In Cloud/Framework-Web integration if cloud.51degrees.com is down or unavailable due to networking issues - the request to the IIS will fail in the PipelineModule due to the pipeline construction failing despite SuppressProcessExceptions is set to true in the configuration. The observed stack trace would look similar to this:
Exception Details: System.Net.WebException: The remote name could not be resolved: 'cloud.51degrees.com'
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:
[WebException: The remote name could not be resolved: 'cloud.51degrees.com']
System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) +638
System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar) +65
[HttpRequestException: An error occurred while sending the request.]
[AggregateException: One or more errors occurred.]
System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions) +4316222
System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification) +12771596
System.Threading.Tasks.Task`1.get_Result() +34
FiftyOne.Pipeline.CloudRequestEngine.FlowElements.CloudRequestEngine.SendRequestAsync(HttpRequestMessage request) +53
[CloudRequestException: Error waiting for response from the cloud service.]
FiftyOne.Pipeline.CloudRequestEngine.FlowElements.CloudRequestEngine.SendRequestAsync(HttpRequestMessage request) +99
FiftyOne.Pipeline.CloudRequestEngine.FlowElements.CloudRequestEngine.AddCommonHeadersAndSend(HttpRequestMessage request) +226
FiftyOne.Pipeline.CloudRequestEngine.FlowElements.CloudRequestEngine.GetCloudProperties() +98
FiftyOne.Pipeline.CloudRequestEngine.FlowElements.CloudRequestEngine..ctor(ILogger`1 logger, Func`3 aspectDataFactory, HttpClient httpClient, String dataEndpoint, String resourceKey, String licenseKey, String propertiesEndpoint, String evidenceKeysEndpoint, Int32 timeout, List`1 requestedProperties, String cloudRequestOrigin) +593
FiftyOne.Pipeline.CloudRequestEngine.FlowElements.CloudRequestEngineBuilder.NewEngine(List`1 properties) +120
FiftyOne.Pipeline.Engines.FlowElements.AspectEngineBuilderBase`2.BuildEngine() +28
FiftyOne.Pipeline.CloudRequestEngine.FlowElements.CloudRequestEngineBuilder.Build() +152
[TargetInvocationException: Exception has been thrown by the target of an invocation.]
System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) +0
System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) +91
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +105
System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters) +21
FiftyOne.Pipeline.Core.FlowElements.PipelineBuilder.AddElementToList(List`1 elements, ElementOptions elementOptions, String elementLocation) +1750
FiftyOne.Pipeline.Core.FlowElements.PipelineBuilder.BuildFromConfiguration(PipelineOptions options) +205
FiftyOne.Pipeline.Web.Framework.WebPipeline..ctor() +1229
FiftyOne.Pipeline.Web.Framework.WebPipeline.GetInstance() +107
FiftyOne.Pipeline.Web.Framework.PipelineModule.OnBeginRequestJavascript(Object sender, EventArgs e) +59
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +144
System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +50
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +73
To reproduce you may disable cloud.51degrees.com in the hosts file by adding a line:
127.0.0.1 cloud.51degrees.com
Root Cause
The pipeline is not even constructed, because CloudRequestEngine as one of its flow elements throws during construction. This happens because on construction it requests the CloudProperties and CloudEvidenceKeys:
The design decision is that CloudProperties and CloudEvidenceKeys should be converted into lazy properties and should be requested from the server (requested once and then cached) - closer to the point of their use during processing of the evidence. This will allow any exceptions thrown from their initialization be controlled by the SuppressProcessExceptions option value and if it is set to true - the exceptions won't propagate up and fail the whole request to IIS. This should prevent the downtimes of the main service due to downtime of cloud.51degrees.com.
Problem
Observed
In Cloud/Framework-Web integration if cloud.51degrees.com is down or unavailable due to networking issues - the request to the IIS will fail in the PipelineModule due to the pipeline construction failing despite
SuppressProcessExceptionsis set to true in the configuration. The observed stack trace would look similar to this:To reproduce you may disable cloud.51degrees.com in the hosts file by adding a line:
Root Cause
The pipeline is not even constructed, because CloudRequestEngine as one of its flow elements throws during construction. This happens because on construction it requests the CloudProperties and CloudEvidenceKeys:
CloudRequestEnginehttps://github.com/51Degrees/pipeline-dotnet/blob/main/FiftyOne.Pipeline.CloudRequestEngine/FlowElements/CloudRequestEngine.cs#L151-L152Solution
The design decision is that
CloudPropertiesandCloudEvidenceKeysshould be converted into lazy properties and should be requested from the server (requested once and then cached) - closer to the point of their use during processing of the evidence. This will allow any exceptions thrown from their initialization be controlled by theSuppressProcessExceptionsoption value and if it is set to true - the exceptions won't propagate up and fail the whole request to IIS. This should prevent the downtimes of the main service due to downtime of cloud.51degrees.com.