[CASSANDRA-8066] High Heap Consumption due to high number of SSTableReader

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 2.1.1
• Component/s: Legacy/Local Write-Read Paths, Local/Compaction

Environment

Cassandra 2.1.0

• Severity: Normal
• Assignee: T Jake Luciani
• Reporter: Benoit Lacelle

Authors

T Jake Luciani

Reviewers

Jason Brown

• Created: 07/Oct/14 07:39
• Updated: 16/Apr/19 09:31
• Resolved: 14/Oct/14 12:58

Description

Given a workload with quite a lot of reads, I recently encountered high heap memory consumption. Given 2GB of Heap, it appears I have 750.000+ tasks in SSTableReader.syncExecutor, consuming more than 1.2GB. These tasks have type SSTableReader$5, which I guess corresponds to :

readMeterSyncFuture = syncExecutor.scheduleAtFixedRate(new Runnable()
{
public void run()
{
if (!isCompacted.get())
{
meterSyncThrottle.acquire();
SystemKeyspace.persistSSTableReadMeter(desc.ksname, desc.cfname, desc.generation, readMeter);
}
}
}, 1, 5, TimeUnit.MINUTES);

I do not have have to the environment right now, but I could provide a threaddump later if necessary.