() : creationTimestamp_;
+      } else {
+        return creationTimestampBuilder_.getMessage();
+      }
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public Builder setCreationTimestamp(com.google.protobuf.Timestamp value) {
+      if (creationTimestampBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        creationTimestamp_ = value;
+        onChanged();
+      } else {
+        creationTimestampBuilder_.setMessage(value);
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public Builder setCreationTimestamp(
+        com.google.protobuf.Timestamp.Builder builderForValue) {
+      if (creationTimestampBuilder_ == null) {
+        creationTimestamp_ = builderForValue.build();
+        onChanged();
+      } else {
+        creationTimestampBuilder_.setMessage(builderForValue.build());
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public Builder mergeCreationTimestamp(com.google.protobuf.Timestamp value) {
+      if (creationTimestampBuilder_ == null) {
+        if (creationTimestamp_ != null) {
+          creationTimestamp_ =
+            com.google.protobuf.Timestamp.newBuilder(creationTimestamp_).mergeFrom(value).buildPartial();
+        } else {
+          creationTimestamp_ = value;
+        }
+        onChanged();
+      } else {
+        creationTimestampBuilder_.mergeFrom(value);
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public Builder clearCreationTimestamp() {
+      if (creationTimestampBuilder_ == null) {
+        creationTimestamp_ = null;
+        onChanged();
+      } else {
+        creationTimestamp_ = null;
+        creationTimestampBuilder_ = null;
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public com.google.protobuf.Timestamp.Builder getCreationTimestampBuilder() {
+      
+      onChanged();
+      return getCreationTimestampFieldBuilder().getBuilder();
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    public com.google.protobuf.TimestampOrBuilder getCreationTimestampOrBuilder() {
+      if (creationTimestampBuilder_ != null) {
+        return creationTimestampBuilder_.getMessageOrBuilder();
+      } else {
+        return creationTimestamp_ == null ?
+            com.google.protobuf.Timestamp.getDefaultInstance() : creationTimestamp_;
+      }
+    }
+    /**
+     * <pre>
+     * Time that this channel was created.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+     */
+    private com.google.protobuf.SingleFieldBuilderV3<
+        com.google.protobuf.Timestamp, com.google.protobuf.Timestamp.Builder, com.google.protobuf.TimestampOrBuilder> 
+        getCreationTimestampFieldBuilder() {
+      if (creationTimestampBuilder_ == null) {
+        creationTimestampBuilder_ = new com.google.protobuf.SingleFieldBuilderV3<
+            com.google.protobuf.Timestamp, com.google.protobuf.Timestamp.Builder, com.google.protobuf.TimestampOrBuilder>(
+                getCreationTimestamp(),
+                getParentForChildren(),
+                isClean());
+        creationTimestamp_ = null;
+      }
+      return creationTimestampBuilder_;
+    }
+
+    private java.util.List<io.grpc.channelz.v1.ChannelTraceEvent> events_ =
+      java.util.Collections.emptyList();
+    private void ensureEventsIsMutable() {
+      if (!((bitField0_ & 0x00000004) == 0x00000004)) {
+        events_ = new java.util.ArrayList<io.grpc.channelz.v1.ChannelTraceEvent>(events_);
+        bitField0_ |= 0x00000004;
+       }
+    }
+
+    private com.google.protobuf.RepeatedFieldBuilderV3<
+        io.grpc.channelz.v1.ChannelTraceEvent, io.grpc.channelz.v1.ChannelTraceEvent.Builder, io.grpc.channelz.v1.ChannelTraceEventOrBuilder> eventsBuilder_;
+
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public java.util.List<io.grpc.channelz.v1.ChannelTraceEvent> getEventsList() {
+      if (eventsBuilder_ == null) {
+        return java.util.Collections.unmodifiableList(events_);
+      } else {
+        return eventsBuilder_.getMessageList();
+      }
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public int getEventsCount() {
+      if (eventsBuilder_ == null) {
+        return events_.size();
+      } else {
+        return eventsBuilder_.getCount();
+      }
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public io.grpc.channelz.v1.ChannelTraceEvent getEvents(int index) {
+      if (eventsBuilder_ == null) {
+        return events_.get(index);
+      } else {
+        return eventsBuilder_.getMessage(index);
+      }
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder setEvents(
+        int index, io.grpc.channelz.v1.ChannelTraceEvent value) {
+      if (eventsBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        ensureEventsIsMutable();
+        events_.set(index, value);
+        onChanged();
+      } else {
+        eventsBuilder_.setMessage(index, value);
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder setEvents(
+        int index, io.grpc.channelz.v1.ChannelTraceEvent.Builder builderForValue) {
+      if (eventsBuilder_ == null) {
+        ensureEventsIsMutable();
+        events_.set(index, builderForValue.build());
+        onChanged();
+      } else {
+        eventsBuilder_.setMessage(index, builderForValue.build());
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder addEvents(io.grpc.channelz.v1.ChannelTraceEvent value) {
+      if (eventsBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        ensureEventsIsMutable();
+        events_.add(value);
+        onChanged();
+      } else {
+        eventsBuilder_.addMessage(value);
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder addEvents(
+        int index, io.grpc.channelz.v1.ChannelTraceEvent value) {
+      if (eventsBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        ensureEventsIsMutable();
+        events_.add(index, value);
+        onChanged();
+      } else {
+        eventsBuilder_.addMessage(index, value);
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder addEvents(
+        io.grpc.channelz.v1.ChannelTraceEvent.Builder builderForValue) {
+      if (eventsBuilder_ == null) {
+        ensureEventsIsMutable();
+        events_.add(builderForValue.build());
+        onChanged();
+      } else {
+        eventsBuilder_.addMessage(builderForValue.build());
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder addEvents(
+        int index, io.grpc.channelz.v1.ChannelTraceEvent.Builder builderForValue) {
+      if (eventsBuilder_ == null) {
+        ensureEventsIsMutable();
+        events_.add(index, builderForValue.build());
+        onChanged();
+      } else {
+        eventsBuilder_.addMessage(index, builderForValue.build());
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder addAllEvents(
+        java.lang.Iterable<? extends io.grpc.channelz.v1.ChannelTraceEvent> values) {
+      if (eventsBuilder_ == null) {
+        ensureEventsIsMutable();
+        com.google.protobuf.AbstractMessageLite.Builder.addAll(
+            values, events_);
+        onChanged();
+      } else {
+        eventsBuilder_.addAllMessages(values);
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder clearEvents() {
+      if (eventsBuilder_ == null) {
+        events_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000004);
+        onChanged();
+      } else {
+        eventsBuilder_.clear();
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public Builder removeEvents(int index) {
+      if (eventsBuilder_ == null) {
+        ensureEventsIsMutable();
+        events_.remove(index);
+        onChanged();
+      } else {
+        eventsBuilder_.remove(index);
+      }
+      return this;
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public io.grpc.channelz.v1.ChannelTraceEvent.Builder getEventsBuilder(
+        int index) {
+      return getEventsFieldBuilder().getBuilder(index);
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public io.grpc.channelz.v1.ChannelTraceEventOrBuilder getEventsOrBuilder(
+        int index) {
+      if (eventsBuilder_ == null) {
+        return events_.get(index);  } else {
+        return eventsBuilder_.getMessageOrBuilder(index);
+      }
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public java.util.List<? extends io.grpc.channelz.v1.ChannelTraceEventOrBuilder> 
+         getEventsOrBuilderList() {
+      if (eventsBuilder_ != null) {
+        return eventsBuilder_.getMessageOrBuilderList();
+      } else {
+        return java.util.Collections.unmodifiableList(events_);
+      }
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public io.grpc.channelz.v1.ChannelTraceEvent.Builder addEventsBuilder() {
+      return getEventsFieldBuilder().addBuilder(
+          io.grpc.channelz.v1.ChannelTraceEvent.getDefaultInstance());
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public io.grpc.channelz.v1.ChannelTraceEvent.Builder addEventsBuilder(
+        int index) {
+      return getEventsFieldBuilder().addBuilder(
+          index, io.grpc.channelz.v1.ChannelTraceEvent.getDefaultInstance());
+    }
+    /**
+     * <pre>
+     * List of events that have occurred on this channel.
+     * </pre>
+     *
+     * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+     */
+    public java.util.List<io.grpc.channelz.v1.ChannelTraceEvent.Builder> 
+         getEventsBuilderList() {
+      return getEventsFieldBuilder().getBuilderList();
+    }
+    private com.google.protobuf.RepeatedFieldBuilderV3<
+        io.grpc.channelz.v1.ChannelTraceEvent, io.grpc.channelz.v1.ChannelTraceEvent.Builder, io.grpc.channelz.v1.ChannelTraceEventOrBuilder> 
+        getEventsFieldBuilder() {
+      if (eventsBuilder_ == null) {
+        eventsBuilder_ = new com.google.protobuf.RepeatedFieldBuilderV3<
+            io.grpc.channelz.v1.ChannelTraceEvent, io.grpc.channelz.v1.ChannelTraceEvent.Builder, io.grpc.channelz.v1.ChannelTraceEventOrBuilder>(
+                events_,
+                ((bitField0_ & 0x00000004) == 0x00000004),
+                getParentForChildren(),
+                isClean());
+        events_ = null;
+      }
+      return eventsBuilder_;
+    }
     public final Builder setUnknownFields(
         final com.google.protobuf.UnknownFieldSet unknownFields) {
       return super.setUnknownFieldsProto3(unknownFields);
diff --git a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceEvent.java b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceEvent.java
new file mode 100644
index 000000000..32206843d
--- /dev/null
+++ b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceEvent.java
@@ -0,0 +1,1490 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: grpc/channelz/v1/channelz.proto
+
+package io.grpc.channelz.v1;
+
+/**
+ * <pre>
+ * A trace event is an interesting thing that happened to a channel or
+ * subchannel, such as creation, address resolution, subchannel creation, etc.
+ * </pre>
+ *
+ * Protobuf type {@code grpc.channelz.v1.ChannelTraceEvent}
+ */
+public  final class ChannelTraceEvent extends
+    com.google.protobuf.GeneratedMessageV3 implements
+    // @@protoc_insertion_point(message_implements:grpc.channelz.v1.ChannelTraceEvent)
+    ChannelTraceEventOrBuilder {
+private static final long serialVersionUID = 0L;
+  // Use ChannelTraceEvent.newBuilder() to construct.
