Re: active session waiting for SQL*Net more data from client for very long time

From: kyle Hailey <kylelf_at_gmail.com>
Date: Fri, 20 Jan 2012 10:54:03 -0800
Message-ID: <CADsdiQjkv_cxheKoBLK_SX=cK+e8EF_=KCVHUvdoiazignr8QA_at_mail.gmail.com>



Sounds like an application side bug.
If the JDBC goes out to pasture mid-query then the Oracle shadow will wait indefinitely to get the rest of the data from the client which is JDBC in this case:

https://sites.google.com/site/embtdbo/wait-event-documentation/oracle-network-waits

  • Kyle

On Fri, Jan 20, 2012 at 7:27 AM, Denis <denis.sun_at_yahoo.com> wrote:

> Hi, Listers,
>
> Recently we have encountered sessions ( from weblogic JDBC thin client)
> that are waiting for "SQL*Net more data from client" event and in active
> status indefinitively (could be more than 10 hours). In two instances,
> such sessions eventually block other sessions in the morning when business
> transactions become busy. we have to kill such a session to release the
> locks it held to avoid serious lost of service.
>
> The sessions are doing a relatively simple select statement with very
> selective index scan when they were hanging with above event. The largest
> rows it can return at most several hundred. By google, there is a case
> described here: http://blogs.warwick.ac.uk/java/entry/wait_class_network/ ,
> which solved this issue by upgrading JDBC driver. But I am not sure this is
> reason for my case as we use same JDBC driver for all app server and we
> don't have long sql text as described in the webpage. ( to be honest I have
> little knowlege about weblogic that managed by other team and to get other
> team's coordination requires a bit more effort).
>
> Our dev team is trying to enable time-out at statement level in their
> java code. Hope this can prevent such kind of running away
> transaction.(Weblogic transaction time-out seems not working as they said
> they set the value for 180s already) Anyone has similar experience and can
> give me some clue to dig into the root cause?
>
> Thanks,
>
> Denis
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

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Received on Fri Jan 20 2012 - 12:54:03 CST

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