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https://issues.apache.org/jira/browse/DBCP-244?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12565756#action_12565756
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Andrus Adamchik commented on DBCP-244:
--------------------------------------
I am observing a similar behavior with MySQL 5.0, dbcp-1.2.1, pool-1.2.... Also
no visible deadlock in a thread dump. It happens once every few weeks, but
usually simultaneously on multiple applications, so I suspect it is caused by
temporary network outages... The problem of course is that the pool never
recovers.
Stuck threads look like this:
btpool0-873" prio=10 tid=0x01001c50 nid=0x26a3 runnable [0x679fc000..0x679ffaf0]
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
at
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
at
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
- locked <0xab4f6b20> (a com.mysql.jdbc.util.ReadAheadInputStream)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1902)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2351)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2862)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1571)
at
com.mysql.jdbc.ServerPreparedStatement.serverExecute(ServerPreparedStatement.java:1124)
- locked <0xac8430b0> (a java.lang.Object)
at
com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:676)
at
com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1030)
- locked <0xac8430b0> (a java.lang.Object)
- locked <0xa69343f0> (a com.mysql.jdbc.ServerPreparedStatement)
at
org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:92)
at
org.apache.cayenne.access.jdbc.SelectAction.performAction(SelectAction.java:72)
DBCP pool is wrapped in a Cayenne decorator, but this is still a DBCP pool with
the following settings:
cayenne.dbcp.maxActive=8
cayenne.dbcp.minIdle=1
cayenne.dbcp.maxIdle=4
cayenne.dbcp.validationQuery=select 1 from nhldb.division limit 1;
cayenne.dbcp.testWhileIdle=true
Can't even say that DBCP is here to blame, but still figured I provide this
data point.
> Connection socket hangs sporadically in DBCP 1.2.2 but not 1.2.1
> ----------------------------------------------------------------
>
> Key: DBCP-244
> URL: https://issues.apache.org/jira/browse/DBCP-244
> Project: Commons Dbcp
> Issue Type: Bug
> Affects Versions: 1.2.2
> Environment: Fedora Core 3, MySQL 4.1.22. with the latest driver
> (5.07). Exceptions only occur in the "job processing" JVM, which sits idle
> for long periods of time and occasionally wakes up to interact with the
> database.
> Reporter: ori
> Fix For: 1.3
>
>
> I think I've traced an exception to DBCP's code.
> Communication with the database is hanging sporadically in a production
> environment. If I don't set the socketTimeout property on the underlying
> connection, it will hang forever. With the socketTimeout property, I get the
> following exception:
> -------
> com.mysql.jdbc.CommunicationsException: Communications link failure due to
> underlying exception:
> ** BEGIN NESTED EXCEPTION **
> java.net.SocketTimeoutException
> MESSAGE: Read timed out
> STACKTRACE:
> java.net.SocketTimeoutException: Read timed out
> at java.net.SocketInputStream.socketRead0(Native Method)
> at java.net.SocketInputStream.read(SocketInputStream.java:129)
> at
> com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
> at
> com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
> at
> com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
> at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1994)
> at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2411)
> at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916)
> at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
> at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
> at com.mysql.jdbc.Connection.execSQL(Connection.java:3250)
> at com.mysql.jdbc.Statement.executeUpdate(Statement.java:1355)
> at com.mysql.jdbc.Statement.executeUpdate(Statement.java:1270)
> at
> org.apache.commons.dbcp.DelegatingStatement.executeUpdate(DelegatingStatement.java:228)
> ...
> -------
> It always happens in an infrequently used JVM (not an app server handling
> frequent connections). So it's likely the offending connection was asleep for
> a long time before the exception occurs.
> I've confirmed that this issue only occurs using 1.2.2 and not 1.2.1. I've
> been looking through the changelogs but can't find anything that would cause
> this behavior.
> Does somebody familiar with the codebase have any idea what change
> (1.2.1->1.2.2) could be causing this behavior?
> Thanks
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