Mongo Event store improved.

src/Squidex.Infrastructure.MongoDb/CQRS/Events/MongoEventStore.cs

@@ -26,7 +26,7 @@ namespace Squidex.Infrastructure.CQRS.Events
     public class MongoEventStore : MongoRepositoryBase<MongoEventCommit>, IEventStore
     {
         private const long AnyVersion = long.MinValue;
-        private const int AppendTimeoutMs = 5000;
+        private const int MaxAttempts = 20;
         private static readonly BsonTimestamp EmptyTimestamp = new BsonTimestamp(0);
         private static readonly FieldDefinition<MongoEventCommit, BsonTimestamp> TimestampField = Fields.Build(x => x.Timestamp);
         private static readonly FieldDefinition<MongoEventCommit, long> EventsCountField = Fields.Build(x => x.EventsCount);
@@ -52,9 +52,10 @@ namespace Squidex.Infrastructure.CQRS.Events
             return new MongoCollectionSettings { ReadPreference = ReadPreference.Primary, WriteConcern = WriteConcern.WMajority };
         }
 
-        protected override Task SetupCollectionAsync(IMongoCollection<MongoEventCommit> collection)
+        protected override async Task SetupCollectionAsync(IMongoCollection<MongoEventCommit> collection)
         {
-            return collection.Indexes.CreateOneAsync(Index.Ascending(x => x.EventStreamOffset).Ascending(x => x.EventStream), new CreateIndexOptions { Unique = true });
+            await collection.Indexes.CreateOneAsync(Index.Ascending(x => x.Timestamp).Ascending(x => x.EventStream));
+            await collection.Indexes.CreateOneAsync(Index.Ascending(x => x.EventStream).Descending(x => x.EventStreamOffset), new CreateIndexOptions { Unique = true });
         }
 
         public IEventSubscription CreateSubscription(string streamFilter = null, string position = null)
@@ -138,15 +139,13 @@ namespace Squidex.Infrastructure.CQRS.Events
                 throw new WrongEventVersionException(currentVersion, expectedVersion);
             }
 
-            var cts = new CancellationTokenSource(AppendTimeoutMs);
-
             var commit = BuildCommit(commitId, streamName, expectedVersion >= -1 ? expectedVersion : currentVersion, events);
 
-            while (!cts.IsCancellationRequested)
+            for (var attempt = 0; attempt < MaxAttempts; attempt++)
             {
                 try
                 {
-                    await Collection.InsertOneAsync(commit, new InsertOneOptions(), cts.Token);
+                    await Collection.InsertOneAsync(commit);
 
                     notifier.NotifyEventsStored();
 
@@ -162,13 +161,13 @@ namespace Squidex.Infrastructure.CQRS.Events
                         {
                             throw new WrongEventVersionException(currentVersion, expectedVersion);
                         }
-                        else if (!cts.IsCancellationRequested)
+                        else if (attempt < MaxAttempts)
                         {
-                            commit.EventStreamOffset = currentVersion;
+                            expectedVersion = currentVersion;
                         }
                         else
                         {
-                            throw new TaskCanceledException("Could not acquire a free slot for the commit within the provided time.");
+                            throw new TimeoutException("Could not acquire a free slot for the commit within the provided time.");
                         }
                     }
                     else