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joe,
Steve may have completely different information that I, but
at present I'm not seeing empirical or preferred practice recommendations around
64-bit GCs in relation to Exchange. So, the recommendation is not changing
- again, as I know it. Steve's environment is very different from mine and
he is likely to have zero-day information that I won't have until it's posted
internally on a DL or whitepaper. I'll be looking for his answer,
too.
Currently, unless I get data that tells me otherwise, Dual
Core and MP == ~ same - even more so when dealing with AMD as, IMO Intel blew
their first dual core in an effort to get it to market.
That being said, I suspect that the very benefit of being
able to load up on memory and get the DIT in RAM is going to affect the
recommendation more than proc will. By that I mean that it might be very
realistic to see that I/O may begin to be a limiting factor - not so much
network, but disk subsystems are going to have to be designed a bit more towards
performance with the massive number of queries that these systems are capable
of.
As to the use single proc GCs and scaling not being linear
- I would suspect that the very fact that linear performance is not seen in MP
has already been taken into account. Otherwise, the recommendation might
have been 5 or 6 to 1.
When you mention that you see some GCs get 'beta down' when
others are pretty light, is this assuming the practice of creating a AD site for
Exchange with dedicated DC/GCs, or a general population scheme? If the
former, I haven't seen the issue that you cite in practice, if the latter -
design to the former.
I suppose that - in relation to counters, etc., that would
be why I like to do a more formal capacity planning and performance gathering
over time. I don't believe in point-in-time perf counter gathering as (you
know this...)seeing it when the problem is occurring with no history for what is
normal is basically - well, useless. I have no trail of bread crumbs in
which to track down the problem.
In relation to the counter gathering (I have no experience
with Argent's offering, and SOME experience with MOM 2000 and 2005) I've found
that MOM 2005 and the AD and Exchange MPs do a great job of gathering
information that is valuable to me as someone who has to figure out what's wrong
with these systems now and then. Before I joined Microsoft, we had MOM
installed for just this reason. The history gathering abilities and
leveraging AD and EXCH data over time allowed us to see exactly where our pain
point was - and fix it in a relatively short period of time.
This is as I know it today...... It could change
later today or tomorrow.... :-)
Rick [msft]
-- Posting is provided "AS IS", and confers no rights or warranties ... From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of joe Sent: Friday, October 14, 2005 4:58 AM To: ActiveDir@mail.activedir.org Subject: RE: [ActiveDir] Domain Controller Consolidation utilizing Dual Core CPUs Speaking of which Steve........
I am starting to see questions of the type of how does 64
bit DC change the best practice 4:1 proc recommendations for Exchange to GC
processor. Does PSS/MCS/Dev have any thoughts? Especially if you are able
to cache the entire DIT. I have seen some 64 bit testing numbers from third
parties but that is far from authoritative in terms of what MS thinks for the
best practice numbers which weigh heavily with customers who want to do it the
"Microsoft way".
Ditto the dual core CPUs.
Another one that recently came across my desk was if you
have 4000 users on a 4 proc Exchange server and are currently using a single 1
proc GC and then you decide due to load on Exchange (say RPC load due to
search/archive software which isn't impacting GCs) you want to go to 2 4 proc
Exchange servers with 2000 users each do you have to go to a dual proc
GC or add another single proc GC or is it ok to stay with the one single proc
GC?
Oh and another question I was asked was about using single
proc GCs versus MP GCs and how the scaling of MP wasn't linear so should that be
somehow involved in the Exchange best practice numbers?
It seems from my experience that you do better with making
bigger and more powerful GCs in general because while Exchange does
some limited logic round-robin load balancing at the server level, it doesn't do
it at the site level amongst all Exchange servers so you can really start
beating down a few GCs while the others see relatively light loading. Of
course you don't want to have few GCs though in case you do have a problem so
you throw a couple of extra larger GCs into the mix for fault tolerance for when
you have to bring a GC down for maint or it just falls down for some reason.
Also it seems that there is no real good way of determing
exactly when you need to change your GC strategy for Exchange because your
various Exchange AD related counters could be poor yet AD is still seeming to be
performant and possibly even under utilized. This seems to really come into play
if a lot of DL expansion of very large groups is coming into play. Possibly it
is simply related to bad queries from Exchange due to, well bad queries, or
third party event sinks a la Exclaimer or multiple to software, etc.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steve Linehan Sent: Friday, October 14, 2005 1:25 AM To: ActiveDir@mail.activedir.org Subject: RE: [ActiveDir] Domain Controller Consolidation utilizing Dual Core CPUs In my opinion the
biggest bang for the buck is consolidation of servers to the 64bit platform
assuming of course that you have a large enough database, greater than 3 GB, and
put enough memory in the servers to cache the entire database contents. I
have come across very few cases where Domain Controllers were truly CPU bound
and in almost all cases they were I/O bound. These servers perform
extremely well for servers that are taking large amounts of ldap traffic from
applications like Exchange. Thanks, -Steve From:
[EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Mauricio F.
Funes Gentleman, Thanks for your input,
Mauricio
Funes |
Title: Domain Controller Consolidation utilizing Dual Core CPUs
- RE: [ActiveDir] Domain Controller Consolidation utilizing ... Rick Kingslan
