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https://issues.apache.org/jira/browse/DBCP-244?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12635869#action_12635869
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Carl Gould commented on DBCP-244:
---------------------------------
I'm seeing this too. I get one thread with the following dump (see below) and
then the rest all block on
org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:294)
This is on Windows Server 2003 Standard Ed, Java 1.5.0_11, DBCP 1.2.2, Pool 1.4
MySQL Connector/J 5.0.4
We used DBCP 1.2.1 for years, and never saw this. It seems to happen after a
network drop between DBCP and the database.
Of course, we upgraded to DBCP 1.2.2 to fix the bug in 1.2.1 that caused the
pool to leak connections when the underlying connection closed itself due to
socket error and then the framework didn't catch the "already closed"
exception...
Anyhow, I digress, the stack trace of the blocked thread is:
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(Unknown Source)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1910)
com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:501)
com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:971)
com.mysql.jdbc.Connection.createNewIO(Connection.java:2670)
com.mysql.jdbc.Connection.(Connection.java:1531)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:294)
org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:974)
org.apache.commons.dbcp.AbandonedObjectPool.borrowObject(AbandonedObjectPool.java:84)
org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:96)
org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
...[ application code ]
> 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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