Intermittent failures of Web Services calls

B

Bruce

I am developing a .NET 2.0 WinForms client application which communicates
with a Windows 2003 Server (actually SBS 2003, running ISA Server 2004) via
Web Services calls. The client application works fine within our firewall.
But when I access the server from outside the firewall, I get rare and
intermittent failures on the Web Services calls to the server.



I wrapped the Web Services calls in try/catch and watched the exceptions.
The Exception type is System.Net.WebException. The Exception.Message value
for most of the failing calls contains "HTTP 403". On a very rare instance,
I saw a different error involving "Error Code 10061" which looks
suspiciously like an ISA server error.



The full text of each of these errors is appended below.



What are possible causes of intermittent failures like this?



Would anyone with ISA expertise be able to assess whether ISA settings could
be at fault, and if so what settings should I modify?



Thanks, Bruce





------ This exception happens most often -------------------



Exception: [The request failed with HTTP status 403: Forbidden ( The server
denied the specified Uniform Resource Locator (URL). Contact the server
administrator. ).]



------- This exception happens rarely ----------------------



Client found response content type of 'text/html', but expected 'text/xml'.

The request failed with the error message:

--

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<HTML dir=ltr><HEAD><TITLE>The page cannot be displayed</TITLE>

<STYLE id=L_10061r_1>A:link {

FONT: 8pt/11pt verdana; COLOR: #ff0000

}

A:visited {

FONT: 8pt/11pt verdana; COLOR: #4e4e4e

}

</STYLE>



<META content=NOINDEX name=ROBOTS>

<META http-equiv=Content-Type content="text-html; charset=UTF-8">



<META content="MSHTML 5.50.4522.1800" name=GENERATOR></HEAD>

<BODY bgColor=#ffffff>

<TABLE cellSpacing=5 cellPadding=3 width=410>

<TBODY>

<TR>

<TD vAlign=center align=left width=360>

<H1 id=L_10061r_2 style="FONT: 13pt/15pt verdana; COLOR: #000000"><ID
id=L_10061r_3><!--Problem-->The page cannot be displayed

</ID></H1></TD></TR>

<TR>

<TD width=400 colSpan=2><FONT id=L_10061r_4

style="FONT: 8pt/11pt verdana; COLOR: #000000"><ID
id=L_10061r_5><B>Explanation: </B>The Web server refused the connection,
possibly because a service on the upstream server is
inactive.</ID></FONT></TD></TR>

<TR>

<TD width=400 colSpan=2><FONT id=L_10061r_6

style="FONT: 8pt/11pt verdana; COLOR: #000000">

<HR color=#c0c0c0 noShade>



<P id=L_10061r_7><B>Try the following:</B></P>

<UL>

<LI id=L_10061r_8><B>Refresh page:</B> Search for the page again by
clicking the Refresh button. The timeout may have occurred due to Internet
congestion.

<LI id=L_10061r_9><B>Check spelling:</B> Check that you typed the Web page
address correctly. The address may have been mistyped.

<LI id=L_10061r_10><B>Access from a link:</B> If there is a link to the page
you are looking for, try accessing the page from that link.

<LI id=L_10061r_11><B>Contact website:</B> You may want to contact the
website administrator to make sure the Web page still exists. You can do
this by using the e-mail address or phone number listed on the website home
page.



</UL>

<HR color=#c0c0c0 noShade>



<P id=L_10061r_12>Technical Information (for support personnel)</P>

<UL>

<LI id=L_10061r_13>Error Code 10061: Connection refused

<LI id=L_10061r_14>Background: When the gateway or proxy server contacted
the upstream (Web) server, the connection was refused. This usually results
from trying to connect to a service that is inactive on the upstream server.



</UL></FONT></TD></TR></TBODY></TABLE></BODY></HTML>





--.
 
B

Bruce

Ooops, I meant to post this on the webservices forum. Never mind, I'm
posting it there now.

