Tomcat – Apache & Tomcat Load balancing via Mod_jk issue

apache-2.2load balancingload-balancemod-jktomcat

I hope this finds you all in the best of your health and spirits.
I have an issue with a new setup where I currently have 1 APACHE 2.2.15 & Tomcat 6.0.14 on RHEL. Mod_JK version 1.2.30.
Ill add the second Tomcat when this starts working.

So when I try to point my browser to apache-host: port i get IT WORKS , but if point browser to host: port //examples/jsp/
i get a 404….apache isnt forwarding requests to Tomcat
Tomcat works fine , i can browse to the JSP examples page and run stuff.
I just cannot do it through the apache.
Any help is very much appreciated…please help!!!!!

Here are my configs….
no virtual hosts configured…

HTTPD.CONF 
Include conf/jk/mod_jk.conf 
LoadModule jk_module modules/mod_jk.so 

MOD_JK.CONF 
JkWorkersFile conf/jk/workers.properties 
JkShmFile logs/mod_jk.shm 
JkLogFile logs/mod_jk.log 
JkLogLevel info 
JkLogStampFormat "[%a %b %d %H:%M:%S %Y] " 

WORKERS.PROPERTIES 
worker.list=loadbalancer,status 

# Node #1 properties 
worker.worker1.type=ajp13 
worker.worker1.host=localhost 
worker.worker1.port=8009 
worker.worker1.lbfactor=1 

# Node #2 properties(will be configured later when apache and node 1 start working) 
worker.worker2.type=ajp13 
worker.worker2.host=localhost 
worker.worker2.port=001 
worker.worker2.lbfactor=1 

# Load-balancing behaviour 
worker.loadbalancer.type=lb 
worker.loadbalancer.balance_workers=worker1,worker2 

# Status worker for managing load balancer 
worker.status.type=status 

#JkMount /* loadbalancer 
JkMount /examples/jsp lb 
JkMount /examples/jsp/* lb 


tomcat server.xml has this 
<Service name="Catalina"> 
... 
<!-- Define an AJP 1.3 Connector on port 8009 --> 
<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" /> 
... 
</Service>

Best Answer

WORKERS.PROPERTIES

# Load-balancing behaviour 
worker.loadbalancer.type=lb 
worker.loadbalancer.balance_workers=worker1,worker2 

#JkMount /* loadbalancer 
JkMount /examples/jsp lb 
JkMount /examples/jsp/* lb

This is wrong. Move the JkMount directive to the mod_jk.conf, something like this:

JkWorkersFile conf/jk/workers.properties 
JkShmFile logs/mod_jk.shm 
JkLogFile logs/mod_jk.log 
JkLogLevel info 
JkLogStampFormat "[%a %b %d %H:%M:%S %Y] " 

JkMount /examples/jsp loadbalancer
JkMount /examples/jsp/* loadbalancer

Notice that the Tomcat worker should be loadbalancer as you defined in the workers.properties, instead of lb.

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Tomcat – Adobe Coldfusion Railo OpenBD Apache Tomcat Multiple Sites

You generally want your Tomcat Host's appbase="webapps" (default) and have the Context's docBase point to your Web root (docBase="/Users/[my username]/Websites/example.mydev/wwwroot/"). Your Web root will contain a WEB-INF for whichever WAR you're using (ColdFusion/OpenBD/Railo). It sounds like you're using a symlink or something for the WEB-INF dir?

In any case, you can't run requests against 3 different WARs in the same Web root (at least not without some fancy connector stuff--you could let a JRun instance/connector run while having WEB-INF of Railo or OpenBD in the Web root to then use 2 different Apache vhosts to handle... but this all sounds messy:). So, since you can't run them at the same time with this setup, I'm not sure why you're using separate host names?

It's also worth noting that you'll likely need to restart the Tomcat service each time you replace (re-map symlink) the WEB-INF folder.

Finally, if you do have the same Web root (docBase) for all three Tomcat Host entries, I'd imagine this will most certainly cause problems -- this could be the root of your errors, but not sure. Since you want the same Web root for each host, you might as well use an Alias (or just one host), something like this:

<Host name="local.mydev" appBase="webapps">
<Alias>local.mydev.railo</Alias>
<Alias>local.mydev.openbd</Alias>
<Context path="" docBase="/Users/[my username]/Websites/example.mydev/wwwroot" />
</Host>

Tomcat – How to configure uriworkermap.properties in server.xml for Apache – Tomcat integration

Badly Badly misread the title of the question - Long day. The command directive you are looking for is this:

JkMountFile

You would put this directive in your httpd.conf (or a seperate mod_jk.conf depending on how you are setup)

From the documentation for apache

File containing multiple mappings from a context to a Tomcat worker. It is usually called uriworkermap.properties. For inheritance rules, see: JkMountCopy. There is no default value.

I'll leave this here in case anyone is interested.

So, since you have a workers.properties you are probably using mod_jk (which has been depreciated for mod_proxy_ajp*). workers.properties are actually part of the mod_jk configuration.

Yes, the documentation for mod_jk is pretty light. So I'll just go ahead and show you my production configuration as an example - you might have to modify it slightly as we run *nix boxes but the concepts are the same.

You httpd.conf should have something similar to this: This tells apache to include a seperate mod_jk configuration file (you can actually put those directives right in the httpd.conf but... i like modularity). Then configure the alias, and the mount point for your jsp files.
```
Include <path_to_mod_jk.conf>
<VirtualHost *:80>
JkAutoAlias /usr/tomcat/webapps
JkMount /<your_webapp>/*.jsp <your_worker>
```
Your mod_jk.conf should look something like this:

This is where you set all of your generic mod_jk setting for apache, logs, workers file, etc.

    #MOD_JK Config File
    JkWorkersFile <path_to_your_workers.properties>
    JkLogFile /var/log/httpd/mod_jk.log
    JkLogLevel error
    JkShmFile /var/run/mod_jk.shm

3. And finally you should have a workers.properties similar to: Finally we get to the meat of the config. This is where you setup the worker. the options are pretty self explanatory.

    worker.<your_worker_name>.type=ajp13
    worker.list=<your_worker_name>
    #Worker Config
    worker.<your_worker_name>.host=127.0.0.1
    worker.<your_worker_name>.port=8009

And yes, i still run this in production although we are starting a modernization project that will probably see the end of mod_jk and a migration to mod_proxy_ajp

Best Answer

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Tomcat – How to configure uriworkermap.properties in server.xml for Apache – Tomcat integration

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