Apache NiFi Cluster in Docker over 3 VM's - docker

Question

I want to make a NiFi cluster in docker over 3 vm's.
I found a docker-compose file that creates a cluster on one node and try to edit this file.
I found out that i need zookeeper, but do i need one zookeeper each instance? and what ports should i open or map in docker?
the docker-compose file i found:
version: "3"
services:
zookeeper:
hostname: zookeeper
container_name: zookeeper
image: zookeeper:3.6.1
environment:
- ALLOW_ANONYMOUS_LOGIN=yes
nifi:
image: apache/nifi:1.11.4
ports:
- 8080 # Unsecured HTTP Web Port
environment:
- NIFI_WEB_HTTP_PORT=8080
- NIFI_CLUSTER_IS_NODE=true
- NIFI_CLUSTER_NODE_PROTOCOL_PORT=8082
- NIFI_ZK_CONNECT_STRING=zookeeper:2181
- NIFI_ELECTION_MAX_WAIT=1 min
I changed the file like this (on each VM the ip is correct )
version: "3"
services:
zookeeper:
hostname: zookeeper
container_name: zookeeper
image: 'zookeeper:3.6.1'
ports:
- 2181
environment:
- ALLOW_ANONYMOUS_LOGIN=yes
nifi:
image: apache/nifi:1.11.4
ports:
- 8080 # Unsecured HTTP Web Port
- 8082
- 9001
environment:
- NIFI_WEB_HTTP_PORT=8080
- NIFI_CLUSTER_IS_NODE=true
- NIFI_CLUSTER_NODE_PROTOCOL_PORT=8082
# - NIFI_ZK_CONNECT_STRING=zookeeper:2181
- NIFI_ZK_CONNECT_STRING=192.168.2.10:2181,192.168.2.20:2181,192.168.2.30:2181
- NIFI_ELECTION_MAX_WAIT=1 min
- NIFI_CLUSTER_ADDRESS=192.168.2.XX
and in the logs i found this message but cant find any solution
ERROR [Curator-Framework-0] o.a.c.f.imps.CuratorFrameworkImpl Background retry gave up
org.apache.curator.CuratorConnectionLossException: KeeperErrorCode = ConnectionLoss
at org.apache.curator.framework.imps.CuratorFrameworkImpl.performBackgroundOperation(CuratorFrameworkImpl.java:972)
at org.apache.curator.framework.imps.CuratorFrameworkImpl.backgroundOperationsLoop(CuratorFrameworkImpl.java:943)
at org.apache.curator.framework.imps.CuratorFrameworkImpl.access$300(CuratorFrameworkImpl.java:66)
at org.apache.curator.framework.imps.CuratorFrameworkImpl$4.call(CuratorFrameworkImpl.java:346)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

Answer 1

I found out that i need zookeeper, but do i need one zookeeper each instance?
No, you can use one zookeeper
and what ports should i open or map in docker?
as I know you need 2888, 3888, 2181 to be open. But only 2181 to communicate with nifi
2888 and 3888 for zookeeper cluster communication.