Wowza Community

Load Balancer installation

I’m installing the load balancer on a fresh EC2 instance. The instructions that I’m finding seem outdated and sometimes contradictory, could someone clarify what the proper steps are (point me to a current doc)?

For example, the instructions I’m following say to copy the wms-plugin-loadbalancer.jar from the load balancer distribution into the /lib directory - but there is already a copy of that file there - which file should I use?

The same goes for <install-dir/conf/Vhost.xml.

Also, the docs state to insert this code in the Server.xml:

  • but this class doesn’t exist in the jar (a class without “general” does).

My current installation is logging this error at startup (although the server seems to start):

ERROR server comment - ServerUtils.loadServerListener: Error creating (com.wowza.wms.plugin.loadbalancer.LoadBalancerServer) : java.lang.InstantiationException: com.wowza.wms.plugin.loadbalancer.LoadBalancerServer|at java.lang.Class.newInstance(|at com.wowza.wms.util.ServerUtils.loadServerListener(|at com.wowza.wms.util.ServerUtils.loadConfigFile(|at com.wowza.wms.server.Server.a(|at com.wowza.wms.server.Server.start(|

Someone has successfully installed a LoadBalancer 4.0 on Streaming Engine Version 4? There are two wms-plugin-loadbalancer.jar files, one with the server distribution, and one with the LoadBalancer distribution. If I use the one from the LoadBalancer, I get:

loadHTTPProvider: error parsing HTTPProvider properties : java.lang.ClassNotFoundException: com.wowza.wms.plugin.loadbalancer.http.LoadBalancerInterface|at$|at$|at Method)|at|at java.lang.ClassLoader.loadClass(|

If I use the one from the Server distribution I get :

 ServerUtils.loadServerListener: Error creating <ServerListener> (com.wowza.wms.plugin.loadbalancer.ServerListenerLoadBalancerListener) : java.lang.ClassNotFoundException: com.wowza.wms.plugin.loadbalancer.ServerListenerLoadBalancerListener|at$|at$|at Method)|at|at java.lang.ClassLoader.loadClass(

It seems like it’s looking for classes in both jars?

Any help would be really appreciated.


If you are using the LoadBalancer 4.0 package, the you should only put the wms-plugin-loadbalancer.jar file from the lib/ folder that is available in the archive you downloaded from here.

The Load Balancer installation and usage instructions can be found in the WowzaDynamicLoadBalancingAddOn_UsersGuide.pdf document that is also available in the same .zip package.



Can you open a ticket with our support team by sending an email to and describing the issue you are encountering.

Please also send us a ZIP archive containing your Wowza conf/ and logs/ folders? Please also add a reference to this forum thread in your ticket.


I’ve renamed the loadbalancer version of the jar and included it in the lib dir along with the original. The server starts without warnings/errors now.

Thanks for the reply.

That is where I got the zip from, and those are the instructions I am following.

But, that simply doesn’t work as far as I can tell. From examining the jar files and the errors, there are classes in BOTH versions of the jar that are required. As I stated before, if I only use the jar that comes with the LoadBalancer distribution, I get this error:

ServerUtils.loadServerListener: Error creating (com.wowza.wms.plugin.loadbalancer.ServerListenerLoadBalancerListener) : java.lang.ClassNotFoundException: com.wowza.wms.plugin.loadbalancer.ServerListenerLoadBalancerListener|at$|at$|at Method)|at|at java.lang.ClassLoader.loadClass(|