 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
.NET Forum / ASP.NET / General / May 2008Cache.EffectivePrivateBytesLimit shrinks as box gets bigger?
Hi... We've been trying to migrate our asp.net apps off older, underpowered hardware to newer, bigger boxes but when we do, we see our databases start to melt. When I started to look into it, I found that the older boxes all had bigger EffectivePrivateBytesLimit values than the newer boxes, which seems very counter-intuitive to me. And it seemed to me that a much smaller Cache would be pushing more requests back to the databases. The old boxes have 2gb physical ram and 3gb pagefile space set aside. The newer boxes start at 3gb physical ram and 4gb pagefile space and go up from there. We're not setting any of the machine.config values or IIS Admin settings that would curb the cache size on any of the boxes. And we have only one worker process on all of them. All boxes are running Windows 2003 SP2 and ASP.Net 2.0. On the smaller boxes, EffectivePrivateBytesLimit = ~60% of physical ram (1.2gb). On the bigger boxes, EffectivePrivateBytesLimit = 800mb. I found this thread: http://forums.asp.net/p/962451/1199949.aspx Neither of the msdn articles mentioned in it are at those locations anymore, but the rules of thumb in the response indicate that the bigger boxes *think* they have <= 2gb of page file. Is there some kind of overflow/signed condition in Windows 2003 or ASP.Net 2.0 where adding too much gig and/or page file ends up having a negative effect because the system can't tell? Thanks Mark Hi Mark, As for the EffectivePrivateBytes property, it does be a value indicate the virtual memory available for cache useage. And this is determined by several things: ** the ASP.NET process's memory limit(for IIS6 win2k3, it is set via IIS application pool's memory limit) ** the privateBytesLimit attribute of <cache> element in ASP.NET web.config If none of the above is set, runtime will automaticalaly calculate one for you. However, the calculation algorithym is internal implemented and may vary from server's hardware condition. Here is a good blog article written by an senior developer which introducing some history about ASP.NET cache and its memory limit configuration: #Some history on the ASP.NET cache memory limits http://blogs.msdn.com/tmarq/archive/2007/06/25/some-history-on-the-asp-net-c ache-memory-limits.aspx Sincerely, Steven Cheng Microsoft MSDN Online Support Lead Delighting our customers is our #1 priority. We welcome your comments and suggestions about how we can improve the support we provide to you. Please feel free to let my manager know what you think of the level of service provided. You can send feedback directly to my manager at: msdnmg@microsoft.com. ================================================== Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif ications. Note: The MSDN Managed Newsgroup support offering is for non-urgent issues where an initial response from the community or a Microsoft Support Engineer within 1 business day is acceptable. Please note that each follow up response may take approximately 2 business days as the support professional working with you may need further investigation to reach the most efficient resolution. The offering is not appropriate for situations that require urgent, real-time or phone-based interactions or complex project analysis and dump analysis issues. Issues of this nature are best handled working with a dedicated Microsoft Support Engineer by contacting Microsoft Customer Support Services (CSS) at http://msdn.microsoft.com/subscriptions/support/default.aspx. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. -------------------- >From: =?Utf-8?B?TWFyaw==?= <mmodrall@nospam.nospam> >Subject: Cache.EffectivePrivateBytesLimit shrinks as box gets bigger? >Date: Tue, 29 Apr 2008 12:47:02 -0700 >Hi... > [quoted text clipped - 31 lines] >Thanks >Mark Hi Steven... Thanks for the link; it had all the same information that was in the other link I posted originally. The problem is that those forumulas don't seem to be working in our case. As I said, we haven't set any of the configuration parameters to directly control the cache size and the machine with 2gb of physical ram/3gb page file is getting more cache space while the machines starting at 3gb phys/4gb page file are getting a much lower cap. The fact that the newer, bigger machines are getting EffectivePrivateBytesLimit coming out at *exactly* 800mb implies that the MIN() formula was inappropriately applied in their case, hence my question about the calculation having some overflow boundary where too much space gets interpreted as too little. They have at least 4gb of pagefile, which should have applied the