Github user tony810430 commented on a diff in the pull request:
https://github.com/apache/flink/pull/5115#discussion_r154907808
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/metrics/groups/AbstractMetricGroup.java
---
@@ -409,6 +404,22 @@ public MetricGroup addGroup(String name) {
return addGroup(name, false);
}
+ @Override
+ public MetricGroup addGroup(String key, String value) {
--- End diff --
In the below case, the `subGroup2` will get a `GenericValueMetricGroup`
back.
```
val subGroup = group.addGroup("key", "value")
val subGroup2 = group.addGroup("key").addGroup("value")
```
I prefer not to change the behavior of original API, so I think it is
better to return a `GenericMetricGroup`.
---
