IIS 7 – worker processes more than one

application-poolsiisiis-7worker-process

if i set worker process as 1, my application pool hangs.
if i set it at least 6, everything works fine.

but every article i read says "don't set it more than 1"

so, in this practice, am i wrong? or who is wrong?

of course i would like to use less memory, cpu.
and another reason i hate about more worker process is sessions.
it is really annoying me.

the site that runs under the app pool has more than 20.000 online visitors
i tried to debug dump files but found nothing interesting

please give me some advice.
thank you.

Best Answer

Chances are, the low-N number is hanging due to a race condition in your code somewhere.

With MaxProcesses=6, you're reducing the level of in-process concurrency, by sending fewer requests to more worker processes.

To debug the original cause:

Configure for 1 worker process
Wait for a hang - you might want to enable OrphanWorkerProcess for the App Pool in order to leave the hung w3wp in memory after it gets recycled
- it presumably does get recycled when it hangs, right? Fails a ping, marked unresponsive, events in the Application and System event logs?
Grab a memory dump of the process while it's in the hung state
Feed that dump into DebugDiag 1.2 and see what it suggests

How did you get the memory dump? (as a rule, you must use a debugger of the same bitness as the worker process to get useful information from it).

Checking your connection strings in web.config

By default, the max pool size for connection strings in a web.config file is 100, so try specifying something higher, like "Max Pool Size=200; Min Pool Size=10; Connect Timeout=45;".

Example:

<add name="SiteSqlServer" connectionString="Server=mydomain.com;Initial Catalog=myDB;User ID=DB;Password=myDB;Max Pool Size=100;Min Pool Size=10;Connect Timeout=45;" providerName="System.Data.SqlClient" />

Checking your settings in Aspnet.config

Location: C:\Windows\Microsoft.NET\Framework\v2.0.50727 and C:\Windows\Microsoft.NET\Framework64\v2.0.50727

Example:

<system.web>
    <applicationPool maxConcurrentRequestsPerCPU="5000" <!-- Default is 12 -->
             maxConcurrentThreadsPerCPU="0" <!-- Default is 0 -->
             requestQueueLimit="5000" <!-- Default is 5000 -->/>
</system.web>

Checking your settings in machine.config

Location: C:\Windows\Microsoft.NET\Framework\v2.0.50727\CONFIG and C:\Windows\Microsoft.NET\Framework64\v2.0.50727\CONFIG

processModel

Example:

<processModel 
   enable="true"
   requestQueueLimit="5000" <!-- Adjust if necessary. Default 5000 -->
   restartQueueLimit="10"  <!-- Adjust if necessary. Default 10 -->
   memoryLimit="60" <!-- Adjust if necessary. Lower for memory leaks. -->
   maxWorkerThreads="100" <!-- Default 20 -->
   maxIoThreads="100" <!-- Default 20 -->
   minWorkerThreads="40" <!-- Default 1 -->
   minIoThreads="30" <!-- Default 1 -->
/>

connectionManagement

Example:

<system.net>
  <connectionManagement>
    <add address="*" maxconnection="100" <!-- Default is 2 --> />
  </connectionManagement>
</system.net>

Best Answer

Related Solutions

IIS, Application Pools and Event Logs

Iis7 large worker process request queue creating process blocking aspnet.config & machine.config amended (bottleneck)

Checking your connection strings in web.config

Checking your settings in Aspnet.config

Checking your settings in machine.config

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