I want to implement load balancing using broker. I want more than one broker to share the load of processing a document and also want other broker to pick up the job if any broker is down.How can I achieve this?

Any suggestions are readily accepted

Load balancing a Broker Server is not supported. The only supported mechansim for failover is to use OS/hardware clustering and set up an active/passive pair.

To distribute load, you have to segregate your integrations such that some connect to a particular Broker Server and some connect to another. Typically, it’s not Broker Server that is a constraining component for volume. One Broker Server (in an active/passive cluster) is normally more than enough for most installations. Of course there are cases where multiple active Broker Servers are needed but this isn’t very common.

There a few threads on the forums about clustering, high availability, failover, etc. for Broker.