I have created an application using the https://amphp.org framework. It is running with the help of a cronjob (every 5 minutes) sending a concurrent request to some sensors (temperatures) and it saves all the responses.
Up to ~1K sensors everything is working fine.
When increased to 1.5k for about 30% of the requests I am getting the following message:
Connecting to tcp://...:502 failed: timeout exceeded (10000 ms)
Any suggestions would be greatly appreciated!
There's usually a limit of up to 1024 file descriptors with stream_select, so you'll need one of the extensions, see https://github.com/amphp/amp#requirements.