topic Re: Server unavailable error in ArcGIS API for Silverlight Questions

Server unavailable error

DonFreeman — Wed, 16 Mar 2011 16:05:18 GMT

Occassionally when first loading my map I will get a Server Unavailable error. This happens even though the server IS available and after restarting the application it will load fine. I assume this is caused by some kind of timeout setting and the server just isn't responding fast enough. Can someone confirm this and suggest how to fix?
Thanks

Re: Server unavailable error

JenniferNery — Wed, 16 Mar 2011 17:38:13 GMT

I'm not sure if this blog post will help but you can have a look at it anyway: http://blogs.esri.com/Dev/blogs/arcgisserver/archive/2008/08/12/The-REST-API-cache.aspx

You may also want to post in the ArcGIS Server forum. This seems to be related thread: http://forums.arcgis.com/threads/18470-Sleeping-Map-service-issue-with-ArcGIS-10

Re: Server unavailable error

DarinaTchountcheva — Wed, 16 Mar 2011 20:11:16 GMT

Hi Don,

Sleepy services have been around for a while. 😉

I have used the VBA script to wake up the services (9.3 and 9.3.1). It is running every 15 minutes (services are idle in 20 minutes in my case). This has bee working pretty well for me.

Here is the script:

http://forums.esri.com/Thread.asp?c=158&f=2276&t=228654&mc=160#812067

I have recently installed ArcGIS Server 10 on Windows Server 2008, and Map Services don't crash the firts time they are accessed, but there is a pretty good delay.

I decided to experiment and use a different approach (not sure where I got the idea from): instead of using a script to ping the services and keep them alive, I have set the Idle Timeout property of the ArcGISServicesAppPool to 240 (4 hours), instead 20 minutes. You can use your own timeout depending how often the services are used. The ArcGISServicesAppPool is the Application Pool that is used to run the /ArcGIS/KML, ArcGIS/rest, ArcGIS/Services... apps.

This seems to be working. I no longer have delays when a service has not been used for 20 minutes.

Here is the link how to set the timeout:

http://technet.microsoft.com/en-us/library/cc771956(WS.10).aspx - IIS 7

http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/83b35271-c93c-49f4-b923-7fdca6fae1cf.mspx?mfr=true - IIS 6

It has a gottcha though: by keeping the worker processes alive you are not releasing server resources. I would say, try it, see if it works for you, and if it works, evaluate how this will affect the server, and if you can afford it.

Good Luck! 🙂