3,000 users going across a slow WAN link for Exchange is a pretty poor design decision so hopefully that's not realistic.
My note was more about the server (specifically I/O) than network. If 3,000 users all come after the same data in a short time window it's going to be in the cache which means it's served out of memory (not disk). RAM is way faster than disk. Thanks, Brian Desmond br...@briandesmond.com c - 312.731.3132 From: Alverson, Tom (Xetron) [mailto:tom.alver...@ngc.com] Sent: Thursday, May 28, 2009 4:36 PM To: NT System Admin Issues Cc: Brian Desmond Subject: RE: Amusing Cached mode actually makes the problem worse. Much worse. Once the message is sent, every single client that is running will see the new email within about 30 seconds and they will all download a separate copy of it to store in their local caches. If the Exchange server is on a WAN link, that link will become unusable while the download is happening, which could take a long time for 9MB times 3000 users. Anyone else trying to use the WAN bandwidth will only get 1/3000 of the speed of the WAN, and the lag will go through the roof. If you turn off cached mode, then at least people will read it at different times and spread out the load. The only way around the problem is to not send large emails to lots of people, or disable cached mode (and then get complaints about slowness) or never have the Exchange server in a location separated by a WAN link from the users. Tom From: Brian Desmond [mailto:br...@briandesmond.com] Sent: Thursday, May 28, 2009 2:51 PM To: NT System Admin Issues Subject: RE: Amusing Almost. SIS is per database. So if you had those 3,000 users in one mailbox store then it's roughly only 9MB stored, however if you had them say in 3 mailbox databases, then it's roughly 27MB and so forth. Note that SIS is gone in Exchange Server 2010. Also take into account cached mode which is Outlook 2003 and newer behavior (unless you turn it off) which would mitigate your scenario of 450 users opening the attachment. Even then so, it shouldn't take down a server. Thanks, Brian Desmond br...@briandesmond.com c - 312.731.3132 Active Directory, 4th Ed - http://www.briandesmond.com/ad4/ Microsoft MVP - https://mvp.support.microsoft.com/profile/Brian From: David Lum [mailto:david....@nwea.org] Sent: Thursday, May 28, 2009 1:37 PM To: NT System Admin Issues Subject: RE: Amusing SIS means that while he sent that 9MB file to 3000 users, if all 3000 are on the same Exchange server then there's only 9MB stored....now, if say, 450 of them decide to open the file or download the file to their desktop around the same time, you might have an issue.... David Lum // SYSTEMS ENGINEER NORTHWEST EVALUATION ASSOCIATION (Desk) 971.222.1025 // (Cell) 503.267.9764 From: Owens, Michael [mailto:michael.ow...@dys.ohio.gov] Sent: Thursday, May 28, 2009 11:24 AM To: NT System Admin Issues Subject: RE: Amusing Yeah. :) ________________________________ From: Sean Martin [mailto:seanmarti...@gmail.com] Sent: Thursday, May 28, 2009 2:21 PM To: NT System Admin Issues Subject: Re: Amusing So I take it you weren't brought on as an Exchange Consultant....just happen to be there during this particular incident? - Sean On Thu, May 28, 2009 at 10:01 AM, Owens, Michael <michael.ow...@dys.ohio.gov<mailto:michael.ow...@dys.ohio.gov>> wrote: I really wish I knew more about exchange, I am a citrix admin through and through.... I used exchange once! :) ________________________________ From: Brian Desmond [mailto:br...@briandesmond.com<mailto:br...@briandesmond.com>] Sent: Thursday, May 28, 2009 1:54 PM To: NT System Admin Issues Subject: RE: Amusing That shouldn't have happened ... You have bigger problems than a single attachment. Thanks, Brian Desmond br...@briandesmond.com<mailto:br...@briandesmond.com> c - 312.731.3132 Active Directory, 4th Ed - http://www.briandesmond.com/ad4/ Microsoft MVP - https://mvp.support.microsoft.com/profile/Brian From: Owens, Michael [mailto:michael.ow...@dys.ohio.gov<mailto:michael.ow...@dys.ohio.gov>] Sent: Thursday, May 28, 2009 12:34 PM To: NT System Admin Issues Subject: RE: Amusing Haha, they dont have it set up here, I am a consultant just brought on... and the exchange server was slowed to a halt... ________________________________ From: Sam Cayze [mailto:sam.ca...@rollouts.com<mailto:sam.ca...@rollouts.com>] Sent: Thursday, May 28, 2009 1:24 PM To: NT System Admin Issues Subject: RE: Amusing Probably a vid that was already on YouTube! Thank god for Single Instance Storage ________________________________ From: Owens, Michael [mailto:michael.ow...@dys.ohio.gov<mailto:michael.ow...@dys.ohio.gov>] Sent: Thursday, May 28, 2009 12:20 PM To: NT System Admin Issues Subject: Amusing Amusing user dunce moment: We just had a user (one of the higher ups, obviously since not everyone has access to do this) send a 9 meg file to all users. (3000) Hilarity ensues. ________________________________ This message, and any response to it, may constitute a public record and thus may be publicly available to anyone who requests it in accordance with Chapter 149 of the Ohio Revised Code. ________________________________ This message, and any response to it, may constitute a public record and thus may be publicly available to anyone who requests it in accordance with Chapter 149 of the Ohio Revised Code. ________________________________ This message, and any response to it, may constitute a public record and thus may be publicly available to anyone who requests it in accordance with Chapter 149 of the Ohio Revised Code. ________________________________ This message, and any response to it, may constitute a public record and thus may be publicly available to anyone who requests it in accordance with Chapter 149 of the Ohio Revised Code. ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
