[ https://issues.apache.org/jira/browse/CASSANDRA-9146?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14576373#comment-14576373 ]
Anuj Wadehra commented on CASSANDRA-9146: ----------------------------------------- We have 24 cores and concurrent_compactors are 12. Does concurrent compactors impact creation of tiny sstables during repair? We haven't set cold_ reads_to_omit. Anyways making it 0 doesnt have any impact in 2.0.3. > Ever Growing sstables after every Repair > ---------------------------------------- > > Key: CASSANDRA-9146 > URL: https://issues.apache.org/jira/browse/CASSANDRA-9146 > Project: Cassandra > Issue Type: Bug > Components: Core > Reporter: Anuj Wadehra > Attachments: sstables.txt, system-modified.log > > > Cluster has reached a state where every "repair -pr" operation on CF results > in numerous tiny sstables being flushed to disk. Due to thousands of > sstables, reads have started timing out. Even though compaction begins for > one of the secondary index, sstable count after repair remains very high > (thousands). Every repair adds thousands of sstables. > Problems: > 1. Why burst of tiny tables are flushed during repair ? What is triggering > frequent/premature flush of sstable (more than hundred in every burst)? At > max we see one ParNew GC pauses >200ms. > 2. Why auto-compaction is not compacting all sstables. Is it related to > coldness issue(CASSANDRA-8885) where compaction doesn't works even when > cold_reads_to_omit=0 by default? > If coldness is the issue, we are stuck in infinite loop: reads will > trigger compaction but reads timeout as sstable count is in thousands > 3. What's the way out if we face this issue in Prod? > Is this issue fixed in latest production release 2.0.13? Issue looks similar > to CASSANDRA-8641, but the issue is fixed in only 2.1.3. I think it should be > fixed in 2.0 branch too. > Configuration: > Compaction Strategy: STCS > memtable_flush_writers=4 > memtable_flush_queue_size=4 > in_memory_compaction_limit_in_mb=32 > concurrent_compactors=12 -- This message was sent by Atlassian JIRA (v6.3.4#6332)