Windows Azure Caching “No such host is known”

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Few days ago(on 31st July), the Azure Caching libraries were updated to v2.1.0.0 (previous version was v2.0.0.0).

If you are trying to use Windows Azure Caching on your new project from past few days, and if it is mysteriously not working, not even for the simplest of the projects, then you may be running into a dependency scenario!

A lot of us may have probably missed that this new version of Azure Caching has a dependency on Azure SDK v 2.1

See the highlighted part (easy to miss if we are in a hurry Smile).




So what would happen if we try to use Azure Caching with Azure SDK 2.0 or older?


You may run into following issues

1. Your project may appear to hang for a while (browser spinning etc.).

2. Eventually you may see errors like

Exception Details: System.Net.Sockets.SocketException: No such host is known

DataCacheException: ErrorCode<ERRCA0017>:SubStatus<ES0006>

Detailed exception:

Server Error in '/' Application.

No such host is known
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Net.Sockets.SocketException: No such host is known

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace:

[SocketException (0x2af9): No such host is known]
Microsoft.ApplicationServer.Caching.AsyncResultNoResult.EndInvoke() +202
Microsoft.ApplicationServer.Caching.AsyncResult`1.EndInvoke() +40
Microsoft.ApplicationServer.Caching.SocketConnectionFactory.EndConnect(IAsyncResult asyncResult) +75
Microsoft.ApplicationServer.Caching.TcpClientChannelFactory.TcpConnectionCallback(IAsyncResult result) +182
[DataCacheException: ErrorCode<ERRCA0017>:SubStatus<ES0006>:There is a temporary failure. Please retry later. (One or more specified cache servers are unavailable, which could be caused by busy network or servers. For on-premises cache clusters, also verify the following conditions. Ensure that security permission has been granted for this client account, and check that the AppFabric Caching Service is allowed through the firewall on all cache hosts. Also the MaxBufferSize on the server must be greater than or equal to the serialized object size sent from the client.). Additional Information : The client was trying to communicate with the server: net.tcp://WebRole1:24233.]
Microsoft.ApplicationServer.Caching.DataCache.ThrowException(ErrStatus errStatus, Guid trackingId, Exception responseException, Byte[][] payload, EndpointID destination) +767
Microsoft.ApplicationServer.Caching.DataCache.ThrowException(ResponseBody respBody, EndpointID destination) +149
Microsoft.ApplicationServer.Caching.DataCacheFactory.EstablishConnection(IEnumerable`1 servers, RequestBody request, Func`3 sendMessageDelegate, DataCacheReadyRetryPolicy retryPolicy) +1313
Microsoft.ApplicationServer.Caching.<>c__DisplayClass5.<Initialize>b__2(RequestBody req) +198
Microsoft.ApplicationServer.Caching.SocketClientProtocol.SendReceive(IVelocityRequestPacket request, Func`2 delegate, EndpointID& destination) +121
Microsoft.ApplicationServer.Caching.SocketClientProtocol.Initialize(IEnumerable`1 servers) +1225
Microsoft.ApplicationServer.Caching.DataCacheFactory.GetCache(String cacheName, CreateNewCacheDelegate cacheCreationDelegate, DataCacheInitializationViaCopyDelegate initializeDelegate) +1104
Microsoft.ApplicationServer.Caching.DataCacheFactory.GetCache(String cacheName) +131
Microsoft.Web.DistributedCache.DataCacheFactoryWrapper.CreateDataCacheFromFactory(DataCacheFactory factory, String cacheName) +63
Microsoft.Web.DistributedCache.CacheHelpers.RunCacheCreationHooks(CacheConnectingEventArgs fetchingEventArgs, IDataCacheFactory dataCacheFactory, Object sender, EventHandler`1 fetchingHandler, EventHandler`1 fetchedHandler) +356
Microsoft.Web.DistributedCache.DistributedCacheSessionStateStoreProvider.CreateInternalProvider(IHttpRuntime httpRuntime, SessionInitializationData initData, IDataCacheFactory dataCacheFactory, EventHandler`1 cacheFetching, EventHandler`1 cacheFetched) +447
Microsoft.Web.DistributedCache.DistributedCacheSessionStateStoreProvider.GetInternalProvider() +315
Microsoft.Web.DistributedCache.DistributedCacheSessionStateStoreProvider.CreateNewStoreData(HttpContext context, Int32 timeout) +59
System.Web.SessionState.SessionStateModule.InitStateStoreItem(Boolean addToContext) +160
System.Web.SessionState.SessionStateModule.CompleteAcquireState() +363
System.Web.SessionState.SessionStateModule.BeginAcquireState(Object source, EventArgs e, AsyncCallback cb, Object extraData) +1269
System.Web.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +12598974
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18033

Please note that only including the new package in your solution will NOT cause these issues. These symptoms will appear only when you are actually trying to ‘use’ caching features. Like, enabling the Azure Caching Session State provide, or instantiating the DataCache objects etc..

Okay, we know there is a dependency. But what do we do now?

Here are two easy options

1. Upgrade your Azure SDK to the latest version (v2.1) (this should be the right and recommended way)

Download Latest Azure SDK

2. If for some reason, you can not upgrade your Azure SDK at the moment, then you can manually install previous version of Azure Caching. (of course you will be missing on the new things v2.10.0 has to offer)

a. Go to Visual Studio –> Open your project where you want to install Azure Caching libraries 

b. Tools –> Library Package Manager –> Package Manager Console

c. This should bring up ‘Package Manager Console’ window

d. Run following command in that console window

>Install-Package Microsoft.WindowsAzure.Caching -Version

This should install the v2.0.0.0 of Azure Caching which you can use with your older versions of Azure SDK (<v2.1)



Hope this help!

Comments (6)
  1. Steve says:

    Thanks!  This really saved my bacon.

  2. Ashish Goyal says:

    @Steve: Glad it helped!

  3. Chris says:

    Any other advice if this doesn't work?  I have been troubleshooting this problem for days, and have had no luck.  I have totally reinstalled Azure SDK (2.1) and uninstalled Azure SDK (2.0).  I have redeployed several times, triple checked the name of my role, triple checked that all my caching / Azure related DLLs are coming from the latest version, but cannot get this error to go away.  I am using caching for both session state and to store some runtime data.

    Thanks for any help!

     – Chris

  4. Steinar says:

    Thanx!! Saved my day!! 😉

  5. Ashish Goyal says:

    @Chris, do you see the same error codes? And does this ever worked before? Also it would be a good test to create a new test project and see if that works with Session State enabled. This will tell if the problem lies within the project or in the environment. Enabling Diagnostics (level 4) can also be a good option to know more about what is going wrong.

    I would also recommend posting this issue on MSDN Forum where it gets more visibility and inputs by other experts.…/forums  

  6. Andreas says:

    Thank you so much, this really helped me out. The same error appears, if you try to use the in-role cache with SDK 2.6 and WindowsAzureCache 2.7.

    Thanks again 🙂

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