Re: Lockup fetching from database

It seems it could have been caused by some database dead-locks. Not
sure how those happened. I've set the statement_timeout to 3 minutes,
so hopefully that'll prevent our threads from deadlocking too.

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

On Jan 13, 2006, at 9:24 AM, Dave Cramer wrote:

> 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._bindInputVariablesWithBinding
>> sAndExecute(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.deactivateProductsForMerchantHavingNoOth
>> erMerchantOffers(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
>>
>