mod cluster not balancing requests and not detecting application lifecycle

[markboletti]

Hi all !

I'm trying to achieve load balancing using mod cluster on AS 7.

I have installed mod_cluster libraries on httpd as shown in the docs:

Listen 192.168.10.1:8888

<VirtualHost 192.168.10.1:8888>

   <Location />

      Order deny,allow

      Deny from all

      Allow from 192.168.10.

  </Location>

KeepAliveTimeout 60

MaxKeepAliveRequests 0

ManagerBalancerName mycluster

ServerAdvertise On

<Location /mod_cluster_manager>

       SetHandler mod_cluster-manager

       Order deny,allow

       Deny from all

       Allow from 192.168.10.

</Location>

</VirtualHost>

When I restart httpd, the mod_cluster_manager correctly displays the two AS 7 instances which are part of a cluster.

However, once I deploy a web application to both nodes of the cluster, mod_cluster always forwards to the first host that joined the cluster. In other words, there is no load balancing.

If I remove the application from that node, then I get an "Internal server error", so it seems that application lifecycle is not propagated to httpd.

Have I missed something on the configuration on the httpd side or on the AS7 side ????

Thanks a lot

Mark

[markboletti]

Well it seems that mod_cluster uses by default Sticky Sessions on AS 7.

I've run a grid of tests with JMeter and actually requests are balanced correctly.

Anybody knows how to set the properties such as stickySessions (on/off) on AS 7 ?

Thanks

Mark

[rhusar]

Hi Mark,

First make sure you are running the latest, at least 7.0.1 or master -- that might be responsible for the server side error as its a known issue.

The sessions in distributable app will be automatically sticky, so wont see the "automatic balancing" using the way you described.

Rado

[rhusar]

mark boletti wrote:

Anybody knows how to set the properties such as stickySessions (on/off) on AS 7 ?

Fist check the documentation for the parameters supported in AS5, AS6, Tomcat:

http://docs.jboss.org/mod_cluster/1.1.0/html/java.properties.html (stickySession and related params is what you are after)

Then look at the configuration for the AS7 integration docs:

http://docs.jboss.org/mod_cluster/1.1.0/html/java.AS7config.html (haven't checked if everything is already supported -- maybe it wont be)

There will be cleaner documentation available here once its migrated:

https://docs.jboss.org/author/display/AS7/mod_cluster+in+AS7

HTH,

Rado

[mbabacek]

As Rado said, it is about setting properties. You may edit your standalone-ha.xml as:

<subsystem xmlns="urn:jboss:domain:modcluster:1.0">
     <mod-cluster-config advertise-socket="modcluster" sticky-session="true" sticky-session-force="false" sticky-session-remove="false"/>
</subsystem>