[Zodb-checkins] CVS: ZODB3/Doc/ZEO - SIGNALS.txt:1.1

[Guido van Rossum]

Update of /cvs-repository/ZODB3/Doc/ZEO
In directory cvs.zope.org:/tmp/cvs-serv1224

Added Files:
	SIGNALS.txt 
Log Message:
Attempt to document signals.

Note that I'm not sure the pids written to the pidfile always make
sense.


=== Added File ZODB3/Doc/ZEO/SIGNALS.txt ===
Signals are a posix inter-process communications mechanism.  If you
are using Windows then this documentation is not for you.

The ZEO storage server process (started with ZEO/start.py) responds to
signals which are sent to the process id written to the file
.../var/ZEO_SERVER.pid.

    SIGHUP -  Rotate the log files.
	      kill -SIGHUP `cat .../var/ZEO_SERVER.pid`

    SIGTERM - Close open storages and sockets, then shut down.
              kill -SIGTERM `cat .../var/ZEO_SERVER.pid`

    SIGINT  - Close open storages and sockets, then restart.
              kill -SIGINT `cat .../var/ZEO_SERVER.pid`

The pid file contains two pids: the pid of the parent process and the
pid of the child process, in that order.  The child process is always
the actual storage server process.  When using zdaemon (the default),
the parent is the zdaemon process.  Otherwise (when the -s option is
used), the parent is the shell (script) that started the storage
server.

Note that zdaemon forwards signals to the child process.
(Specifically, it forwards all those signals listed above, plus
SIGQUIT and SIGUSR1.)