runtime: failed to create new OS thread with Docker

Question

I'm running 7 docker containers on an Ubuntu machine.

When I start all the containers, they run fine. However, after a while, two of them stop running (even though I ran the docker run command with the --restart always option).

Then, I inspected these two containers (using the docker inspect command) and saw that the following error was thrown: runtime: failed to create new OS thread (have 7 already; errno=11)

I also counted the number of threads that are running in the docker process (20), using the command ps huH p <PID> | wc -l.

I suppose I can't have so many containers running at the same time, right?

What should I do to avoid this system overload?

Answer 1

You may be getting out of memory or other limits:

• runtime: failed to create new OS thread
• golang runtime: failed to create new OS thread (have 2049 already; errno=12)
• And, as possible solutions: Python subprocess.Popen "OSError: [Errno 12] Cannot allocate memory"
• https://forum.gitlab.com/t/runtime-may-need-to-increase-max-user-processes-ulimit-u/22055