topic Re: Print Task and Proxy page in ArcGIS JavaScript Maps SDK Questions

Print Task and Proxy page

BryanLynn — Tue, 04 Feb 2014 15:22:59 GMT

I seem to have the opposite problem from most posts that I have seen on this issue. If I use a proxy page with my PrintTask - it fails. If I set "alwaysUseProxy" to false - it works as expected. When I execute the task with the proxy page, it throws a 500 error immediately. The PrintTask will eventually return a timeout error to the client. Proxy page works fine with all the map services.

Any thoughts?

Thanks,
Bryan

Re: Print Task and Proxy page

JohnGravois — Tue, 04 Feb 2014 16:53:34 GMT

this is just a guess, but i've seen proxy pages that threw up when they encountered spaces in the url of the resource they are attempting to forward. this is relevant because the out of the box print task includes the operation name 'Export Web Map Task'.

what happens when you try and ping the url below directly in the browser?
http://localhost/yourproxy.ashx?http://sampleserver6.arcgisonline.com/arcgis/rest/services/Utilities/PrintingTools/GPServer/Export%20Web%20Map%20Task

Re: Print Task and Proxy page

BryanLynn — Tue, 04 Feb 2014 18:11:19 GMT

OK, that makes sense but now I am a little confused.

The following link to your site brings back the REST API page:
http://test2.kgis.org/proxy/proxy.ashx?http://sampleserver6.arcgisonline.com/arcgis/rest/services/Utilities/PrintingTools/GPServer/Export%20Web%20Map%20Task

The following link to our site brings backa 500 ProtocolError and the body of the page simply says "System.Net.HttpWebResponse"
http://test2.kgis.org/proxy/proxy.ashx?http://test2.kgis.org/arcgis/rest/services/PrintingTools/PrintTask2/GPServer/Export%20Web%20Map

In my mind, if the problem is with the proxy page, shouldn't it have returned the error for both links? By no means do I think our proxy page is error free, it just seems odd to me.

Thanks,
Bryan

Re: Print Task and Proxy page

JohnGravois — Tue, 04 Feb 2014 18:17:16 GMT

sounds like the space itself isn't a problem, but for some reason some (or all?) requests to internal resources fail. does that sound like an accurate assessment?

if so, my first suggestion would be to logon to the server machine and see if you can access those resources directly in the browser. if so, it might be worth asking for IT help to create a new application pool for the proxy and assign it to utilize a different identity so that you could use a tool like fiddler to inspect the actual web traffic the proxy is spawning to the resource itself.

Re: Print Task and Proxy page

BryanLynn — Tue, 18 Feb 2014 14:01:34 GMT

Thanks for the info jgravois.

Turns out John was correct the spaces in the URL were causing problems with my proxy page. Essentially the spaces were being replaced with "+" characters.

Here is the fix I used to get around it:

        if (theUri.Contains("Export+Web+Map+Task"))         {             theUri = theUri.Replace("Export+Web+Map+Task", "Export%20Web%20Map%20Task");         }