Merge pull request apache#9155 from rohdesamuel/update-versions

[BEAM-7820] Add hot key detection protos to Windmill

runners/google-cloud-dataflow-java/worker/windmill/src/main/proto/windmill.proto

@@ -134,6 +134,12 @@ message WatermarkHold {
  optional string state_family = 4;
 }
 
+// Proto describing a hot key detected on a given WorkItem.
+message HotKeyInfo {
+ // The age of the hot key measured from when it was first detected.
+ optional int64 hot_key_age_usec = 1;
+}
+
 message WorkItem {
  required bytes key = 1;
  required fixed64 work_token = 2;
@@ -149,6 +155,11 @@ message WorkItem {
  // Indicates that this is a new key with no data associated. This allows
  // the harness to optimize data fetching.
  optional bool is_new_key = 10;
+
+ // A hot key is a symptom of poor data distribution in which there are enough
+ // elements mapped to a single key to impact pipeline performance. When
+ // present, this field includes metadata associated with any hot key.
+ optional HotKeyInfo hot_key_info = 11;
 }
 
 message ComputationWorkItems {