Azure Application Insights–MassTransit integration

One of the features that Application Insights has to offer is ‘Dependency Tracking'. It allows you to monitor components that are called by your application. This can be a service called using HTTP, or a database, or a file system. Application Insights measures the duration of dependency calls, whether its failing or not, along with additional information like name of dependency and so on. You can investigate specific dependency calls, and correlate them to requests and exceptions.

Automatically tracked dependencies

Out-of-the-box the following dependencies are tracked automatically:

Dependencies	Details
Http/Https	Local or Remote http/https calls.
WCF Calls	Only tracked automatically if Http-based bindings are used.
SQL	SQL Calls made with SqlClient.
Azure storage	Calls made with Azure Storage Client.
EventHub Client SDK	EventHub Client SDK Version 1.1.0 and above.
ServiceBus Client SDK	ServiceBus Client SDK Version 3.0.0 and above.
Azure Cosmos DB	Only tracked automatically if HTTP/HTTPS is used. TCP mode won't be captured by Application Insights.

Setup dependency tracking for MassTransit

To extend dependency tracking and track calls to MassTransit we need to configure the built-in DependencyTrackingTelemetryModule and include an extra ‘MassTransit’ diagnostic source:

After adding this code, you should see the MassTransit calls show up as dependencies in your Telemetry data:

And here are the details:

Podman– Command execution failed with exit code 125

After updating WSL on one of the developer machines, Podman failed to work. When we took a look through Podman Desktop, we noticed that Podman had stopped running and returned the following error message: Error: Command execution failed with exit code 125 Here are the steps we tried to fix the issue: We started by running podman info to get some extra details on what could be wrong: >podman info OS: windows/amd64 provider: wsl version: 5.3.1 Cannot connect to Podman. Please verify your connection to the Linux system using `podman system connection list`, or try `podman machine init` and `podman machine start` to manage a new Linux VM Error: unable to connect to Podman socket: failed to connect: dial tcp 127.0.0.1:2655: connectex: No connection could be made because the target machine actively refused it. That makes sense as the podman VM was not running. Let’s check the VM: >podman machine list NAME ...

Cache stampede: when our cache turned against us

While investigating some performance issues, we ran into an ASP.NET Core API that cached a fairly expensive aggregation query for 60 seconds. Under normal load, that was fine: one request rebuilds the cache, everyone else reads from it. Under peak load, dozens of requests would arrive in that same expiry window, all see a cache miss, and all fire the same expensive query in parallel. The database didn't like that. That was the moment when our caching layer stopped helping and started hurting. A burst of requests comes in at the same time, all miss the cache, and all go hammer the database or the downstream API at once. That's a cache stampede . The cache was supposed to protect our backend, and for a few hundred milliseconds it did the opposite. Why this happens IMemoryCache.GetOrCreate (and its async sibling) looks like it protects you, but it doesn't add any locking on its own. Look at the naive version: public async Task<Report> GetReportAsync(string key) ...

A complex system designed from scratch never works

A few years ago, I worked as an architect on a big mainframe rewrite. I still count it as one of my failures. Not because the technology was wrong, but because I couldn't convince the management team to simplify the approach. Years later, the organization is still struggling to get the new system up and running. I left the project at the time, because I couldn't put my name behind an approach that would take very long and cost a lot of money without a working system to show for it along the way. Gall’s Law That memory keeps coming back to me, because it's a textbook case of Gall's Law playing out in real life. Gall's Law , from John Gall's Systemantics , states it plainly: A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works, and it cannot be patched to make it work. You have to start over with a simple system that works. What does that mean in practice,...

The art of simplicity

Search This Blog