proxool-developer

[Proxool-developer] Property maximum-active-time

[Per T. J. <Per...@nr...>]

Hi,

I'm using Proxool with Hibernate 2.1.1 and in the hibernate.cfg.xml
there is the Proxool property set to maximum-active-time 500. Is that
milliseconds? It seems like my application closes databases connections
to early. Could maximum-active-time = 500 be the problem?


Thanks
Per Thomas

Stack trace:

2004-01-13 15:36:45,406 DEBUG [ThreadPoolWorker:Thread-9]
(per@156.116.2.165) (JDBCExceptionReporter.java:36) - SQL Exception
java.sql.SQLException: No operations allowed after connection closed.

Connection was closed explicitly by the application at the following
location:

** BEGIN NESTED EXCEPTION ** 

java.lang.Throwable

STACKTRACE:

java.lang.Throwable
at com.mysql.jdbc.Connection.close(Connection.java:1107)
at
org.logicalcobwebs.proxool.AbstractProxyConnection.reallyClose(AbstractProxyConnection.java:173)
at
org.logicalcobwebs.proxool.ConnectionPool.removeProxyConnection(ConnectionPool.java:413)
at org.logicalcobwebs.proxool.HouseKeeper.sweep(HouseKeeper.java:139)
at
org.logicalcobwebs.proxool.HouseKeeperThread.run(HouseKeeperThread.java:39)


** END NESTED EXCEPTION **


at com.mysql.jdbc.Connection.checkClosed(Connection.java:2741)
at com.mysql.jdbc.Connection.prepareStatement(Connection.java:1373)
at com.mysql.jdbc.Connection.prepareStatement(Connection.java:1353)
at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at
org.logicalcobwebs.proxool.ProxyConnection.invoke(ProxyConnection.java:68)
at
org.logicalcobwebs.cglib.proxy.Proxy$ProxyImpl$$EnhancerByCGLIB$$9d354a27.prepareStatement(<generated>)
at
net.sf.hibernate.impl.BatcherImpl.getPreparedStatement(BatcherImpl.java:228)
at
net.sf.hibernate.impl.BatcherImpl.prepareQueryStatement(BatcherImpl.java:61)
at net.sf.hibernate.loader.Loader.prepareQueryStatement(Loader.java:703)
at net.sf.hibernate.loader.Loader.doQuery(Loader.java:184)
at
net.sf.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:132)
at net.sf.hibernate.loader.Loader.loadCollection(Loader.java:909)
at net.sf.hibernate.loader.Loader.loadCollection(Loader.java:884)
at
net.sf.hibernate.loader.CollectionLoader.initialize(CollectionLoader.java:69)
at
net.sf.hibernate.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:284)
at
net.sf.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:3133)
at
net.sf.hibernate.collection.PersistentCollection.initialize(PersistentCollection.java:203)
at
net.sf.hibernate.collection.PersistentCollection.read(PersistentCollection.java:69)
at net.sf.hibernate.collection.Bag.size(Bag.java:231)



-- 
Per Thomas Jahr

Re: [Proxool-developer] Property maximum-active-time

[Bill H. <bi...@lo...>]

Hi Per Thomas,

On Tue, 2004-01-13 at 16:44, Per Thomas Jahr wrote:

> I'm using Proxool with Hibernate 2.1.1 and in the hibernate.cfg.xml
> there is the Proxool property set to maximum-active-time 500. Is that
> milliseconds? It seems like my application closes databases connections
> to early. Could maximum-active-time = 500 be the problem?

Yep, it's in milliseconds. That important bit of information seems to be
missing from the doc. I'll fix that.

maximum-active-time = 500 means that if the house keeper spots that a
connection is used for more than half a second it will kill it. Since
the house keeper only runs every 30 seconds (by default) it effectively
means the maximum-active-time is anywhere between 0.5 seconds and a tad
over 30.5 seconds.

- Bill