[GH-ISSUE #100] System.Net.WebException: The underlying connection was closed #1000

New issue

Closed

opened 2026-03-13 23:46:11 +03:00 by kerem · 1 comment

kerem commented

2026-03-13 23:46:11 +03:00

Owner

Originally created by @maybeec on GitHub (Jan 14, 2016).
Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/100

With since release 1.14.0, in addtion to #99, I also observed a connection issue.
This issue does not occur regularily. I had this once for now:

<?xml version="1.0" encoding="utf-16"?>
<SynchronizationReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <ProfileName>CalDAV</ProfileName>
  <ProfileId>d20d7d59-d52b-4972-a770-949eee35a303</ProfileId>
  <StartTime>2016-01-13T15:46:25.5785213Z</StartTime>
  <InitialEntityMatchingPerformed>false</InitialEntityMatchingPerformed>
  <LoadErrors />
  <EntitySynchronizationReports />
  <ExceptionThatLeadToAbortion>System.Net.Http.HttpRequestException: An error occurred while sending the request. ---&gt; System.Net.WebException: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.
   at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
   at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar)
   --- End of inner exception stack trace ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.&lt;ExecuteWebDavRequest&gt;d__a.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.&lt;ExecuteWebDavRequestAndReadResponse&gt;d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.DataAccess.CalDavDataAccess.&lt;GetEntities&gt;d__2c.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at CalDavSynchronizer.Implementation.CalDavRepository.&lt;Get&gt;d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at GenSync.Synchronization.Synchronizer`6.EntityContainer.&lt;FillIfEmpty&gt;d__43.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at GenSync.Synchronization.Synchronizer`6.&lt;Synchronize&gt;d__3a.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at GenSync.Synchronization.Synchronizer`6.&lt;SynchronizeNoThrow&gt;d__4.MoveNext()</ExceptionThatLeadToAbortion>
  <Duration>00:00:10.4400439</Duration>
</SynchronizationReport>

Originally created by @maybeec on GitHub (Jan 14, 2016). Original GitHub issue: https://github.com/aluxnimm/outlookcaldavsynchronizer/issues/100 With since release 1.14.0, in addtion to #99, I also observed a connection issue. This issue does not occur regularily. I had this once for now: ``` xml <?xml version="1.0" encoding="utf-16"?> <SynchronizationReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <ProfileName>CalDAV</ProfileName> <ProfileId>d20d7d59-d52b-4972-a770-949eee35a303</ProfileId> <StartTime>2016-01-13T15:46:25.5785213Z</StartTime> <InitialEntityMatchingPerformed>false</InitialEntityMatchingPerformed> <LoadErrors /> <EntitySynchronizationReports /> <ExceptionThatLeadToAbortion>System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server. at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar) --- End of inner exception stack trace --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<ExecuteWebDavRequest>d__a.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.DataAccess.HttpClientBasedClient.WebDavClient.<ExecuteWebDavRequestAndReadResponse>d__0.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.DataAccess.CalDavDataAccess.<GetEntities>d__2c.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at CalDavSynchronizer.Implementation.CalDavRepository.<Get>d__2.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at GenSync.Synchronization.Synchronizer`6.EntityContainer.<FillIfEmpty>d__43.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) at GenSync.Synchronization.Synchronizer`6.<Synchronize>d__3a.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) at GenSync.Synchronization.Synchronizer`6.<SynchronizeNoThrow>d__4.MoveNext()</ExceptionThatLeadToAbortion> <Duration>00:00:10.4400439</Duration> </SynchronizationReport> ```

kerem closed this issue

2026-03-13 23:46:20 +03:00

kerem commented

2026-03-13 23:46:34 +03:00

Author

Owner

@aluxnimm commented on GitHub (Jan 14, 2016):

this is a server issue with keepalive. you can also try the setting close connection after each request in advanced options do disable keepalive. could be slower though. or check servef keepalive settings.

@aluxnimm commented on GitHub (Jan 14, 2016): this is a server issue with keepalive. you can also try the setting close connection after each request in advanced options do disable keepalive. could be slower though. or check servef keepalive settings.