Bruce said:
I am developing a .NET 2.0 WinForms client application which communicates
with a Windows 2003 Server (actually SBS 2003, running ISA Server 2004)
via Web Services calls. The client application works fine within our
firewall. But when I access the server from outside the firewall, I get
rare and intermittent failures on the Web Services calls to the server.



I wrapped the Web Services calls in try/catch and watched the exceptions.
The Exception type is System.Net.WebException. The Exception.Message
value for most of the failing calls contains "HTTP 403". On a very rare
instance, I saw a different error involving "Error Code 10061" which looks
suspiciously like an ISA server error.



The full text of each of these errors is appended below.



What are possible causes of intermittent failures like this?



Would anyone with ISA expertise be able to assess whether ISA settings
could be at fault, and if so what settings should I modify?



Thanks, Bruce





------ This exception happens most often -------------------



Exception: [The request failed with HTTP status 403: Forbidden ( The
server denied the specified Uniform Resource Locator (URL). Contact the
server administrator. ).]



------- This exception happens rarely ----------------------



Client found response content type of 'text/html', but expected
'text/xml'.

The request failed with the error message:

--

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<HTML dir=ltr><HEAD><TITLE>The page cannot be displayed</TITLE>

<STYLE id=L_10061r_1>A:link {

FONT: 8pt/11pt verdana; COLOR: #ff0000

}

A:visited {

FONT: 8pt/11pt verdana; COLOR: #4e4e4e

}

</STYLE>



<META content=NOINDEX name=ROBOTS>

<META http-equiv=Content-Type content="text-html; charset=UTF-8">



<META content="MSHTML 5.50.4522.1800" name=GENERATOR></HEAD>

<BODY bgColor=#ffffff>

<TABLE cellSpacing=5 cellPadding=3 width=410>

<TBODY>

<TR>

<TD vAlign=center align=left width=360>

<H1 id=L_10061r_2 style="FONT: 13pt/15pt verdana; COLOR: #000000"><ID
id=L_10061r_3><!--Problem-->The page cannot be displayed

</ID></H1></TD></TR>

<TR>

<TD width=400 colSpan=2><FONT id=L_10061r_4

style="FONT: 8pt/11pt verdana; COLOR: #000000"><ID
id=L_10061r_5><B>Explanation: </B>The Web server refused the connection,
possibly because a service on the upstream server is
inactive.</ID></FONT></TD></TR>

<TR>

<TD width=400 colSpan=2><FONT id=L_10061r_6

style="FONT: 8pt/11pt verdana; COLOR: #000000">

<HR color=#c0c0c0 noShade>



<P id=L_10061r_7><B>Try the following:</B></P>

<UL>

<LI id=L_10061r_8><B>Refresh page:</B> Search for the page again by
clicking the Refresh button. The timeout may have occurred due to Internet
congestion.

<LI id=L_10061r_9><B>Check spelling:</B> Check that you typed the Web page
address correctly. The address may have been mistyped.

<LI id=L_10061r_10><B>Access from a link:</B> If there is a link to the
page you are looking for, try accessing the page from that link.

<LI id=L_10061r_11><B>Contact website:</B> You may want to contact the
website administrator to make sure the Web page still exists. You can do
this by using the e-mail address or phone number listed on the website
home page.



</UL>

<HR color=#c0c0c0 noShade>



<P id=L_10061r_12>Technical Information (for support personnel)</P>

<UL>

<LI id=L_10061r_13>Error Code 10061: Connection refused

<LI id=L_10061r_14>Background: When the gateway or proxy server contacted
the upstream (Web) server, the connection was refused. This usually
results from trying to connect to a service that is inactive on the
upstream server.



</UL></FONT></TD></TR></TBODY></TABLE></BODY></HTML>





--.
 
S

Steven Cheng[MSFT]

Hi Bruce,

Thanks for your posting.

I have seen your new post in the webservice newsgroup and have posted my
reply there. If you feel it convenient that we continue to discuss in that
newsgroup, please feel free to post in that thread. Looking forward to your
response there.

Regards,

Steven Cheng
Microsoft Online Community Support


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When responding to posts, please "Reply to Group" via your newsreader so
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learn and benefit from your issue.

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