Remove error messages from the event log

docs/eventlog-design.md

@@ -2,7 +2,7 @@
 
 ## What it is
 
-The event log is the primary instance's activity feed: the chronological "what has this instance noticed" list that ServicePulse shows. Message failures, retries, redirects, heartbeats, custom checks and integration failures all surface here.
+The event log is the primary instance's activity feed: the chronological "what has this instance noticed" list that ServicePulse shows. Retries, redirects, heartbeats, custom checks and integration failures all surface here. Message failures do not: they are visible on the failed messages screen instead, and recording one row per failure in the feed was removed as write and retention overhead on the hot ingest path.
 
 It is a **projection of domain events, not a log file**. Nothing writes to it directly. Components raise domain events for their own reasons, and the event log turns a chosen subset of those into feed items. An event only appears if someone has declared how it should read, which makes the feed an editorial selection rather than a dump.
 

src/ServiceControl.AcceptanceTests/Recoverability/MessageFailures/When_a_message_has_failed.cs

@@ -12,7 +12,6 @@ namespace ServiceControl.AcceptanceTests.Recoverability.MessageFailures
     using AcceptanceTesting;
     using AcceptanceTesting.EndpointTemplates;
     using CompositeViews.Messages;
-    using EventLog;
     using Infrastructure;
     using NServiceBus;
     using NServiceBus.AcceptanceTesting;
@@ -169,30 +168,6 @@ public async Task Should_be_listed_in_the_messages_list(CancellationToken cancel
             }
         }
 
-        [Test]
-        public async Task Should_add_an_event_log_item()
-        {
-            EventLogItem entry = null;
-
-            var context = await Define<MyContext>()
-                .WithEndpoint<Receiver>(b => b.When(bus => bus.SendLocal(new MyMessage())).DoNotFailOnErrorMessages())
-                .Done(async c =>
-                {
-                    var result = await this.TryGetSingle<EventLogItem>("/api/eventlogitems/", e => e.RelatedTo.Any(r => r.Contains(c.UniqueMessageId)) && e.EventType == nameof(Contracts.MessageFailures.MessageFailed));
-                    entry = result;
-                    return result;
-                })
-                .Run();
-
-            using (Assert.EnterMultipleScope())
-            {
-                Assert.That(entry.Severity, Is.EqualTo(Severity.Error), "Failures should be treated as errors");
-                Assert.That(entry.Description, Does.Contain("exception"), "For failed messages, the description should contain the exception information");
-                Assert.That(entry.RelatedTo.Any(item => item == "/message/" + context.UniqueMessageId), Is.True, "Should contain the api url to retrieve additional details about the failed message");
-                Assert.That(entry.RelatedTo.Any(item => item == "/endpoint/" + context.EndpointNameOfReceivingEndpoint), Is.True, "Should contain the api url to retrieve additional details about the endpoint where the message failed");
-            }
-        }
-
         [Test]
         public async Task Should_be_able_to_search_queueaddresses()
         {

src/ServiceControl.AcceptanceTests/Recoverability/When_hosting_error_ingestion_only.cs

@@ -136,10 +136,6 @@ public async Task Should_ingest_a_failed_message_into_the_shared_database()
                     Assert.That(knownEndpoints.Select(endpoint => endpoint.Name), Does.Contain("IngestOnly.Receiver"));
                 }
 
-                await WaitFor(host, async dbContext => await dbContext.EventLogItems.AsNoTracking()
-                        .AnyAsync(item => item.EventType == "MessageFailed" && item.Description == "Simulated failure"),
-                    "an event log entry for the failure");
-
                 using var client = host.GetTestClient();
 
                 var liveness = await client.GetAsync("/health");
@@ -212,27 +208,6 @@ await infrastructure.Dispatcher.Dispatch(
             }
         }
 
-        static async Task WaitFor(IHost host, Func<ServiceControlDbContext, Task<bool>> condition, string description)
-        {
-            var scopeFactory = host.Services.GetRequiredService<IServiceScopeFactory>();
-            var timeout = Stopwatch.StartNew();
-
-            while (timeout.Elapsed < TimeSpan.FromSeconds(60))
-            {
-                await using var scope = scopeFactory.CreateAsyncScope();
-                var dbContext = scope.ServiceProvider.GetRequiredService<ServiceControlDbContext>();
-
-                if (await condition(dbContext))
-                {
-                    return;
-                }
-
-                await Task.Delay(TimeSpan.FromMilliseconds(200));
-            }
-
-            Assert.Fail($"Timed out waiting for {description}.");
-        }
-
         static async Task<FailedMessageEntity> WaitForFailedMessage(IHost host, string messageId)
         {
             var scopeFactory = host.Services.GetRequiredService<IServiceScopeFactory>();

src/ServiceControl/Recoverability/RecoverabilityComponent.cs

@@ -125,7 +125,6 @@ public override void Configure(Settings settings, ITransportCustomization transp
             services.AddEventLogMapping<FailedMessageGroupArchivedDefinition>();
             services.AddEventLogMapping<FailedMessageGroupUnarchivedDefinition>();
             services.AddEventLogMapping<FailedMessageUnArchivedDefinition>();
-            services.AddEventLogMapping<MessageFailedDefinition>();
             services.AddEventLogMapping<MessageFailedInStagingDefinition>();
             services.AddEventLogMapping<MessageFailureResolvedByRetryDefinition>();
             services.AddEventLogMapping<MessageFailureResolvedManuallyDefinition>();