replying to self: maybe few reason for the "out of memory" exception are:
1. usage manager reference (http://activemq.org/site/xbean-xml-reference-41.html#XBeanXMLReference4.1-usageManagerelement) says, "limit" property sets memory limit in bytes. I have switched to using "limitMb" property instead 2. In case "limit" of "2048 MB" was correct, the ACTIVEMQ_OPTS had max memory pool (-Xmx) as 512. I have switched to 4096MB (big iron server yay!) 3. few threads indicated multicast transport could be the culprit, I have removed the auto discover mode (multicast discovery) for now. I hope these steps would solve the issue. If anyone is following this, pls post your comments. I'll update with whether this worked or not. - Sandeep
