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This product reached the end of support date on March 31, 2021.

WARNING [ClusterTimeProvider] Exception synchronization cluster time: COMMUNICATION_ERROR


Hello everyone,

We are installing dynatrace appmon 7 (linux). It's all right. However, a message in the collectors insists on appearing: "xxxx-xx -xx: xx: xx WARNING [ClusterTimeProvider] Exception synchronization cluster time: COMMUNICATION_ERROR [log message will be suppressed for 1 hour]".

Our suspicion was something related to ntpdate, however everything is ok.

Does anyone know anything about this error?

Thanks in advance.




Hello Fernando,

I was able to find a support ticket where users were experiencing a similar issue to yours and here is the description of the issue and how to resolve it:

"The message you mentioned, means that most probably the port 8041 not being opened. In general this is as follows:
This warning indicates that the collector component that is responsible for oneAgent(NodeJS agents for example) management is unable to synchronize it's internal timer with the dynatrace server. This is often caused by the relevant ports being closed by the firewall. If you don't have any NodeJS agents(or beta OneAgents), then this warning has no effect on your environment.
There're 2 ways which can remove this warning for good:

  • By disabling the one agent adapter on the collector side (the collector will not establish the one-agent-data-specific server connection), this can be done by adding the debug flag "com.dynatrace.diagnostics.startDtangAdapter" to the collector config with the client in debug mode (settings -> server settings -> collectors -> debug flags) and set it to value "false", no need to restart the collector.
  • If OneAgents are used, then by opening the relevant ports for the communication between the collector and server (ports 8040 and 8041) so data can flow freely between them."

Hope that helps,

David Nicholls

Thanks David. It worked!

I have the same problem with 6.5. Does the suggested fix also apply to 6.5?

Hello Enrico,

Yes, it should work, actually, that was where the person in the support ticket experienced this issue (6.5 environment).

You can check it out here:


David Nicholls

Hi David,

The Support ticket is not accessible. Can you please share the solution for 6.5 environment. Right now we are having the same issue on our production environment.


Ravi Kumar