อาจจะเกิดได้จากหลายสาเหตุ หรือถูกค่าจากอย่างอื่นมาแทนที่ค่าที่ตั้งไว้(Override)
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การตั้งค่ามีหลายวิธี Timeout/Sessiontimeout/Idle-timeout/executionTimeout
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1) App Pool Idle Time-out – In IIS
The Application Pool of your web app has an “Idle Time-out (in minutes)” setting in “Advanced Settings” (IIS7) The help text says: “Amount of time (in minutes ) a worker process will remain idle before it shuts down.”
2) Recycle Worker Process – in IIS
Not really a timeout but it will have that effect. The default is 29 hours, so you will rarely need to change it.
3) Session State – In web.config
<system.web>
<sessionState timeout="60" />
</system.web>
4) Forms Authentication Timeout – In web.config
<system.web>
<authentication mode="Forms">
<forms timeout="50"/>
</authentication>
</system.web>
5) Execution Timeout – in web.config and in code
<system.web>
<httpRuntime executionTimeout="180" />
</system.web>
The HttpServerUtility class has a property called ScriptTimeout .
Server.ScriptTimeout = 600; //in seconds