On 2010-05-31T18:16:30, Lars Ellenberg <[email protected]> wrote:
> There are several flavors of overhead.
> One underestimated is programming and code maintenance overhead ;-)
>
> Why would we "register pid with lrm" and duplicate code from heartbeat
> proper to lrmd and whatnot, or even rewrite the respawn from scratch
> again, if the same thing can be achieved with a few lines of shell code?
Uhm, because, well, like, heartbeat isn't available? And because
heartbeat can't attach to processes that are being started by some
obscure parts deep inside SAP/Oracle/DB2? ;-)
Of course this should reuse some of the clplumbing infrastructure.
> I suggested to have the loop in the script, and monitor that script.
> sort of what the mysql guys did with their "mysql_safe" thing,
> or whatever it is called.
You're quite missing the point, I'm afraid. This is _still_ an
additional process running and a rather slow script language. And you'd
still end up "monitoring" that script.
The whole POINT is to generate async notification failures on process
death instead of waiting for several seconds until the next lrmd exec'ed
monitor comes along.
> while :; do
> echo "(re)starting $whatever... "
> $your_daemon_here
You're embedding policy into code here. Who said anything about the
proper response being the daemon being restarted being the right
response? Maybe the whole point is to initiate full PE-level recovery?
> Of course you can get fancy, background the daemon, then wait,
> have a trap on sigterm, put in some ulimits, ...
>
> Write the "respawn_everything" RA.
BUT THAT ISN"T THE FUCKING POINT.
The point is to make _monitor_ better. Not replace the whole rest of the
solution. Argh.
Regards,
Lars
--
Architect Storage/HA, OPS Engineering, Novell, Inc.
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde
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