On Mon, Aug 22, 2022 at 9:48 AM Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > It's also pretty unclear why the kernel would want to return > EAGAIN instead of letting the nonblock connection path do the > waiting, which is why I'm suspecting a bug rather than designed > behavior. Could it be that it fails like that if the listen queue is full on the other side? https://github.com/torvalds/linux/blob/master/net/unix/af_unix.c#L1493 If it's something like that, maybe increasing /proc/sys/net/core/somaxconn would help? I think older kernels only had 128 here.