RPC Latency query
Hello
Our environment is Exchange 2007 SP1. I had some questions about RPC Latency which I can't seem to understand the basis of.
1. What exactly is RPC latency? Could you say it's the 'speed' of a connection from an Outlook client to Exchange mailbox.
2. Is there a way to measure RPC latency?
3. What should be the threshold?
4. What can affect RPC latency?
October 15th, 2010 2:25pm
RPC latency ( Remote procedure call latency , outlook uses rpc protocol to connect to exchange ). The more of this can affect your clients accesssing Exchange server
You can set Performance counters to measure RPC latency., ( tools option in emc should help)
Many factors other than network connectivity, not so good database health to Av scanning DB will affect RPC latency. You can also increase diagnostic logging for rpc counters to check individual sessions.
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October 15th, 2010 2:44pm
On Fri, 15 Oct 2010 18:23:20 +0000, Sheen1990 wrote:
>Our environment is Exchange 2007 SP1. I had some questions about RPC Latency which I can't seem to understand the basis of.
>
>1. What exactly is RPC latency? Could you say it's the 'speed' of a connection from an Outlook client to Exchange mailbox.
No, it's the time it takes to 'process' a RPC packet.
>2. Is there a way to measure RPC latency?
Use Performance Monitor. "MSExchangeIS \ RPC average latency" is the
counter.
>3. What should be the threshold?
Not more than 50ms.
>4. What can affect RPC latency?
The ability of the server to handle the workload. That might be IOPS
(too many for the disks to handle), but it may also be CPU (the
ability to multi-thread), or memory (more is good because it reduces
the need for I/O -- refer to IOPS).
---
Rich Matheisen
MCSE+I, Exchange MVP
--- Rich Matheisen MCSE+I, Exchange MVP
October 15th, 2010 3:11pm
Thanks Rich.
One last question, if we were experiencing an issue and wanted to check RPC latency, would we need to increase diagnostic logging, or can we just run Perfmon straight off with this counter?
And - if the value was more than 50ms, does this mean that the problem is Exchange server related (i.e not networking, client-side issues etc)?
Thanks again!
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October 16th, 2010 3:02pm
On Sat, 16 Oct 2010 19:00:16 +0000, Sheen1990 wrote:
>One last question, if we were experiencing an issue and wanted to check RPC latency, would we need to increase diagnostic logging, or can we just run Perfmon straight off with this counter?
I'd go get a copy of Performance Analyzer of Logs
(http://pal.codeplex.com) and install the prerquisites and then the
tool. Then get the Exchange 2007 PerfWiz and us it to set up the
perfmon on the server:
http://blogs.technet.com/b/mikelag/archive/2008/05/02/perfwiz-replacement-for-exchange-2007.aspx
Now, let it run for a while. It's a good idea to do this before you
have a problem so you know, more or less, what things normally look
like. Run the logs through PAL and address the stuff in red first. :-)
Oh, you should run ExBPA too. There's no sense trying to find wht's
out of spec on your own when someone's already done it for you.
>And - if the value was more than 50ms, does this mean that the problem is Exchange server related (i.e not networking, client-side issues etc)?
If that's where you're measuring, yes.
---
Rich Matheisen
MCSE+I, Exchange MVP
--- Rich Matheisen MCSE+I, Exchange MVP
October 16th, 2010 7:27pm