I am making a Http Webrequest to an available site that I can visit fine, but the HTTP Web request keeps timing out. Is there any reason why this code might allow it to timeout when it shouldn't?
I've tried upping the timeout setting, but it still continues to timeout.
Uri CameraUrl = new Uri("http://" + cfg_cameraIps[i]);
HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(CameraUrl);
myRequest.Timeout = 5000;
myRequest.Method = "HEAD";
try
{
HttpWebResponse webresponse;
webresponse = (HttpWebResponse)myRequest.GetResponse();
if (webresponse.StatusCode.ToString() == "OK")
{
continue;
}
You're not closing your web response - if you find that the first couple of requests work, but ones after that don't, then that's the problem. It's trying to reuse the existing connection to the server, but it can't because you haven't closed the response.
Change your code to:
using (HttpWebResponse webresponse = (HttpWebResponse) myRequest.GetResponse())
{
if (webresponse.StatusCode == HttpStatusCode.OK)
{
continue;
}
...
}
and see if that helps.
If it's failing on the very first request to the server, then that's something different. In that case, use Wireshark to see what's going on at the network level.
Note that in the code above I've also removed the string conversion in favour of comparing the status codes directly.
Related
I am currently developing in Unity (in particular using C#) and I'm stuck with HttpWebRequest - HttpWebResponse random timeouts.
I have some methods that send a POST request to a server I host on my local machine (XAMPP) to use various php scripts which are going to fetch informations from MySQL Database (hosted with XAMPP) and give back those info in JSON format.
Then I handle these JSON informations with my C# scripts.
The problem is that when I run the first test all is good:I can get the JSON data from my Server and show it in the Debug Console.
When I run the second test,a WebException is raised with error:
WebException - The request timed out
After that second test,if I run again and again,the problem keeps presenting in a random way.
I followed all the guidelines I found on the internet on how to setup a webrequest - webresponse properly,in particular I tried to use ServicePoint.DefaultConnectionLimit and ServicePoint.MaxServicePointIdleTime,without any result.
The general structure of my methods (regarding the web request/response part) is something like that:
public void WebMethod(){
string post_url = "http://localhost/service.php?someparam=1&someparam=2";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(post_url);
request.Method = "POST";
request.KeepAlive = false;
request.Timeout = 5000;
request.Proxy = null;
string Response = "";
try
{
using (HttpWebResponse resp = request.GetResponse() as HttpWebResponse)
{
using (Stream objStream = resp.GetResponseStream())
{
using (StreamReader objReader = new StreamReader(objStream, Encoding.UTF8))
{
Response = objReader.ReadToEnd();
objReader.Close();
}
objStream.Flush();
objStream.Close();
}
resp.Close();
}
}catch(WebException e)
{
Debug.Log(e.Message);
}
finally
{
request.Abort();
}
//tried this one after reading some related answers here on StackOverflow,without results
//GC.Collect();
Debug.Log("SERVER RESPONSE:" + Response);
//Response Handling
}
I know that it may be something related to a wrong abort on the HttpWebRequest / Response or maybe related to the HTTP 1.1 connections limit,but I can't figure out any solution at the moment.
Any help is appreciated.
I've been working on a project which makes use of an RTC API and forms authentication. I've hit a bit of bizarre behaviour and I just can't figure this one out.
The scenario that has played out to date is that I can successfully run this project locally end to end. That is, this specific piece of code can:
Contact the remote server and successfully authenticate
After authentication I'm able to pass XML to update a ticket in RTC
The problem starts when I publish to our IIS (7.5) server. All works fine right up until the last .GetResponse call which uses a PUT method to pass my XML to update the ticket in RTC. I keep getting 'The operation has timed out'.
I've spent literally days trying to figure this one out doing all manner of things but nothing has proved useful.
As a test I changed the PUT method on the second call to a GET. And it works! If I used a PUT with the .AllowAutoRedirect = false it works in that I get a response back, but then nothing happens on the RTC side so the request is clearly being ignored. I also noticed that the status being returned is marked as 'Found' instead of 'OK'.
Some people thought at this stage perhaps it was a lack of connectivity between the remote server and the web server. This wouldn't be the case as authentication works and this happens against the same server. I have also manually passed the XML / PUT call using the RESTClient on the web server which was accepted fine.
I just can't understand why it works end to end when running locally, but plays up once deployed to IIS?
I tried using log tracing and I'm not entirely sure if I'm getting anything useful from it. It might be totally unrelated but I can see this in the log that is generated on the IIS server:
<EventData>
<Data Name="ContextId">{00000000-0000-0000-12AF-0080000000F8}</Data>
<Data Name="ModuleName">ManagedPipelineHandler</Data>
<Data Name="Notification">128</Data>
<Data Name="HttpStatus">500</Data>
<Data Name="HttpReason">Internal Server Error</Data>
<Data Name="HttpSubStatus">0</Data>
<Data Name="ErrorCode">0</Data>
<Data Name="ConfigExceptionInfo"></Data>
</EventData>
As I say, I'm not sure if this is even related to the problem I'm having, but rather than ignore it I thought I'd share.
