You see a large number of amqrmppa channel processes that are spawned very quickly in a WebSphere MQ system Symptom A large number of amqrmppa processes are created in a short period of time. Their parent process is a runmqlsr process. Sometimes there are multiple runmqlsr processes that were spawned, which has this runmqlsr process as a parent process as well. The number of spawned processes might keep increasing and sometimes reaches the maxuproc limit of the operating system, hence it could cause a queue manager outage. Cause The cause of the large number of amqrmppa and runmqlsr processes is that these processes are attached to an old set of shared memory segments. Diagnosing the problem When a MQCONN request is received by the runmqlsr process it seems that it has no active amqrmppa processes listed in its old shared memory segments and so runmqlsr starts a new amqrmppa process. However it fails to communicate with the newly started amqrmppa process b