Skip to main content

CosmosDB - Cleanup items automatically

I'm currently attending NDC Oslo. During one of the sessions, this one to be exact, the speaker shared a nice CosmosDB feature; Time to Live.

Some of the typical questions, you ask yourself when building applications are:

  • Should I use hard or soft deletes?
  • Are there any regulations on how long I can keep this data(e.g. GDPR)?
  • How can I keep the amount of data under control?

In the talk, the example they mention is weather data that is collected through various services. This data captured and used to feed an artificial intelligence algorithm to predict the most fuel-efficient way to operate a vessel in the North and Baltic sea.

After a prediction is done, the weather data is no longer necessary and can safely be deleted. Thanks to the Time to Live(TTL) feature in CosmosDB implementing this requirement is really easy.

You have to 2 ways to control the TTL value:

  • At the container level
  • At the item level

Control TTL at the container level

  1. Open the Data Explorer pane for your Azure CosmosDB account.

  2. Select an existing container, expand the Settings tab and modify the following values:

    • Under Setting find, Time to Live.

    • Change the TTL value to On with a value specified in seconds.

    • Select Save to save the changes.

If you prefer to do it through code:

 

Control TTL at the item level

To enable this at the item, we need to introduce an extra ‘ttl’ field on the item:

Is this for free?

One question you probably ask yourself, does this feature comes with a cost? Unfortunately the answer is yes. Deletion of expired items is a background task that consumes left-over Request Units, that is Request Units that haven't been consumed by user requests. Even after the TTL has expired, if the container is overloaded with requests and if there aren't enough RU's available, the data deletion is delayed (although the data will no longer be returned by any queries).

If you want to learn more about this feature, have a look at the documentation here.

Labels:

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...
Read more

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.
Read more

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...
Read more