Cryosparc stalls at command_core:started

Install, Configure and Update
1

Hello everybody,

I have a cryosparc installation on a cluster, version 4.7.0. I have been using this for a few years with no issues. Today, after coming back from a few days away, I tried starting cryosparc
cryosparcm restart.

The starting process stalls at ‘command_core: started’. If I look into command_core.log, I see multiple repetitions of:

2025-07-29 16:26:26 error                ERROR    | Connection in use: ('0.0.0.0', 44476)
2025-07-29 16:26:26 error                ERROR    | Retrying in 1 second.
2025-07-29 16:26:27 error                ERROR    | Connection in use: ('0.0.0.0', 44476)
2025-07-29 16:26:27 error                ERROR    | Retrying in 1 second.
2025-07-29 16:26:28 error                ERROR    | Can't connect to ('0.0.0.0', 44476)
2025-07-29 16:26:30 info                 INFO     | Starting gunicorn 22.0.0
2025-07-29 16:26:30 error                ERROR    | Connection in use: ('0.0.0.0', 44476)
2025-07-29 16:26:30 error                ERROR    | Retrying in 1 second.
2025-07-29 16:26:31 error                ERROR    | Connection in use: ('0.0.0.0', 44476)
2025-07-29 16:26:31 error                ERROR    | Retrying in 1 second.

I have tried changing port but that did not help.
Appreciate any help. thanks!!

2

Welcome to the forum @DD1D.

You may want to

  1. determine which process is using the relevant port. Consider a suitable sudo ss command, similar to the one mentioned under Web interface is not connecting due to port issue - #2 by wtempel.
  2. ensure there are no lingering processes](https://guide.cryosparc.com/setup-configuration-and-management/troubleshooting#id-2.-find-and-if-necessary-terminate-zombie-processes) related to your own CryoSPARC instance, but be sure to not inadvertently disrupt someone else’s CryoSPARC instance.

Which command did you use to change the port?

  1. Did you select a port range that is
    • not overlapping with ports used by another application and/or another user
    • and outside the ephemeral port range configured on the computer
  2. Did you use the cryosparcm changeport command?
3

Thank you! It appears that the issue was that the port range I had selected was within the ephemeral port range. Moving it outside the range solved the issue immediately.

Thanks again

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