[NIFI-2478] Can not use the same Zookeeper by multiple NiFi clusters

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.0.0
• Fix Version/s: 1.0.0, 1.0.0-Beta
• Component/s: Core Framework
• Assignee: Mark Payne
• Reporter: Koji Kawamura
• Created: 04/Aug/16 08:05
• Updated: 04/Aug/16 21:23
• Resolved: 04/Aug/16 12:19

Description

I am trying to use the same external Zookeeper from two NiFi clusters. It's expected this deployment is supported since there is 'nifi.zookeeper.root.node' setting.

Set 'nifi.zookeeper.root.node' to '/nifi-cluster-1' for cluster-1, and '/nifi-cluster-2' for cluster-2.

Cluster-1 started successfully. But Cluster-2 can't start with following error:

2016-08-04 07:45:58,787 INFO [main] o.a.c.f.imps.CuratorFrameworkImpl Starting
2016-08-04 07:45:58,794 INFO [main-EventThread] o.a.c.f.state.ConnectionStateManager State change: CONNECTED
2016-08-04 07:45:58,795 INFO [main] o.a.n.c.c.node.CuratorNodeProtocolSender No node has yet been elected Cluster Coordinator. Cannot establish connection to cluster yet.
2016-08-04 07:45:58,795 INFO [Curator-Framework-0] o.a.c.f.imps.CuratorFrameworkImpl backgroundOperationsLoop exiting
2016-08-04 07:45:58,797 WARN [main] o.a.nifi.controller.StandardFlowService Failed to connect to cluster due to: org.apache.nifi.cluster.protocol.ProtocolException: No node has yet been elected Cluster Coordinator. Cannot establish connection to cluster yet.
org.apache.nifi.cluster.protocol.ProtocolException: No node has yet been elected Cluster Coordinator. Cannot establish connection to cluster yet.
        at org.apache.nifi.cluster.coordination.node.CuratorNodeProtocolSender.getServiceAddress(CuratorNodeProtocolSender.java:108) ~[nifi-framework-cluster-1.0.0-SNAPSHOT.jar:1.0.0-SNAPSHOT]

I looked at the Zookeeper znodes and found 'leaders' is not under configured root node:

[zk: localhost:2181(CONNECTED) 17] ls /
[leaders, nifi-cluster-1, zookeeper]

Then, I looked at the source code, and found CuratorLeaderElectionManager has following code:

        final String rootPath = zkConfig.getRootPath();
        final String leaderPath = (rootPath.endsWith("/") ? "" : "/") + "leaders/" + roleName;

It doesn't include rootPath while it should.

Issue Links

• links to: GitHub Pull Request #783