Calling Lokalise REST Api From Azure Function Sometimes SocketException: No such host is known

Question

We are intermittingly seeing in logs SocketException: No such host is known in Azure function while calling https://api.lokalise.com/api2/projects/{id}/keys using HttpClient.

The problem is that there is no way to know whether issue is from HttpClient (Microsoft.NETCore.App.Ref\3.1.0\ref\netcoreapp3.1\System.Net.Http.dll) or its from host api.lokalise.com. After every couple of days we are seeing this issue.

Here is full stack,

Microsoft.Azure.WebJobs.Host.FunctionInvocationException:
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<ExecuteWithLoggingAsync>d__26.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.32.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.cs:367)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<TryExecuteAsync>d__18.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.32.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.cs:108)
Inner exception System.Net.Http.HttpRequestException handled at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw:
   at System.Net.Http.ConnectHelper+<ConnectAsync>d__1.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.Tasks.ValueTask`1.get_Result (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1+ConfiguredValueTaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<ConnectAsync>d__52.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.Tasks.ValueTask`1.get_Result (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1+ConfiguredValueTaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<CreateHttp11ConnectionAsync>d__53.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.Tasks.ValueTask`1.get_Result (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1+ConfiguredValueTaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<GetHttpConnectionAsync>d__45.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.Tasks.ValueTask`1.get_Result (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1+ConfiguredValueTaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<SendWithRetryAsync>d__47.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.RedirectHandler+<SendAsync>d__4.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.DiagnosticsHandler+<SendAsync>d__2.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpClient+<FinishSendAsyncBuffered>d__70.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at MyApp.Triggers.LokaliseService+<GetTranslations>d__2.MoveNext (MyApp-Triggers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: D:\home\site\repository\LokaliseService.cs:23)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at MyApp.Triggers.LokaliseService+<GetTranslationString>d__3.MoveNext (MyApp-Triggers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: D:\home\site\repository\LokaliseService.cs:35)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at MyApp.Triggers.EmailSender+<Run>d__10.MoveNext (MyApp-Triggers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: D:\home\site\repository\EmailSender.cs:47)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.VoidTaskMethodInvoker`2+<InvokeAsync>d__2.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.32.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\VoidTaskMethodInvoker.cs:20)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionInvoker`2+<InvokeAsync>d__10.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.32.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionInvoker.cs:52)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<InvokeWithTimeoutAsync>d__33.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.32.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.cs:596)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<ExecuteWithWatchersAsync>d__32.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.32.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.cs:542)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<ExecuteWithLoggingAsync>d__26.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.32.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.cs:320)
Inner exception System.Net.Sockets.SocketException handled at System.Net.Http.ConnectHelper+<ConnectAsync>d__1.MoveNext:
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.ConnectHelper+<ConnectAsync>d__1.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)

Update 2022-04-08: We got this error again without our code involved and this time it is connecting to https://profiler.monitor.azure.com:443/api/hostagent/v1/config. Look like issue is with HTTP client library not with loklise.

System.Net.Http.HttpRequestException:
   at System.Net.Http.ConnectHelper+<ConnectAsync>d__1.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<ConnectAsync>d__52.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<CreateHttp11ConnectionAsync>d__53.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<GetHttpConnectionAsync>d__45.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.HttpConnectionPool+<SendWithRetryAsync>d__47.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.RedirectHandler+<SendAsync>d__4.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.DiagnosticsHandler+<SendAsync>d__2.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
Inner exception System.Net.Sockets.SocketException handled at System.Net.Http.ConnectHelper+<ConnectAsync>d__1.MoveNext:
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Net.Http.ConnectHelper+<ConnectAsync>d__1.MoveNext (System.Net.Http, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)

Is it happening during the newer version of deployment of `api.lokalise.com` app? — user1672994, Apr 01 '22 at 03:12

score 0 · Answer 1 · answered Apr 09 '22 at 06:43

It seemed Like DNS issues:
tcpclient prefers an ip address and not a name.
Use Dns.GetHostEntry to strip the characters and change it to an ip.

IPHostEntry hostInfo = Dns.GetHostEntry(hostnamehere);

Dns.GetHostEntry Resolves a host name or IP address to an IPHostEntry instance.

or

You could try catching exception and implementing retry mechanism if this exception is thrown.

Ref: link1 Link2 Link3

Calling Lokalise REST Api From Azure Function Sometimes SocketException: No such host is known

1 Answers1