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javaapachetomcatload-balancingfailover
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Reputation: 5313

Tomcat, Apache : Failover not working even after configuration

I am working on Apache and tomcat to setup Load-balancing and fail-over. Initially I thought that load-balancing would include fail-over, but I was wrong. I thought that if one instance is not active, then consuming other instance also becomes a part of load-management. Enough with the terminologies, I setup fail-over, but the ironical part is fail-over itself is failing.

As soon as I shut down one instance of tomcat, the entire setup is dead and I am getting 503. Can someone help me understand what is the problem.

Added this in apache2.conf :

JkWorkersFile /etc/apache2/workers.properties

JkMount /* loadbalancer

workers.properties :

GNU nano 2.2.6 File: workers.properties 

 worker.list=loadbalancer
 worker.server1.port=8010
 worker.server1.host=localhost
 worker.server1.type=ajp13

 worker.server2.port=8011
 worker.server2.host=localhost
 worker.server2.type=ajp13

 worker.server1.lbfactor=1
 worker.server2.lbfactor=1

 worker.loadbalancer.type=lb
 worker.loadbalancer.balance_workers=server1,server2
worker.loadbalancer.method=B
worker.balancer.sticky_session=True

000-default in sites-enabled :

JkMountCopy On
<Proxy balancer://mycluster>
    BalancerMember ajp://localhost:8010 route=server1 connectiontimeout=10
    BalancerMember ajp://localhost:8011 route=server2 connectiontimeout=10

   ProxySet stickysession=JSESSIONID|jsessionid
   Order Deny,Allow
   Deny from none
   Allow from all

</Proxy>

<VirtualHost *:80>
ProxyRequests off

ProxyPass /balancer-manager !
ProxyPass / balancer://mycluster/
ProxyPassReverse / balancer://mycluster/
</VirtualHost>

<Location /balancer-manager>
SetHandler balancer-manager

Order Deny,Allow
Deny from none
Allow from all
</Location>

First tomcat's server.xml :

<Connector port="8080" proxyPort="80" protocol="HTTP/1.1" compression="force" compressionMinSize="1024" 
               connectionTimeout="20000"
               redirectPort="443" URIEncoding="utf-8"
 compressableMimeType="text/html,text/xml,text/plain,text/css,text/ javascript,application/x-javascript,application/javascript"/>


<Connector port="443" enableLookups="false" protocol="HTTP/1.1" SSLEnabled="true" maxThreads="200" compression="force"
              compressionMinSize="1024" scheme="https" secure="true" clientAuth="false"  sslProtocol="TLS"
                keystoreFile="keystore_file" keystorePass="PASSWORD" URIEncoding="utf-8"
 compressableMimeType="text/html,text/xml,text/plain,text/css,text/ javascript,application/x-javascript,application/javascript"
/>
   <Connector port="8010" protocol="AJP/1.3" redirectPort="443" URIEncoding="utf-8"
 compressableMimeType="text/html,text/xml,text/plain,text/css,text/ javascript,application/x-javascript,application/javascript"
/>
    <Engine name="Catalina" defaultHost="localhost" jvmRoute="server1">
    // No modifications inside
</Engine>

Second Tomcat's server.xml :

<Connector port="8081" proxyPort="80" protocol="HTTP/1.1" compression="force" compressionMinSize="1024" 
               connectionTimeout="20000"
               redirectPort="443" URIEncoding="utf-8"
 compressableMimeType="text/html,text/xml,text/plain,text/css,text/ javascript,application/x-javascript,application/javascript"/>


<Connector port="443" enableLookups="false" protocol="HTTP/1.1" SSLEnabled="true" maxThreads="200" compression="force"
              compressionMinSize="1024" scheme="https" secure="true" clientAuth="false"  sslProtocol="TLS"
                keystoreFile="keystore_file" keystorePass="PASSWORD" URIEncoding="utf-8"
 compressableMimeType="text/html,text/xml,text/plain,text/css,text/ javascript,application/x-javascript,application/javascript"
/>
 <Connector port="8011" protocol="AJP/1.3" redirectPort="8443" URIEncoding="utf-8"
 compressableMimeType="text/html,text/xml,text/plain,text/css,text/ javascript,application/x-javascript,application/javascript"
/>
    <Engine name="Catalina" defaultHost="localhost" jvmRoute="server2">
    // No modifications here
    </Engine>

What mistake I am making in the config for implementing load-balancing and fail-over together. Thanks a lot.

Upvotes: 0

Views: 940

Answers (1)

Fredi
Fredi

Reputation: 216

First, you are using two different proxy modules, dont do that.

One is mod_jk, and the configuration files are workers.properties, uriworkermap.properties and in apache.conf this part:

JkMount /* loadbalancer

And in 000-default

JkMountCopy On

The other is mod_proxy and the relative configuration in 000-default :

<Proxy balancer://mycluster>
    BalancerMember ajp://localhost:8010 route=server1 connectiontimeout=10
    BalancerMember ajp://localhost:8011 route=server2 connectiontimeout=10

    ProxySet stickysession=JSESSIONID|jsessionid
    Order Deny,Allow
    Deny from none
    Allow from all

    </Proxy>

<VirtualHost *:80>

ProxyRequests off

ProxyPass /balancer-manager !
ProxyPass / balancer://mycluster/
ProxyPassReverse / balancer://mycluster/
</VirtualHost>

<Location /balancer-manager>
SetHandler balancer-manager

Order Deny,Allow
Deny from none
Allow from all
</Location>

As for comments, let's go the mod_jk route. First remove the mod_proxy configuration part, essentially all that is in 000-default leaving only:

JkMountCopy On

Then disable loading of this modules (not neccessary but better):

mod_proxy_*

Then add this to you'r loadbalancer's worker in workers.properties:

worker.loadbalancer.sticky_session_force = false

And check if things work, based on that i'll update the answer

Upvotes: 1

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