+  private ChannelTraceEvent(com.google.protobuf.GeneratedMessageV3.Builder<?> builder) {
+    super(builder);
+  }
+  private ChannelTraceEvent() {
+    description_ = "";
+    severity_ = 0;
+  }
+
+  @java.lang.Override
+  public final com.google.protobuf.UnknownFieldSet
+  getUnknownFields() {
+    return this.unknownFields;
+  }
+  private ChannelTraceEvent(
+      com.google.protobuf.CodedInputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    this();
+    if (extensionRegistry == null) {
+      throw new java.lang.NullPointerException();
+    }
+    int mutable_bitField0_ = 0;
+    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+        com.google.protobuf.UnknownFieldSet.newBuilder();
+    try {
+      boolean done = false;
+      while (!done) {
+        int tag = input.readTag();
+        switch (tag) {
+          case 0:
+            done = true;
+            break;
+          default: {
+            if (!parseUnknownFieldProto3(
+                input, unknownFields, extensionRegistry, tag)) {
+              done = true;
+            }
+            break;
+          }
+          case 10: {
+            java.lang.String s = input.readStringRequireUtf8();
+
+            description_ = s;
+            break;
+          }
+          case 16: {
+            int rawValue = input.readEnum();
+
+            severity_ = rawValue;
+            break;
+          }
+          case 26: {
+            com.google.protobuf.Timestamp.Builder subBuilder = null;
+            if (timestamp_ != null) {
+              subBuilder = timestamp_.toBuilder();
+            }
+            timestamp_ = input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(timestamp_);
+              timestamp_ = subBuilder.buildPartial();
+            }
+
+            break;
+          }
+          case 34: {
+            io.grpc.channelz.v1.ChannelRef.Builder subBuilder = null;
+            if (childRefCase_ == 4) {
+              subBuilder = ((io.grpc.channelz.v1.ChannelRef) childRef_).toBuilder();
+            }
+            childRef_ =
+                input.readMessage(io.grpc.channelz.v1.ChannelRef.parser(), extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom((io.grpc.channelz.v1.ChannelRef) childRef_);
+              childRef_ = subBuilder.buildPartial();
+            }
+            childRefCase_ = 4;
+            break;
+          }
+          case 42: {
+            io.grpc.channelz.v1.SubchannelRef.Builder subBuilder = null;
+            if (childRefCase_ == 5) {
+              subBuilder = ((io.grpc.channelz.v1.SubchannelRef) childRef_).toBuilder();
+            }
+            childRef_ =
+                input.readMessage(io.grpc.channelz.v1.SubchannelRef.parser(), extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom((io.grpc.channelz.v1.SubchannelRef) childRef_);
+              childRef_ = subBuilder.buildPartial();
+            }
+            childRefCase_ = 5;
+            break;
+          }
+        }
+      }
+    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+      throw e.setUnfinishedMessage(this);
+    } catch (java.io.IOException e) {
+      throw new com.google.protobuf.InvalidProtocolBufferException(
+          e).setUnfinishedMessage(this);
+    } finally {
+      this.unknownFields = unknownFields.build();
+      makeExtensionsImmutable();
+    }
+  }
+  public static final com.google.protobuf.Descriptors.Descriptor
+      getDescriptor() {
+    return io.grpc.channelz.v1.ChannelzProto.internal_static_grpc_channelz_v1_ChannelTraceEvent_descriptor;
+  }
+
+  protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+      internalGetFieldAccessorTable() {
+    return io.grpc.channelz.v1.ChannelzProto.internal_static_grpc_channelz_v1_ChannelTraceEvent_fieldAccessorTable
+        .ensureFieldAccessorsInitialized(
+            io.grpc.channelz.v1.ChannelTraceEvent.class, io.grpc.channelz.v1.ChannelTraceEvent.Builder.class);
+  }
+
+  /**
+   * <pre>
+   * The supported severity levels of trace events.
+   * </pre>
+   *
+   * Protobuf enum {@code grpc.channelz.v1.ChannelTraceEvent.Severity}
+   */
+  public enum Severity
+      implements com.google.protobuf.ProtocolMessageEnum {
+    /**
+     * <code>CT_UNKNOWN = 0;</code>
+     */
+    CT_UNKNOWN(0),
+    /**
+     * <code>CT_INFO = 1;</code>
+     */
+    CT_INFO(1),
+    /**
+     * <code>CT_WARNING = 2;</code>
+     */
+    CT_WARNING(2),
+    /**
+     * <code>CT_ERROR = 3;</code>
+     */
+    CT_ERROR(3),
+    UNRECOGNIZED(-1),
+    ;
+
+    /**
+     * <code>CT_UNKNOWN = 0;</code>
+     */
+    public static final int CT_UNKNOWN_VALUE = 0;
+    /**
+     * <code>CT_INFO = 1;</code>
+     */
+    public static final int CT_INFO_VALUE = 1;
+    /**
+     * <code>CT_WARNING = 2;</code>
+     */
+    public static final int CT_WARNING_VALUE = 2;
+    /**
+     * <code>CT_ERROR = 3;</code>
+     */
+    public static final int CT_ERROR_VALUE = 3;
+
+
+    public final int getNumber() {
+      if (this == UNRECOGNIZED) {
+        throw new java.lang.IllegalArgumentException(
+            "Can't get the number of an unknown enum value.");
+      }
+      return value;
+    }
+
+    /**
+     * @deprecated Use {@link #forNumber(int)} instead.
+     */
+    @java.lang.Deprecated
+    public static Severity valueOf(int value) {
+      return forNumber(value);
+    }
+
+    public static Severity forNumber(int value) {
+      switch (value) {
+        case 0: return CT_UNKNOWN;
+        case 1: return CT_INFO;
+        case 2: return CT_WARNING;
+        case 3: return CT_ERROR;
+        default: return null;
+      }
+    }
+
+    public static com.google.protobuf.Internal.EnumLiteMap<Severity>
+        internalGetValueMap() {
+      return internalValueMap;
+    }
+    private static final com.google.protobuf.Internal.EnumLiteMap<
+        Severity> internalValueMap =
+          new com.google.protobuf.Internal.EnumLiteMap<Severity>() {
+            public Severity findValueByNumber(int number) {
+              return Severity.forNumber(number);
+            }
+          };
+
+    public final com.google.protobuf.Descriptors.EnumValueDescriptor
+        getValueDescriptor() {
+      return getDescriptor().getValues().get(ordinal());
+    }
+    public final com.google.protobuf.Descriptors.EnumDescriptor
+        getDescriptorForType() {
+      return getDescriptor();
+    }
+    public static final com.google.protobuf.Descriptors.EnumDescriptor
+        getDescriptor() {
+      return io.grpc.channelz.v1.ChannelTraceEvent.getDescriptor().getEnumTypes().get(0);
+    }
+
+    private static final Severity[] VALUES = values();
+
+    public static Severity valueOf(
+        com.google.protobuf.Descriptors.EnumValueDescriptor desc) {
+      if (desc.getType() != getDescriptor()) {
+        throw new java.lang.IllegalArgumentException(
+          "EnumValueDescriptor is not for this type.");
+      }
+      if (desc.getIndex() == -1) {
+        return UNRECOGNIZED;
+      }
+      return VALUES[desc.getIndex()];
+    }
+
+    private final int value;
+
+    private Severity(int value) {
+      this.value = value;
+    }
+
+    // @@protoc_insertion_point(enum_scope:grpc.channelz.v1.ChannelTraceEvent.Severity)
+  }
+
+  private int childRefCase_ = 0;
+  private java.lang.Object childRef_;
+  public enum ChildRefCase
+      implements com.google.protobuf.Internal.EnumLite {
+    CHANNEL_REF(4),
+    SUBCHANNEL_REF(5),
+    CHILDREF_NOT_SET(0);
+    private final int value;
+    private ChildRefCase(int value) {
+      this.value = value;
+    }
+    /**
+     * @deprecated Use {@link #forNumber(int)} instead.
+     */
+    @java.lang.Deprecated
+    public static ChildRefCase valueOf(int value) {
+      return forNumber(value);
+    }
+
+    public static ChildRefCase forNumber(int value) {
+      switch (value) {
+        case 4: return CHANNEL_REF;
+        case 5: return SUBCHANNEL_REF;
+        case 0: return CHILDREF_NOT_SET;
+        default: return null;
+      }
+    }
+    public int getNumber() {
+      return this.value;
+    }
+  };
+
+  public ChildRefCase
+  getChildRefCase() {
+    return ChildRefCase.forNumber(
+        childRefCase_);
+  }
+
+  public static final int DESCRIPTION_FIELD_NUMBER = 1;
+  private volatile java.lang.Object description_;
+  /**
+   * <pre>
+   * High level description of the event.
+   * </pre>
+   *
+   * <code>string description = 1;</code>
+   */
+  public java.lang.String getDescription() {
+    java.lang.Object ref = description_;
+    if (ref instanceof java.lang.String) {
+      return (java.lang.String) ref;
+    } else {
+      com.google.protobuf.ByteString bs = 
+          (com.google.protobuf.ByteString) ref;
+      java.lang.String s = bs.toStringUtf8();
+      description_ = s;
+      return s;
+    }
+  }
+  /**
+   * <pre>
+   * High level description of the event.
+   * </pre>
+   *
+   * <code>string description = 1;</code>
+   */
+  public com.google.protobuf.ByteString
+      getDescriptionBytes() {
+    java.lang.Object ref = description_;
+    if (ref instanceof java.lang.String) {
+      com.google.protobuf.ByteString b = 
+          com.google.protobuf.ByteString.copyFromUtf8(
+              (java.lang.String) ref);
+      description_ = b;
+      return b;
+    } else {
+      return (com.google.protobuf.ByteString) ref;
+    }
+  }
+
+  public static final int SEVERITY_FIELD_NUMBER = 2;
+  private int severity_;
+  /**
+   * <pre>
+   * the severity of the trace event
+   * </pre>
+   *
+   * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+   */
+  public int getSeverityValue() {
+    return severity_;
+  }
+  /**
+   * <pre>
+   * the severity of the trace event
+   * </pre>
+   *
+   * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+   */
+  public io.grpc.channelz.v1.ChannelTraceEvent.Severity getSeverity() {
+    io.grpc.channelz.v1.ChannelTraceEvent.Severity result = io.grpc.channelz.v1.ChannelTraceEvent.Severity.valueOf(severity_);
+    return result == null ? io.grpc.channelz.v1.ChannelTraceEvent.Severity.UNRECOGNIZED : result;
+  }
+
+  public static final int TIMESTAMP_FIELD_NUMBER = 3;
+  private com.google.protobuf.Timestamp timestamp_;
+  /**
+   * <pre>
+   * When this event occurred.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+   */
+  public boolean hasTimestamp() {
+    return timestamp_ != null;
+  }
+  /**
+   * <pre>
+   * When this event occurred.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+   */
+  public com.google.protobuf.Timestamp getTimestamp() {
+    return timestamp_ == null ? com.google.protobuf.Timestamp.getDefaultInstance() : timestamp_;
+  }
+  /**
+   * <pre>
+   * When this event occurred.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+   */
+  public com.google.protobuf.TimestampOrBuilder getTimestampOrBuilder() {
+    return getTimestamp();
+  }
+
+  public static final int CHANNEL_REF_FIELD_NUMBER = 4;
+  /**
+   * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+   */
+  public boolean hasChannelRef() {
+    return childRefCase_ == 4;
+  }
+  /**
+   * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+   */
+  public io.grpc.channelz.v1.ChannelRef getChannelRef() {
+    if (childRefCase_ == 4) {
+       return (io.grpc.channelz.v1.ChannelRef) childRef_;
+    }
+    return io.grpc.channelz.v1.ChannelRef.getDefaultInstance();
+  }
+  /**
+   * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+   */
+  public io.grpc.channelz.v1.ChannelRefOrBuilder getChannelRefOrBuilder() {
+    if (childRefCase_ == 4) {
+       return (io.grpc.channelz.v1.ChannelRef) childRef_;
+    }
+    return io.grpc.channelz.v1.ChannelRef.getDefaultInstance();
+  }
+
+  public static final int SUBCHANNEL_REF_FIELD_NUMBER = 5;
+  /**
+   * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+   */
+  public boolean hasSubchannelRef() {
+    return childRefCase_ == 5;
+  }
+  /**
+   * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+   */
+  public io.grpc.channelz.v1.SubchannelRef getSubchannelRef() {
+    if (childRefCase_ == 5) {
+       return (io.grpc.channelz.v1.SubchannelRef) childRef_;
+    }
+    return io.grpc.channelz.v1.SubchannelRef.getDefaultInstance();
+  }
+  /**
+   * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+   */
+  public io.grpc.channelz.v1.SubchannelRefOrBuilder getSubchannelRefOrBuilder() {
+    if (childRefCase_ == 5) {
+       return (io.grpc.channelz.v1.SubchannelRef) childRef_;
+    }
+    return io.grpc.channelz.v1.SubchannelRef.getDefaultInstance();
+  }
+
+  private byte memoizedIsInitialized = -1;
+  public final boolean isInitialized() {
+    byte isInitialized = memoizedIsInitialized;
