tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Christopher Schultz <ch...@christopherschultz.net>
Subject Re: Tomcat pausing and no java process
Date Thu, 03 May 2012 20:04:52 GMT
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Miguel,

On 5/3/12 2:25 PM, Miguel González Castaños wrote:
>> Just the -XX:+HeapDumpOnOutOfMemoryError you already have.
>> Tomcat usually doesn't shut down nicely (as evidenced by the
>> "pausing" of connectors in your log file) when you get an OOME.
>> Are you sure that weekly Tomcat-restart process isn't still
>> running?
> 
> Yes, it's still running. Should i disable it?

Well, if it's shutting-down your JVM while you're trying to observe
it, then maybe you don't want it doing that. *shrug* I'm just saying
that Tomcat doesn't usually just decide to shut down for no good reason.

> I have set logAbandoned=true. I haven't enabled the removeAbandoned
> and the removeAbandonedTimeout just in case. Will I get the info in
> the catalina log?

Yes. logAbandoned IIRC logs to System.out, so you'll get that stuff in
catalina.out. I also recommend setting logAbandonedTimeout to
something reasonable. I don't remember the default.

> Right now I get the following cronjob forwarded to my email
> 
> /usr/bin/mysqldumpslow -s -t /var/log/mysql-slow.log | mail -s
> ....

Whoever wrote that didn't read the mysqldump manual. Who knows *what*
that's going to give you.

> Yes, I have pinpointed several queries that took quite long and 
> specially subqueries. I forwarded this info to the developer but
> she said it was alright. More than a second to run a query seems to
> be a lot to me.

That depends on what the query does. If it checks permissions to
login, that's insane and you should get a new programmer. If it's a
reporting query that gathers lots of data then 1 second might not be
quite so far-fetched.

> The problem is that since the database E/R is not documented, it's
> going to take a while to improve the performance of the queries.

Look into SchemaSpy.

> The developer is quitting so I hope a new developer is more
> cooperative and we can work out these things.

So you're saying that you're not going to get a lot of good
information out of him/her?

> In the meantime I will check what I can do. I have also downloaded 
> mysqltuner script and mysqlfragfinder a long time ago and follow
> the output of these tuning scripts.

Just rememeber to vet all the recommendations. Don't just read
"increase your query cache size" as a recommendation and blindly apply
that rule. Many times the query cache is less useful that you might think.

- -chris
-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
Comment: GPGTools - http://gpgtools.org
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAk+i5OQACgkQ9CaO5/Lv0PA/GwCgrrZL44k33jhm1AG4rPOefy3n
aFgAoKm3mqmr3bvOY1sTyogSPunPL4kt
=gl93
-----END PGP SIGNATURE-----

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
For additional commands, e-mail: users-help@tomcat.apache.org


Mime
View raw message