owt-cluster queue deleted if !!Double master!! occur on cluster_manager service

[dboyzhong]

summary:

cluster_manager stop working and whole cluster stopped service.

environment：

CentOS7.6 mcu server: 4.3.x

steps:

1. two cluster_managers: A for master, B for slave
2. network flash，B became master,
3. network recover, A & B both master, B life_time is shorter, so B process exit.
4. rabbitmq queue "owt-cluster" deleted. so A can not received any message from queue "owt-cluster", all other service lost connection with cluster_manager

   reason:

   amqp_client.js:157

   handler.close = function() {
       request_q && request_q.destroy();
       request_q = undefined;
       exc && exc.destroy(true);
       exc = undefined;
   };

   the handler.close will called if cluster_manager process exited by calling "process.exit(1);" and request_q.destroy() will delete the queue even if the other cluster_manager still connected on it.

   manually reproduce:

5. start master cluster_manager A.

6. modify slave cluster_manager B file: clusterManager.js at last lines for simulate

   exports.run = function (topicChannel, clusterName, id, spec) {
   var manager = new ClusterManager(clusterName, id, spec);
   
   runAsCandidate(topicChannel, manager);  //just using runAsMaster(topicChannel, manager); instead
   };

7. start cluster_manager B.
8. cluster_manager B detected "Double master" and exit.
9. cluster_manager A stopped service.

[dboyzhong]

suggestion: request_q.destroy(); using option: request_q.destroy({ifUnused : true});

[starwarfan]

Hi, thanks for your suggestion and will you create a pull request for this issue?

[dboyzhong]

@starwarfan Yes, i created a pull request for this issue, thanks.