[JAMES-294] Database Pool becomes exhausted after a short time when heavily polled

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: 2.2.0
• Fix Version/s: 2.2.0
• Component/s: UsersStore & UsersRepository
• Environment: Windows NT v4.0, Java 1.4.2
• Assignee: Noel J. Bergman
• Reporter: Chris Means
• Created: 25/May/04 12:50
• Updated: 05/Jun/04 04:22
• Resolved: 05/Jun/04 04:22

Description

I've had RC3 running for the past week.

Other than an issue I ran into with the config.xml when translating changes from my 0a4 configuration, RC3 has been running quite well except for a new problem that appears to have surfaced.

This issue may relate to the fact that I've also been evaluating Mars
(http://leapfrog-mars.sourceforge.net/) for monitoring services.

Here's the exception that's occurring in the pop3server log:

23/05/04 11:01:58 ERROR pop3server: Exception during connection from intfar.com (66.92.129.218) : An exception occurred getting a database connection.
org.apache.avalon.framework.CascadingRuntimeException: An exception occurred getting a database connection.
at
org.apache.james.userrepository.AbstractJdbcUsersRepository.openConnection(A
bstractJdbcUsersRepository.java:601)
at
org.apache.james.userrepository.AbstractJdbcUsersRepository.getUserByName(Ab
stractJdbcUsersRepository.java:506)
at
org.apache.james.userrepository.AbstractUsersRepository.test(AbstractUsersRe
pository.java:284)
at
org.apache.james.pop3server.POP3Handler.doPASS(POP3Handler.java:528)
at
org.apache.james.pop3server.POP3Handler.parseCommand(POP3Handler.java:470)
at
org.apache.james.pop3server.POP3Handler.handleConnection(POP3Handler.java:26
6)
at
org.apache.james.util.connection.ServerConnection$ClientConnectionRunner.run
(ServerConnection.java:417)
at
org.apache.james.util.thread.ExecutableRunnable.execute(ExecutableRunnable.j
ava:55)
at
org.apache.james.util.thread.WorkerThread.run(WorkerThread.java:90)
Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot get a connection, pool exhausted, cause: Timeout waiting for idle object
at
org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.ja
va:148)
at
org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:5
18)
at
org.apache.james.util.dbcp.JdbcDataSource.getConnection(JdbcDataSource.java:
218)
at
org.apache.james.userrepository.AbstractJdbcUsersRepository.openConnection(A
bstractJdbcUsersRepository.java:598)
... 8 more
Caused by: java.util.NoSuchElementException: Timeout waiting for idle object
at
org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPoo
l.java:801)
at
org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.ja
va:140)
... 11 more

This an exception from mailstore log:

23/05/04 10:31:09 ERROR mailstore: Error retrieving messageCannot get a connection, pool exhausted0nullnull
23/05/04 10:31:09 ERROR mailstore: Exception during retrieve – skipping item Mail1085326264738-657
javax.mail.MessagingException: Exception while retrieving mail: Cannot get a connection, pool exhausted
at
org.apache.james.mailrepository.JDBCMailRepository.retrieve(JDBCMailReposito
ry.java:905)
at
org.apache.james.mailrepository.JDBCSpoolRepository.accept(JDBCSpoolReposito
ry.java:199)
at
org.apache.james.mailrepository.JDBCSpoolRepository.accept(JDBCSpoolReposito
ry.java:124)
at
org.apache.james.transport.JamesSpoolManager.run(JamesSpoolManager.java:350)
at java.lang.Thread.run(Thread.java:536)

Some background:

I am the primary user of this mail server. My M$ Outlook checks 5 different accounts every 5 minutes.

Since I've been evaluating Mars, I've had it monitoring access for POP3 and SMTP every minute, with a 5 second timeout.

I think it's this last point that's likely causing the problem. Am I expecting too much from James? My monitoring too aggressive?

As this seems to be a new issue, I didn't think RC4 was likely to solve it.