Switch default LoadBalancingStrategy to Greedy (Azure#19460)

Author: pakrym

sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/CHANGELOG.md

@@ -1,7 +1,10 @@
 # Release History
 
-## 5.0.0-beta.3 (Unreleased)
+## 5.0.0-beta.3 (2021-03-11)
 
+### Changes
+
+- Default balancing strategy changed to greedy.
 
 ## 5.0.0-beta.2 (2021-03-09)
 

sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/src/Config/EventHubOptions.cs

@@ -5,6 +5,7 @@
 using Azure.Messaging.EventHubs;
 using Azure.Messaging.EventHubs.Consumer;
 using Azure.Messaging.EventHubs.Primitives;
+using Azure.Messaging.EventHubs.Processor;
 using Microsoft.Azure.WebJobs.EventHubs.Processor;
 using Microsoft.Azure.WebJobs.Hosting;
 using Newtonsoft.Json;
@@ -21,6 +22,7 @@ public EventHubOptions()
             {
                 TrackLastEnqueuedEventProperties = false,
                 MaximumWaitTime = TimeSpan.FromMinutes(1),
+                LoadBalancingStrategy = LoadBalancingStrategy.Greedy,
                 PrefetchCount = 300,
                 DefaultStartingPosition = EventPosition.Earliest,
             };

sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/tests/EventHubsClientFactoryTests.cs

@@ -8,6 +8,7 @@
 using Azure.Messaging.EventHubs;
 using Azure.Messaging.EventHubs.Consumer;
 using Azure.Messaging.EventHubs.Primitives;
+using Azure.Messaging.EventHubs.Processor;
 using Azure.Messaging.EventHubs.Producer;
 using Azure.Storage.Blobs;
 using Microsoft.Azure.WebJobs.EventHubs.Processor;
@@ -228,6 +229,22 @@ public void RespectsConnectionOptionsForProcessor(string expectedPathName, strin
             Assert.AreEqual(expectedPathName, processor.EventHubName);
         }
 
+        [Test]
+        public void DefaultStrategyIsGreedy()
+        {
+            EventHubOptions options = new EventHubOptions();
+
+            var configuration = CreateConfiguration(new KeyValuePair<string, string>("connection", ConnectionString));
+            var factory = new EventHubClientFactory(configuration, Mock.Of<AzureComponentFactory>(), Options.Create(options), new DefaultNameResolver(configuration));
+
+            var processor = factory.GetEventProcessorHost("connection", "connection", "consumer");
+            EventProcessorOptions processorOptions = (EventProcessorOptions)typeof(EventProcessor<EventProcessorHostPartition>)
+                .GetProperty("Options", BindingFlags.NonPublic | BindingFlags.Instance)
+                .GetValue(processor);
+
+            Assert.AreEqual(LoadBalancingStrategy.Greedy, processorOptions.LoadBalancingStrategy);
+        }
+
         private IConfiguration CreateConfiguration(params KeyValuePair<string, string>[] data)
         {
             return new ConfigurationBuilder().AddInMemoryCollection(data).Build();