I've seen a couple of problems over the last few weeks with master apparently failing to correctly maintain the prefork pool. We particularly see this problem with pop3d, which has more connects/disconnects than IMAP because of the nature of the protocol.
The first issue is that in shut_down() sockets are not closed. It seems that this can leave sockets in CLOSE_WAIT state in certain error situations where popd_reset() is not called. The second issue is that we sometimes see sockets remain in a CLOSE_WAIT state because there is still data to be read. It appears that prot_fill() should be called in popd_reset() and shut_down(). The third issue is that when a process fails to shutdown correctly, such as if it segfaults, master does not seem to correctly keep track of the child process count. As a result, eventually the pool runs out and no more connections are accepted. Do the resolutions to the first two issues sound correct (we have made these changes and it seems to have fixed things for us)? Does anyone have a fix for the third issue?
