I have set up the following web request:
HttpWebRequest request = (HttpWebRequest) WebRequest.Create(gotoWebinerUrl);
request.Accept = "text/json";
request.Timeout = 5000;
// Allows us to track with Fiddler, for dev use only
request.Proxy = new WebProxy("127.0.0.1", 8888);
try
{
WebResponse response = request.GetResponse();
Stream responseStream = response.GetResponseStream();
...
}
catch (Exception exception)
{
...
}
In Fiddler, I have installed this plugin which delays requests http://fiddlerdelayext.codeplex.com/. Using the plugin, I have added a rule which delays the webinar request URL by 60,000ms (1 min).
I would expect my application to delay for 5 seconds, fail and be caught by my exception. However, it delays for the full 60 seconds.
I'm not sure if this is the plugins problem or my application, but I suspect the latter. In the 60 seconds delay, I can navigate to other web pages and see the requests in Fiddler, so I don't believe the problem exists with the plugin.
I found a couple of similar questions (How to terminate HttpWebRequest Connection in C#?It doesn't work even set timeout or readwritetimeout), but I'm not very familiar with threads and if they apply here or not.
Additional Info
A bit more research into this stepping through the code and I've noticed some interesting behaviour. The GetResponse is fired successfully and I see the request made in Fiddler. I then have my 60 seconds wait time. However, when I can continue stepping through, I notice that it has been caught as a TimeoutException, despite the fact it's actually waited the full 60s and has received a successful response. This does suggest that maybe something in the plugin is fooling the application into holding on somehow.
Related
I am stuck with this, I am calling a simple report server URL which returns report's PDF, but strangely the WebRequest.GetResponse method doesn't return anything, when I say this, I mean the code just stop executing at that point, no exception, no error, no status code, no event viewer log on server, nothing!! And so I am not able to debug it
This is my code
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
req.PreAuthenticate = true;
req.UseDefaultCredentials = true;
req.Credentials = CredentialCache.DefaultNetworkCredentials;
req.ImpersonationLevel = TokenImpersonationLevel.Impersonation;
req.Timeout = int.MaxValue;
Log.Write("Log before");
var response = req.GetResponse();
Log.Write("Log after");
It just prints Log before log and then nothing is printed after that.
This code works perfectly fine when I run through visual studio and stops working when it is deployed in dev and test servers!
I am just expecting it to atleast through the exception or return unauthorized or any other status code, then I will be able to debug the issue.
Any suggestions what I can try to debug it?
Have you tried leaving it for 24 days 20 hours 31 minutes and 24 seconds? In other words, have you left it for as long as you have set the timeout to?
The server is not returning a response and the code is waiting int.MaxValue milliseconds to tell you that. The most likely cause of this is that there is a piece of networking infrastructure between your client and server that is stopping the request. This could be a firewall or proxy. It may also be being caused by the server not liking the request and refusing to respond.
Things I would try:
Try accessing the URL though a web browser on the machine that the code is failing on.
Set the timeout to something sensible like one minute and run the request to timeout.
Try pinging the remote server from the client machine.
Use a product like Fiddler to check what is actually being sent and received.
Have a chat with your network provider to see if they can help.
Check the server logs to see if the server has erred.
Change the first log to Log.Write("Log before: " + url); to check what is actually being requested.
I know I can perform a normal HTTP get and check the response but in my case i have some limitations as the video feed server is only allowing 1 connection at a time, which mean any HTTP request while watching the video stream on any player will interrupt the main stream and make it stop.
I have tried different headers with the HTTP GET request (AddRange , ReadWriteTimeout) but all were causing the feed to stop playing on any player
I have tried the HEAD request but for some reason its stuck at GetResponse() as it try to download the content which goes into infinity
var request = WebRequest.Create("http://xyss.ts") as HttpWebRequest;
request.Method = "HEAD";
var response = request.GetResponse(); //doesn't stop trying to download content
request.Abort();
response.Close();
Any idea how we can test if the feed still exist without interrupting the main server feed so it doesn't affect any client streaming
I'm writing code to send a request to my web service in windows azure, and it turned out I cannot get response until timeout. What's confusing is that i'm sure everything inside my service has been done, and yet the response did not come back.
My service code looks like this:
public virtual JsonResult ServiceMethod()
{
// 1. do the work
// 2. write something to database
return Json(result, JsonRequestBehavior.AllowGet);
}
And my client code looks like this:
HttpWebRequest webRequest = WebRequest.Create(new Uri(httpAddress)) as HttpWebRequest;
webRequest.Timeout = 1000 * 1000;
webRequest.ServicePoint.ConnectionLeaseTimeout = 40 * 60 * 1000;
webRequest.ServicePoint.MaxIdleTime = 40 * 60 * 1000;
webRequest.ServicePoint.SetTcpKeepAlive(true, 50 * 1000, 1000);
webRequest.Method = "GET";
using (HttpWebResponse response = webRequest.GetResponse() as HttpWebResponse)
{
// handle the response
}
Now I'm pretty sure my code in my service has completed because i tried to write something to database and that happened. I also checked the iis log on the virtual machine where the service is hosted and it showed http 200 is returned. But the call GetResponse() in my client code hanged until the 1000 seconds timeout is reached.
Update
There is a parameter to my web API which will affect how long the method runs.(I didn't show it in the above code for simplicity). If the service method runs for sufficiently long time (like 6 or 7 minutes), then the hanging problem will happen. Otherwise, the web response can successfully return. So i guess there might be some problem within the timeout setting. But there are several timeout properties in the HttpWebRequest and its base classes, i don't know what combination of them can result in or solve this problem.
