Adar Dembo has posted comments on this change. ( http://gerrit.cloudera.org:8080/11420 )
Change subject: [docs] Add basic advice on setting block cache size ...................................................................... Patch Set 1: (5 comments) http://gerrit.cloudera.org:8080/#/c/11420/1//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/11420/1//COMMIT_MSG@9 PS1, Line 9: improving Nit: "improving" is an odd choice here, since the subject is "the block cache size" rather than "the performance of the block cache". http://gerrit.cloudera.org:8080/#/c/11420/1//COMMIT_MSG@11 PS1, Line 11: e.g. : consider a workload doing full table scans vs. one mostly re-scanning : a small range checking for updates) Worth noting that the scanner API has a SetCacheBlocks() method to control whether an individual scan's resulting blocks are cached in the block cache or not. http://gerrit.cloudera.org:8080/#/c/11420/1/docs/troubleshooting.adoc File docs/troubleshooting.adoc: http://gerrit.cloudera.org:8080/#/c/11420/1/docs/troubleshooting.adoc@542 PS1, Line 542: the memory pressure percentage times the hard limit Nit: clearer as "`--memory_pressure_percentage` of `--memory_limit_hard_bytes`", to better connect to the previous sentence? http://gerrit.cloudera.org:8080/#/c/11420/1/docs/troubleshooting.adoc@543 PS1, Line 543: With the defaults, this means the `--block_cache_capacity_mb` should not exceed : 30% of `--memory_limit_hard_bytes` Nit: wouldn't it be clearer to use "block cache capacity" and "memory hard limit" respectively in this sentence, since you're referring to tangible concepts and not to gflags? http://gerrit.cloudera.org:8080/#/c/11420/1/docs/troubleshooting.adoc@596 PS1, Line 596: block_cache_usage` Won't block_cache_usage be 100% of block_cache_capacity_mb given enough uptime? Meaning, the only case where it won't be the same value is a freshly started tserver with a cold cache. -- To view, visit http://gerrit.cloudera.org:8080/11420 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Idc7411c38b6fcc8694509ec89c32e2fe74e6c0db Gerrit-Change-Number: 11420 Gerrit-PatchSet: 1 Gerrit-Owner: Will Berkeley <[email protected]> Gerrit-Reviewer: Adar Dembo <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Andrew Wong <[email protected]> Gerrit-Reviewer: Attila Bukor <[email protected]> Gerrit-Reviewer: Kudu Jenkins Gerrit-Comment-Date: Wed, 12 Sep 2018 21:00:31 +0000 Gerrit-HasComments: Yes
