Alexey Plotnik created CASSANDRA-6744:
-----------------------------------------
Summary: Network streaming is locked by a cleanup comapction
Key: CASSANDRA-6744
URL: https://issues.apache.org/jira/browse/CASSANDRA-6744
Project: Cassandra
Issue Type: Bug
Components: Core
Environment: CentOS 6.4
Reporter: Alexey Plotnik
Attachments: receiver.dump, sender.dump
When I rebalanced my Cassandra cluster moving SSTables from one node to another
I saw that sometimes the streaming process stucked without any exeptions in
logs on both sides. It was like a pause. I investigated Thread dumps from node
that sends the data and found that it waits for response here:
{noformat}
"Streaming to /192.168.25.232:2" - Thread t@26058
java.lang.Thread.State: RUNNABLE
...
at
org.apache.cassandra.streaming.FileStreamTask.receiveReply(FileStreamTask.java:193)
at
org.apache.cassandra.streaming.FileStreamTask.runMayThrow(FileStreamTask.java:101)
at
org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)
{noformat}
Source:
{code:title=org.apache.cassandra.streaming.FileStreamTask|borderStyle=solid}
public class FileStreamTask extends WrappedRunnable {
....
protected void receiveReply() throws IOException
{
MessagingService.validateMagic(input.readInt()); // <-- stucked here
{code}
Ok, it waits for answer from the opposite endpoint.
Let's go further. After investigating receiving endpoint tread dump I found
where it stucks:
{noformat}
"Thread-104503" - Thread t@268602
java.lang.Thread.State: WAITING
at
org.apache.cassandra.db.index.SecondaryIndexManager.maybeBuildSecondaryIndexes(SecondaryIndexManager.java:144)
at
org.apache.cassandra.streaming.StreamInSession.closeIfFinished(StreamInSession.java:187)
at
org.apache.cassandra.streaming.IncomingStreamReader.read(IncomingStreamReader.java:138)
at
org.apache.cassandra.net.IncomingTcpConnection.stream(IncomingTcpConnection.java:243)
at
org.apache.cassandra.net.IncomingTcpConnection.handleStream(IncomingTcpConnection.java:183)
at
org.apache.cassandra.net.IncomingTcpConnection.run(IncomingTcpConnection.java:79)
{noformat}
It build secondary indexes (my CF has no secondaries).
*SecondaryIndexManager.maybeBuildSecondaryIndexes* creates a *Future* and
wait's for it. Inside *Future* it synchronizes with common lock of
*CompactionManager*:
{code:title=org.apache.cassandra.db.compaction.CompactionManager|borderStyle=solid}
compactionLock.readLock().lock(); // line #797
{code}
The same lock is used by a cleanup process as the *performCleanup()* executes
*performAllSSTableOperation()* method which is aquire the lock.
This ticket is created because on large nodes (1Tb-2Tb) especially hosted on
network storages the delay can reach up to few days. Correct me if I wrong: we
shouldn't lock in rebuild secondary indexes stage because there is no secondary
indexes for this CF. It's not a problem when Cleanup process is paused by
Streaming but not vice versa, because streaming process has much more important.
Both thread dumps attached.
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