ClusterMasterExecutor dose not work well caused by wrong result type.

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.0 M3
• Fix Version/s: 6.2.4 CE GA5, 6.2.X EE, 7.0.0 M3
• Component/s: Core Infrastructure, Fault Tolerance, Fault Tolerance > Clustering Framework, Portal Services > Background Tasks
• Labels:
  • QA-TP
  • liferay-fixpack-portal-76-6210
• Branch Version/s:
  6.2.x
• Backported to Branch:
  Committed
• Story Points: 12
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/21740

Steps to reproduce:

1) Enable cluster on Node1 and start it
2) After node1 is fully started, enable cluster on Node2 and start it
3) Login Node2 by default user [e-mail]
4) Go to jsonws api page, for example if node2 is started on http://localhost:8081/, then go to http://localhost:8081/api/jsonws
5) Search "get-background-task-status-json" and click the api
6) Set backgroundTaskId to a number like "12345"
7) Click "Invoke".

Before fix, on console of Node2, you will see:
ERROR [http-bio-8081-exec-10][JSONWebServiceServiceAction:97] com.liferay.portal.kernel.cluster.ClusterNodeResponse cannot be cast to java.lang.String

After fix, you won'tt see the error.

It is caused by a commit of LPS-40371, git id is : 4562637cdf7619587ae55b53389b74ec7e4a48b0; git message is: LPS-40371 Make ClusterMasterExecutor.executeOnMaster() returns Future