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Posted to users@tomcat.apache.org by Srinivas Jonnalagadda <sa...@earthlink.net> on 2008/10/10 16:29:47 UTC
refresh bad db connection on tomcat - urgent help
Hi All,
what is the syntaxt to refresh bad db connection on tomcat - context.xml? We are using tomcata 5.5.9 connecting to oracle 10. The issue is that our jvm crashed because in the connection pool we had bad db connection and it the connections were out of limit. we could not detect and it happened in our prod environment. if there is any command for that it would be great help.
Thanks,
Srinivas Jonnalagadda
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Re: refresh bad db connection on tomcat - urgent help
Posted by Flavio Reis <fl...@ibest.com.br>.
Hi Srinivas,
Have you already solved this problem?
I have the same, an i can`t get the solution.
Regards.
Christopher Schultz-2 wrote:
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Srinivas,
>
> Srinivas Jonnalagadda wrote:
>> what is the syntaxt to refresh bad db connection on tomcat -
>> context.xml? We are using tomcata 5.5.9 connecting to oracle 10. The
>> issue is that our jvm crashed because in the connection pool we had
>> bad db connection and it the connections were out of limit. we could
>> not detect and it happened in our prod environment. if there is any
>> command for that it would be great help.
>
> Just to be clear: you ran out of database connections, or your database
> connections went stale and you just need to replace one connection at a
> time?
>
> If you are getting stale connections, you just need to set a "validation
> query" in your connection configuration. In your application's
> META-INF/context.xml, you should have a <Resource> element which defines
> your data source (this may also be in Tomcat's server.xml if you have a
> global data source). Just add
>
> validationQuery="SELECT 1 FROM DUAL"
>
> to detect stale connections. The query itself is irrelevant, except that
> it needs to return successfully and you want something that's not going
> to put a load on the server. Some drivers/servers support a 'ping' query
> that is super lightweight (for instance, recent versions of MySQL's
> Connector/J allows a query starting with '/* ping */' to be used as a
> lightweight communications check).
>
> If you are leaking connections from your pool, you should review your
> application for proper try/finally processing of JDBC connections.
> Tomcat's connection pool (which is really commons-dbcpo in disguise) can
> help you find places where connection are being leaked using a few other
> attributes:
>
> logAbandoned="true"
> removeAbandoned="true"
> removeAbandonedTimeout="30"
>
> These settings tell the connection pool that it should keep track of
> where connections are borrowed from the connection pool. If the
> connection hasn't been returned to the pool within
> "removeAbandonedTimeout" seconds, then the connection will be purged
> from the pool, and a stack trace showing the code that borrowed the
> connection will be dumped into your log.
>
> See http://commons.apache.org/dbcp/configuration.html for more
> information.
>
> Hope that helps,
> - -chris
>
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Re: refresh bad db connection on tomcat - urgent help
Posted by Christopher Schultz <ch...@christopherschultz.net>.
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Hash: SHA1
Srinivas,
Srinivas Jonnalagadda wrote:
> what is the syntaxt to refresh bad db connection on tomcat -
> context.xml? We are using tomcata 5.5.9 connecting to oracle 10. The
> issue is that our jvm crashed because in the connection pool we had
> bad db connection and it the connections were out of limit. we could
> not detect and it happened in our prod environment. if there is any
> command for that it would be great help.
Just to be clear: you ran out of database connections, or your database
connections went stale and you just need to replace one connection at a
time?
If you are getting stale connections, you just need to set a "validation
query" in your connection configuration. In your application's
META-INF/context.xml, you should have a <Resource> element which defines
your data source (this may also be in Tomcat's server.xml if you have a
global data source). Just add
validationQuery="SELECT 1 FROM DUAL"
to detect stale connections. The query itself is irrelevant, except that
it needs to return successfully and you want something that's not going
to put a load on the server. Some drivers/servers support a 'ping' query
that is super lightweight (for instance, recent versions of MySQL's
Connector/J allows a query starting with '/* ping */' to be used as a
lightweight communications check).
If you are leaking connections from your pool, you should review your
application for proper try/finally processing of JDBC connections.
Tomcat's connection pool (which is really commons-dbcpo in disguise) can
help you find places where connection are being leaked using a few other
attributes:
logAbandoned="true"
removeAbandoned="true"
removeAbandonedTimeout="30"
These settings tell the connection pool that it should keep track of
where connections are borrowed from the connection pool. If the
connection hasn't been returned to the pool within
"removeAbandonedTimeout" seconds, then the connection will be purged
from the pool, and a stack trace showing the code that borrowed the
connection will be dumped into your log.
See http://commons.apache.org/dbcp/configuration.html for more information.
Hope that helps,
- -chris
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iEYEARECAAYFAkjvcOEACgkQ9CaO5/Lv0PDVWACfTxkUIKm/M6mcGVnFQ9yQjsKe
RfYAnjnaW8aSH4ZGOJqrg4GAXshyasyk
=FsRS
-----END PGP SIGNATURE-----
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