Mac IMAP client maxing out IMAP service

Mac IMAP client maxing out IMAP service

Post by S3Vyd » Sun, 01 Nov 2009 06:06:01


Hi,


Though IMAP logging and performance logging I have determined that a Mac
client with Snow Leopard is maxing out the IMAP process and thus pegging the
quad CPU's at 100%. This happens a few times a day for 5 minutes or so, then
the service is available again. This user has 740,000 messages and is 15GB.
So my questions are:

Is an IMAP connection to a mailbox of this size and number of messages a
known problem?

Is IMAP pegging the CPUs like this a known issue? I see that it was an
issue previously that was fixed in several of the Exchange rollups, but we
are up to date with rollup 9.

Thanks for any input,


Kurt
 
 
 

Mac IMAP client maxing out IMAP service

Post by Ed Crowley » Mon, 02 Nov 2009 06:04:36

It couldn't be a Mac. According to the commercials, they're perfection.
--
Ed Crowley MVP
"There are seldom good technological solutions to behavi *** problems."
.

 
 
 

Mac IMAP client maxing out IMAP service

Post by Rich Mathe » Mon, 02 Nov 2009 11:44:08

On Fri, 30 Oct 2009 14:06:01 -0700, Kurt



I suppose that depends on what the client is doing with the mailbox.
You have the IMAP logs so you should be able to see what's going on,
or at least what commands were sent to the server to induce that
behavior.
---
Rich Matheisen
MCSE+I, Exchange MVP
 
 
 

Mac IMAP client maxing out IMAP service

Post by S3Vyd » Thu, 05 Nov 2009 00:28:01

hanks. Here are two examples from the IMAP logs. You can see in the first
one a 2 minute time break and in the second about an 11 minute time break.
It looks like it has to do with the IMAP SEARCH command. Can you tell what
the client is trying to do looking at this?:

2009-11-03T15:00:23.815Z,,0000000000F7C2C1,17,10.1.15.25:993,71.184.193.240:64737,>,* 152537 EXISTS,
2009-11-03T15:00:23.815Z,,0000000000F7C2C1,18,10.1.15.25:993,71.184.193.240:64737,>,* 1 RECENT,
2009-11-03T15:00:23.815Z,,0000000000F7C2C1,19,10.1.15.25:993,71.184.193.240:64737,>,* FLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent),
2009-11-03T15:00:23.815Z,,0000000000F7C2C1,20,10.1.15.25:993,71.184.193.240:64737,>,*
OK [PERMANENTFLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent)]
Permanent flags,
2009-11-03T15:00:23.815Z,,0000000000F7C2C1,21,10.1.15.25:993,71.184.193.240:64737,>,* OK [UIDVALIDITY 26338] UIDVALIDITY value,
2009-11-03T15:00:23.815Z,,0000000000F7C2C1,22,10.1.15.25:993,71.184.193.240:64737,>,* OK [UIDNEXT 153834] The next unique identifier value,
2009-11-03T15:00:23.815Z,,0000000000F7C2C1,23,10.1.15.25:993,71.184.193.240:64737,>,6.226 OK [READ-WRITE] SELECT completed.,
2009-11-03T15:00:23.846Z,,0000000000F7C2C1,24,10.1.15.25:993,71.184.193.240:64737,<,7.226
UID SEARCH UID 1:* RECENT HEADER MESSAGE-ID
< XXXX@XXXXX.COM >,
2009-11-03T15:02:32.410Z,,000000000362D4A1,25,10.1.15.25:993,71.184.193.240:64656,>,* SEARCH 153830,
2009-11-03T15:02:32.410Z,,000000000362D4A1,26,10.1.15.25:993,71.184.193.240:64656,>,* 4 RECENT,
2009-11-03T15:02:32.410Z,,000000000362D4A1,27,10.1.15.25:993,71.184.193.240:64656,>,7.213 OK SEARCH completed.,

