Re: Mysql deadlock / timeout - fixed I hope

[Jin Bal <ji...@hotmail.com>]

We found that there is a bug with MySQL 4.0.20 that causes deadlocks in 
transactions


we have upgraded thanks for the responses

----- Original Message ----- 
From: "Robert S. Sfeir" <ro...@codepuccino.com>
To: "OJB Users List" <oj...@db.apache.org>
Sent: Tuesday, November 30, 2004 5:53 PM
Subject: Re: Mysql deadlock / timeout


> Huh is OJB competing with some other processes trying to update the same
> table/db?  It looks like it's complaining that it can't get a lock on row,
> and what ever process is not giving it up.
>
> Make also sure that all your transactions end by closing the PB instance.
>
> I would add some debugging info to see which record is being updated at 
> the
> time, with a timestamp to tell you when it was happening, and I would try 
> to
> catch this specific exception and resubmit the update again once or twice
> before failing, if there indeed is another process updating the DB.
>
> Last thought... Is it around a time when you have a DB backup going on?
> Some backups make the db/table read only, and that could be a problem.
>
> HTH
> R
>
>
> On 11/30/04 12:43 PM, "Jin Bal" <ji...@hotmail.com> wrote:
>
>> Hello
>>
>> I have an app in production that occasionally suffers from what seems to 
>> be a
>> deadlock or timout when doing a simple update inside a transaction
>>
>> here is the stacktrace - can anyone shed any light on things??
>>
>> TIA
>>
>> Caused by: org.apache.ojb.broker.PersistenceBrokerSQLException:
>> java.sql.SQLException: Deadlock found when trying to get lock; Try 
>> restarting
>> transaction, message from server: "Lock wait timeout exceeded; Try 
>> restarting
>> transaction"
>>
>> at 
>> org.apache.ojb.broker.accesslayer.JdbcAccessImpl.executeUpdateSQL(Unknown
>> Source)
>>
>> at org.apache.ojb.broker.core.MtoNBroker.deleteMtoNImplementor(Unknown 
>> Source)
>>
>> at 
>> org.apache.ojb.broker.core.PersistenceBrokerImpl.storeAndLinkMtoN(Unknown
>> Source)
>>
>> at 
>> org.apache.ojb.broker.core.PersistenceBrokerImpl.storeCollections(Unknown
>> Source)
>>
>> at org.apache.ojb.broker.core.PersistenceBrokerImpl.storeToDb(Unknown 
>> Source)
>>
>> at org.apache.ojb.broker.core.PersistenceBrokerImpl.store(Unknown Source)
>>
>> at org.apache.ojb.broker.core.PersistenceBrokerImpl.store(Unknown Source)
>>
>> at org.apache.ojb.broker.core.DelegatingPersistenceBroker.store(Unknown
>> Source)
>>
>> at org.apache.ojb.broker.core.DelegatingPersistenceBroker.store(Unknown
>> Source)
>>
>> at 
>> com.buyacar.dtofactory.OJBTransactionImpl.save(OJBTransactionImpl.java:54)
>>
>> at com.buyacar.dtofactory.UserFactory.saveUser(UserFactory.java:28)
>>
>>
>
>
>
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