What are the default connection limits for a worker? Is there a maximum number of connections a worker can handle?
The only thing that I know off that could limit opening connections at the node level is the /proc/sys/fs/file-max value. Weve encountered that once so far with a customer who was using a Linux distro that had a very low default value for that for some reason. But the default for that same setting on a Ubuntu 20.04 system in my lab is over 9 billion so the defaults will vary across Linux distributions.
As for per worker process, the standard ulimit open file limit at the OS level can limit it. That applies at a per process level as well.
S2S limits to 1000 by default and HTTP inputs limit to 256 by default. TCP JSON and TCP Raw also have default connection limit of 1000. All of those are at the Stream level and are applied per worker process. Obviously if the OS-level settings are too low then the application-level default values may not be obtainable. I dont believe any other inputs at this time have any connection limits.