All Zope process will respond to signals in the specified manner:

  SIGHUP -  close open database connections and sockets, then restart the
            process

  SIGTERM - close open database connections and sockets, then shut down.

  SIGINT  - same as SIGTERM

  SIGUSR2 - rotate all Zope log files (z2.log, event log, detailed log)

The common idiom for doing automated logfile rotation will become:

kill -USR2 `cat /path/to/var/z2.pid`

The common idiom for doing "prophylactic" restarts will become:

kill -HUP `cat /path/to/var/z2.pid`

When a process is interrupted via ctrl-C or via a TERM signal (INT, TERM),
all open database connections and sockets will be closed before
the process dies.  This will speed up restart time for sites that
use a FileStorage as its index will be written to the filesystem before
shutdown.

Unspecified signals kill the process without doing cleanup.