mod_jk - apache tomcat problem

[Chong Yu Meng]

Net Llama! wrote:

> Hi Pascal,
> Thanks for the pointer.  I fixed httpd.conf so that only the 
> Load_Module directive for mod_jk2, and now apache is firing up ok.  
> Looks like my problem now is that i've got workers.properties syntax 
> rather than workers2.properties.  I just can't figure out how to 
> convert to the new version.  Here's what I have:
>
> worker.list= worker1
> worker.worker1.type=ajp13
> worker.worker1.host=localhost
> worker.worker1.port=8009
> worker.worker1.lbfactor=50
> worker.worker1.cachesize=10
> worker.worker1.cache_timeout=100
> worker.worker1.socket_keepalive=1
> worker.worker1.socket_timeout=300
>
> type, host and port i'm able to convert, but the cache and socket 
> entries don't seem to convert over.  Any suggestions?
>
> thanks!
> Lonni

Hi Lonni !

You need to make a decision on what mode of connection you want, and 
this is largely dependent on how you have deployed the physical servers. 
There are 2 modes for Linux :
1. UNIX sockets - this is covered inside my documentation and refers to 
a deployment where Tomcat and Apache are deployed on the *same* physical 
server. This will not work if you have Tomcat on one box and Apache on 
another. If this is what you want, you can follow my instructions in the 
document. You will notice that it differs greatly from the mod_jk 
syntax. This method is supposed to be faster than channel sockets (see 
next point)
2. Channel sockets - this is not covered inside my document. It appears 
that your current configuration (mod_jk) uses channel sockets, because 
it specifies localhost (you don't do that in UNIX sockets, because you 
*have* to run Tomcat and Apache on the same box). I did not cover this 
inside my document, but I'll need some time to look up my notes. Can we 
talk offlist on this ? If you have a Yahoo Instant Messenger ID it would 
be easier to do troubleshooting.

What I can't figure out is this : In the section you quoted above, it 
mentions worker.worker1.xxx. This bothers me because you would not use 
that syntax unless Tomcat was in a load-balanced configuration (or the 
original configuration engineer was not rigorous in his thinking). Do 
you have a configuration where your Apache servers load balance between 
multiple Tomcat servers ?

Anyway, just to set expectations, this integration problem is rarely 
easy to do in a few emails.

I also need the following information:
1. Are you using a RPM package for mod_jk2 or the source tarball ? I 
highly recommend the source tarball, because there may be issues with 
the RPM package -- chiefest of which is version 2.0.4, the latest 
version of jk2, actually fixes a lot of bugs in the previous version, 
but the RPM package may be using the previous version.
2. What version of Java are you using (1.3/1.4) ? Sun , IBM or some 
other ? This is important because certain versions of Sun's Java will 
cause you plenty of strange problems.
3. Is RHEL 3 using NPTL? Is it enabled ?


Regards,
pascal chong