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Jeff Klukas commented on KAFKA-3753: ------------------------------------ Since there's refactoring going on right now with the metrics interface for streams (https://issues.apache.org/jira/browse/KAFKA-3715), I think we should delay actually adding size metrics to a different issue. The PR I attached here adds the size() method so that it can be used for a metric in the future. > Metrics for StateStores > ----------------------- > > Key: KAFKA-3753 > URL: https://issues.apache.org/jira/browse/KAFKA-3753 > Project: Kafka > Issue Type: Improvement > Components: streams > Reporter: Jeff Klukas > Assignee: Guozhang Wang > Priority: Minor > Labels: api > Fix For: 0.10.1.0 > > > As a developer building a Kafka Streams application, I'd like to have > visibility into what's happening with my state stores. How can I know if a > particular store is growing large? How can I know if a particular store is > frequently needing to hit disk? > I'm interested to know if there are existing mechanisms for extracting this > information or if other people have thoughts on how we might approach this. > I can't think of a way to provide metrics generically, so each state store > implementation would likely need to handle this separately. Given that the > default RocksDBStore will likely be the most-used, it would be a first target > for adding metrics. > I'd be interested in knowing the total number of entries in the store, the > total size on disk and in memory, rates of gets and puts, and hit/miss ratio > for the MemoryLRUCache. Some of these numbers are likely calculable through > the RocksDB API, others may simply not be accessible. > Would there be value to the wider community in having state stores register > metrics? -- This message was sent by Atlassian JIRA (v6.3.4#6332)