System.WebExcep tion | The operation has timed out

[Sachin Surana]

We use HttpWebRequest to send the request at a URL. But some times the method
GetResponse throws a time out exception.

But when we check the IIS logs, there is no such entry. So the request never
reached the server but the client is getting a time out exception.

What could be the possible reasons? Confirmed that the request does not get
lost in the network.

[William F. Robertson, Jr.]

Set the KeepAlive property of the HttpWebRequest object to false.

When this is set to true, default, it will keep the connection open to your
server. After a couple uses, the connection will timeout from the server,
so the next time you make a request to it, it will try to use the "pooled"
connection, but that pooled connection has timed out, thus you are receiving
the error.

private static string GetResponseStri ng( string url )
{
HttpWebRequest request = ( HttpWebRequest ) WebRequest.Crea te( url );
request.KeepAli ve = false;
using ( HttpWebResponse response = ( HttpWebResponse )
request.GetResp onse() )
{
using ( StreamReader reader = new StreamReader(
response.GetRes ponseStream() ) )
{
return reader.ReadToEn d();
}
}
}

HTH,

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message
news:D0******** *************** ***********@mic rosoft.com...

We use HttpWebRequest to send the request at a URL. But some times the method GetResponse throws a time out exception.

But when we check the IIS logs, there is no such entry. So the request never reached the server but the client is getting a time out exception.

What could be the possible reasons? Confirmed that the request does not get lost in the network.

[Sachin Surana]

Thanks.

But I fail to understand one thing. Does that mean that .NET does not have a
clena support for keep alives? Do you mean that if I ever use keep alives in
ASPNET I will always get intermittent timeouts?

Is there any patch available?

Regards,
SAchin

"William F. Robertson, Jr." wrote:

Set the KeepAlive property of the HttpWebRequest object to false.

When this is set to true, default, it will keep the connection open to your
server. After a couple uses, the connection will timeout from the server,
so the next time you make a request to it, it will try to use the "pooled"
connection, but that pooled connection has timed out, thus you are receiving
the error.

private static string GetResponseStri ng( string url )
{
HttpWebRequest request = ( HttpWebRequest ) WebRequest.Crea te( url );
request.KeepAli ve = false;
using ( HttpWebResponse response = ( HttpWebResponse )
request.GetResp onse() )
{
using ( StreamReader reader = new StreamReader(
response.GetRes ponseStream() ) )
{
return reader.ReadToEn d();
}
}
}

HTH,

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message
news:D0******** *************** ***********@mic rosoft.com...

We use HttpWebRequest to send the request at a URL. But some times the

method

GetResponse throws a time out exception.

But when we check the IIS logs, there is no such entry. So the request

never

reached the server but the client is getting a time out exception.

What could be the possible reasons? Confirmed that the request does not

get

lost in the network.

[William F. Robertson, Jr.]

No, I believe the support is there. KeepAlive = true will instruct the
webserver to keep a persistent connection open. You are timing out because
the webserver has timed out the KeepAlive session, but you, the client, has
not.

When I experienced this problem, it was because I was making a hit to a
webserver, then intermittedly making hits every second to an interval of 1
hour. The first couple connections always worked, then they would start
timing out, especially near the end of the day when the frequency of hits
decreased.

When I was testing and hitting the server every 5 seconds or so, I never
received the timeout error. It was only in a production environment.

If you don't feel comfortable setting the KeepAlive to false, then perhaps
make you HttpWebRequest every couple seconds, then you might not experience
this problem.

I don't believe there is a patch, this is the behavior I would expect.

HTH,

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message
news:8F******** *************** ***********@mic rosoft.com...

Thanks.

But I fail to understand one thing. Does that mean that .NET does not have a clena support for keep alives? Do you mean that if I ever use keep alives in ASPNET I will always get intermittent timeouts?

Is there any patch available?

Regards,
SAchin

"William F. Robertson, Jr." wrote:

Set the KeepAlive property of the HttpWebRequest object to false.

When this is set to true, default, it will keep the connection open to your server. After a couple uses, the connection will timeout from the server, so the next time you make a request to it, it will try to use the "pooled" connection, but that pooled connection has timed out, thus you are receiving the error.

private static string GetResponseStri ng( string url )
{
HttpWebRequest request = ( HttpWebRequest ) WebRequest.Crea te( url );
request.KeepAli ve = false;
using ( HttpWebResponse response = ( HttpWebResponse )
request.GetResp onse() )
{
using ( StreamReader reader = new StreamReader(
response.GetRes ponseStream() ) )
{
return reader.ReadToEn d();
}
}
}

HTH,

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message news:D0******** *************** ***********@mic rosoft.com...

We use HttpWebRequest to send the request at a URL. But some times the

method

GetResponse throws a time out exception.

But when we check the IIS logs, there is no such entry. So the request

never

reached the server but the client is getting a time out exception.

What could be the possible reasons? Confirmed that the request does

not get

lost in the network.

[Sachin Surana]

Yes, it is webserver that has timed out. But the error I am receiving is at
the client side.

When web server times out, the error received by the client is "The
underlying connection is closed. Unexpected error occured on receive"

But when client times out, the error received is "The operation has timed
out".

SO it is client that is timing out and intermittently. Please let me know if
I am correct.

