KNIME Server Error : RabbitMQHandler could not acquire enough core tokens from server

Hi KNIME,

I have tried to build up the Distributed Executors in accordance with the instruction : https://docs.knime.com/2018-12/server_admin_guide/index.html#knime-server-distributed-executors.

However, I met an error that is “Executor> ERROR main RabbitMQHandler Could not acquire enough core tokens from server, quitting” on the way to start the executor manually.

The KNIME server, RabbitMQ, and Executor were installed in one same machine with a partner license.

How can I solve this problem?

Best,
EXEM_KIM

Hi @EXEM-Kim,

How many executors are you trying to start? And how many cores are provided in your license? (You can just check in the xml in case you’re unsure) And most importantly, can you confirm that the license you have is for KNIME Server Large?

Cheers,
Roland

1 Like

Hi @RolandBurger,

Thank you for your quick reply.

Here answers.

  1. I tried to start only one executor.

  2. The number of cores that are provided in my license is 8. I checked in the xml.

  3. The license that I have is for KNIME Server Large. I also checked it in the xml.

Is it because of the maximum number of cores in the license?
There was nothing wrong with using just one executor instead of Distributed Executor with RabbitMQ.

Best,
EXEM-Kim

Hi @EXEM-Kim,

Any chance the CPU on the server has more than 4 CPUs? In that case, it will try to acquire more tokens than the license provides. (4*2 due to hyperthreading)

To prevent this from happening, please add the parameter
-Dorg.knime.core.maxThreads=8
as the last line in the executor’s knime.ini.

That should take care of this situation.

Cheers,
Roland

2 Likes

Hi @RolandBurger,

I did what you said, and I succeeded.

Thank you!

Best,
EXEM-Kim

2 Likes

Great, happy to hear that it’s working now :slight_smile:

Cheers,
Roland

1 Like

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