graceful

Library to write graceful shutdown / upgrade service.

Install

$ cabal update
$ cabal install graceful

Controll Graceful Application

A graceful application can be controlled with signals. The master process supports the following signals

• TERM/INT
  • fast shutdown
• QUIT
  • graceful shutdown
• HUP
  • restart workers
    1. starting new worker processes
    2. graceful shutdown old worker processes
• USR2
  • upgrading an executable file (starting new master & worker processes)

Upgrading Executable on the Fly

1. Send USR2
2. Send QUIT to old process