+    if (isInitialized == 1) return true;
+    if (isInitialized == 0) return false;
+
+    memoizedIsInitialized = 1;
+    return true;
+  }
+
+  public void writeTo(com.google.protobuf.CodedOutputStream output)
+                      throws java.io.IOException {
+    if (!getDescriptionBytes().isEmpty()) {
+      com.google.protobuf.GeneratedMessageV3.writeString(output, 1, description_);
+    }
+    if (severity_ != io.grpc.channelz.v1.ChannelTraceEvent.Severity.CT_UNKNOWN.getNumber()) {
+      output.writeEnum(2, severity_);
+    }
+    if (timestamp_ != null) {
+      output.writeMessage(3, getTimestamp());
+    }
+    if (childRefCase_ == 4) {
+      output.writeMessage(4, (io.grpc.channelz.v1.ChannelRef) childRef_);
+    }
+    if (childRefCase_ == 5) {
+      output.writeMessage(5, (io.grpc.channelz.v1.SubchannelRef) childRef_);
+    }
+    unknownFields.writeTo(output);
+  }
+
+  public int getSerializedSize() {
+    int size = memoizedSize;
+    if (size != -1) return size;
+
+    size = 0;
+    if (!getDescriptionBytes().isEmpty()) {
+      size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, description_);
+    }
+    if (severity_ != io.grpc.channelz.v1.ChannelTraceEvent.Severity.CT_UNKNOWN.getNumber()) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeEnumSize(2, severity_);
+    }
+    if (timestamp_ != null) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeMessageSize(3, getTimestamp());
+    }
+    if (childRefCase_ == 4) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeMessageSize(4, (io.grpc.channelz.v1.ChannelRef) childRef_);
+    }
+    if (childRefCase_ == 5) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeMessageSize(5, (io.grpc.channelz.v1.SubchannelRef) childRef_);
+    }
+    size += unknownFields.getSerializedSize();
+    memoizedSize = size;
+    return size;
+  }
+
+  @java.lang.Override
+  public boolean equals(final java.lang.Object obj) {
+    if (obj == this) {
+     return true;
+    }
+    if (!(obj instanceof io.grpc.channelz.v1.ChannelTraceEvent)) {
+      return super.equals(obj);
+    }
+    io.grpc.channelz.v1.ChannelTraceEvent other = (io.grpc.channelz.v1.ChannelTraceEvent) obj;
+
+    boolean result = true;
+    result = result && getDescription()
+        .equals(other.getDescription());
+    result = result && severity_ == other.severity_;
+    result = result && (hasTimestamp() == other.hasTimestamp());
+    if (hasTimestamp()) {
+      result = result && getTimestamp()
+          .equals(other.getTimestamp());
+    }
+    result = result && getChildRefCase().equals(
+        other.getChildRefCase());
+    if (!result) return false;
+    switch (childRefCase_) {
+      case 4:
+        result = result && getChannelRef()
+            .equals(other.getChannelRef());
+        break;
+      case 5:
+        result = result && getSubchannelRef()
+            .equals(other.getSubchannelRef());
+        break;
+      case 0:
+      default:
+    }
+    result = result && unknownFields.equals(other.unknownFields);
+    return result;
+  }
+
+  @java.lang.Override
+  public int hashCode() {
+    if (memoizedHashCode != 0) {
+      return memoizedHashCode;
+    }
+    int hash = 41;
+    hash = (19 * hash) + getDescriptor().hashCode();
+    hash = (37 * hash) + DESCRIPTION_FIELD_NUMBER;
+    hash = (53 * hash) + getDescription().hashCode();
+    hash = (37 * hash) + SEVERITY_FIELD_NUMBER;
+    hash = (53 * hash) + severity_;
+    if (hasTimestamp()) {
+      hash = (37 * hash) + TIMESTAMP_FIELD_NUMBER;
+      hash = (53 * hash) + getTimestamp().hashCode();
+    }
+    switch (childRefCase_) {
+      case 4:
+        hash = (37 * hash) + CHANNEL_REF_FIELD_NUMBER;
+        hash = (53 * hash) + getChannelRef().hashCode();
+        break;
+      case 5:
+        hash = (37 * hash) + SUBCHANNEL_REF_FIELD_NUMBER;
+        hash = (53 * hash) + getSubchannelRef().hashCode();
+        break;
+      case 0:
+      default:
+    }
+    hash = (29 * hash) + unknownFields.hashCode();
+    memoizedHashCode = hash;
+    return hash;
+  }
+
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      java.nio.ByteBuffer data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      java.nio.ByteBuffer data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      com.google.protobuf.ByteString data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      com.google.protobuf.ByteString data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(byte[] data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      byte[] data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      java.io.InputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input, extensionRegistry);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseDelimitedFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseDelimitedWithIOException(PARSER, input);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseDelimitedFrom(
+      java.io.InputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseDelimitedWithIOException(PARSER, input, extensionRegistry);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      com.google.protobuf.CodedInputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input);
+  }
+  public static io.grpc.channelz.v1.ChannelTraceEvent parseFrom(
+      com.google.protobuf.CodedInputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input, extensionRegistry);
+  }
+
+  public Builder newBuilderForType() { return newBuilder(); }
+  public static Builder newBuilder() {
+    return DEFAULT_INSTANCE.toBuilder();
+  }
+  public static Builder newBuilder(io.grpc.channelz.v1.ChannelTraceEvent prototype) {
+    return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
+  }
+  public Builder toBuilder() {
+    return this == DEFAULT_INSTANCE
+        ? new Builder() : new Builder().mergeFrom(this);
+  }
+
+  @java.lang.Override
+  protected Builder newBuilderForType(
+      com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+    Builder builder = new Builder(parent);
+    return builder;
+  }
+  /**
+   * <pre>
+   * A trace event is an interesting thing that happened to a channel or
+   * subchannel, such as creation, address resolution, subchannel creation, etc.
+   * </pre>
+   *
+   * Protobuf type {@code grpc.channelz.v1.ChannelTraceEvent}
+   */
+  public static final class Builder extends
+      com.google.protobuf.GeneratedMessageV3.Builder<Builder> implements
+      // @@protoc_insertion_point(builder_implements:grpc.channelz.v1.ChannelTraceEvent)
+      io.grpc.channelz.v1.ChannelTraceEventOrBuilder {
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return io.grpc.channelz.v1.ChannelzProto.internal_static_grpc_channelz_v1_ChannelTraceEvent_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return io.grpc.channelz.v1.ChannelzProto.internal_static_grpc_channelz_v1_ChannelTraceEvent_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              io.grpc.channelz.v1.ChannelTraceEvent.class, io.grpc.channelz.v1.ChannelTraceEvent.Builder.class);
+    }
+
+    // Construct using io.grpc.channelz.v1.ChannelTraceEvent.newBuilder()
+    private Builder() {
+      maybeForceBuilderInitialization();
+    }
+
+    private Builder(
+        com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+      super(parent);
+      maybeForceBuilderInitialization();
+    }
+    private void maybeForceBuilderInitialization() {
+      if (com.google.protobuf.GeneratedMessageV3
+              .alwaysUseFieldBuilders) {
+      }
+    }
+    public Builder clear() {
+      super.clear();
+      description_ = "";
+
+      severity_ = 0;
+
+      if (timestampBuilder_ == null) {
+        timestamp_ = null;
+      } else {
+        timestamp_ = null;
+        timestampBuilder_ = null;
+      }
+      childRefCase_ = 0;
+      childRef_ = null;
+      return this;
+    }
+
+    public com.google.protobuf.Descriptors.Descriptor
+        getDescriptorForType() {
+      return io.grpc.channelz.v1.ChannelzProto.internal_static_grpc_channelz_v1_ChannelTraceEvent_descriptor;
+    }
+
+    public io.grpc.channelz.v1.ChannelTraceEvent getDefaultInstanceForType() {
+      return io.grpc.channelz.v1.ChannelTraceEvent.getDefaultInstance();
+    }
+
+    public io.grpc.channelz.v1.ChannelTraceEvent build() {
+      io.grpc.channelz.v1.ChannelTraceEvent result = buildPartial();
+      if (!result.isInitialized()) {
+        throw newUninitializedMessageException(result);
+      }
+      return result;
+    }
+
+    public io.grpc.channelz.v1.ChannelTraceEvent buildPartial() {
+      io.grpc.channelz.v1.ChannelTraceEvent result = new io.grpc.channelz.v1.ChannelTraceEvent(this);
+      result.description_ = description_;
+      result.severity_ = severity_;
+      if (timestampBuilder_ == null) {
+        result.timestamp_ = timestamp_;
+      } else {
+        result.timestamp_ = timestampBuilder_.build();
+      }
+      if (childRefCase_ == 4) {
+        if (channelRefBuilder_ == null) {
+          result.childRef_ = childRef_;
+        } else {
+          result.childRef_ = channelRefBuilder_.build();
+        }
+      }
+      if (childRefCase_ == 5) {
+        if (subchannelRefBuilder_ == null) {
+          result.childRef_ = childRef_;
+        } else {
+          result.childRef_ = subchannelRefBuilder_.build();
+        }
+      }
+      result.childRefCase_ = childRefCase_;
+      onBuilt();
+      return result;
+    }
+
+    public Builder clone() {
+      return (Builder) super.clone();
+    }
+    public Builder setField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        java.lang.Object value) {
+      return (Builder) super.setField(field, value);
+    }
+    public Builder clearField(
+        com.google.protobuf.Descriptors.FieldDescriptor field) {
+      return (Builder) super.clearField(field);
+    }
+    public Builder clearOneof(
+        com.google.protobuf.Descriptors.OneofDescriptor oneof) {
+      return (Builder) super.clearOneof(oneof);
+    }
+    public Builder setRepeatedField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        int index, java.lang.Object value) {
+      return (Builder) super.setRepeatedField(field, index, value);
+    }
+    public Builder addRepeatedField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        java.lang.Object value) {
+      return (Builder) super.addRepeatedField(field, value);
+    }
+    public Builder mergeFrom(com.google.protobuf.Message other) {
+      if (other instanceof io.grpc.channelz.v1.ChannelTraceEvent) {
+        return mergeFrom((io.grpc.channelz.v1.ChannelTraceEvent)other);
+      } else {
+        super.mergeFrom(other);
+        return this;
+      }
+    }
+
+    public Builder mergeFrom(io.grpc.channelz.v1.ChannelTraceEvent other) {
+      if (other == io.grpc.channelz.v1.ChannelTraceEvent.getDefaultInstance()) return this;
+      if (!other.getDescription().isEmpty()) {
+        description_ = other.description_;
+        onChanged();
+      }
+      if (other.severity_ != 0) {
+        setSeverityValue(other.getSeverityValue());
+      }
+      if (other.hasTimestamp()) {
+        mergeTimestamp(other.getTimestamp());
+      }
+      switch (other.getChildRefCase()) {
+        case CHANNEL_REF: {
+          mergeChannelRef(other.getChannelRef());
+          break;
+        }
+        case SUBCHANNEL_REF: {
+          mergeSubchannelRef(other.getSubchannelRef());
+          break;
+        }
+        case CHILDREF_NOT_SET: {
+          break;
+        }
+      }
+      this.mergeUnknownFields(other.unknownFields);
+      onChanged();
+      return this;
+    }
+
+    public final boolean isInitialized() {
+      return true;
+    }
+
+    public Builder mergeFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      io.grpc.channelz.v1.ChannelTraceEvent parsedMessage = null;
+      try {
+        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        parsedMessage = (io.grpc.channelz.v1.ChannelTraceEvent) e.getUnfinishedMessage();
+        throw e.unwrapIOException();
+      } finally {
+        if (parsedMessage != null) {
+          mergeFrom(parsedMessage);
+        }
+      }
+      return this;
+    }
+    private int childRefCase_ = 0;
+    private java.lang.Object childRef_;
+    public ChildRefCase
+        getChildRefCase() {
+      return ChildRefCase.forNumber(
+          childRefCase_);
+    }
+
+    public Builder clearChildRef() {
+      childRefCase_ = 0;
+      childRef_ = null;
+      onChanged();
+      return this;
+    }
+
+
+    private java.lang.Object description_ = "";
+    /**
+     * <pre>
+     * High level description of the event.
