search for: persistent_mail_process

...greatly increases scalability especially when clients are idle. Here's how it works. When there are no mail processes, or none serving fewer than mail_max_connections clients, the master creates a new mail process pretty much like it does now, but with some new environment variables (PERSISTENT_MAIL_PROCESS and CONNECTION_ID, and ADVISE_SET[GU]ID instead of RESTRICT_SET[GU]ID) and a unix-domain socket connection back to the master. For future clients the master sends the client socket and a full dump of the environment via that connection. Persistent mail processes multiplex I/O for their...