catch exceptions in event hub trigger if orchestration service has not started

test/EventConsumer/EventHubTrigger.cs

@@ -3,6 +3,7 @@
 
 namespace EventConsumer
 {
+    using System;
     using System.Collections.Generic;
     using System.IO;
     using System.Threading.Tasks;
@@ -20,48 +21,66 @@ namespace EventConsumer
             [DurableClient] IDurableClient client,
             ILogger log)
         {
-            if (TestConstants.BatchSignals)
+            int numTries = 0;
+
+            while (numTries < 10)
             {
-                // we pack all the events into a byte sequence, and then
-                // send those bytes as a signals to the entity
+                numTries++;
 
-                var stream = new MemoryStream();
-                using var streamWriter = new BinaryWriter(stream);
-
-                for (int i = 0; i < eventDataSet.Length; i++)
+                try
                 {
-                    var eventData = eventDataSet[i];
-                    var sp = eventData.SystemProperties;
-                    streamWriter.Write((int) eventData.Body[0]);
-                    streamWriter.Write(eventData.SystemProperties.SequenceNumber);
-                    streamWriter.Write(eventData.Body.Count);
-                    streamWriter.Write(eventData.Body);
+                    if (TestConstants.BatchSignals)
+                    {
+                        // we pack all the events into a byte sequence, and then
+                        // send those bytes as a signals to the entity
+
+                        var stream = new MemoryStream();
+                        using var streamWriter = new BinaryWriter(stream);
+
+                        for (int i = 0; i < eventDataSet.Length; i++)
+                        {
+                            var eventData = eventDataSet[i];
+                            var sp = eventData.SystemProperties;
+                            streamWriter.Write((int)eventData.Body[0]);
+                            streamWriter.Write(eventData.SystemProperties.SequenceNumber);
+                            streamWriter.Write(eventData.Body.Count);
+                            streamWriter.Write(eventData.Body);
+                        }
+
+                        streamWriter.Flush();
+                        await client.SignalEntityAsync(new EntityId(nameof(ReceiverEntity), "0"), nameof(ReceiverEntity.ReceiveBatch), stream.ToArray());
+                    }
+                    else
+                    {
+                        var signalTasks = new List<Task>();
+
+                        // send one signal for each packet
+                        for (int i = 0; i < eventDataSet.Length; i++)
+                        {
+                            var eventData = eventDataSet[i];
+                            var sp = eventData.SystemProperties;
+                            byte[] payload = eventData.Body.ToArray();
+                            var evt = new Event()
+                            {
+                                Partition = payload[0],
+                                SeqNo = eventData.SystemProperties.SequenceNumber,
+                                Payload = payload
+                            };
+                            log.LogInformation($"Sending signal for {evt}");
+                            signalTasks.Add(client.SignalEntityAsync(new EntityId(nameof(ReceiverEntity), "0"), nameof(ReceiverEntity.Receive), evt));
+                        }
+
+                        await Task.WhenAll(signalTasks);
+                    }
+
+                    break;
                 }
-
-                streamWriter.Flush();
-                await client.SignalEntityAsync(new EntityId(nameof(ReceiverEntity), "0"), nameof(ReceiverEntity.ReceiveBatch), stream.ToArray());
-            }
-            else
-            {
-                var signalTasks = new List<Task>();
-
-                // send one signal for each packet
-                for (int i = 0; i < eventDataSet.Length; i++)
+                catch (NullReferenceException)
                 {
-                    var eventData = eventDataSet[i];
-                    var sp = eventData.SystemProperties;
-                    byte[] payload = eventData.Body.ToArray();
-                    var evt = new Event()
-                    { 
-                        Partition = payload[0],
-                        SeqNo = eventData.SystemProperties.SequenceNumber,
-                        Payload = payload
-                    };
-                    log.LogInformation($"Sending signal for {evt}");
-                    signalTasks.Add(client.SignalEntityAsync(new EntityId(nameof(ReceiverEntity), "0"), nameof(ReceiverEntity.Receive), evt));
+                    // during startup we may get these exceptions if the trigger goes off before the
+                    // Orchestration service has been started
+                    await Task.Delay(TimeSpan.FromSeconds(1));
                 }
-
-                await Task.WhenAll(signalTasks);
             }
         }
     }

test/EventConsumer/host.json

@@ -20,7 +20,13 @@
       "UseGracefulShutdown": "true",
       "storageProvider": {
         "StorageConnectionString": "$AzureWebJobsStorage",
-        "EventHubsConnectionString": "$EventHubsConnection"
+        "EventHubsConnectionString": "$EventHubsConnection",
+        "LogLevelLimit": "Information",
+        "StorageLogLevelLimit": "Debug",
+        "TransportLogLevelLimit": "Information",
+        "EventLogLevelLimit": "Information",
+        "WorkItemLogLevelLimit": "Information",
+        "TraceToBlob": "true"
       }
     }
   }