Re: Lockup fetching from database

Hi Brendan,

I'd be looking at the underlying cause before timing out. This is a
pretty robust system usually.

There is a query timeout in the backend if that is causing the problem.
Is this a very long query ?

Dave
On 13-Jan-06, at 10:56 AM, Brendan Duddridge wrote:

> Hi,
>
> I'm running PostgreSQL 8.1 on OS X Server 10.4.3 using
> postgresql-8.1-404.jdbc3.jar and I'm experiencing some lockups when
> querying from the database through our java WebObjects program.
>
> Here is a dump of the thread where the problem occurs:
>
> "CSThreadPoolThread-0" prio=5 tid=0x00563ab0 nid=0x1894600 runnable
> [f1111000..f1112ac0]
> at java.net.SocketInputStream.socketRead0(Native Method)
> at java.net.SocketInputStream.read(SocketInputStream.java:129)
> at java.io.BufferedInputStream.fill
> (BufferedInputStream.java:183)
> at java.io.BufferedInputStream.read
> (BufferedInputStream.java:201)
> - locked <0x541cb7f8> (a java.io.BufferedInputStream)
> at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:254)
> at org.postgresql.core.v3.QueryExecutorImpl.processResults
> (QueryExecutorImpl.java:1163)
> at org.postgresql.core.v3.QueryExecutorImpl.execute
> (QueryExecutorImpl.java:188)
> - locked <0x541c8860> (a
> org.postgresql.core.v3.QueryExecutorImpl)
> at org.postgresql.jdbc2.AbstractJdbc2Statement.execute
> (AbstractJdbc2Statement.java:430)
> at
> org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags
> (AbstractJdbc2Statement.java:332)
> at org.postgresql.jdbc2.AbstractJdbc2Statement.execute
> (AbstractJdbc2Statement.java:324)
> at
> com.webobjects.jdbcadaptor.JDBCChannel._bindInputVariablesWithBindings
> AndExecute(JDBCChannel.java:237)
> at
> com.webobjects.jdbcadaptor.JDBCChannel._evaluateExpression
> (JDBCChannel.java:303)
> at com.webobjects.jdbcadaptor.JDBCChannel.evaluateExpression
> (JDBCChannel.java:261)
> at com.webobjects.eoaccess.EOUtilities._rawRowsForSQL
> (EOUtilities.java:584)
> at com.webobjects.eoaccess.EOUtilities.rawRowsForSQL
> (EOUtilities.java:550)
> at
> ca.shopshop.ssmodel.Merchant.deactivateProductsForMerchantHavingNoOthe
> rMerchantOffers(Merchant.java:614)
> at ca.shopshop.ssmodel.Merchant.deactivateMerchant
> (Merchant.java:685)
> at MerchantAccountStatusCheckerThread.performAction
> (MerchantAccountStatusCheckerThread.java:131)
> at
> com.clickspace.csutilities.threads.DatabaseUpdateThread.run
> (DatabaseUpdateThread.java:41)
> at com.clickspace.csutilities.threads.CSThreadPool
> $ThreadPoolThread.run(CSThreadPool.java:200)
>
> So it seems that it's locking up retrieving data from the database.
> Is there a timeout parameter or something that can be set so if it
> takes too long to retrieve from the database I can handle an
> exception and continue on with my program? Right now all the other
> threads in my application start to block waiting for this one to
> complete and eventually my entire application instance locks up.
>
> Thanks,
>
> ____________________________________________________________________
> Brendan Duddridge | CTO | 403-277-5591 x24 | brendan(at)clickspace(dot)com
>
> ClickSpace Interactive Inc.
> Suite L100, 239 - 10th Ave. SE
> Calgary, AB T2G 0V9
>
> http://www.clickspace.com
>