jStudios

Max Number of Concurrent ASP Connections on IIS7

Tue, 29 Mar 2011 17:28:00 -0600

A little while back, November 2009, we were moving to another data center for our production servers and during the process we were upgrading from IIS6 on Windows Server 2003 to IIS7 on Widows Server 2008. Our QA department had been testing the new servers for about a month and they kept reporting timeout. Our planned switch to the new data center was only a couple of weeks away and we had no idea what the issue was.

I’m not sure how it came to be but we still were given the green light for this new environment. Since this was a pretty big environment change and there was new code being released at the same time we pushed for this to be an in office release night (meaning all hands involved from development to product to infrastructure had to be in the office for the release). The night of the release while we were waiting on the DNS update I was still searching for an answer to our timeout issue when another engineer said that he was noticing it only on the ASP portions of the site.

With this realization I was able to narrow my Google searches down and to learn more about how ASP is treated with IIS 7. As it turns out, in IIS 7 ASP threads are limited by default as the expectation is that your site by now should be running VB or C#. The limit is set to 12 concurrent threads per processor. On our site this was extremely limiting. So I continued to search for a way to modify this limitation and here is what I had to change.

In the registry I had to add this key.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ASP.NET\2.0.50727.0]

"MaxConcurrentRequestsPerCPU"=dword:00000064In the ASPNet.config (C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet.config) I had to add a system.web section.

<system.web>
   <applicationPool maxConcurrentRequestsPerCPU="100" maxConcurrentThreadsPerCPU="0" requestQueueLimit="5000"/>
</system.web>

The aspnet.config looked like this after I added the system.web section:

<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
    <runtime>
        <legacyUnhandledExceptionPolicy enabled="false" />
        <legacyImpersonationPolicy enabled="true"/>
        <alwaysFlowImpersonationPolicy enabled="false"/>
        <SymbolReadingPolicy enabled="1" />
    </runtime>
    <system.web>
        <applicationPool maxConcurrentRequestsPerCPU="100" maxConcurrentThreadsPerCPU="0" requestQueueLimit="5000"/>
    </system.web>
</configuration>

With these two changes our site was running smoothly and the switch over was pretty flawless. If you’d like a more detailed explanation of the problem and resolution you can checkout these links below as these are the ones that helped me come to this fix.

http://blogs.msdn.com/tmarq/archive/2007/07/21/asp-net-thread-usage-on-iis-7-0-and-6-0.aspx
http://blogs.iis.net/webtopics/archive/2009/02/13/asp-net-hang-in-iis-7-0.aspx
http://support.microsoft.com/kb/312941

I Expanded the Disk in Disk Manager but It Doesn't Show in Windows Explorer

Fri, 02 Jul 2010 19:55:00 -0600

Over the past few months I’ve been running out of space on a SAN drive in both the production and DR sites running Windows Server 2008. (That’s one of those expensive growing pains). We put in a request to have a LUN expanded then waited. When we were given word that the LUN had been expanded I went into Disk Manager and rescanned the drives. Disk Manager saw the expanded portion of the disk. Now I needed to expand the partition. So I right clicked the drive and chose Extend Volume.

(note: this screen shot for security purposes is not the actual server involved)

Now I had to sit and wait while Windows did its thing. When it was finished Disk Manager showed a much larger disk. J

I exited out of Disk Manager and opened My Computer only to find that Windows Explorer was not reporting new size of the disk. After a little more searching, via Google, I came across this Microsoft article which in the More Information section talks about an undocumented command for Disk Part.

At a command prompt you need to enter the following:

C:\ > DISKPART
DISKPART> List Volume
DISKPART> select volume # (this is the number of the volume listed by the above ‘List Volume’ command)
DISKPART> extend filesystem
DISKPART> exit

Now Windows Explorer shows the new expanded size of the disk.

Windows Server 2008 and Hibernate Option

Thu, 01 Jul 2010 23:03:00 -0600

By default hibernation is not available in Windows Server 2008 and for good reason. Why would you want your server go into hibernation? Well there are exceptions when you might want to use hibernation, I just can’t think of any that would involve production servers though.

In my case one of those exceptions happens to be that I use Windows Server 2008 on my laptop as the primary OS. Mostly because I like to have an additional machine to test things on before I test them on our other environments; and a few of our developers work on Server installations for their local development environments, so having the ability to reproduce issues on a like environment without touching a server is a plus. Now that you know why I have Server as my primary OS I’ll explain why I want to be able to hibernate. It’s pretty simple booting and shutting down the laptop takes way too much time with a Server OS. I’d rather reboot once during the week and hibernate the machine the rest of the time.

So now how to enable the hibernate option in the power management settings. It’s just one line that has to be entered at the command prompt and Microsoft has documented it.

powercfg.exe /hibernate on

It’s that simple. Now you can set your machine to go into hibernation.