formula MIN(60% phys ram, 1800mb). Instead it applied the smaller case MIN(60% phys ram, 800mb). The smaller machine EffectivePrivateBytesLimit comes out at 60% of physical ram (1.2gb of 2) which implies that it recognized the pagefile as > 2gb, according to the formulas. Thanks Mark > Hi Mark, > [quoted text clipped - 96 lines] > >Thanks > >Mark Thanks for your reply Mark, Yes, as you didn't explicitly set those memory limit value, then the runtime will help caclulated one for you. So far I haven't any information about how to number is calculated, per the document it will rely on hardware condition also. BTW, on the server machine that has more physical memory, are there also many other applications running on it? Maybe some other applications occupy some certain memory or may cause more memory fragment than the smaller box. Sincerely, Steven Cheng Microsoft MSDN Online Support Lead Delighting our customers is our #1 priority. We welcome your comments and suggestions about how we can improve the support we provide to you. Please feel free to let my manager know what you think of the level of service provided. You can send feedback directly to my manager at: msdnmg@microsoft.com. ================================================== Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif ications. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. -------------------- >From: =?Utf-8?B?TWFyaw==?= <mmodrall@nospam.nospam> >References: <3BBAF825-4927-47A5-9D69-AE7F22E7B80C@microsoft.com> <hvPmb6mqIHA.6028@TK2MSFTNGHUB02.phx.gbl> >Subject: RE: Cache.EffectivePrivateBytesLimit shrinks as box gets bigger? >Date: Wed, 30 Apr 2008 07:13:00 -0700 >Hi Steven... > [quoted text clipped - 42 lines] >> >> #Some history on the ASP.NET cache memory limits http://blogs.msdn.com/tmarq/archive/2007/06/25/some-history-on-the-asp-net-c >> ache-memory-limits.aspx >> [quoted text clipped - 12 lines] >> ================================================== >> Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif >> ications. >> [quoted text clipped - 58 lines] >> >Thanks >> >Mark Hi Steven... Both of the links mentioned in this thread did lay out some rules used to calculate the memory limit when none of the parameters are explicitly set. My question comes from the fact that these rules don't seem to be followed on the machines where I noticed this. The bigger boxes are only for running the web server and at the time all have 95% of their physical ram unused. Since the rules mention that the calculation thresholds are based on the page file size, I have tried playing with that on the bigger boxes but it didn't seem to help. The rules in the articles said that the calculation was MIN(60% phys ram, 800MB) when the page file was <= 2gb MIN(60% phys ram, 1800MB) when the page file was > 2gb. The smaller box has the page file set a hair under 3gb. The bigger boxes had it at > 4gb. To see if there was an overflow condition, I lowered the big boxes to about 3gb page file but the EffectivePrivateBytesLimit didn't change. The only other variables I can think of is that the older box is running 2003 Web Edition and is old enough to have all that "hyperthreading" garbage. I think it only has one real cpu but it's counting the fpu etc when task manager says it has several cpus. The newer boxes are running 2003 R2 standard edition and have dual dual or quad dual cores. Maybe the EffectivePrivateBytesLimit also has a limiting factor based on number of actual cpus? Or maybe R2 does things differently than the old Web Edition? Thanks Mark > Thanks for your reply Mark, > [quoted text clipped - 188 lines] > >> >Thanks > >> >Mark Thanks for your reply Mark, I'll do some further research on this and update you as soon as possible. Sincerely, Steven Cheng Microsoft MSDN Online Support Lead Delighting our customers is our #1 priority. We welcome your comments and suggestions about how we can improve the support we provide to you. Please feel free to let my manager know what you think of the level of service provided. You can send feedback directly to my manager at: msdnmg@microsoft.com. ================================================== Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif ications. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. -------------------- >From: =?Utf-8?B?TWFyaw==?