Alexey Serbin has posted comments on this change. ( http://gerrit.cloudera.org:8080/21389 )
Change subject: KUDU-613: Introduce new BlockCache metrics ...................................................................... Patch Set 4: (2 comments) http://gerrit.cloudera.org:8080/#/c/21389/2/src/kudu/util/block_cache_metrics.cc File src/kudu/util/block_cache_metrics.cc: PS2: > I was thinking more in the terms of a single entry life journey tracking i. I don't think we could provide a per-element metric in this context. The way how it's usually achieved is maintaining a histogram-like metric that accumulates stats on the distribution of a gauge. I guess you are suggesting to collect stats on the frequency of seeing a particular key. But that's rather in the design of the cache, not just metrics of the SLRU cache. E.g., the TinyLFU cache keeps similar stats on per-element basis (actually, it's closer to Bloom filter's approach) and uses that for admission control decisions. But I might misunderstood your suggestion, though. Please feel free to chime in and correct my misunderstanding, if any. PS2: > I definitely considered just providing top level metrics for the SLRU cache Sure, we need to have detailed metrics for the parts of the SLRU cache. Re-using the set of LRU metrics for both the protected and the probational segments of the cache is quite natural and those stats provide information for generic troubleshooting and assessing the ratio of the segment sizes. However, you could provide function gauges for the high-level cache metrics that an end-user might be interested in, improving the usability for an end-user. If you prefer to address it in a separate patch, I'm OK with that approach. -- To view, visit http://gerrit.cloudera.org:8080/21389 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1c8181ec6bea301605aaef7db0003c3eaef3072d Gerrit-Change-Number: 21389 Gerrit-PatchSet: 4 Gerrit-Owner: Mahesh Reddy <mre...@cloudera.com> Gerrit-Reviewer: Abhishek Chennaka <achenn...@cloudera.com> Gerrit-Reviewer: Alexey Serbin <ale...@apache.org> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Mahesh Reddy <mre...@cloudera.com> Gerrit-Reviewer: Wang Xixu <1450306...@qq.com> Gerrit-Comment-Date: Wed, 22 May 2024 02:59:10 +0000 Gerrit-HasComments: Yes