Code that forms the call (excuse the standard of coding, it's work in progress and got messy trying out different things to fix this problem)
//Setup webrequest
CookieContainer _cookies = new CookieContainer();
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(getPath);
var test44 = test4.ToString();
request.CookieContainer = _cookies;
request.ContentType = "application/rdf+xml";
request.Accept = "application/rdf+xml";
request.Method = "PUT";
request.AllowAutoRedirect = true;
request.AllowWriteStreamBuffering = true;
request.Timeout = 40000;
byte[] bytes = Encoding.ASCII.GetBytes(test44);
request.ContentLength = bytes.Length;
Stream dataStream = request.GetRequestStream();
dataStream.Write(bytes, 0, bytes.Length);
dataStream.Close();
//Pass request
logger.Info("Made it up to start of RTC request for secure document.");
using (HttpWebResponse getrespn = requestSecureDocument(request, "https://myserver:9100/jazz", "username", "pass", test44))
{
//Stream ReceiveStream = getrespn.GetResponseStream();
// Encoding encode = System.Text.Encoding.GetEncoding("utf-8");
//StreamReader readStream = new StreamReader(ReceiveStream);
//response = readStream.ReadToEnd();
getrespn.Close();
}
The segment of code which interacts with the RTC server (based on the example from: https://nkumar83.wordpress.com/2013/06/13/consuming-rtc-rational-team-concert-oslc-apis-using-c-post-1-authentication/ with my own tweaks):
public static HttpWebResponse requestSecureDocument(HttpWebRequest _requestItem, string _rtcServerURL, string _userName, string _password, string passXml)
{
try
{
//FormBasedAuth Step 1: Request the resource
HttpWebRequest _request = (HttpWebRequest)WebRequest.Create(_requestItem.RequestUri);
_request.CookieContainer = _requestItem.CookieContainer;
//store the response in _docResponse variable
HttpWebResponse _docResponse = (HttpWebResponse)_request.GetResponse();
//HttpStatusCode.OK indicates that the request succeeded
if (_docResponse.StatusCode == HttpStatusCode.OK)
{
//X-com-ibm-team... header signifies form based authentication is being used
string _rtcAuthHeader = _docResponse.Headers["X-com-ibm-team-repository-web-auth-msg"];
if ((_rtcAuthHeader != null) && _rtcAuthHeader.Equals("authrequired"))
{
_docResponse.GetResponseStream().Flush();
_docResponse.Close();
//Prepare form for authentication
HttpWebRequest _formPost = (HttpWebRequest)WebRequest.Create(_rtcServerURL + "/j_security_check");
_formPost.Method = "POST";
_formPost.Timeout = 30000;
_formPost.CookieContainer = _request.CookieContainer;
_formPost.Accept = "text/xml";
_formPost.ContentType = "application/x-www-form-urlencoded";
string _authString = "j_username=" + _userName + "&j_password=" + _password;
Byte[] _outBuffer = Encoding.UTF8.GetBytes(_authString);
_formPost.ContentLength = _outBuffer.Length;
Stream _str = _formPost.GetRequestStream();
_str.Write(_outBuffer, 0, _outBuffer.Length);
_str.Close();
//FormBasedAuth Step 2: Submit the login form and get response
HttpWebResponse _formResponse = (HttpWebResponse)_formPost.GetResponse();
_rtcAuthHeader = _formResponse.Headers["X-com.ibm-team.repository-web-auth-msg"];
//Check if auth failed
if ((_rtcAuthHeader != null) && _rtcAuthHeader.Equals("authfailed"))
{
//auth fialed
var fail = "";
}
else
{
//login successful
//FormBasedAuth Step 3: Resend the request for the protected resource
_formResponse.GetResponseStream().Flush();
_formResponse.Close();
using (HttpWebResponse getresp = (HttpWebResponse)_requestItem.GetResponse()) *** THIS IS TH LINE WHICH THROWS THE EXCEPTION ***
{
return getresp;
}
}
}
}
return _docResponse;
}
catch (WebException e)
{
var filePath = AppDomain.CurrentDomain.GetData("DataDirectory") + #"/trapA.xml";
using (StreamWriter writer = new StreamWriter(filePath, true))
{
writer.WriteLine("Message: Failed to trigger getresponse successfully: " + e);
}
}
return null;
}
Hope someone out there can help :o)
Well I'm pleased to say I've finally got to the bottom of this one. Turns out the problem wasn't anything to do with IIS and does actually work when published 'if' I'm not using the RTC client to make updates to a ticket.
