>
> > > > hmmm...more thought, code reading, and whiteboard doodling is called
> > > > for. Off the top of my head, I would think one of the config hooks in
> > > > mod_status could allocate a big chuck of shmem for its use on every
> > > > restart. Then the new worker processes would see the Right Stuff as far
> > >
> > > You can't allocate on every restart,
> >
> > sure we can, if we are careful about cleaning up
> >
> > > because if you do, the information
> > > won't survive a restart. Imagine the pathological case, where a single
> > > request is very long-lived, and it happens to survive multiple restarts.
> > > If we reallocate during each restart, we will lose the status of that
> > > request.
> >
> > good point...easily solved I think. "last guy out turns out the lights"
> > - when the last process for generation x goes away, it's time to clean
> > up generation x's huge chunk of shmem.
> >
> > >
> > > > as pointers. The core should also allocate a new chunk of shmem to
> > > > represent the processes at restart time, so we can get rid of the
> > > > HARD_SERVER_LIMIT stuff (it's a PITA...think of admins in big shops who
> > >
> > > Again, you can't do that,
> >
> > understand your concern, but it just requires code.
>
> You are talking about adding a lot of logic that has very little benefit
> IMO. The purpose for these changes, are to remove HARD_SERVER_LIMIT, and
> to make it easier to remove some shared memory if mod_status is not
> loaded. How big a hardship is HARD_SERVER_LIMIT, and how much memory are
> we really talking about?
>
I am working with a customer that wants to support 10,000 concurrent clients on a
single machine.
That number will just grow in the future. I think the actual memory used by the
scoreboard in this
case may be trivial compared the savings with moving to a threaded server. On some
systems, shared
memory is pinned (non-pagable) real memory. How big a chunk can you expect to allocate
at a time?
If we can safely allocate say 20MB of shared storage, then maybe you are right and we
shouldn't be
worrying about eliminating HARD_SERVER_LIMIT.
Bill
