Skip to main content

MassTransit - Stop handling erroneous messages

By default when a MassTransit consumer fails to handle a message (and throws an exception), the message is moved to an _error queue (prefixed by the receive endpoint queue name). This is OK for transient exceptions but probably not what you want when you have a bug in your system or there is another reason why none of the messages can be handled succesfully.

In that case, another feature of MassTransit becomes handy; the kill switch.

A Kill Switch is used to prevent failing consumers from moving all the messages from the input queue to the error queue. By monitoring message consumption and tracking message successes and failures, a Kill Switch stops the receive endpoint when a trip threshold has been reached.

You can configure a kill switch for a specific endpoint or for all receiver endpoints on the bus.

Here is a short example on how to configure the kill switch for all receiver endpoints:

 

In the above example, the kill switch will activate after 10 messages have been consumed. If the ratio of failures/attempts exceeds 15%, the kill switch with trip and stop the receive endpoint. After 1 minute, the receive endpoint will be restarted. Once restarted, if exceptions are still observed, the receive endpoint will be stopped again for 1 minute.

If you want to learn more about this feature, check out this video by Chris Patterson, the creator of Masstransit:

Popular posts from this blog

.NET 8–Keyed/Named Services

A feature that a lot of IoC container libraries support but that was missing in the default DI container provided by Microsoft is the support for Keyed or Named Services. This feature allows you to register the same type multiple times using different names, allowing you to resolve a specific instance based on the circumstances. Although there is some controversy if supporting this feature is a good idea or not, it certainly can be handy. To support this feature a new interface IKeyedServiceProvider got introduced in .NET 8 providing 2 new methods on our ServiceProvider instance: object? GetKeyedService(Type serviceType, object? serviceKey); object GetRequiredKeyedService(Type serviceType, object? serviceKey); To use it, we need to register our service using one of the new extension methods: Resolving the service can be done either through the FromKeyedServices attribute: or by injecting the IKeyedServiceProvider interface and calling the GetRequiredKeyedServic...

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.

Kubernetes–Limit your environmental impact

Reducing the carbon footprint and CO2 emission of our (cloud) workloads, is a responsibility of all of us. If you are running a Kubernetes cluster, have a look at Kube-Green . kube-green is a simple Kubernetes operator that automatically shuts down (some of) your pods when you don't need them. A single pod produces about 11 Kg CO2eq per year( here the calculation). Reason enough to give it a try! Installing kube-green in your cluster The easiest way to install the operator in your cluster is through kubectl. We first need to install a cert-manager: kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.14.5/cert-manager.yaml Remark: Wait a minute before you continue as it can take some time before the cert-manager is up & running inside your cluster. Now we can install the kube-green operator: kubectl apply -f https://github.com/kube-green/kube-green/releases/latest/download/kube-green.yaml Now in the namespace where we want t...