High CPU usage on SiteFinity on version 4.3

Hello,

We are having very high CPU and RAM usage on our website we just deployed on production, to a point where the site goes to a stand-still.

All pages are cached, except one page, as there's user profile on this page.
Web.config has been change to debug=false.

There are only 2 custom usercontrols we've done, and those have been cached as well.

Any idea what can be done ?

Hello Zyad,

Unfortunately there are multiple issues that might cause a high CPU usage. Is by any chance your SQL server on the same machine as the web server? What is the RAM load that you experience?

Dear Zyad

Some things that pop into my mind

a) are you using your own .master pages
b) are we talking about a mutlilingual page (front)
c) have you installed mulitple languages (back)

I had spike going very high once http://www.sitefinity.com/devnet/forums/sitefinity-4-x/bugs-issues/memory-license-issue.aspx

I guess the best thing would be to update to 4.4 or wait three weeks for 5.0 and udate it to 5.0 usually updating helps since they have bug fixes in every release and since Telerik does only support two versions back an update to 4.4 would  help you update to 5.1 later.

Markus

I had/have the same issue on a 4.3 install.  I have been told by Telerik that a upgrade to 4.4 should fix my issue, however I am waiting for 5.0 to upgrade.

I have been playing around in my dev sandbox and have noticed a couple of other things that my be causing my problem as well if you are using LDAP for roles or users.  We have a really large (120,000+ entries) Active Directory and because of the way it is structured I have to use a OU very close to the top of the hierarchy.  When I go to users under my normal configuration, I will never see them listed.  It seems that it is simply too much data and it never populates.  I noticed my website would hang with a spike in CPU usually when someone was attempting to make and edit.  If no one was editing everything was fine.  I also noticed that I had never made an edit that caused the spike, even though I was making 85% of the changes.  My account is using LDAP, but I am checked as an administrator in the Sitefinity backend.  Everyone elses permissions would be managed by a role they belong to in AD.

I have narrowed down my sandbox environment to a OU with aprox 10,000 users and it seems to be much more responsive and will actually return the users in a list within 15 or so seconds. 

Additionally, someone was working in our server room and accidentally unplugged the LDAP server I was connecting to.  I happen to be making edits to the website at this time and I experienced the exact same issue with the CPU spiking to 80+ percent and the site becoming non-responsive.

I have not checked with Sitefinity on this, but is it possible that a connection from Sitefinity to the LDAP server could take to long and be aborted causing a process to not complete and hang the server CPU up?  Is a check made to LDAP every step through the editing process, (when user sees page list, upon clicking page and loading controls, upon saving as draft, publishing, returning to the page listing) or is it done once upon login and stored somehow?  If the former, I could see how this may be part of our problem. 

Sorry for the muggled, confusing explanation.  A chime in from Telerik would be good.

Anthony

Hi,Anthony
I want to explain a little bit how the LDAP authentication works. We connect to the LDAP server only during the user login to check the password. Once the user is authenticated successfully the user id and the user roles are kept in an encrypted cookie, so we don't call the LDAP server anymore (unless the user session expires and she needs to login again). The LDAP performance is slow mainly when an administrator browses the Users and Roles screens where we call the LDAP server to return the user entries. One additional performance hit can be if you use roles coming from the LDAP server - cause when a user logs in, we check all the registered Role providers for roles assigned to this user. You can disable the LDAP roles provider if you use LDAP just for the Users and assign to them only Sitefinity roles like(Administrator,Editor,Designer etc).
Again the LDAP roles provider concerns only the initial login performance. During the normal operation of the user(browsing ,editing etc.) we don't call the LDAP cause the roles are cached in the encrypted cookie.

Greetings,
Nikolay Datchev
the Telerik team

Hello Zyad,
I think that considering the multiple possible reasons for the performance problem, it would be best if you provide us with your project + database and instructions which page causes the biggest performance issue.
Some important questions also:
- what approximate amount of simultaneous users/request do you have when the site hangs.
- are your users mostly front-end or back-end users
- do you serve big media files coming from libraries(videos, documents, large images)
- do you use security for page widgets. If some widget in a page is secured with permissions -this invalidates the output cache.
- can you check your windows application/system  log - for app pool recycle event. Site hanging is often caused by the fact that your application pool is configured to recycle when a certain memory limit is reached and if the site is recycling very often - it will look like it is hanging, since sitefinity start up is not very fast and during start up all requests wait.
- Check also that other app pool recycle constraints are not taking effect - processor usage, errors, number of requests, pings etc,.

All the best,
Nikolay Datchev
the Telerik team