Error Nifi Cluster Setup: Attempted to register Leader Election for role 'Cluster Coordinator' but this role is already registered

[#1]

I was trying to setup Nifi cluster.

All these hosts pings one another.

I have tried everything i could on the web, but no success.

This is my configuration for master node:

Thanks.

MASTERNODE:

nifi.state.management.embedded.zookeeper.start true
nifi.zookeeper.connect.string =masternode:2181,workernode02:2181,workernode03:2181

nifi.cluster.is.node=true
nifi.cluster.node.address=masternode
nifi.cluster.node.protocol.port=9991
nifi.cluster.node.protocol.threads=10
nifi.cluster.node.event.history.size=25
nifi.cluster.node.connection.timeout=5 sec
nifi.cluster.node.read.timeout=5 sec
nifi.cluster.firewall.file=
nifi.cluster.protocol.is.secure=false
nifi.cluster.load.balance.host=masternode
nifi.cluster.load.balance.port=6342

nifi.remote.input.host=masternode
nifi.remote.input.secure=false
nifi.remote.input.socket.port=10000
nifi.remote.input.http.enabled=true
nifi.remote.input.http.transaction.ttl=30 sec

nifi.web.http.host=masternode
nifi.web.http.port=9443

------------------------------------------------------

WORKERNODE 02:

nifi.state.management.embedded.zookeeper.start=true
nifi.zookeeper.connect.string=masternode:2181,workernode02:2181,workernode03:2181
nifi.cluster.is.node=true
nifi.cluster.node.address=workernode02
nifi.cluster.node.protocol.port=9991
nifi.cluster.node.protocol.threads=10
nifi.cluster.node.event.history.size=25
nifi.cluster.node.connection.timeout=5 sec
nifi.cluster.node.read.timeout=5 sec
nifi.cluster.firewall.file =
nifi.cluster.protocol.is.secure=false
nifi.cluster.load.balance.host=workernode02
nifi.cluster.load.balance.port=6342
nifi.remote.input.host=workernode02
nifi.remote.input.secure=false
nifi.remote.input.socket.port=10000
nifi.remote.input.http.enabled=true
nifi.remote.input.http.transaction.ttl=30 sec
nifi.web.http.host=workernode02
nifi.web.http.port=9443

-----------------------------------------

WORKERNODE 03: same as above except the host.

------------------------------------------------------------

state-maanagement.xml:

<cluster-provider>
<id>zk-provider</id>
<class>org.apache.nifi.controller.state.providers.zookeeper.ZooKeeperStateProvider</class>
<property name="Connect String">masternode:2181,workernode02:2181,workernode03:2181</property>
<property name="Root Node">/nifi</property>
<property name="Session Timeout">10 seconds</property>
<property name="Access Control">Open</property>
</cluster-provider>

-------------------------------------------------------

zookeeper.properties:

server.1=masternode:2888:3888;2181
server.2=workernode02:2888:3888;2181
server.3=workernode03:2888:3888;2181

------------------------------------------

ERROR:

