Re: [PATCH] immortal helpers

lör 2010-02-20 klockan 18:25 -0700 skrev Alex Rousskov:

> The reasons you mention seem like a good justification for this option
> official existence. I do not quite get the "fork bomb" analogy because
> we are not creating more than a configured number of concurrent forks,
> are we? We may create processes at a high rate but there is nothing
> exploding here, is there?

With our large in-memory cache index even two concurrent forks is kind
of exploding on a large server. Consider for example the not unrealistic
case of a 8GB cache index.. I actually have some clients with such
indexes.

Thankfully having ample amounts of swap silently eats up this explosion,
but it may be a little hard to explain why one needs orders of magnitude
more swap than memory..

> The forking/waitpid code in main.cc analyses the exit status of a kid.
> Can we rely on that to cover your use case? I think we can ignore the
> fact that some helpers are poorly written because we are not making
> things worse for them (but may be making things better for well-written
> ones).

exit code checks should cover most crashing helpers.

but does it matter to Squid other than for diagnostic purposes if the
helper crashed or simply exited of free will?

Regards
Henrik
Received on Sun Feb 21 2010 - 21:27:10 MST