+     * </pre>
+     *
+     * <code>string description = 1;</code>
+     */
+    public java.lang.String getDescription() {
+      java.lang.Object ref = description_;
+      if (!(ref instanceof java.lang.String)) {
+        com.google.protobuf.ByteString bs =
+            (com.google.protobuf.ByteString) ref;
+        java.lang.String s = bs.toStringUtf8();
+        description_ = s;
+        return s;
+      } else {
+        return (java.lang.String) ref;
+      }
+    }
+    /**
+     * <pre>
+     * High level description of the event.
+     * </pre>
+     *
+     * <code>string description = 1;</code>
+     */
+    public com.google.protobuf.ByteString
+        getDescriptionBytes() {
+      java.lang.Object ref = description_;
+      if (ref instanceof String) {
+        com.google.protobuf.ByteString b = 
+            com.google.protobuf.ByteString.copyFromUtf8(
+                (java.lang.String) ref);
+        description_ = b;
+        return b;
+      } else {
+        return (com.google.protobuf.ByteString) ref;
+      }
+    }
+    /**
+     * <pre>
+     * High level description of the event.
+     * </pre>
+     *
+     * <code>string description = 1;</code>
+     */
+    public Builder setDescription(
+        java.lang.String value) {
+      if (value == null) {
+    throw new NullPointerException();
+  }
+  
+      description_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <pre>
+     * High level description of the event.
+     * </pre>
+     *
+     * <code>string description = 1;</code>
+     */
+    public Builder clearDescription() {
+      
+      description_ = getDefaultInstance().getDescription();
+      onChanged();
+      return this;
+    }
+    /**
+     * <pre>
+     * High level description of the event.
+     * </pre>
+     *
+     * <code>string description = 1;</code>
+     */
+    public Builder setDescriptionBytes(
+        com.google.protobuf.ByteString value) {
+      if (value == null) {
+    throw new NullPointerException();
+  }
+  checkByteStringIsUtf8(value);
+      
+      description_ = value;
+      onChanged();
+      return this;
+    }
+
+    private int severity_ = 0;
+    /**
+     * <pre>
+     * the severity of the trace event
+     * </pre>
+     *
+     * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+     */
+    public int getSeverityValue() {
+      return severity_;
+    }
+    /**
+     * <pre>
+     * the severity of the trace event
+     * </pre>
+     *
+     * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+     */
+    public Builder setSeverityValue(int value) {
+      severity_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <pre>
+     * the severity of the trace event
+     * </pre>
+     *
+     * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+     */
+    public io.grpc.channelz.v1.ChannelTraceEvent.Severity getSeverity() {
+      io.grpc.channelz.v1.ChannelTraceEvent.Severity result = io.grpc.channelz.v1.ChannelTraceEvent.Severity.valueOf(severity_);
+      return result == null ? io.grpc.channelz.v1.ChannelTraceEvent.Severity.UNRECOGNIZED : result;
+    }
+    /**
+     * <pre>
+     * the severity of the trace event
+     * </pre>
+     *
+     * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+     */
+    public Builder setSeverity(io.grpc.channelz.v1.ChannelTraceEvent.Severity value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      
+      severity_ = value.getNumber();
+      onChanged();
+      return this;
+    }
+    /**
+     * <pre>
+     * the severity of the trace event
+     * </pre>
+     *
+     * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+     */
+    public Builder clearSeverity() {
+      
+      severity_ = 0;
+      onChanged();
+      return this;
+    }
+
+    private com.google.protobuf.Timestamp timestamp_ = null;
+    private com.google.protobuf.SingleFieldBuilderV3<
+        com.google.protobuf.Timestamp, com.google.protobuf.Timestamp.Builder, com.google.protobuf.TimestampOrBuilder> timestampBuilder_;
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public boolean hasTimestamp() {
+      return timestampBuilder_ != null || timestamp_ != null;
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public com.google.protobuf.Timestamp getTimestamp() {
+      if (timestampBuilder_ == null) {
+        return timestamp_ == null ? com.google.protobuf.Timestamp.getDefaultInstance() : timestamp_;
+      } else {
+        return timestampBuilder_.getMessage();
+      }
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public Builder setTimestamp(com.google.protobuf.Timestamp value) {
+      if (timestampBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        timestamp_ = value;
+        onChanged();
+      } else {
+        timestampBuilder_.setMessage(value);
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public Builder setTimestamp(
+        com.google.protobuf.Timestamp.Builder builderForValue) {
+      if (timestampBuilder_ == null) {
+        timestamp_ = builderForValue.build();
+        onChanged();
+      } else {
+        timestampBuilder_.setMessage(builderForValue.build());
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public Builder mergeTimestamp(com.google.protobuf.Timestamp value) {
+      if (timestampBuilder_ == null) {
+        if (timestamp_ != null) {
+          timestamp_ =
+            com.google.protobuf.Timestamp.newBuilder(timestamp_).mergeFrom(value).buildPartial();
+        } else {
+          timestamp_ = value;
+        }
+        onChanged();
+      } else {
+        timestampBuilder_.mergeFrom(value);
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public Builder clearTimestamp() {
+      if (timestampBuilder_ == null) {
+        timestamp_ = null;
+        onChanged();
+      } else {
+        timestamp_ = null;
+        timestampBuilder_ = null;
+      }
+
+      return this;
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public com.google.protobuf.Timestamp.Builder getTimestampBuilder() {
+      
+      onChanged();
+      return getTimestampFieldBuilder().getBuilder();
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    public com.google.protobuf.TimestampOrBuilder getTimestampOrBuilder() {
+      if (timestampBuilder_ != null) {
+        return timestampBuilder_.getMessageOrBuilder();
+      } else {
+        return timestamp_ == null ?
+            com.google.protobuf.Timestamp.getDefaultInstance() : timestamp_;
+      }
+    }
+    /**
+     * <pre>
+     * When this event occurred.
+     * </pre>
+     *
+     * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+     */
+    private com.google.protobuf.SingleFieldBuilderV3<
+        com.google.protobuf.Timestamp, com.google.protobuf.Timestamp.Builder, com.google.protobuf.TimestampOrBuilder> 
+        getTimestampFieldBuilder() {
+      if (timestampBuilder_ == null) {
+        timestampBuilder_ = new com.google.protobuf.SingleFieldBuilderV3<
+            com.google.protobuf.Timestamp, com.google.protobuf.Timestamp.Builder, com.google.protobuf.TimestampOrBuilder>(
+                getTimestamp(),
+                getParentForChildren(),
+                isClean());
+        timestamp_ = null;
+      }
+      return timestampBuilder_;
+    }
+
+    private com.google.protobuf.SingleFieldBuilderV3<
+        io.grpc.channelz.v1.ChannelRef, io.grpc.channelz.v1.ChannelRef.Builder, io.grpc.channelz.v1.ChannelRefOrBuilder> channelRefBuilder_;
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public boolean hasChannelRef() {
+      return childRefCase_ == 4;
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public io.grpc.channelz.v1.ChannelRef getChannelRef() {
+      if (channelRefBuilder_ == null) {
+        if (childRefCase_ == 4) {
+          return (io.grpc.channelz.v1.ChannelRef) childRef_;
+        }
+        return io.grpc.channelz.v1.ChannelRef.getDefaultInstance();
+      } else {
+        if (childRefCase_ == 4) {
+          return channelRefBuilder_.getMessage();
+        }
+        return io.grpc.channelz.v1.ChannelRef.getDefaultInstance();
+      }
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public Builder setChannelRef(io.grpc.channelz.v1.ChannelRef value) {
+      if (channelRefBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        childRef_ = value;
+        onChanged();
+      } else {
+        channelRefBuilder_.setMessage(value);
+      }
+      childRefCase_ = 4;
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public Builder setChannelRef(
+        io.grpc.channelz.v1.ChannelRef.Builder builderForValue) {
+      if (channelRefBuilder_ == null) {
+        childRef_ = builderForValue.build();
+        onChanged();
+      } else {
+        channelRefBuilder_.setMessage(builderForValue.build());
+      }
+      childRefCase_ = 4;
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public Builder mergeChannelRef(io.grpc.channelz.v1.ChannelRef value) {
+      if (channelRefBuilder_ == null) {
+        if (childRefCase_ == 4 &&
+            childRef_ != io.grpc.channelz.v1.ChannelRef.getDefaultInstance()) {
+          childRef_ = io.grpc.channelz.v1.ChannelRef.newBuilder((io.grpc.channelz.v1.ChannelRef) childRef_)
+              .mergeFrom(value).buildPartial();
+        } else {
+          childRef_ = value;
+        }
+        onChanged();
+      } else {
+        if (childRefCase_ == 4) {
+          channelRefBuilder_.mergeFrom(value);
+        }
+        channelRefBuilder_.setMessage(value);
+      }
+      childRefCase_ = 4;
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public Builder clearChannelRef() {
+      if (channelRefBuilder_ == null) {
+        if (childRefCase_ == 4) {
+          childRefCase_ = 0;
+          childRef_ = null;
+          onChanged();
+        }
+      } else {
+        if (childRefCase_ == 4) {
+          childRefCase_ = 0;
+          childRef_ = null;
+        }
+        channelRefBuilder_.clear();
+      }
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public io.grpc.channelz.v1.ChannelRef.Builder getChannelRefBuilder() {
+      return getChannelRefFieldBuilder().getBuilder();
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    public io.grpc.channelz.v1.ChannelRefOrBuilder getChannelRefOrBuilder() {
+      if ((childRefCase_ == 4) && (channelRefBuilder_ != null)) {
+        return channelRefBuilder_.getMessageOrBuilder();
+      } else {
+        if (childRefCase_ == 4) {
+          return (io.grpc.channelz.v1.ChannelRef) childRef_;
+        }
+        return io.grpc.channelz.v1.ChannelRef.getDefaultInstance();
+      }
+    }
+    /**
+     * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+     */
+    private com.google.protobuf.SingleFieldBuilderV3<
+        io.grpc.channelz.v1.ChannelRef, io.grpc.channelz.v1.ChannelRef.Builder, io.grpc.channelz.v1.ChannelRefOrBuilder> 
+        getChannelRefFieldBuilder() {
+      if (channelRefBuilder_ == null) {
+        if (!(childRefCase_ == 4)) {
+          childRef_ = io.grpc.channelz.v1.ChannelRef.getDefaultInstance();
+        }