2022-06-16 11:50:03,954 WARN [main] o.a.nifi.controller.StandardFlowService There is currently no Cluster Coordinator. This often happens upon restart of NiFi when running an embedded ZooKeeper. Will register this node to become the active Cluster Coordinator and will attempt to connect to cluster again
2022-06-16 11:50:03,954 INFO [main] o.a.n.c.l.e.CuratorLeaderElectionManager CuratorLeaderElectionManager[stopped=false] Attempted to register Leader Election for role 'Cluster Coordinator' but this role is already registered
2022-06-16 11:50:05,119 WARN [Heartbeat Monitor Thread-1] o.a.n.c.l.e.CuratorLeaderElectionManager Unable to determine leader for role 'Cluster Coordinator'; returning null
org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /nifi/leaders/Cluster Coordinator
at org.apache.zookeeper.KeeperException.create(KeeperException.java:102)
at org.apache.zookeeper.KeeperException.create(KeeperException.java:54)
at org.apache.zookeeper.ZooKeeper.getChildren(ZooKeeper.java:2707)
at org.apache.curator.framework.imps.GetChildrenBuilderImpl$3.call(GetChildrenBuilderImpl.java:242)
at org.apache.curator.framework.imps.GetChildrenBuilderImpl$3.call(GetChildrenBuilderImpl.java:231)
at org.apache.curator.RetryLoop.callWithRetry(RetryLoop.java:93)
at org.apache.curator.framework.imps.GetChildrenBuilderImpl.pathInForeground(GetChildrenBuilderImpl.java:228)
at org.apache.curator.framework.imps.GetChildrenBuilderImpl.forPath(GetChildrenBuilderImpl.java:219)
at org.apache.curator.framework.imps.GetChildrenBuilderImpl.forPath(GetChildrenBuilderImpl.java:41)
at org.apache.curator.framework.recipes.locks.LockInternals.getSortedChildren(LockInternals.java:154)
at org.apache.curator.framework.recipes.locks.LockInternals.getParticipantNodes(LockInternals.java:134)
at org.apache.curator.framework.recipes.locks.InterProcessMutex.getParticipantNodes(InterProcessMutex.java:170)
at org.apache.curator.framework.recipes.leader.LeaderSelector.getLeader(LeaderSelector.java:337)
at org.apache.nifi.controller.leader.election.CuratorLeaderElectionManager.getLeader(CuratorLeaderElectionManager.java:281)
at org.apache.nifi.controller.leader.election.CuratorLeaderElectionManager$ElectionListener.verifyLeader(CuratorLeaderElectionManager.java:571)
at org.apache.nifi.controller.leader.election.CuratorLeaderElectionManager$ElectionListener.isLeader(CuratorLeaderElectionManager.java:525)
at org.apache.nifi.controller.leader.election.CuratorLeaderElectionManager$LeaderRole.isLeader(CuratorLeaderElectionManager.java:466)
at org.apache.nifi.controller.leader.election.CuratorLeaderElectionManager.isLeader(CuratorLeaderElectionManager.java:262)
at org.apache.nifi.cluster.coordination.node.NodeClusterCoordinator.isActiveClusterCoordinator(NodeClusterCoordinator.java:824)
at org.apache.nifi.cluster.coordination.heartbeat.AbstractHeartbeatMonitor.monitorHeartbeats(AbstractHeartbeatMonitor.java:132)
at org.apache.nifi.cluster.coordination.heartbeat.AbstractHeartbeatMonitor$1.run(AbstractHeartbeatMonitor.java:84)
at org.apache.nifi.engine.FlowEngine$2.run(FlowEngine.java:110)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305)
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
2022-06-16 11:50:11,732 INFO [Cleanup Archive for default] o.a.n.c.repository.FileSystemRepository Successfully deleted 0 files (0 bytes) from archive
2022-06-16 11:50:11,733 INFO [Cleanup Archive for default] o.a.n.c.repository.FileSystemRepository Archive cleanup completed for container default; will now allow writing to this container. Bytes used = 10.06 GB, bytes free = 7.63 GB, capacity = 17.7 GB

[#2]

Not sure if this is related , but if you are setting up a secure cluster the property

nifi.cluster.protocol.is.secure should be true. If not just make sure you follow steps mentioned in the following url and you have not missed anything:

https://nifi.apache.org/docs/nifi-docs/html/walkthroughs.html#creating-and-securing-a-nifi-cluster-w...

[#3]

Thanks sir.

I'm not setting a secured one.

Infact, i disable selinux.

[#4]

Have you added the nodes in the authorizers.xml under userGroupProvider and AccessPolicyProvider

[#5]

No sir,

I have not done that.

[#6]

I have added these. I am still having same error.

AccessPolicyProvider

<property name="Node Identity 1">cn=masternode</property>
<property name="Node Identity 2">cn=workernode02</property>
<property name="Node Identity 3">cn=workernode03</property>

userGroupProvider

<property name="Initial User Identity 1">cn=masternode</property>
<property name="Initial User Identity 2">cn=workersnode02</property>
<property name="Initial User Identity 3">cn=workersnode03</property>

[#7]

I cannot login because of the above issue.

[#8]

What the screenshot is telling that its still initializing the data flow, so give it some time and refresh.

[#9]

Though, i gave it some time before.

Now, i would leave it for several minutes and give you a feedback. 

Thank you sir. 

[#10]

It's more than 2hrs now, same "Invalid State" at the login.

While the log trace is still showing:

CuratorLeaderElectionManager Unable to determine leader for role 'Cluster Coordinator'; returning null
org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /nifi/leaders/Cluster Coordinator