= <mmodrall@nospam.nospam> >References: <3BBAF825-4927-47A5-9D69-AE7F22E7B80C@microsoft.com> <hvPmb6mqIHA.6028@TK2MSFTNGHUB02.phx.gbl> <39CCBBC6-2B4C-4149-A9C5-F05CC24013C2@microsoft.com> <trzgmCCrIHA.1788@TK2MSFTNGHUB02.phx.gbl> >Subject: RE: Cache.EffectivePrivateBytesLimit shrinks as box gets bigger? >Date: Fri, 2 May 2008 06:57:03 -0700 >Hi Steven... > [quoted text clipped - 28 lines] >>> >> >> >> Micro Hi Mark, Here is some further comments from the blog entry's engineer: ======================== The cache privateBytesLimit has nothing to do with the pagefile. By default it is bounded above by 800MB on x86, unless you're using /3GB, in which case it is bounded above by 1800MB. ======================== Sincerely, Steven Cheng Microsoft MSDN Online Support Lead Delighting our customers is our #1 priority. We welcome your comments and suggestions about how we can improve the support we provide to you. Please feel free to let my manager know what you think of the level of service provided. You can send feedback directly to my manager at: msdnmg@microsoft.com. ================================================== Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif ications. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. -------------------- >Content-Transfer-Encoding: 7bit >From: stcheng@online.microsoft.com (Steven Cheng [MSFT]) >Organization: Microsoft >Date: Tue, 06 May 2008 08:53:24 GMT >Subject: RE: Cache.EffectivePrivateBytesLimit shrinks as box gets bigger? >Thanks for your reply Mark, > [quoted text clipped - 66 lines] >>>> >> >>> >> Micro Hi Steven... Thank you for asking, but that's exactly the problem I'm asking about. *IT'S NOT WORKING THAT WAY!* Our smaller x86 with 2gb of ram is showing a EffectivePrivateBytesLimit of 1.2gb (60% ram) while our newer x86 boxes with 3+gb are showing it capped at 800mb. Thanks Mark > Hi Mark, > [quoted text clipped - 109 lines] > >>>> >> > >>> >> Micro Hi Mark, Thanks for your reply. The dev engineer also think the behavior is not expected according to the calculation formula. Also, due to the support limitation, it's abit hard for me to continue involve them directly into newsgroup issue. Since the problem is environmenet specific which may require further troubleshooting on the target server, I would suggest you consider contacting CSS for incident based support which can help perform some more thorough and detailed troubleshooting: Microsoft Customer Support Services (CSS) at ttp://msdn.microsoft.com/subscriptions/support/default.aspx Sincerely, Steven Cheng Microsoft MSDN Online Support Lead Delighting our customers is our #1 priority. We welcome your comments and suggestions about how we can improve the support we provide to you. Please feel free to let my manager know what you think of the level of service provided. You can send feedback directly to my manager at: msdnmg@microsoft.com. ================================================== Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif ications. This posting is provided "AS IS" with no warranties, and confers no rights. -------------------- >From: =?Utf-8?B?TWFyaw==?= <mmodrall@nospam.nospam> >References: <3BBAF825-4927-47A5-9D69-AE7F22E7B80C@microsoft.com> <hvPmb6mqIHA.6028@TK2MSFTNGHUB02.phx.gbl> <39CCBBC6-2B4C-4149-A9C5-F05CC24013C2@microsoft.com> <trzgmCCrIHA.1788@TK2MSFTNGHUB02.phx.gbl> <978E9049-80FD-4D37-948F-CBCDE64E77A8@microsoft.com> <0DYEra1rIHA.1784@TK2MSFTNGHUB02.phx.gbl> <6kxwAPBtIHA.5848@TK2MSFTNGHUB02.phx.gbl> >Subject: RE: Cache.EffectivePrivateBytesLimit shrinks as box gets bigger? >Date: Mon, 12 May 2008 07:31:03 -0700 >Hi Steven... > [quoted text clipped - 32 lines] >> ================================================== >> Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif Hi Steven... Thank you for responding. You are right; this is a very environment-specific issue, not a general coding question. I'll check with my management if we want to open a case for this. Thanks Mark Thanks for your understanding Mark. If you got any new results later, also welcome to share us here. Sincerely, Steven Cheng Microsoft MSDN Online Support Lead Delighting our customers is our #1 priority. We welcome your comments and suggestions about how we can improve the support we provide to you. Please feel free to let my manager know what you think of the level of service provided. You can send feedback directly to my manager at: msdnmg@microsoft.com. -------------------- >From: =?Utf-8?B?TWFyaw==?= <mmodrall@nospam.nospam> >References: <3BBAF825-4927-47A5-9D69-AE7F22E7B80C@microsoft.com> <hvPmb6mqIHA.6028@TK2MSFTNGHUB02.phx.gbl> <39CCBBC6-2B4C-4149-A9C5-F05CC24013C2@microsoft.com> <trzgmCCrIHA.1788@TK2MSFTNGHUB02.phx.gbl> <978E9049-80FD-4D37-948F-CBCDE64E77A8@microsoft.com> <0DYEra1rIHA.1784@TK2MSFTNGHUB02.phx.gbl> <6kxwAPBtIHA.5848@TK2MSFTNGHUB02.phx.gbl> <F05628F1-5783-4787-B7AB-9DCBCDDF40DA@microsoft.com> <F$xdrTZtIHA.4284@TK2MSFTNGHUB02.phx.gbl> >Subject: RE: Cache.EffectivePrivateBytesLimit shrinks as box gets bigger? >Date: Wed, 14 May 2008 09:11:08 -0700 >Hi Steven... > [quoted text clipped - 4 lines] >Thanks >Mark Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.