+        channelRefBuilder_ = new com.google.protobuf.SingleFieldBuilderV3<
+            io.grpc.channelz.v1.ChannelRef, io.grpc.channelz.v1.ChannelRef.Builder, io.grpc.channelz.v1.ChannelRefOrBuilder>(
+                (io.grpc.channelz.v1.ChannelRef) childRef_,
+                getParentForChildren(),
+                isClean());
+        childRef_ = null;
+      }
+      childRefCase_ = 4;
+      onChanged();;
+      return channelRefBuilder_;
+    }
+
+    private com.google.protobuf.SingleFieldBuilderV3<
+        io.grpc.channelz.v1.SubchannelRef, io.grpc.channelz.v1.SubchannelRef.Builder, io.grpc.channelz.v1.SubchannelRefOrBuilder> subchannelRefBuilder_;
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public boolean hasSubchannelRef() {
+      return childRefCase_ == 5;
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public io.grpc.channelz.v1.SubchannelRef getSubchannelRef() {
+      if (subchannelRefBuilder_ == null) {
+        if (childRefCase_ == 5) {
+          return (io.grpc.channelz.v1.SubchannelRef) childRef_;
+        }
+        return io.grpc.channelz.v1.SubchannelRef.getDefaultInstance();
+      } else {
+        if (childRefCase_ == 5) {
+          return subchannelRefBuilder_.getMessage();
+        }
+        return io.grpc.channelz.v1.SubchannelRef.getDefaultInstance();
+      }
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public Builder setSubchannelRef(io.grpc.channelz.v1.SubchannelRef value) {
+      if (subchannelRefBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        childRef_ = value;
+        onChanged();
+      } else {
+        subchannelRefBuilder_.setMessage(value);
+      }
+      childRefCase_ = 5;
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public Builder setSubchannelRef(
+        io.grpc.channelz.v1.SubchannelRef.Builder builderForValue) {
+      if (subchannelRefBuilder_ == null) {
+        childRef_ = builderForValue.build();
+        onChanged();
+      } else {
+        subchannelRefBuilder_.setMessage(builderForValue.build());
+      }
+      childRefCase_ = 5;
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public Builder mergeSubchannelRef(io.grpc.channelz.v1.SubchannelRef value) {
+      if (subchannelRefBuilder_ == null) {
+        if (childRefCase_ == 5 &&
+            childRef_ != io.grpc.channelz.v1.SubchannelRef.getDefaultInstance()) {
+          childRef_ = io.grpc.channelz.v1.SubchannelRef.newBuilder((io.grpc.channelz.v1.SubchannelRef) childRef_)
+              .mergeFrom(value).buildPartial();
+        } else {
+          childRef_ = value;
+        }
+        onChanged();
+      } else {
+        if (childRefCase_ == 5) {
+          subchannelRefBuilder_.mergeFrom(value);
+        }
+        subchannelRefBuilder_.setMessage(value);
+      }
+      childRefCase_ = 5;
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public Builder clearSubchannelRef() {
+      if (subchannelRefBuilder_ == null) {
+        if (childRefCase_ == 5) {
+          childRefCase_ = 0;
+          childRef_ = null;
+          onChanged();
+        }
+      } else {
+        if (childRefCase_ == 5) {
+          childRefCase_ = 0;
+          childRef_ = null;
+        }
+        subchannelRefBuilder_.clear();
+      }
+      return this;
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public io.grpc.channelz.v1.SubchannelRef.Builder getSubchannelRefBuilder() {
+      return getSubchannelRefFieldBuilder().getBuilder();
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    public io.grpc.channelz.v1.SubchannelRefOrBuilder getSubchannelRefOrBuilder() {
+      if ((childRefCase_ == 5) && (subchannelRefBuilder_ != null)) {
+        return subchannelRefBuilder_.getMessageOrBuilder();
+      } else {
+        if (childRefCase_ == 5) {
+          return (io.grpc.channelz.v1.SubchannelRef) childRef_;
+        }
+        return io.grpc.channelz.v1.SubchannelRef.getDefaultInstance();
+      }
+    }
+    /**
+     * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+     */
+    private com.google.protobuf.SingleFieldBuilderV3<
+        io.grpc.channelz.v1.SubchannelRef, io.grpc.channelz.v1.SubchannelRef.Builder, io.grpc.channelz.v1.SubchannelRefOrBuilder> 
+        getSubchannelRefFieldBuilder() {
+      if (subchannelRefBuilder_ == null) {
+        if (!(childRefCase_ == 5)) {
+          childRef_ = io.grpc.channelz.v1.SubchannelRef.getDefaultInstance();
+        }
+        subchannelRefBuilder_ = new com.google.protobuf.SingleFieldBuilderV3<
+            io.grpc.channelz.v1.SubchannelRef, io.grpc.channelz.v1.SubchannelRef.Builder, io.grpc.channelz.v1.SubchannelRefOrBuilder>(
+                (io.grpc.channelz.v1.SubchannelRef) childRef_,
+                getParentForChildren(),
+                isClean());
+        childRef_ = null;
+      }
+      childRefCase_ = 5;
+      onChanged();;
+      return subchannelRefBuilder_;
+    }
+    public final Builder setUnknownFields(
+        final com.google.protobuf.UnknownFieldSet unknownFields) {
+      return super.setUnknownFieldsProto3(unknownFields);
+    }
+
+    public final Builder mergeUnknownFields(
+        final com.google.protobuf.UnknownFieldSet unknownFields) {
+      return super.mergeUnknownFields(unknownFields);
+    }
+
+
+    // @@protoc_insertion_point(builder_scope:grpc.channelz.v1.ChannelTraceEvent)
+  }
+
+  // @@protoc_insertion_point(class_scope:grpc.channelz.v1.ChannelTraceEvent)
+  private static final io.grpc.channelz.v1.ChannelTraceEvent DEFAULT_INSTANCE;
+  static {
+    DEFAULT_INSTANCE = new io.grpc.channelz.v1.ChannelTraceEvent();
+  }
+
+  public static io.grpc.channelz.v1.ChannelTraceEvent getDefaultInstance() {
+    return DEFAULT_INSTANCE;
+  }
+
+  private static final com.google.protobuf.Parser<ChannelTraceEvent>
+      PARSER = new com.google.protobuf.AbstractParser<ChannelTraceEvent>() {
+    public ChannelTraceEvent parsePartialFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return new ChannelTraceEvent(input, extensionRegistry);
+    }
+  };
+
+  public static com.google.protobuf.Parser<ChannelTraceEvent> parser() {
+    return PARSER;
+  }
+
+  @java.lang.Override
+  public com.google.protobuf.Parser<ChannelTraceEvent> getParserForType() {
+    return PARSER;
+  }
+
+  public io.grpc.channelz.v1.ChannelTraceEvent getDefaultInstanceForType() {
+    return DEFAULT_INSTANCE;
+  }
+
+}
+
diff --git a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceEventOrBuilder.java b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceEventOrBuilder.java
new file mode 100644
index 000000000..c18ba61ba
--- /dev/null
+++ b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceEventOrBuilder.java
@@ -0,0 +1,97 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: grpc/channelz/v1/channelz.proto
+
+package io.grpc.channelz.v1;
+
+public interface ChannelTraceEventOrBuilder extends
+    // @@protoc_insertion_point(interface_extends:grpc.channelz.v1.ChannelTraceEvent)
+    com.google.protobuf.MessageOrBuilder {
+
+  /**
+   * <pre>
+   * High level description of the event.
+   * </pre>
+   *
+   * <code>string description = 1;</code>
+   */
+  java.lang.String getDescription();
+  /**
+   * <pre>
+   * High level description of the event.
+   * </pre>
+   *
+   * <code>string description = 1;</code>
+   */
+  com.google.protobuf.ByteString
+      getDescriptionBytes();
+
+  /**
+   * <pre>
+   * the severity of the trace event
+   * </pre>
+   *
+   * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+   */
+  int getSeverityValue();
+  /**
+   * <pre>
+   * the severity of the trace event
+   * </pre>
+   *
+   * <code>.grpc.channelz.v1.ChannelTraceEvent.Severity severity = 2;</code>
+   */
+  io.grpc.channelz.v1.ChannelTraceEvent.Severity getSeverity();
+
+  /**
+   * <pre>
+   * When this event occurred.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+   */
+  boolean hasTimestamp();
+  /**
+   * <pre>
+   * When this event occurred.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+   */
+  com.google.protobuf.Timestamp getTimestamp();
+  /**
+   * <pre>
+   * When this event occurred.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp timestamp = 3;</code>
+   */
+  com.google.protobuf.TimestampOrBuilder getTimestampOrBuilder();
+
+  /**
+   * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+   */
+  boolean hasChannelRef();
+  /**
+   * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+   */
+  io.grpc.channelz.v1.ChannelRef getChannelRef();
+  /**
+   * <code>.grpc.channelz.v1.ChannelRef channel_ref = 4;</code>
+   */
+  io.grpc.channelz.v1.ChannelRefOrBuilder getChannelRefOrBuilder();
+
+  /**
+   * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+   */
+  boolean hasSubchannelRef();
+  /**
+   * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+   */
+  io.grpc.channelz.v1.SubchannelRef getSubchannelRef();
+  /**
+   * <code>.grpc.channelz.v1.SubchannelRef subchannel_ref = 5;</code>
+   */
+  io.grpc.channelz.v1.SubchannelRefOrBuilder getSubchannelRefOrBuilder();
+
+  public io.grpc.channelz.v1.ChannelTraceEvent.ChildRefCase getChildRefCase();
+}
diff --git a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceOrBuilder.java b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceOrBuilder.java
index ed7837af0..aabe298a6 100644
--- a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceOrBuilder.java
+++ b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelTraceOrBuilder.java
@@ -6,4 +6,84 @@ package io.grpc.channelz.v1;
 public interface ChannelTraceOrBuilder extends
     // @@protoc_insertion_point(interface_extends:grpc.channelz.v1.ChannelTrace)
     com.google.protobuf.MessageOrBuilder {
+
+  /**
+   * <pre>
+   * Number of events ever logged in this tracing object. This can differ from
+   * events.size() because events can be overwritten or garbage collected by
+   * implementations.
+   * </pre>
+   *
+   * <code>int64 num_events_logged = 1;</code>
+   */
+  long getNumEventsLogged();
+
+  /**
+   * <pre>
+   * Time that this channel was created.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+   */
+  boolean hasCreationTimestamp();
+  /**
+   * <pre>
+   * Time that this channel was created.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+   */
+  com.google.protobuf.Timestamp getCreationTimestamp();
+  /**
+   * <pre>
+   * Time that this channel was created.
+   * </pre>
+   *
+   * <code>.google.protobuf.Timestamp creation_timestamp = 2;</code>
+   */
+  com.google.protobuf.TimestampOrBuilder getCreationTimestampOrBuilder();
+
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  java.util.List<io.grpc.channelz.v1.ChannelTraceEvent> 
+      getEventsList();
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  io.grpc.channelz.v1.ChannelTraceEvent getEvents(int index);
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  int getEventsCount();
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  java.util.List<? extends io.grpc.channelz.v1.ChannelTraceEventOrBuilder> 
+      getEventsOrBuilderList();
+  /**
+   * <pre>
+   * List of events that have occurred on this channel.
