I am using domain socket to get values from another process, like A to get a value from B, It works well for months. But recently, A is failed during "sendto" message to B with "errno 111, connection refused" occasionally.

I checked the B domain socket bind file, it is exists. I also do some tests in another machine, also works well. So, does anyone encounter this problem before? Can anyone have some clues what might be probably wrong in this scenario? Thanks very much.