The short story is that our RTC client uses a custom script to post out to our web api. However the RTC client appears to put a record lock on the ticket your trying to update which is persisted until a response from our API is provided. Of course this can't happen because part of the response is to confirm if the update was successful which can't happen due to the lock made by the RTC client.
The solution was to get the call in from RTC closed as quickly as possible. So the segment of code which authenticates and calls back out to RTC to make updates is now wrapped around with some new code to create a new thread. This has allowed the connection to be closed in about 5 seconds, all the while our app continues to make the necessary calls to complete the transaction.
Thread t = new Thread(() = > {
//code here
}
I am writing code to surf a website using spring webflow.
I have to update my cookie with his set-cookie header every request else my session will be terminated.
Sometime a request could bump into webException so I need to catch the webException response headers for the cookie update so my next request is still valid
The problem happens with timeout exception, other exceptions like 503 works fine. The webRespones is always null but I can see the server had respond the header part and only stuck in sending the body part in fiddler. My session will be terminated without catching the header response properly. Is there any work around for this?
try
{
HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create("http://example.com");
webRequest.CookieContainer = new CookieContainer();
webRequest.CookieContainer.Add(cookieCollection);
webRequest.Timeout = 20000;
webRequest.ReadWriteTimeout = 20000;
using (HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse())
{
//A function handling the cookie adding
AddCookies(webResponse.Headers, cookieCollection, webResponse.ResponseUri.Host);
}
}
catch (WebException ex)
{
HttpWebResponse webResponse = ex.Response as HttpWebResponse;
if (webResponse == null) throw ex;
//Null webResponse when timeout, the received header information is dropped.
AddCookies(webResponse.Headers, cookieCollection, webResponse.ResponseUri.Host);
}
The timeout exception is implemented on the client side so the response will be null. You could use raw sockets to implement the get, but the easiest solution would probably be to increase the timeout value so you get the response.
I have tested a few plugins for Firefox and Chrome which can identify IP number of a given website ofcause. But some of them can also show what server-side technology the website runs on.
How do they do this? I know about client-user-agent, is there something similar in the HTTP protocol where the server sendes a "server-host-agent" kinda string?
And if so, how would the code for retreiving this look. I guess its something with WebClient?
Anyone?
Using the HttpWebRequest and setting the Method property to HEAD, you can do a HTTP HEAD request, which is very lightweight. It will return the HTTP Headers (which may or may not be correct). They HTTP Headers may also differ from server to server as there is no standard for what headers a server should expose.
The code:
HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create("http://www.contoso.com/");
myReq.Method = "HEAD";
WebResponse myRes = myReq.GetResponse();
for(int i=0; i < myHttpWebResponse.Headers.Count; ++i) {
Console.WriteLine(
"\nHeader Name:{0}, Value :{1}",
myHttpWebResponse.Headers.Keys[i], myHttpWebResponse.Headers[i]
);
}
EDIT:
var request = (HttpWebRequest)WebRequest.Create("http://www.http500.com");
try
{
var response = request.GetResponse();
}
catch (WebException wex)
{
// Safe cast to HttpWebResponse using 'as', will return null if unsuccessful
var httpWebResponse = wex.Response as HttpWebResponse;
if(httpWebResponse != null)
{
var httpStatusCode = httpWebResponse.StatusCode;
// HttpStatusCode is an enum, cast it to int for its actual value
var httpStatusCodeInt = (int)httpWebResponse.StatusCode;
}
}
How can I check whether a page exists at a given URL?
I have this code:
private void check(string path)
{
try
{
Uri uri = new Uri(path);
WebRequest request = WebRequest.Create(uri);
request.Timeout = 3000;
WebResponse response;
response = request.GetResponse();
}
catch(Exception loi) { MessageBox.Show(loi.Message); }
}
But that gives an error message about the proxy. :(
First, you need to understand that your question is at least twofold,
you must first check if the server is responsive, using ping for example - that's the first check, while doing this, consider timeout, for which timeout you will consider a page as not existing?
second, try retrieving the page using many methods which are available on google, again, you need to consider the timeout, if the server taking long to replay, the page might still "be there" but the server is just under tons of pressure.
If the proxy needs to authenticate you with your Windows credentials (e.g. you are in a corporate network) use:
WebRequest request=WebRequest.Create(url);
request.UseDefaultCredentials=true;
request.Proxy.Credentials=request.Credentials;
try
{
Uri uri = new Uri(path);
HttpWebRequest request = HttpWebRequest.Create(uri);
request.Timeout = 3000;
HttpWebResponse response;
response = request.GetResponse();
if (response.StatusCode.Equals(200))
{
// great - something is there
}
}
catch (Exception loi)
{
MessageBox.Show(loi.Message);
}
You can check the content-type and length, see MSDN HTTPWebResponse.
At a guess, without knowing the specific error message or path, you could try casting the WebRequest to a HttpWebRequest and then setting the WebProxy.
See MSDN: HttpWebRequest - Proxy Property