loadbalancer with mod_jk on ubuntu 12.04: status page won't show

[Highjo]

am a little confused when setting up 2 tomcat6 instances cluster in a clean ubuntu server 12.04. i didn't install default tomcat6 i used tomcat6-user's tomcat6-instance-create to create 2 instances.

I'm using ..:: Loadbalancing with mod_jk and Apache > Tips and Tricks > Encodo Blogs ::.. tutorial, unfortunately i haven't come across any tutorial using ubuntu with how apache2 is configured like ubuntu 12.o4. i mean by that , the structure of sites-available/enabled folder and mods-available/enabled that ubuntu uses.


i've installed libapache2-mod-jk and mods-enabled has jk.load,jk.conf.

server instance-1 uses port 8081 for http, port 8009 for ajp with jvmRoute="worker1" and instance-2 uses port 8082 for http, port 8010 for ajp with jvmRoute="worker2"

    #/etc/apache2/workers.propeties
     worker.list=loadbalancer,jk-status

    #setup instance-1
    worker.instance-1.port=8009
    worker.instance-1.host=localhost
    worker.instance-1.type=ajp13
    #worker.instance-1.lbfactor=50

    #setup instance-2
    worker.instance-2.port=8010
    worker.instance-2.host=localhost
    worker.instance-2.type=ajp13
    #worker.instance-2.lbfactor=100

    #setup the load-balancer
    worker.loadbalancer.type=lb
    worker.loadbalancer.balance_workers=instance-1,instance-2
    worker.loadbalancer.sticky_session=True
    #worker.loadbalancer.sticky_session_force=True

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

here is the /etc/apache2/mods-available/jk.conf

  
    <IfModule jk_module>
        JkWorkersFile /etc/apache2/workers.properties

        JkLogFile /var/log/apache2/mod_jk.log

        JkLogLevel info

        JkShmFile /var/log/apache2/jk-runtime-status

        JkWatchdogInterval 60

        <Location /jk-status>
        # Inside Location we can omit the URL in JkMount
        JkMount jk-status
        Order deny,allow
        Deny from all
        Allow from 127.0.0.1 xxx.xxx.xxx.xxx
        </Location>
        <Location /jk-manager>
        # Inside Location we can omit the URL in JkMount
        JkMount jk-manager
        Order deny,allow
        Deny from all
        Allow from 127.0.0.1 xxx.xxx.xxx.xxx
        </Location>

        # Example for Mounting a context to the worker "balancer"
        # The URL syntax "a|b" instantiates two mounts at once,
        # the first one is "a", the second one is "ab".
        # JkMount /myapp|/* balancer

        # Example for UnMounting requests for all workers
        # using a simple URL pattern
        # Since: 1.2.26
        # JkUnMount /myapp/static/* *

        # Example for UnMounting requests for a named worker
        # JkUnMount /myapp/images/* balancer

        # Example for UnMounting requests using regexps
        # SetEnvIf REQUEST_URI "\.(htm|html|css|gif|jpg|js)$" no-jk

        # Example for setting a reply timeout depending on the requets URL
        # Since: 1.2.27
        # SetEnvIf Request_URI "/transactions/" JK_REPLY_TIMEOUT=600000

        # Example for disabling reply timeouts for certain request URLs
        # Since: 1.2.27
        # SetEnvIf Request_URI "/reports/" JK_REPLY_TIMEOUT=0
    </IfModule>

here is my virtualhost

    <VirtualHost *:80>
      ServerAdmin support@myserver.com
      ServerAlias live.myserver.com
      #DocumentRoot /var/www
      ServerName go2.myserver.com
      JkMount /* loadbalancer
      JkMount /status/* jk-status
      JkMount /jk-manager/* jk-status
      #Loglevel warn
      ErrorLog /var/log/apache2/go.myserver_error_log
      CustomLog /var/log/apache2/go.myserver_access_log combined
    </VirtualHost>

**EDIT:** after few hours of struggling the load balancing itself seems to work. just that i can't access the load balancer manager page via xxx.xxx.xxx.xxx/jk-status nor xxx.xxx.xxx.xxx/jk-manager. there are also this entries in the mod_jk.log file

    [Mon May 06 13:34:48.633 2013] [9845:139723554592576] [info] init_jk::mod_jk.c (3252): mod_jk/1.2.32 () initialized
    [Mon May 06 13:34:48.633 2013] [9845:139723554592576] [error] uri_worker_map_ext::jk_uri_worker_map.c (506): Could not find worker with name 'jk-manager' in uri map post processing.
    [Mon May 06 13:34:48.633 2013] [9845:139723554592576] [error] uri_worker_map_ext::jk_uri_worker_map.c (506): Could not find worker with name 'jk-status' in uri map p/var/log/apache2/mod_jk.log

Question 1 : what am i missing? why it doesn't work?

