Trouble with Blast.

Dec 30, 2011 at 5:35 PM

I am having some trouble getting blast to work. I created a new project with all of the stranded NCBIBlast template code. However when I run my app The error I get is:

  SubmitHttpRequest failed. Status: WebException: Page not available.

Has anybody else had this problem. I was hoping that blast would work straight out of the box. Is it broken or am I doing something wrong.


Thanks for any input.

 

Coordinator
Jan 3, 2012 at 3:01 PM

Hi Jake,

It should just work out of the box, but since this accesses a webservice run by NCBI, success is dependent on the availability of that service. In your case, the error message 'Page not available' indicates the service is probably down.

It might be helpful for you to take a look at the Microsoft Research Biology Extension for Excel, available from the downloads page of this project. This implements a ribbon with a set of biological functions - for example you can load a FASTA file, highlight a sequence and run NCBI BLAST. Since this functionality uses the webservice connector you are trying to use, looking at the code might be useful for you. Also, you can use the extension itself to test to see if the webservice is running - in fact I just did this, and it works fine for me.

Simon

 

Coordinator
Jan 4, 2012 at 3:25 PM

Jake here is some additional information:

This issue is related with the proxy connection of the browser. If the browser is using any proxy, this exception will be thrown.

The property UseBrowserProxy of the class Bio.Web.ConfigParameters is by default false and all the instances of the NCBIBlastHandler class created using default constructer will use false only.

 To test you can replaced the code excerpt ( in the Bio.Web.Blast.NCBIBlastHandler)

             if (Configuration.UseBrowserProxy)

            {

                accessor.GetBrowserProxy();

            }

 

by

 

            if (true)

            {

                accessor.GetBrowserProxy();

            }

 

and everything works fine.

 

BioExcel takes the input from the user regarding the use of browser proxy. In BioExcel, the value of the checkbox is used to set the value of the ConfigParameters which is then used to set the value of the Configuration property of the BlastServiceHandler object. The code snippet for the same is given below:

 

. . .

configParams.UseBrowserProxy = (bool)this.chkUseBrowerProxy.IsChecked;

. . .

blastServiceHandler.Configuration = configParams;

. . .

 

In the Module 07 (Web service) of the NET Bio V1 Training Materials, available on the Codeplex site, only task3/after/Lab06.sln has the right implementation to work with proxy enabled scenario.

Rick for the .NET Bio team