2009-11-03T15:04:58.901Z,,00000000027A7025,17,10.1.15.25:993,71.184.193.240:64757,>,* 152539 EXISTS,
2009-11-03T15:04:58.901Z,,00000000027A7025,18,10.1.15.25:993,71.184.193.240:64757,>,* 1 RECENT,
2009-11-03T15:04:58.901Z,,00000000027A7025,19,10.1.15.25:993,71.184.193.240:64757,>,* FLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent),
2009-11-03T15:04:58.901Z,,00000000027A7025,20,10.1.15.25:993,71.184.193.240:64757,>,*
OK [PERMANENTFLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent)]
Permanent flags,
2009-11-03T15:04:58.901Z,,00000000027A7025,21,10.1.15.25:993,71.184.193.240:64757,>,* OK [UIDVALIDITY 26338] UIDVALIDITY value,
2009-11-03T15:04:58.901Z,,00000000027A7025,22,10.1.15.25:993,71.184.193.240:64757,>,* OK [UIDNEXT 153836] The next unique identifier value,
2009-11-03T15:04:58.901Z,,00000000027A7025,23,10.1.15.25:993,71.184.193.240:64757,>,6.230 OK [READ-WRITE] SELECT completed.,
2009-11-03T15:04:58.933Z,,00000000027A7025,24,10.1.15.25:993,71.184.193.240:64757,<,7.230
UID SEARCH UID 1:* RECENT HEADER MESSAGE-ID
< XXXX@XXXXX.COM >,
2009-11-03T15:15:12.793Z,,0000000000A4BE50,25,10.1.15.25:993,71.184.193.240:64727,>,* SEARCH 153832,
2009-11-03T15:15:12.793Z,,0000000000A4BE50,26,10.1.15.25:993,71.184.193.240:64727,>,* 4 RECENT,
2009-11-03T15:15:12.793Z,,0000000000A4BE50,27,10.1.15.25:993,71.184.193.240:64727,>,7.224 OK SEARCH completed.,

Thanks,

Kurt



"Rich Matheisen [MVP]" wrote:

 
 
 

Mac IMAP client maxing out IMAP service

Post by Rich Mathe » Thu, 05 Nov 2009 12:47:00

On Tue, 3 Nov 2009 07:28:01 -0800, Kurt



It looks like it's searching for unique message numbers.

http://www.yqcomputer.com/ #page-49
---
Rich Matheisen
MCSE+I, Exchange MVP
 
 
 

Mac IMAP client maxing out IMAP service

Post by S3Vyd » Sat, 07 Nov 2009 04:43:01

Hi Rich,

Are you refering to message sequence numbers or to unique identifiers?

I have determined that each time the client does a search the CPU maxes out.
One item of note is that her Sent Items box has 163,000 messages in it.
Should the server CPU's be maxing out from this? It is a 4 CPU Nehalem
server. I am trying to determine if this is a bug similar to those mentioned
in previous Exchange rollups or if her foldrs and mailbox is just too big for
the server to handle.

Thanks,

Kurt
 
 
 

Mac IMAP client maxing out IMAP service

Post by Rich Mathe » Sat, 07 Nov 2009 12:21:26

On Thu, 5 Nov 2009 11:43:01 -0800, Kurt



Message sequence numbers. There were no other criteria in the search.


Are the CAS and MBX roles installed on the same machine?


The CAS is actually using RPC to get the information from the mailbox.
Having that many messages in a folder would lead me to believe that
the CAS and MBX roles are both contributing to the large CPU
consumption.

Is there a reason why there are that many messages in one folder?
---
Rich Matheisen
MCSE+I, Exchange MVP
 
 
 

Mac IMAP client maxing out IMAP service

Post by William Sm » Wed, 11 Nov 2009 13:49:15


[snip]


Did the user really send 163,000 messages herself!? Sounds like she's
using an automated process.

I'm certainly not an Exchange expert, but I would think 163,000 messages
in any single folder is enough to cause problems. With Microsoft
Entourage connected to an Exchange Server as an Exchange client, for
example, I recommend that messages be kept to a minimum in the Inbox and
other folders that get synchronized more frequently than the others. No
more than a few hundred.

My guess is that the user is simply opening the Sent Items folder and
triggering a sync verification of some sort. More messages would mean a
longer verification.

--

bill

Entourage Help Page < http://www.yqcomputer.com/ ;
Entourage Help Blog < http://www.yqcomputer.com/ ;
YouTalk < http://www.yqcomputer.com/ ;
Twitter: follow < http://www.yqcomputer.com/ ;
 
 
 

Mac IMAP client maxing out IMAP service

Post by Ed Crowley » Wed, 11 Nov 2009 17:16:15

That answer is expert enough. Keep each folder below something like 5,000
items. If one needs to keep 163,000 messages, divide them up among 50
folders.
--
Ed Crowley MVP
"There are seldom good technological solutions to behavi *** problems."
.

"William Smith [MVP]" < XXXX@XXXXX.COM > wrote in