[Q&A] Session runs inactive and fails to execute endpoints

[virginiafdez]

Python version (python3 -V)

3.12

NVFlare version (python3 -m pip list | grep "nvflare")

2.5.2

NVFlare branch (if running examples, please use the branch that corresponds to the NVFlare version, git branch)

No response

Operating system

Ubuntu 22.04

Have you successfully run any of the following examples?

• hello-numpy-sag with simulator
• hello-pt with simulator
• hello-numpy-sag with POC
• hello-pt with POC

Please describe your question

Hello!

We are in the process of testing a test system we have created with one client, one server and one admin, and if we leave the session instance for a while and then try to call an endpoint function, we get:

File "/app/.venv/lib/python3.12/site-packages/nvflare/fuel/flare_api/flare_api.py", line 349, in list_jobs
result = self._do_command(command)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.12/site-packages/nvflare/fuel/flare_api/flare_api.py", line 197, in _do_command
raise InternalError(f"{cmd_status}: {info}")
nvflare.fuel.flare_api.api_spec.InternalError: error: session_inactive

Is there a way to customise the Session so that it doesn't become inactive if you don't call it? Or to extend this time after which this happens?

We are using nvflare 2.5.2, and the basic config for all three services.

Thank you!

[chesterxgchen]

@nvidianz @yanchengnv how to keep the session alive ?

[yanchengnv]

This feature is designed to prevent idle sessions from taking system resources and minimize security risks. To keep the session alive, the easiest way is to periodically send a command (e.g. sess.get_system_info() every few minutes) in a separate thread.

[YuanTingHsieh]

@virginiafdez ^ for vis. "To keep the session alive, the easiest way is to periodically send a command (e.g. sess.get_system_info() every few minutes) in a separate thread."