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Ekaterina Dimitrova commented on CASSANDRA-16261: ------------------------------------------------- Right for the link, apologize, looks like my copy-paste didn't work. Yes, I kept the old and the new PRs until we are done with the reviews. I believe the old ones are good for reference on what we discussed/agreed on. It was easy to squash everything but I guess it would have been harder and frustrating for everyone. :) It is on my list to update the ticket and leave only the latest ones when we are done. Thank you! > Prevent unbounded number of flushing tasks > ------------------------------------------ > > Key: CASSANDRA-16261 > URL: https://issues.apache.org/jira/browse/CASSANDRA-16261 > Project: Cassandra > Issue Type: Bug > Components: Legacy/Local Write-Read Paths > Reporter: Ekaterina Dimitrova > Assignee: Ekaterina Dimitrova > Priority: Normal > Fix For: 3.0.x, 3.11.x, 4.0-beta > > > The cleaner thread is not prevented from queueing an unbounded number of > flushing tasks for memtables that are almost empty. > This patch adds a mechanism to track the number of pending flushing > tasks in the memtable cleaner. Above the maximum number (2x the flushing > threads by default), only memtables using at least MCT memory will be > flushed, where MCT stands for Memory Cleanup Threshold. > This patch also fixes a possible problem tracking the memory marked as > "reclaiming" in the memtable allocators and pool. Writes that complete > only after a memtable has been scheduled for flushing, did not report > their memory as reclaiming. Normally this should be a small value of no > consequence, but if the flushing tasks are blocked for a long period, > and there is a sufficient number of writes, or these writes use > a sufficiently large quantity of memory, this would cause the memtable > cleaning algorithm to schedule repeated flushing tasks because the used > memory is always > reclaiming memory + MCT. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org