+   * </pre>
+   *
+   * <code>repeated .grpc.channelz.v1.ChannelTraceEvent events = 3;</code>
+   */
+  io.grpc.channelz.v1.ChannelTraceEventOrBuilder getEventsOrBuilder(
+      int index);
 }
diff --git a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelzProto.java b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelzProto.java
index 8fc83ef1f..1c56589e5 100644
--- a/services/src/generated/main/java/io/grpc/channelz/v1/ChannelzProto.java
+++ b/services/src/generated/main/java/io/grpc/channelz/v1/ChannelzProto.java
@@ -35,6 +35,11 @@ public final class ChannelzProto {
     com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
       internal_static_grpc_channelz_v1_ChannelData_fieldAccessorTable;
   static final com.google.protobuf.Descriptors.Descriptor
+    internal_static_grpc_channelz_v1_ChannelTraceEvent_descriptor;
+  static final 
+    com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+      internal_static_grpc_channelz_v1_ChannelTraceEvent_fieldAccessorTable;
+  static final com.google.protobuf.Descriptors.Descriptor
     internal_static_grpc_channelz_v1_ChannelTrace_descriptor;
   static final 
     com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
@@ -231,123 +236,135 @@ public final class ChannelzProto {
       "hannelz.v1.ChannelTrace\022\025\n\rcalls_started" +
       "\030\004 \001(\003\022\027\n\017calls_succeeded\030\005 \001(\003\022\024\n\014calls" +
       "_failed\030\006 \001(\003\022?\n\033last_call_started_times" +
-      "tamp\030\007 \001(\0132\032.google.protobuf.Timestamp\"\016" +
-      "\n\014ChannelTrace\"R\n\nChannelRef\022\022\n\nchannel_" +
-      "id\030\001 \001(\003\022\014\n\004name\030\002 \001(\tJ\004\010\003\020\004J\004\010\004\020\005J\004\010\005\020\006" +
-      "J\004\010\006\020\007J\004\010\007\020\010J\004\010\010\020\t\"X\n\rSubchannelRef\022\025\n\rs" +
-      "ubchannel_id\030\007 \001(\003\022\014\n\004name\030\010 \001(\tJ\004\010\001\020\002J\004" +
-      "\010\002\020\003J\004\010\003\020\004J\004\010\004\020\005J\004\010\005\020\006J\004\010\006\020\007\"P\n\tSocketRe" +
-      "f\022\021\n\tsocket_id\030\003 \001(\003\022\014\n\004name\030\004 \001(\tJ\004\010\001\020\002" +
-      "J\004\010\002\020\003J\004\010\005\020\006J\004\010\006\020\007J\004\010\007\020\010J\004\010\010\020\t\"P\n\tServer" +
-      "Ref\022\021\n\tserver_id\030\005 \001(\003\022\014\n\004name\030\006 \001(\tJ\004\010\001" +
-      "\020\002J\004\010\002\020\003J\004\010\003\020\004J\004\010\004\020\005J\004\010\007\020\010J\004\010\010\020\t\"\222\001\n\006Ser" +
-      "ver\022(\n\003ref\030\001 \001(\0132\033.grpc.channelz.v1.Serv" +
-      "erRef\022*\n\004data\030\002 \001(\0132\034.grpc.channelz.v1.S" +
-      "erverData\0222\n\rlisten_socket\030\003 \003(\0132\033.grpc." +
-      "channelz.v1.SocketRef\"\302\001\n\nServerData\022-\n\005" +
-      "trace\030\001 \001(\0132\036.grpc.channelz.v1.ChannelTr" +
-      "ace\022\025\n\rcalls_started\030\002 \001(\003\022\027\n\017calls_succ" +
-      "eeded\030\003 \001(\003\022\024\n\014calls_failed\030\004 \001(\003\022?\n\033las" +
-      "t_call_started_timestamp\030\005 \001(\0132\032.google." +
-      "protobuf.Timestamp\"\366\001\n\006Socket\022(\n\003ref\030\001 \001" +
-      "(\0132\033.grpc.channelz.v1.SocketRef\022*\n\004data\030" +
-      "\002 \001(\0132\034.grpc.channelz.v1.SocketData\022(\n\005l" +
-      "ocal\030\003 \001(\0132\031.grpc.channelz.v1.Address\022)\n" +
-      "\006remote\030\004 \001(\0132\031.grpc.channelz.v1.Address" +
-      "\022,\n\010security\030\005 \001(\0132\032.grpc.channelz.v1.Se" +
-      "curity\022\023\n\013remote_name\030\006 \001(\t\"\356\004\n\nSocketDa" +
-      "ta\022\027\n\017streams_started\030\001 \001(\003\022\031\n\021streams_s" +
-      "ucceeded\030\002 \001(\003\022\026\n\016streams_failed\030\003 \001(\003\022\025" +
-      "\n\rmessages_sent\030\004 \001(\003\022\031\n\021messages_receiv" +
-      "ed\030\005 \001(\003\022\030\n\020keep_alives_sent\030\006 \001(\003\022G\n#la" +
-      "st_local_stream_created_timestamp\030\007 \001(\0132" +
-      "\032.google.protobuf.Timestamp\022H\n$last_remo" +
-      "te_stream_created_timestamp\030\010 \001(\0132\032.goog" +
-      "le.protobuf.Timestamp\022?\n\033last_message_se" +
-      "nt_timestamp\030\t \001(\0132\032.google.protobuf.Tim" +
-      "estamp\022C\n\037last_message_received_timestam" +
-      "p\030\n \001(\0132\032.google.protobuf.Timestamp\022>\n\031l" +
-      "ocal_flow_control_window\030\013 \001(\0132\033.google." +
-      "protobuf.Int64Value\022?\n\032remote_flow_contr" +
-      "ol_window\030\014 \001(\0132\033.google.protobuf.Int64V" +
-      "alue\022.\n\006option\030\r \003(\0132\036.grpc.channelz.v1." +
-      "SocketOption\"\350\002\n\007Address\022?\n\rtcpip_addres" +
-      "s\030\001 \001(\0132&.grpc.channelz.v1.Address.TcpIp" +
-      "AddressH\000\022;\n\013uds_address\030\002 \001(\0132$.grpc.ch" +
-      "annelz.v1.Address.UdsAddressH\000\022?\n\rother_" +
-      "address\030\003 \001(\0132&.grpc.channelz.v1.Address" +
-      ".OtherAddressH\000\0320\n\014TcpIpAddress\022\022\n\nip_ad" +
-      "dress\030\001 \001(\014\022\014\n\004port\030\002 \001(\005\032\036\n\nUdsAddress\022" +
-      "\020\n\010filename\030\001 \001(\t\032A\n\014OtherAddress\022\014\n\004nam" +
-      "e\030\001 \001(\t\022#\n\005value\030\002 \001(\0132\024.google.protobuf" +
-      ".AnyB\t\n\007address\"\276\002\n\010Security\022-\n\003tls\030\001 \001(" +
-      "\0132\036.grpc.channelz.v1.Security.TlsH\000\0229\n\005o" +
-      "ther\030\002 \001(\0132(.grpc.channelz.v1.Security.O" +
-      "therSecurityH\000\032{\n\003Tls\022\027\n\rstandard_name\030\001" +
-      " \001(\tH\000\022\024\n\nother_name\030\002 \001(\tH\000\022\031\n\021local_ce" +
-      "rtificate\030\003 \001(\014\022\032\n\022remote_certificate\030\004 " +
-      "\001(\014B\016\n\014cipher_suite\032B\n\rOtherSecurity\022\014\n\004" +
-      "name\030\001 \001(\t\022#\n\005value\030\002 \001(\0132\024.google.proto" +
-      "buf.AnyB\007\n\005model\"U\n\014SocketOption\022\014\n\004name" +
-      "\030\001 \001(\t\022\r\n\005value\030\002 \001(\t\022(\n\nadditional\030\003 \001(" +
-      "\0132\024.google.protobuf.Any\"B\n\023SocketOptionT" +
-      "imeout\022+\n\010duration\030\001 \001(\0132\031.google.protob" +
-      "uf.Duration\"Q\n\022SocketOptionLinger\022\016\n\006act" +
-      "ive\030\001 \001(\010\022+\n\010duration\030\002 \001(\0132\031.google.pro" +
-      "tobuf.Duration\"\256\005\n\023SocketOptionTcpInfo\022\022" +
-      "\n\ntcpi_state\030\001 \001(\r\022\025\n\rtcpi_ca_state\030\002 \001(" +
-      "\r\022\030\n\020tcpi_retransmits\030\003 \001(\r\022\023\n\013tcpi_prob" +
-      "es\030\004 \001(\r\022\024\n\014tcpi_backoff\030\005 \001(\r\022\024\n\014tcpi_o" +
-      "ptions\030\006 \001(\r\022\027\n\017tcpi_snd_wscale\030\007 \001(\r\022\027\n" +
-      "\017tcpi_rcv_wscale\030\010 \001(\r\022\020\n\010tcpi_rto\030\t \001(\r" +
-      "\022\020\n\010tcpi_ato\030\n \001(\r\022\024\n\014tcpi_snd_mss\030\013 \001(\r" +
-      "\022\024\n\014tcpi_rcv_mss\030\014 \001(\r\022\024\n\014tcpi_unacked\030\r" +
-      " \001(\r\022\023\n\013tcpi_sacked\030\016 \001(\r\022\021\n\ttcpi_lost\030\017" +
-      " \001(\r\022\024\n\014tcpi_retrans\030\020 \001(\r\022\024\n\014tcpi_facke" +
-      "ts\030\021 \001(\r\022\033\n\023tcpi_last_data_sent\030\022 \001(\r\022\032\n" +
-      "\022tcpi_last_ack_sent\030\023 \001(\r\022\033\n\023tcpi_last_d" +
-      "ata_recv\030\024 \001(\r\022\032\n\022tcpi_last_ack_recv\030\025 \001" +
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-      "sh\030\027 \001(\r\022\020\n\010tcpi_rtt\030\030 \001(\r\022\023\n\013tcpi_rttva" +
-      "r\030\031 \001(\r\022\031\n\021tcpi_snd_ssthresh\030\032 \001(\r\022\025\n\rtc" +
-      "pi_snd_cwnd\030\033 \001(\r\022\023\n\013tcpi_advmss\030\034 \001(\r\022\027" +
-      "\n\017tcpi_reordering\030\035 \001(\r\"1\n\025GetTopChannel" +
-      "sRequest\022\030\n\020start_channel_id\030\001 \001(\003\"Q\n\026Ge" +
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-      "grpc.channelz.v1.Channel\022\013\n\003end\030\002 \001(\010\",\n" +
-      "\021GetServersRequest\022\027\n\017start_server_id\030\001 " +
-      "\001(\003\"K\n\022GetServersResponse\022(\n\006server\030\001 \003(" +
-      "\0132\030.grpc.channelz.v1.Server\022\013\n\003end\030\002 \001(\010" +
-      "\"E\n\027GetServerSocketsRequest\022\021\n\tserver_id" +
-      "\030\001 \001(\003\022\027\n\017start_socket_id\030\002 \001(\003\"X\n\030GetSe" +
-      "rverSocketsResponse\022/\n\nsocket_ref\030\001 \003(\0132" +
-      "\033.grpc.channelz.v1.SocketRef\022\013\n\003end\030\002 \001(" +
-      "\010\"\'\n\021GetChannelRequest\022\022\n\nchannel_id\030\001 \001" +
-      "(\003\"@\n\022GetChannelResponse\022*\n\007channel\030\001 \001(" +
-      "\0132\031.grpc.channelz.v1.Channel\"-\n\024GetSubch" +
-      "annelRequest\022\025\n\rsubchannel_id\030\001 \001(\003\"I\n\025G" +
-      "etSubchannelResponse\0220\n\nsubchannel\030\001 \001(\013" +
-      "2\034.grpc.channelz.v1.Subchannel\"%\n\020GetSoc" +
-      "ketRequest\022\021\n\tsocket_id\030\001 \001(\003\"=\n\021GetSock" +
-      "etResponse\022(\n\006socket\030\001 \001(\0132\030.grpc.channe" +
-      "lz.v1.Socket2\304\004\n\010Channelz\022c\n\016GetTopChann" +
-      "els\022\'.grpc.channelz.v1.GetTopChannelsReq" +
-      "uest\032(.grpc.channelz.v1.GetTopChannelsRe" +
-      "sponse\022W\n\nGetServers\022#.grpc.channelz.v1." +
-      "GetServersRequest\032$.grpc.channelz.v1.Get" +
-      "ServersResponse\022i\n\020GetServerSockets\022).gr" +
