Apache proxying Multiple Tomcat Instances with Mod_JK

Question

I have an Apache server, which is suppose to redirect all the requests to two Tomcat instances: "geonetwork" and "geoserver".

They are both accessible from the Apache server, but somehow I cannot make the redirection work.

My hosts file looks like this:

<VirtualHost *:80>
        ServerName localhost
        ServerAdmin someemail@email.com
        DocumentRoot /var/www/html
</VirtualHost>

<VirtualHost *:80>
        ServerName geonetwork
        ServerAdmin someemail@email.com
        DocumentRoot /usr/local/tomcat_gn/webapps

        <Directory "/usr/local/tomcat_gn/webapps">
           #Options MultiViews FollowSymLinks
           Options All
           AllowOverride all
           Require all granted
        </Directory>

        #LogLevel info ssl:warn
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
        JkMount /geonetwork|/* gn_worker
</VirtualHost>

<VirtualHost *:80>
        ServerName geoserver
        ServerAdmin someemail@email.com
        DocumentRoot /usr/local/tomcat_gs/webapps

        #LogLevel info ssl:warn
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
        JkMount /geoserver|/* gs_worker
</VirtualHost>


# vim: syntax=apache ts=4 sw=4 sts=4 sr noet

The documentRoot directives, point to the tomcat instances mounted directories.

This is the worker.properties file:

#
worker.list=gn_worker,gs_worker

#
#------ ajp13_worker WORKER DEFINITION ------------------------------
#---------------------------------------------------------------------
# 

# 
# Defining a worker named ajp13_worker and of type ajp13
# Note that the name and the type do not have to match.
# 
worker.gs_worker.port=8009
worker.gs_worker.host=geoserver
worker.gs_worker.type=ajp13

worker.gn_worker.port=8009
worker.gn_worker.host=geonetwork
worker.gn_worker.type=ajp13
#
# Specifies the load balance factor when used with
# a load balancing worker.
# Note:
#  ----> lbfactor must be > 0
#  ----> Low lbfactor means less work done by the worker.
worker.gs.lbfactor=1
worker.gn.lbfactor=1

#
# Specify the size of the open connection cache.
#worker.ajp13_worker.cachesize

# 
#------ DEFAULT LOAD BALANCER WORKER DEFINITION ----------------------
#---------------------------------------------------------------------
#

#
# The loadbalancer (type lb) workers perform wighted round-robin
# load balancing with sticky sessions.
# Note:
#  ----> If a worker dies, the load balancer will check its state
#        once in a while. Until then all work is redirected to peer
#        workers.
worker.loadbalancer.type=lb
worker.loadbalancer.balance_workers=gn_worker,gs_worker

What strikes me the most, is that the first virtualhost always works. So in this example, it resolves to the apache root, but if I put geonetwork or geoserver it resolves correctly to:

http://localhost/geonetwork or http://localhost/geoserver

I'm runnning out of ideas to debug this! Somebody can help me?

Answer 1

I think you may forgot to include the mod_jk configuration prior to do the JkMount in each virtual host:

# Load mod_jk module
LoadModule jk_module modules/tomcat-connector/mod_jk.so

# Add the module (activate this lne for Apache 1.3)
# AddModule     mod_jk.c
# Where to find workers.properties
JkWorkersFile conf/extra/workers.properties
# Where to put jk shared memory
JkShmFile     logs/mod_jk.shm
# Where to put jk logs
JkLogFile     logs/mod_jk.log
# Set the jk log level [debug/error/info]
JkLogLevel    info


<VirtualHost *:80>
        ServerName localhost
        ServerAdmin someemail@email.com
        DocumentRoot /var/www/html
</VirtualHost>

<VirtualHost *:80>
        ServerName geonetwork
        ServerAdmin someemail@email.com
        DocumentRoot /usr/local/tomcat_gn/webapps

        <Directory "/usr/local/tomcat_gn/webapps">
           #Options MultiViews FollowSymLinks
           Options All
           AllowOverride all
           Require all granted
        </Directory>

        #LogLevel info ssl:warn
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
        JkMount /geonetwork|/* gn_worker
</VirtualHost>

<VirtualHost *:80>
        ServerName geoserver
        ServerAdmin someemail@email.com
        DocumentRoot /usr/local/tomcat_gs/webapps

        #LogLevel info ssl:warn
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
        JkMount /geoserver|/* gs_worker
</VirtualHost>

Personally I prefer mod_jk in cases when I do not have to manipulate the context-root of the mapped applications, because when using a balancer I can dinamically manage it through the status worker, but this is just my opinion.