We are experiencing performance problems in our web server (IIS 7.0) during peak times. Microsoft states that IIS 5 and 6 will only use 50% of memory in order to leave memory for other applications and the OS. This made sense when you only had 4 gigs installed
on the machine but when you have 32 gigs or more it doesn't make sense. I have not found any documentation that says that this 50% limit still applies in IIS 7 but during peak periods our server (32 gigs of RAM) only uses 50% of the RAM so that limit does
seem to still exist. I'm guessing that I could improve IIS performance if I could get IIS to use more of the available RAM. Any idea how to do that? I've tried changing "memcachesize" registry value but it doesn't seem to have worked.
It is never a good idea to start claiming I need to use more memory. IIS has its own philosophy on memory usage, so its performance may downgrade swiftly with increasing memory usage (which can be inverse of your initial thought).
Please start from data collection/analysis to identify the performance bottleneck first.
Lex Li
http://lextm.com
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This posting is provided "AS IS" with no warranties, and confers no rights.
Lex, why do you feel compelled to answer questions you don't know the answer to? I don't want a lecture. I want an answer to a straightforward question I asked. If you don't know that answer them don't respond.
The comments Lex are valid. Often the applications are badly architected to request/require too much RAM. Having an understanding of the architecture of applications and where they fit into the web infrastructure is of great benefit.
Why do you need 32GB is the an important question here. Only very rare exceptions I can see why this is and often memory is high because it is just caching pointless information.
Also I am not sure it will improve performance anyway. ...
I would look at separate worker processes for your site though if you are using that much. - it is much more sensible way to architect your applications and you see in detail what is causing the high RAM and better plan and manage it.
It could be that you need more resiliency in your application.
I am not sure how you can do what you request or if it is possible but it it was I would not recommend it.
Telling you something like running the application pool in 64 bit, and then it can use as much memory as you wish is in most cases not a fix to your problems.
Like I wrote explicitly, the philosophy of IIS is to use reasonable memory so as to achieve better performance. You should follow this approach, instead of fighting against.
This is not a lecture, but to ask you to start from learning the bottleneck first. Learning that can help you ask right questions.
Lex Li
http://lextm.com
---------------------------
This posting is provided "AS IS" with no warranties, and confers no rights.
Does anyone have an answer to the question? It is a simple question. Is IIS 7 restricted to using 50% of RAM? I'm well aware of perfmon, application pools, and proper web architecture.
ferrethouse
13 Posts
How to get IIS to use more memory
Apr 28, 2012 06:09 PM|LINK
lextm
4503 Posts
Re: How to get IIS to use more memory
Apr 29, 2012 09:30 AM|LINK
It is never a good idea to start claiming I need to use more memory. IIS has its own philosophy on memory usage, so its performance may downgrade swiftly with increasing memory usage (which can be inverse of your initial thought).
Please start from data collection/analysis to identify the performance bottleneck first.
http://lextm.com
---------------------------
This posting is provided "AS IS" with no warranties, and confers no rights.
ferrethouse
13 Posts
Re: How to get IIS to use more memory
Apr 29, 2012 03:04 PM|LINK
Rovastar
3321 Posts
MVP
Moderator
Re: How to get IIS to use more memory
Apr 29, 2012 07:40 PM|LINK
Ferrethouse,
The comments Lex are valid. Often the applications are badly architected to request/require too much RAM. Having an understanding of the architecture of applications and where they fit into the web infrastructure is of great benefit.
Why do you need 32GB is the an important question here. Only very rare exceptions I can see why this is and often memory is high because it is just caching pointless information.
Also I am not sure it will improve performance anyway. ...
I would look at separate worker processes for your site though if you are using that much. - it is much more sensible way to architect your applications and you see in detail what is causing the high RAM and better plan and manage it.
It could be that you need more resiliency in your application.
I am not sure how you can do what you request or if it is possible but it it was I would not recommend it.
lextm
4503 Posts
Re: How to get IIS to use more memory
Apr 30, 2012 02:24 AM|LINK
Telling you something like running the application pool in 64 bit, and then it can use as much memory as you wish is in most cases not a fix to your problems.
Like I wrote explicitly, the philosophy of IIS is to use reasonable memory so as to achieve better performance. You should follow this approach, instead of fighting against.
This is not a lecture, but to ask you to start from learning the bottleneck first. Learning that can help you ask right questions.
http://lextm.com
---------------------------
This posting is provided "AS IS" with no warranties, and confers no rights.
ferrethouse
13 Posts
Re: How to get IIS to use more memory
May 01, 2012 01:04 AM|LINK
Patrick1972
257 Posts
Re: How to get IIS to use more memory
May 02, 2012 12:19 PM|LINK
Ferrethouse,
Sorry to say but you do overtrow Lex his advice to quickly.
As to my knowledge IIS7 does not handle 50% max. memory. Especially not where app.pools are running 64bit.
As to your bottleneck i believe you have a slow disk/ Raid controller with to small cache problem.
Here is a good guide to start looking for the bottleneck.
http://www.ckode.dk/server-configuration/tuning-iis-7-for-static-content/