-      "pc.channelz.v1.GetServerSocketsRequest\032*" +
-      ".grpc.channelz.v1.GetServerSocketsRespon" +
-      "se\022W\n\nGetChannel\022#.grpc.channelz.v1.GetC" +
-      "hannelRequest\032$.grpc.channelz.v1.GetChan" +
-      "nelResponse\022`\n\rGetSubchannel\022&.grpc.chan" +
-      "nelz.v1.GetSubchannelRequest\032\'.grpc.chan" +
-      "nelz.v1.GetSubchannelResponse\022T\n\tGetSock" +
-      "et\022\".grpc.channelz.v1.GetSocketRequest\032#" +
-      ".grpc.channelz.v1.GetSocketResponseBX\n\023i" +
-      "o.grpc.channelz.v1B\rChannelzProtoP\001Z0goo" +
-      "gle.golang.org/grpc/channelz/grpc_channe" +
-      "lz_v1b\006proto3"
+      "tamp\030\007 \001(\0132\032.google.protobuf.Timestamp\"\333" +
+      "\002\n\021ChannelTraceEvent\022\023\n\013description\030\001 \001(" +
+      "\t\022>\n\010severity\030\002 \001(\0162,.grpc.channelz.v1.C" +
+      "hannelTraceEvent.Severity\022-\n\ttimestamp\030\003" +
+      " \001(\0132\032.google.protobuf.Timestamp\0223\n\013chan" +
+      "nel_ref\030\004 \001(\0132\034.grpc.channelz.v1.Channel" +
+      "RefH\000\0229\n\016subchannel_ref\030\005 \001(\0132\037.grpc.cha" +
+      "nnelz.v1.SubchannelRefH\000\"E\n\010Severity\022\016\n\n" +
+      "CT_UNKNOWN\020\000\022\013\n\007CT_INFO\020\001\022\016\n\nCT_WARNING\020" +
+      "\002\022\014\n\010CT_ERROR\020\003B\013\n\tchild_ref\"\226\001\n\014Channel" +
+      "Trace\022\031\n\021num_events_logged\030\001 \001(\003\0226\n\022crea" +
+      "tion_timestamp\030\002 \001(\0132\032.google.protobuf.T" +
+      "imestamp\0223\n\006events\030\003 \003(\0132#.grpc.channelz" +
+      ".v1.ChannelTraceEvent\"R\n\nChannelRef\022\022\n\nc" +
+      "hannel_id\030\001 \001(\003\022\014\n\004name\030\002 \001(\tJ\004\010\003\020\004J\004\010\004\020" +
+      "\005J\004\010\005\020\006J\004\010\006\020\007J\004\010\007\020\010J\004\010\010\020\t\"X\n\rSubchannelR" +
+      "ef\022\025\n\rsubchannel_id\030\007 \001(\003\022\014\n\004name\030\010 \001(\tJ" +
+      "\004\010\001\020\002J\004\010\002\020\003J\004\010\003\020\004J\004\010\004\020\005J\004\010\005\020\006J\004\010\006\020\007\"P\n\tS" +
+      "ocketRef\022\021\n\tsocket_id\030\003 \001(\003\022\014\n\004name\030\004 \001(" +
+      "\tJ\004\010\001\020\002J\004\010\002\020\003J\004\010\005\020\006J\004\010\006\020\007J\004\010\007\020\010J\004\010\010\020\t\"P\n" +
+      "\tServerRef\022\021\n\tserver_id\030\005 \001(\003\022\014\n\004name\030\006 " +
+      "\001(\tJ\004\010\001\020\002J\004\010\002\020\003J\004\010\003\020\004J\004\010\004\020\005J\004\010\007\020\010J\004\010\010\020\t\"" +
+      "\222\001\n\006Server\022(\n\003ref\030\001 \001(\0132\033.grpc.channelz." +
+      "v1.ServerRef\022*\n\004data\030\002 \001(\0132\034.grpc.channe" +
+      "lz.v1.ServerData\0222\n\rlisten_socket\030\003 \003(\0132" +
+      "\033.grpc.channelz.v1.SocketRef\"\302\001\n\nServerD" +
+      "ata\022-\n\005trace\030\001 \001(\0132\036.grpc.channelz.v1.Ch" +
+      "annelTrace\022\025\n\rcalls_started\030\002 \001(\003\022\027\n\017cal" +
+      "ls_succeeded\030\003 \001(\003\022\024\n\014calls_failed\030\004 \001(\003" +
+      "\022?\n\033last_call_started_timestamp\030\005 \001(\0132\032." +
+      "google.protobuf.Timestamp\"\366\001\n\006Socket\022(\n\003" +
+      "ref\030\001 \001(\0132\033.grpc.channelz.v1.SocketRef\022*" +
+      "\n\004data\030\002 \001(\0132\034.grpc.channelz.v1.SocketDa" +
+      "ta\022(\n\005local\030\003 \001(\0132\031.grpc.channelz.v1.Add" +
+      "ress\022)\n\006remote\030\004 \001(\0132\031.grpc.channelz.v1." +
+      "Address\022,\n\010security\030\005 \001(\0132\032.grpc.channel" +
+      "z.v1.Security\022\023\n\013remote_name\030\006 \001(\t\"\356\004\n\nS" +
+      "ocketData\022\027\n\017streams_started\030\001 \001(\003\022\031\n\021st" +
+      "reams_succeeded\030\002 \001(\003\022\026\n\016streams_failed\030" +
+      "\003 \001(\003\022\025\n\rmessages_sent\030\004 \001(\003\022\031\n\021messages" +
+      "_received\030\005 \001(\003\022\030\n\020keep_alives_sent\030\006 \001(" +
+      "\003\022G\n#last_local_stream_created_timestamp" +
+      "\030\007 \001(\0132\032.google.protobuf.Timestamp\022H\n$la" +
+      "st_remote_stream_created_timestamp\030\010 \001(\013" +
+      "2\032.google.protobuf.Timestamp\022?\n\033last_mes" +
+      "sage_sent_timestamp\030\t \001(\0132\032.google.proto" +
+      "buf.Timestamp\022C\n\037last_message_received_t" +
+      "imestamp\030\n \001(\0132\032.google.protobuf.Timesta" +
+      "mp\022>\n\031local_flow_control_window\030\013 \001(\0132\033." +
+      "google.protobuf.Int64Value\022?\n\032remote_flo" +
+      "w_control_window\030\014 \001(\0132\033.google.protobuf" +
+      ".Int64Value\022.\n\006option\030\r \003(\0132\036.grpc.chann" +
+      "elz.v1.SocketOption\"\350\002\n\007Address\022?\n\rtcpip" +
+      "_address\030\001 \001(\0132&.grpc.channelz.v1.Addres" +
+      "s.TcpIpAddressH\000\022;\n\013uds_address\030\002 \001(\0132$." +
+      "grpc.channelz.v1.Address.UdsAddressH\000\022?\n" +
+      "\rother_address\030\003 \001(\0132&.grpc.channelz.v1." +
+      "Address.OtherAddressH\000\0320\n\014TcpIpAddress\022\022" +
+      "\n\nip_address\030\001 \001(\014\022\014\n\004port\030\002 \001(\005\032\036\n\nUdsA" +
+      "ddress\022\020\n\010filename\030\001 \001(\t\032A\n\014OtherAddress" +
+      "\022\014\n\004name\030\001 \001(\t\022#\n\005value\030\002 \001(\0132\024.google.p" +
+      "rotobuf.AnyB\t\n\007address\"\276\002\n\010Security\022-\n\003t" +
+      "ls\030\001 \001(\0132\036.grpc.channelz.v1.Security.Tls" +
+      "H\000\0229\n\005other\030\002 \001(\0132(.grpc.channelz.v1.Sec" +
+      "urity.OtherSecurityH\000\032{\n\003Tls\022\027\n\rstandard" +
+      "_name\030\001 \001(\tH\000\022\024\n\nother_name\030\002 \001(\tH\000\022\031\n\021l" +
+      "ocal_certificate\030\003 \001(\014\022\032\n\022remote_certifi" +
+      "cate\030\004 \001(\014B\016\n\014cipher_suite\032B\n\rOtherSecur" +
+      "ity\022\014\n\004name\030\001 \001(\t\022#\n\005value\030\002 \001(\0132\024.googl" +
+      "e.protobuf.AnyB\007\n\005model\"U\n\014SocketOption\022" +
+      "\014\n\004name\030\001 \001(\t\022\r\n\005value\030\002 \001(\t\022(\n\naddition" +
+      "al\030\003 \001(\0132\024.google.protobuf.Any\"B\n\023Socket" +
+      "OptionTimeout\022+\n\010duration\030\001 \001(\0132\031.google" +
+      ".protobuf.Duration\"Q\n\022SocketOptionLinger" +
+      "\022\016\n\006active\030\001 \001(\010\022+\n\010duration\030\002 \001(\0132\031.goo" +
+      "gle.protobuf.Duration\"\256\005\n\023SocketOptionTc" +
+      "pInfo\022\022\n\ntcpi_state\030\001 \001(\r\022\025\n\rtcpi_ca_sta" +
+      "te\030\002 \001(\r\022\030\n\020tcpi_retransmits\030\003 \001(\r\022\023\n\013tc" +
+      "pi_probes\030\004 \001(\r\022\024\n\014tcpi_backoff\030\005 \001(\r\022\024\n" +
+      "\014tcpi_options\030\006 \001(\r\022\027\n\017tcpi_snd_wscale\030\007" +
+      " \001(\r\022\027\n\017tcpi_rcv_wscale\030\010 \001(\r\022\020\n\010tcpi_rt" +
+      "o\030\t \001(\r\022\020\n\010tcpi_ato\030\n \001(\r\022\024\n\014tcpi_snd_ms" +
+      "s\030\013 \001(\r\022\024\n\014tcpi_rcv_mss\030\014 \001(\r\022\024\n\014tcpi_un" +
+      "acked\030\r \001(\r\022\023\n\013tcpi_sacked\030\016 \001(\r\022\021\n\ttcpi" +
+      "_lost\030\017 \001(\r\022\024\n\014tcpi_retrans\030\020 \001(\r\022\024\n\014tcp" +
+      "i_fackets\030\021 \001(\r\022\033\n\023tcpi_last_data_sent\030\022" +
+      " \001(\r\022\032\n\022tcpi_last_ack_sent\030\023 \001(\r\022\033\n\023tcpi" +
+      "_last_data_recv\030\024 \001(\r\022\032\n\022tcpi_last_ack_r" +
+      "ecv\030\025 \001(\r\022\021\n\ttcpi_pmtu\030\026 \001(\r\022\031\n\021tcpi_rcv" +
+      "_ssthresh\030\027 \001(\r\022\020\n\010tcpi_rtt\030\030 \001(\r\022\023\n\013tcp" +
+      "i_rttvar\030\031 \001(\r\022\031\n\021tcpi_snd_ssthresh\030\032 \001(" +
+      "\r\022\025\n\rtcpi_snd_cwnd\030\033 \001(\r\022\023\n\013tcpi_advmss\030" +
+      "\034 \001(\r\022\027\n\017tcpi_reordering\030\035 \001(\r\"1\n\025GetTop" +
+      "ChannelsRequest\022\030\n\020start_channel_id\030\001 \001(" +
+      "\003\"Q\n\026GetTopChannelsResponse\022*\n\007channel\030\001" +
+      " \003(\0132\031.grpc.channelz.v1.Channel\022\013\n\003end\030\002" +
+      " \001(\010\",\n\021GetServersRequest\022\027\n\017start_serve" +
+      "r_id\030\001 \001(\003\"K\n\022GetServersResponse\022(\n\006serv" +
+      "er\030\001 \003(\0132\030.grpc.channelz.v1.Server\022\013\n\003en" +
+      "d\030\002 \001(\010\"E\n\027GetServerSocketsRequest\022\021\n\tse" +
+      "rver_id\030\001 \001(\003\022\027\n\017start_socket_id\030\002 \001(\003\"X" +
+      "\n\030GetServerSocketsResponse\022/\n\nsocket_ref" +
+      "\030\001 \003(\0132\033.grpc.channelz.v1.SocketRef\022\013\n\003e" +
+      "nd\030\002 \001(\010\"\'\n\021GetChannelRequest\022\022\n\nchannel" +
+      "_id\030\001 \001(\003\"@\n\022GetChannelResponse\022*\n\007chann" +
+      "el\030\001 \001(\0132\031.grpc.channelz.v1.Channel\"-\n\024G" +
+      "etSubchannelRequest\022\025\n\rsubchannel_id\030\001 \001" +
+      "(\003\"I\n\025GetSubchannelResponse\0220\n\nsubchanne" +
+      "l\030\001 \001(\0132\034.grpc.channelz.v1.Subchannel\"%\n" +
+      "\020GetSocketRequest\022\021\n\tsocket_id\030\001 \001(\003\"=\n\021" +
+      "GetSocketResponse\022(\n\006socket\030\001 \001(\0132\030.grpc" +
+      ".channelz.v1.Socket2\304\004\n\010Channelz\022c\n\016GetT" +
+      "opChannels\022\'.grpc.channelz.v1.GetTopChan" +
+      "nelsRequest\032(.grpc.channelz.v1.GetTopCha" +
+      "nnelsResponse\022W\n\nGetServers\022#.grpc.chann" +