Question 2 : is the #DocumentRoot /var/www really necessary?

Question 3 : what is the difference between the JkMount in the IfModule of the jk.conf file and the JkMount from the virtualhost

Kindly help me set this up correctly. thanks

[nplusplus]

Okay, it's been awhile since I have worked with this stuff, so I am working on vague memory and what you have here, but I noticed a couple of things.

In /etc/apache2/mods-available/jk.conf, you should likely comment out the jk-status location tag section, and under <Location /jk-manager>, change "JkMount jk-manager" to "JkMount jk-status." Give that a try and let me know if it makes a difference.

N

[Highjo]

Hello nplusplus,

i've tried your suggestion and still no luck, i did comment the location tags for jk-status , and modified the the jkmoud to jk-status and even restarted apache2 it's still 404 not found

[nplusplus]

Highjo!

Have you taken a look at the official documentation? You might start here if not. The Apache Tomcat Connector - Reference Guide - Status Worker Reference

N

[Highjo]

Hi, i've read the tutorial, and i made some progress. the mod_jk.log now doesn't complain about any error anymore

 [Tue May 07 17:38:01.654 2013] [32235:140522979305280] [info] init_jk::mod_jk.c (3252): mod_jk/1.2.32 () initialized
[Tue May 07 17:38:01.657 2013] [32236:140522979305280] [info] init_jk::mod_jk.c (3252): mod_jk/1.2.32 () initialized
[Tue May 07 17:54:57.208 2013] [37657:139941972453184] [info] init_jk::mod_jk.c (3252): mod_jk/1.2.32 () initialized
[Tue May 07 17:54:57.212 2013] [37658:139941972453184] [info] init_jk::mod_jk.c (3252): mod_jk/1.2.32 () initialized
[Tue May 07 17:56:35.609 2013] [38305:140655054878528] [info] init_jk::mod_jk.c (3252): mod_jk/1.2.32 () initialized
[Tue May 07 17:56:35.612 2013] [38306:140655054878528] [info] init_jk::mod_jk.c (3252): mod_jk/1.2.32 () initialized 
  

after i changed

 //changed
  worker.status.type=jk-status
//to
  worker.jk-status.type=status 
  

but that's all , still getting 404 Not Found

I aslo commented :

 //from /etc/apache2/mods-available/jk.conf
        #<Location /jk-status>
            # Inside Location we can omit the URL in JkMount
            #JkMount jk-status
            #Order deny,allow
            #Deny from all
            #Allow from 127.0.0.1 xxx.xxx.xxx.xxx
        #</Location>
        #<Location /jk-manager>
            # Inside Location we can omit the URL in JkMount
            #JkMount jk-status
            #Order deny,allow
            #Deny from all
            #Allow from 127.0.0.1 xxx.xxx.xxx.xxx
        #</Location> 
  

then added :

 // /etc/apache2/workers.properties
worker.jk-status.mount=/admin/status 
  

when i accessed myip/admin/status after apache restart it shows not found. I then commented out the JkMount from the virtual host to have this:

     <VirtualHost *:80>
      ServerAdmin support@myserver.com
      ServerAlias live.myserver.com
      #DocumentRoot /var/www
      ServerName go2.myserver.com
      JkMount /* loadbalancer
      #JkMount /status/* jk-status
      #JkMount /jk-manager/* jk-status
      JkMount /admin/status
      #Loglevel warn
      ErrorLog /var/log/apache2/go.myserver_error_log
      CustomLog /var/log/apache2/go.myserver_access_log combined
    </VirtualHost> 
  

still no improvement. i feel like am getting crazy progressively

[nplusplus]

In your original post, you mentioned not having a guide for this on Ubuntu re: sites-available/enabled and mods-available/enabled and I totally disregarded it, but you should make sure you have symlinks in sites-enabled to any site configs you want enabled that you have modified in sites-available. The same goes for mods-available/enabled. Have a look here for how to enable sites and mods in Apache: https://help.ubuntu.com/10.04/serverguide/httpd.html.

If the mods/sites you are configuring do not have the mentioned symlinks in sites/mods-enabled, they will not be served up by apache.

N

[Highjo]

Hi, i think in most ubuntu distros i use , once mods are enabled using

 a2enmod 
  

it creates the symlink to the conf in mods-available. same for sites-available. Because if not the load balancer itself would have not worked.

 // /etc/apache2/mods-enabled
0 lrwxrwxrwx 1 root root 25 May  5 20:08 jk.conf -> ../mods-available/jk.conf
0 lrwxrwxrwx 1 root root 25 May  5 20:08 jk.load -> ../mods-available/jk.load 
  

 0 lrwxrwxrwx 1 root root 36 May  6 11:34 go.myserver.com -> ../sites-available/go.myserver.com 
  

As you can see, all the available conf/load are symlinked