System Net WebException The operation has timed out

Question

I have a big problem  I need to send 200 objects at once and avoid timeouts   while  true         NameValueCollection data   new NameValueCollection        data Add  mode   nat        using  var client   new WebClient                  byte   response   client UploadValues serverA  data           responseData   Encoding ASCII GetString response            string   split   Javab Split new             StringSplitOptions RemoveEmptyEntries           string command   split 0           string server   split 1           string requestCountStr   split 2            switch  command                        case  check                   int requestCount   Convert ToInt32 requestCountStr                    for  int i   0  i  lt  requestCount  i                                          Uri myUri   new Uri server                       WebRequest request   WebRequest Create myUri                       request Timeout   200000                      WebResponse myWebResponse   request GetResponse                                      break                          This produces the error   Unhandled Exception  System Net WebException  The operation has timed out   at System Net HttpWebRequest GetResponse     at vir fu Program Main String   args    The requestCount loop works fine outside my base code but when I add it to my project I get this error   I have tried setting request Timeout   200  but it didn t help

User · Answer

I remember I had the same problem a while back using WCF due the quantity of the data I was passing   I remember I changed timeouts everywhere but the problem persisted   What I finally did was open the connection as stream request  I needed to change the client and the server side  but it work that way   Since it was a stream connection  the server kept reading until the stream ended

User · Answer

I encountered the same error than adding Task Delay 2000    in each request solved the problem

User · Answer

Close dispose your WebResponse object

User · Answer

proxy issue can cause this  IIS webconfig put this in    lt defaultProxy useDefaultCredentials  true  enabled  true  gt             lt proxy usesystemdefault  True    gt           lt  defaultProxy gt

User · Answer

I m not sure about your first code sample where you use WebClient UploadValues  it s not really enough to go on  could you paste more of your surrounding code  Regarding your WebRequest code  there are two things at play here    You re only requesting the headers of the response    you never read the body of the response by opening and reading  to its end  the ResponseStream  Because of this  the WebRequest client helpfully leaves the connection open  expecting you to request the body at any moment  Until you either read the response body to completion  which will automatically close the stream for you   clean up and close the stream  or the WebRequest instance  or wait for the GC to do its thing  your connection will remain open  You have a default maximum amount of active connections to the same host of 2  This means you use up your first two connections and then never dispose of them so your client isn t given the chance to complete the next request before it reaches its timeout  which is milliseconds  btw  so you ve set it to 0 2 seconds - the default should be fine     If you don t want the body of the response  or you ve just uploaded or POSTed something and aren t expecting a response   simply close the stream  or the client  which will close the stream for you   The easiest way to fix this is to make sure you use using blocks on disposable objects   for  int i   0  i  lt  ops1  i          Uri myUri   new Uri site       WebRequest myWebRequest   WebRequest Create myUri         myWebRequest Timeout   200      using  WebResponse myWebResponse   myWebRequest GetResponse                     Do what you want with myWebResponse Headers           Your response will be disposed of here     Another solution is to allow 200 concurrent connections to the same host  However  unless you re planning to multi-thread this operation so you d need multiple  concurrent connections  this won t really help you    ServicePointManager DefaultConnectionLimit   200    When you re getting timeouts within code  the best thing to do is try to recreate that timeout outside of your code  If you can t  the problem probably lies with your code  I usually use cURL for that  or just a web browser if it s a simple GET request      In reality  you re actually requesting the first chunk of data from the response  which contains the HTTP headers  and also the start of the body  This is why it s possible to read HTTP header info  such as Content-Encoding  Set-Cookie etc  before reading from the output stream  As you read the stream  further data is retrieved from the server  WebRequest s connection to the server is kept open until you reach the end of this stream  effectively closing it as it s not seekable   manually close it yourself or it is disposed of  There s more about this here

User · Answer

It means what it says  The operation took too long to complete   BTW  look at WebRequest Timeout and you ll see that you ve set your timeout for 1 5 second

[c#] System.Net.WebException: The operation has timed out

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