+      "elz.v1.GetServersRequest\032$.grpc.channelz" +
+      ".v1.GetServersResponse\022i\n\020GetServerSocke" +
+      "ts\022).grpc.channelz.v1.GetServerSocketsRe" +
+      "quest\032*.grpc.channelz.v1.GetServerSocket" +
+      "sResponse\022W\n\nGetChannel\022#.grpc.channelz." +
+      "v1.GetChannelRequest\032$.grpc.channelz.v1." +
+      "GetChannelResponse\022`\n\rGetSubchannel\022&.gr" +
+      "pc.channelz.v1.GetSubchannelRequest\032\'.gr" +
+      "pc.channelz.v1.GetSubchannelResponse\022T\n\t" +
+      "GetSocket\022\".grpc.channelz.v1.GetSocketRe" +
+      "quest\032#.grpc.channelz.v1.GetSocketRespon" +
+      "seBX\n\023io.grpc.channelz.v1B\rChannelzProto" +
+      "P\001Z0google.golang.org/grpc/channelz/grpc" +
+      "_channelz_v1b\006proto3"
     };
     com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
         new com.google.protobuf.Descriptors.FileDescriptor.    InternalDescriptorAssigner() {
@@ -389,62 +406,68 @@ public final class ChannelzProto {
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_ChannelData_descriptor,
         new java.lang.String[] { "State", "Target", "Trace", "CallsStarted", "CallsSucceeded", "CallsFailed", "LastCallStartedTimestamp", });
-    internal_static_grpc_channelz_v1_ChannelTrace_descriptor =
+    internal_static_grpc_channelz_v1_ChannelTraceEvent_descriptor =
       getDescriptor().getMessageTypes().get(4);
+    internal_static_grpc_channelz_v1_ChannelTraceEvent_fieldAccessorTable = new
+      com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
+        internal_static_grpc_channelz_v1_ChannelTraceEvent_descriptor,
+        new java.lang.String[] { "Description", "Severity", "Timestamp", "ChannelRef", "SubchannelRef", "ChildRef", });
+    internal_static_grpc_channelz_v1_ChannelTrace_descriptor =
+      getDescriptor().getMessageTypes().get(5);
     internal_static_grpc_channelz_v1_ChannelTrace_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_ChannelTrace_descriptor,
-        new java.lang.String[] { });
+        new java.lang.String[] { "NumEventsLogged", "CreationTimestamp", "Events", });
     internal_static_grpc_channelz_v1_ChannelRef_descriptor =
-      getDescriptor().getMessageTypes().get(5);
+      getDescriptor().getMessageTypes().get(6);
     internal_static_grpc_channelz_v1_ChannelRef_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_ChannelRef_descriptor,
         new java.lang.String[] { "ChannelId", "Name", });
     internal_static_grpc_channelz_v1_SubchannelRef_descriptor =
-      getDescriptor().getMessageTypes().get(6);
+      getDescriptor().getMessageTypes().get(7);
     internal_static_grpc_channelz_v1_SubchannelRef_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_SubchannelRef_descriptor,
         new java.lang.String[] { "SubchannelId", "Name", });
     internal_static_grpc_channelz_v1_SocketRef_descriptor =
-      getDescriptor().getMessageTypes().get(7);
+      getDescriptor().getMessageTypes().get(8);
     internal_static_grpc_channelz_v1_SocketRef_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_SocketRef_descriptor,
         new java.lang.String[] { "SocketId", "Name", });
     internal_static_grpc_channelz_v1_ServerRef_descriptor =
-      getDescriptor().getMessageTypes().get(8);
+      getDescriptor().getMessageTypes().get(9);
     internal_static_grpc_channelz_v1_ServerRef_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_ServerRef_descriptor,
         new java.lang.String[] { "ServerId", "Name", });
     internal_static_grpc_channelz_v1_Server_descriptor =
-      getDescriptor().getMessageTypes().get(9);
+      getDescriptor().getMessageTypes().get(10);
     internal_static_grpc_channelz_v1_Server_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_Server_descriptor,
         new java.lang.String[] { "Ref", "Data", "ListenSocket", });
     internal_static_grpc_channelz_v1_ServerData_descriptor =
-      getDescriptor().getMessageTypes().get(10);
+      getDescriptor().getMessageTypes().get(11);
     internal_static_grpc_channelz_v1_ServerData_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_ServerData_descriptor,
         new java.lang.String[] { "Trace", "CallsStarted", "CallsSucceeded", "CallsFailed", "LastCallStartedTimestamp", });
     internal_static_grpc_channelz_v1_Socket_descriptor =
-      getDescriptor().getMessageTypes().get(11);
+      getDescriptor().getMessageTypes().get(12);
     internal_static_grpc_channelz_v1_Socket_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_Socket_descriptor,
         new java.lang.String[] { "Ref", "Data", "Local", "Remote", "Security", "RemoteName", });
     internal_static_grpc_channelz_v1_SocketData_descriptor =
-      getDescriptor().getMessageTypes().get(12);
+      getDescriptor().getMessageTypes().get(13);
     internal_static_grpc_channelz_v1_SocketData_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_SocketData_descriptor,
         new java.lang.String[] { "StreamsStarted", "StreamsSucceeded", "StreamsFailed", "MessagesSent", "MessagesReceived", "KeepAlivesSent", "LastLocalStreamCreatedTimestamp", "LastRemoteStreamCreatedTimestamp", "LastMessageSentTimestamp", "LastMessageReceivedTimestamp", "LocalFlowControlWindow", "RemoteFlowControlWindow", "Option", });
     internal_static_grpc_channelz_v1_Address_descriptor =
-      getDescriptor().getMessageTypes().get(13);
+      getDescriptor().getMessageTypes().get(14);
     internal_static_grpc_channelz_v1_Address_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_Address_descriptor,
@@ -468,7 +491,7 @@ public final class ChannelzProto {
         internal_static_grpc_channelz_v1_Address_OtherAddress_descriptor,
         new java.lang.String[] { "Name", "Value", });
     internal_static_grpc_channelz_v1_Security_descriptor =
-      getDescriptor().getMessageTypes().get(14);
+      getDescriptor().getMessageTypes().get(15);
     internal_static_grpc_channelz_v1_Security_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_Security_descriptor,
@@ -486,97 +509,97 @@ public final class ChannelzProto {
         internal_static_grpc_channelz_v1_Security_OtherSecurity_descriptor,
         new java.lang.String[] { "Name", "Value", });
     internal_static_grpc_channelz_v1_SocketOption_descriptor =
-      getDescriptor().getMessageTypes().get(15);
+      getDescriptor().getMessageTypes().get(16);
     internal_static_grpc_channelz_v1_SocketOption_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_SocketOption_descriptor,
         new java.lang.String[] { "Name", "Value", "Additional", });
     internal_static_grpc_channelz_v1_SocketOptionTimeout_descriptor =
-      getDescriptor().getMessageTypes().get(16);
+      getDescriptor().getMessageTypes().get(17);
     internal_static_grpc_channelz_v1_SocketOptionTimeout_fieldAccessorTable = new
       com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
         internal_static_grpc_channelz_v1_SocketOptionTimeout_descriptor,
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-      getDescriptor().getMessageTypes().get(17);
+      getDescriptor().getMessageTypes().get(18);
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     internal_static_grpc_channelz_v1_SocketOptionTcpInfo_descriptor =
-      getDescriptor().getMessageTypes().get(18);
+      getDescriptor().getMessageTypes().get(19);
     internal_static_grpc_channelz_v1_SocketOptionTcpInfo_fieldAccessorTable = new
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     internal_static_grpc_channelz_v1_GetTopChannelsRequest_descriptor =
-      getDescriptor().getMessageTypes().get(19);
+      getDescriptor().getMessageTypes().get(20);
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diff --git a/services/src/main/proto/grpc/channelz/v1/channelz.proto b/services/src/main/proto/grpc/channelz/v1/channelz.proto
index fa220db25..f0611657f 100644
--- a/services/src/main/proto/grpc/channelz/v1/channelz.proto
+++ b/services/src/main/proto/grpc/channelz/v1/channelz.proto
@@ -117,10 +117,42 @@ message ChannelData {
   google.protobuf.Timestamp last_call_started_timestamp = 7;
 }
 
+// A trace event is an interesting thing that happened to a channel or
+// subchannel, such as creation, address resolution, subchannel creation, etc.
+message ChannelTraceEvent {
+  // High level description of the event.
+  string description = 1;
+  // The supported severity levels of trace events.
+  enum Severity {
+    CT_UNKNOWN = 0;
+    CT_INFO = 1;
+    CT_WARNING = 2;
+    CT_ERROR = 3;
+  }
+  // the severity of the trace event
+  Severity severity = 2;
+  // When this event occurred.
+  google.protobuf.Timestamp timestamp = 3;
+  // ref of referenced channel or subchannel.
+  // Optional, only present if this event refers to a child object. For example,
+  // this field would be filled if this trace event was for a subchannel being
+  // created.
+  oneof child_ref {
+    ChannelRef channel_ref = 4;
+    SubchannelRef subchannel_ref = 5;
+  }
+}
+
 // ChannelTrace represents the recent events that have occurred on the channel.
 message ChannelTrace {
-  // see the proto in the gRFC for channel tracing:
-  // A3-channel-tracing.md
+  // Number of events ever logged in this tracing object. This can differ from
+  // events.size() because events can be overwritten or garbage collected by
+  // implementations.
+  int64 num_events_logged = 1;
+  // Time that this channel was created.
+  google.protobuf.Timestamp creation_timestamp = 2;
+  // List of events that have occurred on this channel.
+  repeated ChannelTraceEvent events = 3;
 }
 
 // ChannelRef is a reference to a Channel.