[mod_cluster-dev] mod-cluster and domains with sticky sessions

[Bela Ban]

Thanks for the explanation !

So I switched to placing the property inside of HAModClusterConfig, and 
this seems to work. However, mod_cluster_manager does *not* show the 
domain ! Does it only show the domain when it is configured in 
ModClusterListener in server.xml ?

Another question: what's the advantage of defining a domain in 
HAModClusterConfig over ModClusterListener ? I assume ModClusterListener 
works in clustered AS mode, too ?


Paul Ferraro wrote:
> Is the mod_cluster-dev list still not working for you?
>
> On Tue, 2009-07-21 at 14:46 +0200, Bela Ban wrote:
>> OK, I read through the archives of this list and came up with a solution
>> for mod-jk, but apparently nobody has so far used domains/sticky
>> sessions with *mod-cluster* !
>>
>> I found 2 different ways of doing this:
>>
>> #1 server.xml:
>> ---------------------
>>
>> <Listener className="org.jboss.modcluster.ModClusterListener"
>> advertize="true" domain="${jboss.Domain:DefaultDomain}" />
>>
>> #2 and in mod-cluster-jboss-beans.xml:
>> ---------------------------------------------------------
>>
>> <bean name="HAModClusterService" ...>
>> <property name="domain">${jboss.Domain:DefaultDomain}</property>
>> </bean>
>
> Configuration properties for the HA service are defined in a separate
> config bean, as documented here:
> http://www.jboss.org/mod_cluster/java/config.html#ha
>
> This should read:
>
> <bean name="HAModClusterService" mode="On Demand"
> class="org.jboss.modcluster.ha.HAModClusterService">
> <constructor>
> <parameter><inject bean="HAPartition"/></parameter>
> <parameter><inject bean="HAModClusterConfig"/></parameter>
> <parameter><inject bean="DynamicLoadBalanceFactorProvider"/></parameter>
> <parameter><bean 
> class="org.jboss.ha.singleton.HASingletonElectionPolicySimple"/></parameter>
> </constructor>
> </bean>
> <bean name="HAModClusterConfig" mode="On Demand"
> class="org.jboss.modcluster.config.ha.HAModClusterConfig">
> <!-- Configuration properties go here -->
> <parameter name="domain">${jboss.Domain:DefaultDomain}</parameter>
> </bean>
>
>> and then started several instances:
>>
>> ./run.sh -b 192.168.1.5 -c all -g *D1* -u 230.1.1.1 -m 10500
>> -Djboss.jvmRoute=*node1* -Djboss.Domain=*D1*
>> ./run.sh -b 192.168.1.9 -c all -g *D1* -u 230.1.1.1 -m 10500
>> -Djboss.jvmRoute=*node2* -Djboss.Domain=*D1*
>>
>> and
>>
>> ./run.sh -b 192.168.1.10 -c all -g *D2* -u 230.2.2.2 -m 11500
>> -Djboss.jvmRoute=*node3* -Djboss.Domain=*D2*
>>
>>
>> So we have domains D1 (cluster D1 with node1 and node2) and D2 (cluster
>> D2 with node3).
>>
>> #1 above seems to work half way, #2 doesn't.
>>
>> Questions
>> ========
>>
>> * What is the recommended way of setting of domains ?
>> o I assume #1, but that's not documented anywhere, I just
>> found out accidentally through a port via google
>
> The location of the domain property depends on how you've configured
> mod_cluster.
>
> Config #1 uses ModClusterListener, defined in server.xml, and is primary
> used with JBoss Web standalone and Tomcat, where you don't have the
> benefit of MC configuration.
> http://www.jboss.org/mod_cluster/java/config.html#web
>
> Config #2, uses HAModClusterService, configured via the microcontainer,
> and is used for configuration in JBoss AS, where all proxy communication
> goes through an HASingleton.
> http://www.jboss.org/mod_cluster/java/config.html#ha
>
> The third option, not yet mentioned, uses ModClusterService, configured
> via the microcontainer, where each AS node communicates directly with
> the proxy. Using this method, the "domain" property is defined within
> the ModClusterService bean, like you tried to do initially.
> http://www.jboss.org/mod_cluster/java/config.html#as
>
>> * Sometimes, a webapp on node2 fails over to node3 rather than node1
>
> Have you verified that node1 is enabled when this happens?
> If so, can you file a JIRA?
>
>> Can someone look into this ? This information should be available via a
>> web page, similar to the one for mod-jk !
>
> Is this what you're looking for?
> http://www.jboss.org/mod_cluster/java/properties.html
>

-- 
Bela Ban
Lead JGroups / Clustering Team
JBoss