Any ideas of what can the problem be?
Thanks a lot.
From your code, and since you're returning JsonResult from your action, it seems that you have a RESTful architecture. One of the ways to debug RESTful architectures is to use browser, specifically in your case where HTTP method is GET.
You can simply copy/paste your URL in the address bar of a browser to see if you get any response. If you see the result, then your client code is the problem, otherwise, the problem is in the server side (azure server).
To monitor HTTP traffic, a good utility is Fiddler.
Run your project locally in the Windows Azure emulator. Then, check the output of the compute emulator. It should show unhandled exceptions there.
It seems that the call to your external service fails, and the exception is not handled properly. We've had a similar case before, and it would even cause the IIS worker process to crash.
Using HttpWebRequest, I'm trying to query a secured (negotiate) url behind a load balancing setup in round-robin mode (two IIS 7.5 servers). Seems simple enough, but I have some problems.
The first anonymous request goes on one server and the negotiate part goes on the other. The problem is that it takes about six seconds between these two requests, so it is way too long. Trying to diagnose the delay, I realized that, going through Fiddler's proxy, all the requests went on the same server, so it took less than one second total. If I disable Fiddlers option "reuse server connections", then my requests have the same behavior as without Fiddler and it takes forever.
Googling this, I ended up on this link: http://fiddler2.com/blog/blog/2013/02/28/help!-running-fiddler-fixes-my-app-
I know that Fiddler is using sockets and its own connection pool, but is there a way to reproduce the same behavior using .NET HttpWebRequest so that my requests (anonymous and negotiate) will reuse connections and end up on the same server?
Here is a quick test that takes about 70 seconds to complete without Fiddler, and about 2 seconds going through Fiddler...
Also, please note that it isn't a Proxy detection delay and that sticky session are disabled on the nlb.
public void Main(string[] args)
{
int i = 0;
while (i < 10)
{
HttpWebRequest wr = (HttpWebRequest)WebRequest.Create("http://nlb/service.asmx");
HttpWebResponse response;
wr.KeepAlive = true;
wr.UseDefaultCredentials = true;
response = (HttpWebResponse)wr.GetResponse();
using (StreamReader sr = new StreamReader(response.GetResponseStream()))
{
Console.WriteLine(sr.ReadToEnd());
}
response.Close();
i++;
}
}
This is another proof that Fiddler is plain awesome!
Thanks for any advice.
Just a shot here, and maybe it seems too easy -
But the last line of your code is Response.Close(). The documentation prior to .NET 4.5 doesn't say much about this other than it "closes the existing socket connection."
In .NET 4.5 however, this is the documentation:
This method terminates the connection to the client in an abrupt
manner and is not intended for normal HTTP request processing.
http://msdn.microsoft.com/en-us/library/system.web.httpresponse.close(v=vs.110).aspx
I'll admit that I don't know some of the subtle differences between .NET 4.5 and the prior versions of HttpResponse; however, I do think that logically, Connection.Close() is not compatible with Keep-Alive; and you could be seeing the behavior of Fiddler intervening (maybe as a bug) to patch over this. Just a theory- needs testing.
We're using the HTTPWebRequest objects to make HTTP requests to our application and we're having a problem when the request requires authentication and there is a transparent proxy (Squid 3.1.10).
string url = "http://www.icode.co.uk/test/auth.php";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Credentials = new NetworkCredential("username", "password");
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream stream = response.GetResponseStream();
StreamReader reader = new StreamReader(stream);
MessageBox.Show(reader.ReadToEnd());
reader.Close();
stream.Close();
response.Close();
Our original code used the WebClient class which exhibited the same problem.
The first time this code runs, it displays the result correctly.
When the code runs a second time, it fails on the GetResponse() line with:
System.Net.WebException was unhandled
Message="The server committed a protocol violation. Section=ResponseStatusLine"
Source="System"
StackTrace:
at System.Net.HttpWebRequest.GetResponse()
at Dummy.DummyForm.button1_Click(Object sender, EventArgs e) in H:\Trial\Dummy\DummyForm.cs:line 42
at ...
On Windows 7, restarting the process causes it to recover and work once, but Server 2003 requires a full reboot.
Looking at the network capture, two requests are identical to start with, the initial unauthenticated request is sent and the server replies, but the failing requests sends the 2nd authenticated request in the middle of the initial reply as if it's ignoring the Content-Length header (which is correct). It then receives the rest of the initial reply and fails with the protocol error.
It does seem odd that the client (HTTPWebRequest) doesn't close the connection cleanly though.
When the proxy is not in use (non port 80 or internal traffic) the requests all work as expected. When there is no authentication, it also works as it only makes the single request.
I've already reduced the problem code to the minimum and reproduced it with the MSDN sample, but does anyone know if this is a known issue or a problem in our (.NET or Squid) configuration?
Since it only fails the second time, would
request.KeepAlive = false;
make a difference?
I think NTLM authentication (NetworkCredential) does not work at the same time with transparent proxy feature of SQUID. :-(
http://www.squid-cache.org/mail-archive/squid-users/201110/0025.html
Could you try another authentication scheme?
Try authenticating yourself, with
request.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(Encoding.ASCII.GetBytes(username + ":" + password));
before the request.GetResponse();
This worked for me. First I tried putting in the whole string myself, which didn't work!