Interns.java outputs "Metrics intern cache over flow" warn log for metrics info/tag when the cache reaches the hard-coded limit and the oldest cache is discarded for the first time. I'm thinking this log level can be changed to info because
- there is no problem when the oldest cache is removed. if the metrics info/tag is not in the cache, simply create it.
- we cannot configure the maximum size of the cache, so there is no way to stop the warn log.