Skip to main content

ORMs - You're doing it wrong

ORMs(Object-Relational-Mappers), can’t live with them, can’t live without them. I always had a love/hate relationship with ORMs. No matter if it’s NHibernate, Entity Framework or a micro-ORM solution, it always feels like too much work just to get some data in and out a database…

Therefore it’s really important to use ORMs in the correct way. Jimmy Bogard has his own opinions about ORM usage and in his presentation ‘ORMs – You’re doing it wrong’, he shares his opinions with the world.

Nothing gets DBAs more riled up than a developer infatuated with an Object-Relational Mapper. ORMs work great at mapping from relational to objects, but can be a crutch. If you want to make your DBA (and your users happy), you’ll want to use your ORM intelligently. In this session, we’ll look at application patterns, ORM features and more to discover the right way of using your ORM. We’ll also look at when to ditch your heavyweight ORM and reach for a lighter one. Finally, we’ll cover why abstracting your ORM is evil and alternatives that give us more flexibility and maintainability in the long run.

image

Popular posts from this blog

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         ...

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.

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) ...