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ASF GitHub Bot commented on KAFKA-5174: --------------------------------------- GitHub user enothereska opened a pull request: https://github.com/apache/kafka/pull/2982 KAFKA-5174: Have at least 2 threads You can merge this pull request into a Git repository by running: $ git pull https://github.com/enothereska/kafka KAFKA-5174-1-core Alternatively you can review and apply these changes as the patch at: https://github.com/apache/kafka/pull/2982.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #2982 ---- ---- > RocksDb might stall in environments with 1 core only > ---------------------------------------------------- > > Key: KAFKA-5174 > URL: https://issues.apache.org/jira/browse/KAFKA-5174 > Project: Kafka > Issue Type: Bug > Components: streams > Affects Versions: 0.10.2.1 > Reporter: Eno Thereska > Assignee: Eno Thereska > > - there is a regression in 0.10.2.1 that impacts RocksDb's behaviour (details > below for first impact) from this PR: > https://github.com/apache/kafka/commit/f9660e16dafb9e1109704bdecb978b7046f0cc6b#diff-046ca566243518c88e007b7499ec9f51 > - worst-case impact: streams might not run out-of-box in deployments with 1 > core only > - workaround: no new jars needed for the workaround, only a config change > that changes a RocksDb parameter, e.g. something like in this PR: > https://github.com/confluentinc/examples/pull/117/files > - full fix: add 1 to the current config (i.e., max cpus + 1) in the default > settings > The RocksDb code might have a bug itself, since when running with one core > it both sets the number of compaction threads to 1 > (https://github.com/facebook/rocksdb/blob/5.0.fb/util/options.cc#L762) AND > the maximum number of compactions variable to 0 > (https://github.com/facebook/rocksdb/blob/5.0.fb/util/options.cc#L760) which > doesn't make much sense. I've sent a message in RocksDb channel. -- This message was sent by Atlassian JIRA (v6.3.15#6346)