[
https://issues.apache.org/jira/browse/CASSANDRA-6275?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13827173#comment-13827173
]
graham sanderson edited comment on CASSANDRA-6275 at 11/20/13 4:44 AM:
-----------------------------------------------------------------------
Note that this would tend to imply that I was wrong (at least about the
particular code path), and the change in leak rate may be attributable to less
throughput without the file cache. Note the leak rate does seem quite related
to how hard we are hitting the server as mentioned before, so a threading bug
elsewhere might be the cause.
Note nominally buffer in RAR should be volatile, but then any code path thru
close where buffer's latest value is stale would end up calling deallocate
anyway (at least in the case that file_cache_size_in_mb is off; I didn't think
through the other case.
So given the finalizer fix - which we can try and build here to test out
(unless someone has it pre-built) - seems to imply that it is just someone
failing to call close() under load conditions.
was (Author: graham sanderson):
Note that this would tend to imply that I was wrong (at least about the
particular code path), and the change in leak rate may be attributable to less
throughput without the file cache. Note the leak rate does seem quite related
to how hard we are hitting the server as mentioned before, so a threading bug
elsewhere might be the cause.
Note nominally buffer in RAR should be volatile, but then any code path thru
close where buffer's latest value is stale would end up calling deallocate
anyway (at least in the case that file_cache_size_in_mb is off; I didn't think
though the other case.
So given the finalizer fix - which we can try and build here to test out
(unless someone has it pre-built) - seems to imply that it is just someone
failing to call close() under load conditions.
> 2.0.x leaks file handles
> ------------------------
>
> Key: CASSANDRA-6275
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6275
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Environment: java version "1.7.0_25"
> Java(TM) SE Runtime Environment (build 1.7.0_25-b15)
> Java HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)
> Linux cassandra-test1 2.6.32-279.el6.x86_64 #1 SMP Thu Jun 21 15:00:18 EDT
> 2012 x86_64 x86_64 x86_64 GNU/Linux
> Reporter: Mikhail Mazursky
> Assignee: Michael Shuler
> Attachments: c_file-descriptors_strace.tbz, cassandra_jstack.txt,
> leak.log, position_hints.tgz, slog.gz
>
>
> Looks like C* is leaking file descriptors when doing lots of CAS operations.
> {noformat}
> $ sudo cat /proc/15455/limits
> Limit Soft Limit Hard Limit Units
> Max cpu time unlimited unlimited seconds
> Max file size unlimited unlimited bytes
> Max data size unlimited unlimited bytes
> Max stack size 10485760 unlimited bytes
> Max core file size 0 0 bytes
> Max resident set unlimited unlimited bytes
> Max processes 1024 unlimited processes
> Max open files 4096 4096 files
> Max locked memory unlimited unlimited bytes
> Max address space unlimited unlimited bytes
> Max file locks unlimited unlimited locks
> Max pending signals 14633 14633 signals
> Max msgqueue size 819200 819200 bytes
> Max nice priority 0 0
> Max realtime priority 0 0
> Max realtime timeout unlimited unlimited us
> {noformat}
> Looks like the problem is not in limits.
> Before load test:
> {noformat}
> cassandra-test0 ~]$ lsof -n | grep java | wc -l
> 166
> cassandra-test1 ~]$ lsof -n | grep java | wc -l
> 164
> cassandra-test2 ~]$ lsof -n | grep java | wc -l
> 180
> {noformat}
> After load test:
> {noformat}
> cassandra-test0 ~]$ lsof -n | grep java | wc -l
> 967
> cassandra-test1 ~]$ lsof -n | grep java | wc -l
> 1766
> cassandra-test2 ~]$ lsof -n | grep java | wc -l
> 2578
> {noformat}
> Most opened files have names like:
> {noformat}
> java 16890 cassandra 1636r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1637r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1638r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1639r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1640r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1641r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1642r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1643r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1644r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1645r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1646r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1647r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1648r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1649r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1650r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1651r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1652r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1653r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1654r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> java 16890 cassandra 1655r REG 202,17 161158485
> 655420 /var/lib/cassandra/data/system/paxos/system-paxos-jb-255-Data.db
> java 16890 cassandra 1656r REG 202,17 88724987
> 655520 /var/lib/cassandra/data/system/paxos/system-paxos-jb-644-Data.db
> {noformat}
> Also, when that happens it's not always possible to shutdown server process
> via SIGTERM. Have to use SIGKILL.
> p.s. See mailing thread for more context information
> https://www.mail-archive.com/user@cassandra.apache.org/msg33035.html
--
This message was sent by Atlassian JIRA
(v6.1#6144)
