[jboss-user] [Performance Tuning] - DS - No managed connections available within blocking timeou
Hi,
I have been performance tuning jboss, and have came across an issue related to
DataSources. Each time I run a 500 user test, the application "pauses" for 200
seconds or so(no responses are seen). I have tracked this down to two separate issues,
the first was with the number of Open file descriptors. I am using RHEL3, and this is set
to 1024, for an indiviual process. I have moved this to 2048, on the grounds that each
user connection(we are connecting directly to jboss), consumes one connection, and
logically since everything in linux is a file, needs one file descriptor. I no longer get
the "Too many open files"(note I have checked for increasing numbers of open
files, but do not see this increasing over time), effectively I have an application that
requires a lot of open file descriptors. Now this is stabalised.
However, I still get the problem with "No managed connections available".
I have changed all the relevant DataSource maximum connections from a default of 20, to a
new default maximum of 200(changed in the ds.xml for each datasource). I have monitored
the application and am getting around 100 data source connections maximum, per data
source(ie I should have another 100 "spare").
However, I still have the error that there are no managed connections available.
Can anyone shed any light on what options I might try next to track this down?
I have included a stack trace from the log file.....
Caused by: org.jboss.util.NestedSQLException: No ManagedConnections available within
configured blocking timeout ( 30000 [ms] ); - neste
d throwable: (javax.resource.ResourceException: No ManagedConnections available within
configured blocking timeout ( 30000 [ms] ))
at
org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:94)
at
org.jboss.ejb.txtimer.GeneralPurposeDatabasePersistencePlugin.insertTimer(GeneralPurposeDatabasePersistencePlugin.java:172)
at
org.jboss.ejb.txtimer.DatabasePersistencePolicy.insertTimer(DatabasePersistencePolicy.java:122)
... 100 more
Caused by: javax.resource.ResourceException: No ManagedConnections available within
configured blocking timeout ( 30000 [ms] )
at
org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:266)
at
org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:454)
at
org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:324)
at
org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:301)
at
org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:379)
at
org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.
java:812)
at
org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:88)
... 102 more
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