Sun Microsystems Netscape Enterprise Server, Руководство администратора

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Chapter 7, Configuring Server Preferences 181
Using the Watchdog (uxwdog) Process (Unix)
The default behavior of the server watchdog process automatically restarts the
server if the server process should terminate unexpectedly. You can revert to
the previous default behavior, which was for the watchdog process to exit if the
server terminates unexpectedly. To revert to the original default behavior, set
the environment variable,
UXWDOG_NO_AUTOSTART
, at the beginning of the
server start script as follows:
(following the “
#!/bin/sh
” line):
UXWDOG_NO_AUTOSTART=1; export UXWDOG_NO_AUTOSTART
You also now have the option to have the watchdog restart the server if the
server process calls
exit()
with a non-zero argument value. This feature is
disabled by default, but can be enabled by setting the
UXWDOG_RESTART_ON_EXIT
environment variable in the server start script as
follows:
UXWDOG_RESTART_ON_EXIT=1; export UXWDOG_RESTART_ON_EXIT
Between Enterprise 3.01 and Enterprise 3.5.1, the Administration Server CGIs
for Enterprise were changed to actually restart, rather than start and stop the
server, when configuration changes are applied. As part of this change, these
CGIs will create a file,
wdnotify
, in the server’s logs directory, which will
contain a TCP port number on which the CGI listens for status from the
watchdog. During a start or restart operation,
uxwdog
checks for the existence
of this file, and if it finds it, connects to that port, and reads the name of a file
to which
stderr
is to be redirected during the operation. uxwdog opens that
file, redirects
stderr
to it, and performs the operation. If the operation is
successful,
uxwdog
writes a single byte value of zero back to the CGI.
Otherwise it writes a non-zero status byte, typically a value of one. Finally
uxwdog
closes the connection to the CGI, and redirects
stderr
to
/dev/
console
.
There may be some cases where
wdnotify
does not get deleted when it
should, which may cause
uxwdog
to exit instead of starting or restarting the
server. This can be corrected by manually removing the
wdnotify
file from
the
logs
directory.