If you have a RabbitMQ cluster and a crashed node fails to start again with
{"init terminating in do_boot",{undef,[{rabbit_prelaunch,start,[]},{init,start_it,1},{init,start_em,1}]}}
in /var/log/rabbitmq/startup_log and something like
Error description:

Log files (may contain more information):
   /var/log/rabbitmq/[email protected]
   /var/log/rabbitmq/[email protected]
in /var/log/rabbitmq/[email protected] then you might want to try to drop the node from the cluster by running
rabbitmqctl forget_cluster_node [email protected]
one a working cluster node and rejoin the node by running
rabbitmqctl join_cluster [email protected]
on the disconnected node (given rabbit-02 is a working cluster member). Note: Doing this might make you lose messages!