ERROR: The remote host closed the connection. The error code is 0x800704CD. (System.Web.HttpException)

[akuryan]

Do you want to request a feature or report a bug?
It is a bug
What is the current behavior?
When I try to sync Unicorn with some long running operation (I observed a project being synced for 500000 ms) via Unicorn.psm1 script - it generates an error

5800 12:33:30 ERROR ERROR: The remote host closed the connection. The error code is 0x800704CD. (System.Web.HttpException)
at System.Web.Hosting.IIS7WorkerRequest.RaiseCommunicationError(Int32 result, Boolean throwOnDisconnect)
   at System.Web.Hosting.IIS7WorkerRequest.ExplicitFlush()
   at System.Web.HttpResponse.Flush(Boolean finalFlush, Boolean async)
   at System.Web.HttpWriter.Write(String s)
   at System.Web.HttpResponseWrapper.Write(String s)
   at Kamsar.WebConsole.TextWebConsole.Write(String statusMessage, MessageType type, Object[] formatParameters)
   at Unicorn.Logging.PubSubLogger.Flush()
   at Unicorn.Pipelines.UnicornSyncComplete.SyncCompleteLogger.Process(UnicornSyncCompletePipelineArgs args)
   at (Object , Object )
   at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
   at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain, Boolean failIfNotExists)
   at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)
   at Unicorn.SerializationHelper.RunUnicornSyncComplete(IConfiguration configuration, DateTime syncStartTimestamp)
   at Unicorn.SerializationHelper.SyncTree(IConfiguration configuration, Action`1 rootLoadedCallback, Boolean runSyncStartPipeline, IItemData partialSyncRoot)
   at Unicorn.SerializationHelper.SyncConfigurations(IConfiguration[] configurations, IProgressStatus progress, ILogger additionalLogger)

When running sync in browser - it is not reproducing

If the current behavior is a bug, please provide the steps to reproduce.

What is the expected behavior?
Is there a way to continue sync in background if Stream could not be read and get sync status via API call?

Please mention your Sitecore version and Unicorn version.
Unicorn version is 4.1.1
Sitecore versin 9.1.0
This issue is reproduced stably when running in geo-replicated master and core databases in failover group with Active-Passive

[akuryan]

I tried to hide this problem by increasing timeout in script:

	$responseStreamReader = new-object System.IO.StreamReader $responseStream
	$responseStreamReader.BaseStream.ReadTimeout = 10800000
	$responseStreamReader.BaseStream.WriteTimeout = 10800000

But, this does not helped.

One more thing - sometimes when this timeout is recorder - my web app is restarted as well :(

[akuryan]

One more thing - same error could be reproduced when running Sync-Unicorn directly on azure webapp SCM (so, it is not related to internet connection quality or some other drops)

[akuryan]

Also, I see these kind of errors thrown, which terminates my ASP.NET process completely:

ERROR Unhandled exception detected. The ASP.NET worker process will be terminated. 
Exception: System.NullReferenceException
Message: Object reference not set to an instance of an object.
Source: System.Web
   at System.Web.HttpWriter.BufferData(Byte[] data, Int32 offset, Int32 size, Boolean needToCopyData)
   at System.Web.HttpWriter.FlushCharBuffer(Boolean flushEncoder)
   at System.Web.HttpWriter.GetBufferedLength()
   at System.Web.HttpResponse.UpdateNativeResponse(Boolean sendHeaders)
   at System.Web.HttpResponse.Flush(Boolean finalFlush, Boolean async)
   at System.Web.HttpWriter.Write(String s)
   at System.Web.HttpResponseWrapper.Write(String s)
   at Kamsar.WebConsole.TextWebConsole.Write(String statusMessage, MessageType type, Object[] formatParameters)
   at Kamsar.WebConsole.WebConsole.<.ctor>b__8_0(Object arg)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.TimerQueueTimer.CallCallback()
   at System.Threading.TimerQueueTimer.Fire()
   at System.Threading.TimerQueue.FireNextTimers()

[cassidydotdk]

Fixed in #390