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From Paul Rasmussen <>
Subject Re: jk2 new shmem using APR
Date Wed, 17 Mar 2004 08:25:59 GMT
Thanks a lot for this synopsis Glenn.  Obviously I am also considering whether 
I should recommmend moving to Apache2 to our team.

- paul r.

In message <>you write:
>On Tue, Mar 16, 2004 at 02:48:26PM -0000, wrote:
>> > Greg,
>> As an aside our team will be looking at apache2 and tomcat5 sooner rather
>> than later as it would appear that more development effort is taking place
>> on these platforms.  However balancing lots of apps and infrastructure
>> upgrades and testing with day to day support means this will not happen
>> soon.
>I went through the process of upgrading our servers to Apache2 over
>the last 9 months. These are Sun servers running Solaris and using
>the Apache 2 worker MPM.  There are alot of advantages to upgrading.
>My testing found Apache 2 to require a great deal fewer system resources
>(CPU,memory) when using the worker MPM and be much more scaleable.
>I also like the way filters work. You can now have Tomcat generate HTML
>with SSI which mod_include can then parse. This can help scaling for
>Tomcat.  We use it with Tomcat4 and mod_jk 1.2.5, both are working very
>reliably for us.
>I did run into a number of problems at first. Most of them were
>Solaris specific.  And some bugs which caused problems. I ended
>up learning a whole lot more about apache internals than I really
>wanted to, and even submitted a number of patches which got rolled
>into later releases.
>All in all it is working pretty well for us but we still get some
>core dumps once in a while, nothing that causes apache to completely
>fail though. We do have one nasty bug we hope the 2.0.49 release will
>fix.  That is a runaway apache process which consumes all memory on
>the server.  That was pretty nasty until we used ulimit on solaris
>to limit the size of the data and virtual memory segments for apache
>processes. Now the infrequent times this bug is triggered the apache
>process core dumps when it hits these memory limits rather than 
>causing general failures on the server due to exhausing all physical
>and virtual memory.
>The biggest effort had to be put into making sure all the third
>party apache modules we use were thread safe. This included patches
>to mod_jk 1.2 to fix a few thread safe problems. The mod_jk 1.2.5
>includes all these patches.
>All in all it was worth the effort, 9 months later it should be
>easier for someone with a similar environment to mine to upgrade
>to apache 2.
>Glenn Nielsen    | /* Spelin donut madder    |
>MOREnet System Programming               |  * if iz ina coment.      |
>Missouri Research and Education Network  |  */                       |
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