And, I receive the error exactly after 60 seconds.
"William F. Robertson, Jr." wrote:

No, I believe the support is there. KeepAlive = true will instruct the
webserver to keep a persistent connection open. You are timing out because
the webserver has timed out the KeepAlive session, but you, the client, has
not.

When I experienced this problem, it was because I was making a hit to a
webserver, then intermittedly making hits every second to an interval of 1
hour. The first couple connections always worked, then they would start
timing out, especially near the end of the day when the frequency of hits
decreased.

When I was testing and hitting the server every 5 seconds or so, I never
received the timeout error. It was only in a production environment.

If you don't feel comfortable setting the KeepAlive to false, then perhaps
make you HttpWebRequest every couple seconds, then you might not experience
this problem.

I don't believe there is a patch, this is the behavior I would expect.

HTH,

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message
news:8F******** *************** ***********@mic rosoft.com...

Thanks.

But I fail to understand one thing. Does that mean that .NET does not have

a

clena support for keep alives? Do you mean that if I ever use keep alives

in

ASPNET I will always get intermittent timeouts?

Is there any patch available?

Regards,
SAchin

"William F. Robertson, Jr." wrote:

Set the KeepAlive property of the HttpWebRequest object to false.

When this is set to true, default, it will keep the connection open to your server. After a couple uses, the connection will timeout from the server, so the next time you make a request to it, it will try to use the "pooled" connection, but that pooled connection has timed out, thus you are receiving the error.

private static string GetResponseStri ng( string url )
{
HttpWebRequest request = ( HttpWebRequest ) WebRequest.Crea te( url );
request.KeepAli ve = false;
using ( HttpWebResponse response = ( HttpWebResponse )
request.GetResp onse() )
{
using ( StreamReader reader = new StreamReader(
response.GetRes ponseStream() ) )
{
return reader.ReadToEn d();
}
}
}

HTH,

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message news:D0******** *************** ***********@mic rosoft.com...
> We use HttpWebRequest to send the request at a URL. But some times the
method
> GetResponse throws a time out exception.
>
> But when we check the IIS logs, there is no such entry. So the request
never
> reached the server but the client is getting a time out exception.
>
> What could be the possible reasons? Confirmed that the request does not get
> lost in the network.
>
>

[William F. Robertson, Jr.]

I was thinking something else entirely different.

Setting KeepAlive to false did not help resolve any of the timeouts?

When your client is making a HttpWebRequest to the server. You receive one
of two timeouts?

Either the Server bombs with "Underlying connection closed."
Or the Client bombs with "The operation has timed out"

The only thing left I could possibly help you with is for you to post your
code and I will look at it and see if there is anything squirrelly

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message
news:48******** *************** ***********@mic rosoft.com...

Yes, it is webserver that has timed out. But the error I am receiving is at the client side.

When web server times out, the error received by the client is "The
underlying connection is closed. Unexpected error occured on receive"

But when client times out, the error received is "The operation has timed
out".

SO it is client that is timing out and intermittently. Please let me know if I am correct.

And, I receive the error exactly after 60 seconds.
"William F. Robertson, Jr." wrote:

No, I believe the support is there. KeepAlive = true will instruct the
webserver to keep a persistent connection open. You are timing out because the webserver has timed out the KeepAlive session, but you, the client, has not.

When I experienced this problem, it was because I was making a hit to a
webserver, then intermittedly making hits every second to an interval of 1 hour. The first couple connections always worked, then they would start
timing out, especially near the end of the day when the frequency of hits decreased.

When I was testing and hitting the server every 5 seconds or so, I never
received the timeout error. It was only in a production environment.

If you don't feel comfortable setting the KeepAlive to false, then perhaps make you HttpWebRequest every couple seconds, then you might not experience this problem.

I don't believe there is a patch, this is the behavior I would expect.

HTH,

bill

"Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in message news:8F******** *************** ***********@mic rosoft.com...

Thanks.

But I fail to understand one thing. Does that mean that .NET does not have

a

clena support for keep alives? Do you mean that if I ever use keep

alives in

ASPNET I will always get intermittent timeouts?

Is there any patch available?

Regards,
SAchin

"William F. Robertson, Jr." wrote:

> Set the KeepAlive property of the HttpWebRequest object to false.
>
> When this is set to true, default, it will keep the connection open

to your

> server. After a couple uses, the connection will timeout from the

server,

> so the next time you make a request to it, it will try to use the

"pooled"

> connection, but that pooled connection has timed out, thus you are

receiving

> the error.
>
> private static string GetResponseStri ng( string url )
> {
> HttpWebRequest request = ( HttpWebRequest ) WebRequest.Crea te(

url ); > request.KeepAli ve = false;
> using ( HttpWebResponse response = ( HttpWebResponse )
> request.GetResp onse() )
> {
> using ( StreamReader reader = new StreamReader(
> response.GetRes ponseStream() ) )
> {
> return reader.ReadToEn d();
> }
> }
> }
>
> HTH,
>
> bill
>
> "Sachin Surana" <Sa**********@d iscussions.micr osoft.com> wrote in

message

> news:D0******** *************** ***********@mic rosoft.com...
> > We use HttpWebRequest to send the request at a URL. But some times the > method
> > GetResponse throws a time out exception.
> >
> > But when we check the IIS logs, there is no such entry. So the request > never
> > reached the server but the client is getting a time out exception.
> >
> > What could be the possible reasons? Confirmed that the request

does not

> get
> > lost in the network.
> >
> >
>
>
>