Hi Jay,
"Austad, Jay" wrote:
> I had both of my QMQP servers bouncing off of the 120 limit
> yesterday, and they were pretty much idle (Dell 2450's with
> 2 striped 9GB 10k rpm drives).
Which RAID level?
I remember somebody mentioning in this list that 0+1 will perform
faster than 3 (or 5 obviously ;).
I can't confirm this since I don't have that kind of artillery
here at home. Anybody?
> I think even if I could get the concurrency up to 1024 or above,
> it still wouldn't be enough to make a difference on the box. I'll
> find out soon if I can make it bounce off of the 509 limit. Our
> Midday Market Report is due to go out within the hour.
Good luck.
> Hopefully when the next version of qmail comes out, it will have
> the big-concurrency and big-todo patch already installed.
AMEN.
But I also remember reading a kernel related doc somewhere
which mentioned that the kernel is limited to 1024 file
descriptors deliberately, since more open files become a
major time loss for excessive CPU usage which results in
more performance loss (somebody please correct me if I'm
wrong).
I also remember DJB mentioning in one of his docs that
multiple files in a single directory becomes a performance
lag (e.g. /var/spool/mail).
That is why I thought "no wonder the queue directory is
full of directories", and I edited conf-split to 100
(default was 20 I think) and recompiled so now I have
100 directories under each queue/* directory :)
I don't know, I could be totally off.
I wish I had more time/hardware/brains to get different
setups rolling so I could really check all of this out
and come up with decent figures.
> What happens if I start a second copy of qmail using /var/qmail2,
> different uids, and bind to another IP on the same box? Will I
> be able to do 509 concurrency out of each copy since they are
> running as different users?
I have never tried it, but I read somewhere in the qmail
related docs that you could have a few instances of qmail
running for heavy loads (e.g. multiple virt domains and
multiple mailing lists), exactly like the setup you have
mentioned above. Darn, can't remember where I read it :(
And of course, DNS resolving and other network related
stuff (e.g. non qmail and/or slow servers on the other
end of the line) etc tend to lag things down...
relativity sucks...in this case at least.
Oh well :)
cheers
jamie
#---------#---------#---------#---------#---------#---------#---------#
-- If somebody can help create a search engine for my room,
I will call them a Saint...
GUI == Graphical User Interference
