Why does Greengrass IPC create so many open file descriptors?

Question

I am using Greengrass IPC for components to communicate.  I fire off a message every 5 seconds.  However, it seems that this begins to fail with the error: `RuntimeError: 45 (AWS_ERROR_MAX_FDS_EXCEEDED): The maximum number of fds has been exceeded..`

I notice that before I start my component and I run the command `lsof | wc -l`, it shows about 41030 open file descriptors.  But when I start my component, the number steadily climbs until it exceeds 1048576 which is the number I found by running the command `ulimit -n`  It only takes a few minutes before it reaches the maximum number and produces that error.

Is there a leak or something in the IPC client?

Accepted Answer

Hi Ken,

It sounds like you're maybe creating a new client to handle each publish request, is that right? You should only create one IPC client and then keep using that client for all requests. See the best practices here: https://docs.aws.amazon.com/greengrass/v2/developerguide/interprocess-communication.html#ipc-best-practices.

Why does Greengrass IPC create so many open file descriptors?

Relevant content