| Phobos - APM for Akka.NET

1.4.0 January 19th 2022

New Minor Version Release for Phobos

Phobos 1.4 is a minor version release that introduces some exciting new capabilities for Akka.NET users, primarily:

All actor lifecycle activity, i.e. everything that occurs during PreStart, PostStop, PreRestart, and PostRestart is now traced by default. This will allow you to visualize everything that happens after an actor is spawned mid-flight. This setting does produce significantly more traces when enabled (naturally) so it can be disabled via the following HOCON setting: phobos.tracing.trace-actor-lifecycle = off.
Phobos 1.4 uses Akka.NET v1.4.32, which contains important changes to the Akka.Persistence Journal base classes that now allow us to properly trace activity that happens within it. As a result, when phobos.tracing.trace-actor-lifecycle = on (this is the default) you can now trace the entire recovery process of all PersistentActor implementations - so long as the Akka.Persistence plugin you're using is built against Akka.NET v1.4.32 or higher. In addition to tracing Akka.Persistence recoveries all Persist calls can now be traced end to end with Phobos.

1.3.3 January 3rd 2022

Patch for Phobos 1.3

Phobos v1.3.3 introduces a bugfix for a very edge-case regression that was introduced in Phobos v1.3.2:

Possible regression: System.NotImplementedException in Akka.Persistence.Sql.Common.Journal.BatchingSqlJournal

This was caused by some of our trace correlation software not fitlering remote IActorRefs that sent messages to actors outside of an actor's scheduled context, a rare case that could only really happen inside a Task closed over a remote IActorRef. Patch v1.3.3 resolves this issue.

1.3.2 December 21st 2021

Minor Version Release for Phobos

Phobos v1.3.2 includes some important tracing enhancements brought about as a result of upgrading Phobos to Akka.NET v1.4.31:

Phobos now supports tracing the output of PipeTo operations! This can be accomplished by making sure that the Sender property of the PipeTo operation contains a reference to the actor kicking of the Task<T> whose results will be piped:

var myActor = Sys.ActorOf(act =>
{
    act.ReceiveAny((o, ctx) =>
    {
        // won't capture trace - no "sender" included
        Task.Delay(TimeSpan.FromMilliseconds(100)).PipeTo(ctx.Sender, success: () => o);

        // will capture trace - "Sender" is specified
        Task.Delay(TimeSpan.FromMilliseconds(100)).PipeTo(ctx.Sender, success: () => o, sender:ctx.Self);
    });
});

1.3.1 December 9th 2021

Minor Version Release for Phobos

Phobos v1.3.1 includes some improvements for metrics support:

phobos.monitoring.monitor-mailbox-depth is now set to on by default as the performance impact is negligible for most actor types and can be found under the akka.actor.mailbox.depth metric header.
Phobos now records an App.Metrics Timer for every message received by an actor under the akka.messages.latency header. This is used to help measure how long an actor takes to process each message and these times will also be measured across an awaits that occur inside your actor's ReceiveAsync methods.

We also have updated all of our built-in Phobos dashboards to include the akka.messages.latency values. You can see an example below:

akka.messages.latency, new metrics introduced in Phobos v1.3.1, being displayed in Grafana

The addition of the akka.messages.latency metric to Phobos' captured Akka.NET data

In addition to these changes, we've also updated our performance benchmarks for Phobos to include the most recent data for v1.3.1. The addition of the akka.messages.latency reduces Phobos 1.3.1's total throughput by about 10% compared to our previous benchmarks, though usually this overhead pales in comparison to user-defined code. However, if this is a problem for you please file an issue with us here: https://github.com/petabridge/phobos-issues

1.3.0 November 18th 2021

Minor Version Release for Phobos

Phobos v1.3.0 includes some significant improvements in its tracing capabilities:

Phobos now properly handles await operations that occur within your actors - so any traces that begin when an actor starts processing a message will be carried all the way through until your ReceiveAsync methods exit. This is convenient when combined with other libraries that emit traces such as EntityFramework and OpenTracing.Contrib.
Phobos no longer records any akka.actor.ask object invocations during the startup of your ActorSystem, which were erroneously being attached to user-generated traces as well.
In some instance of using the WrappedTracer, which gets called whenver you use the WithScopeManager extension method on an existing ITracer object, it was possible for a null ISpan to be passed into the SpanBuilder.ChildOf method. This input is now null-checked and will no longer throw NullReferenceException errors.
All IScopes generated by Phobos are disposed of per their original invocation ordering, which reverses a major change we introduced in Phobos 1.2.0. We were able to introduce this change safely as a result of changing how we track traces around await calls.
The Phobos cluster-listener-actor will no longer log any Unhandled messages when akka.loglevel=DEBUG and akka.actor.debug.unhandled=on any longer.
Phobos has been upgraded to run on Akka.NET v1.4.28.

In addition to these changes, we've also updated our performance benchmarks for Phobos to include the most recent data for v1.3.0.