[DBCP-225] getConnection / borrowObject fails with NullPointerException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.1, 1.2.2
• Fix Version/s: 1.3

Environment

Solaris 10, Oracle 10g RAC

• Assignee: Dain Sundstrom
• Reporter: Alexei Samonov
• Created: 23/May/07 14:12
• Updated: 25/Mar/08 08:11
• Resolved: 23/Jul/07 19:53

Description

We use dbcp PoolingDataSource in Solaris/Oracle 10g RAC environment and our getConnection calls fail sporadically with the following stack trace (1.2.1)

Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot get a connection, pool exhausted
at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:103)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
... more
Caused by: java.util.NoSuchElementException: Could not create a validated object, cause: null
at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:806)
at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:95)
... 24 more

This is definitely not a "pool exhausted" situation, it is just being reported as pool exhausted. Since NoSuchElementException that you use does not allow cause, only Exception message (null) is being printed. With some debugging I was able to recover the root exception:

java.lang.NullPointerException
at org.apache.commons.dbcp.DelegatingConnection.setAutoCommit(DelegatingConnection.java:268)
at org.apache.commons.dbcp.PoolableConnectionFactory.activateObject(PoolableConnectionFactory.java:368)
at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:786)
at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:95)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
...

Looks like it is trying to borrow/validate DelegatingConnection which delegate is null.

Hoping to resolve the issue we upgraded to 1.2.2 but it did not help. Here is is an exception stack trace from 1.2.2:

org.apache.commons.dbcp.SQLNestedException: Cannot get a connection, pool error Could not create a validated object, cause: null
at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:104)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
... more
Caused by: java.util.NoSuchElementException: Could not create a validated object, cause: null
at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:871)
at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:96)
... 28 more

We use the following dbcp properties:

autoCommit="false"
readOnly="false"
maxActive="200"
maxIdle="20"
minIdle="10"
minEvictableIdleIime="300000"
maxWait="200"
accessToUnderlyingConnectionAllowed="true"
validationQuery="SELECT 1 FROM DUAL"
ConnectionCachingEnabled="true"
FastConnectionFailoverEnabled="true"

I could not find the existing reported dbcp/object pool bug but I see similar reports on the web, for example
http://forum.java.sun.com/thread.jspa?threadID=713200&messageID=4124915

Issue Links

• duplicates: DBCP-224 Null delegate possible