Sonarqube data center, app node port 44117, what is it for?

I am running sonarqube data center edition 8.9.1 in k8s, and in the app node, there is error about failure to connect to 44117, is that port needs to be open? Documentation on the purpose of that port?
Thanks
logs:

2021.07.07 16:38:30 INFO web[c.h.i.s.t.TcpServerConnector] [10.32.1.207]:33121 [SonarQube] [4.2] Connecting to /10.32.1.207:44117, timeout: 10000, bind-any: false
2021.07.07 16:38:30 INFO web[c.h.i.s.t.TcpServerConnector] [10.32.1.207]:33121 [SonarQube] [4.2] Could not connect to: /10.32.1.207:44117. Reason: SocketException[Connection refused to address /10.32.1.207:44117]
2021.07.07 16:38:30 INFO ce[c.h.i.i.NodeExtension] [10.32.1.207]:44117 [SonarQube] [4.2] Destroying node NodeExtension.
2021.07.07 16:38:30 INFO ce[c.h.i.impl.Node] [10.32.1.207]:44117 [SonarQube] [4.2] Hazelcast Shutdown is completed in 6002 ms.
2021.07.07 16:38:30 INFO ce[c.h.c.LifecycleService] [10.32.1.207]:44117 [SonarQube] [4.2] [10.32.1.207]:44117 is SHUTDOWN

Hi @tlong ,

Yes, that port needs to be open since it allows Hazelcast to perform cross-node communication (see Configure & Operate a Cluster | SonarQube Docs):

Configuration details

There are three TCP networks to configure:

  • the network of application nodes that relies on Hazelcast.
  • the network used for Elasticsearch internal communication between search nodes ( es properties).
  • the network between application nodes and search nodes ( search properties).

Hazelcast is used to manage the communication between the cluster’s application nodes. You don’t need to install it yourself, it’s provided out of the box.

Also, note this line in Install the Server as a Cluster | SonarQube Docs :

Network traffic should not be restricted between application and search nodes.

Thanks, just follow up question, can this parameter sonar.cluster.hosts be a Loadbalancers, behind which all hosts are targeted?

You’re welcome.

I don’t think you can use load balancers since we specify this description for sonar.cluster.hosts here:

Comma-delimited list of all application hosts in the cluster. This value must contain only application hosts .

You are welcome to try of course, but typically the load balancer will sit in front of SonarQube and Hazelcast will handle the “load balancing” of cross-node communication.