14 posts tagged with "migrations"

Introduction​

The Atlas Kubernetes Operator is a Kubernetes operator that enables you to manage your database schemas natively from your Kubernetes cluster. By exposing custom resource definitions (CRD) the operator extends the Kubernetes API to support database schema management.

In a previous blog post we demonstrated how to use the Atlas Operator for the declarative (state-based) workflow in which you define the desired state of your database schema in a Kubernetes manifest and the operator takes care of the rest.

State vs. versioned based migrations is a common and unresolved debate in the database schema management world, and we built Atlas to support both from the get-go.

Today, we are happy to announce v0.2.0 of the Atlas Kubernetes Operator which adds support support for the versioned migration workflow.

In this blog post we will demonstrate how to use the Atlas Operator this new workflow.

Wikipedia defines Multi-tenancy as:

a software architecture in which a single instance of software runs on a server and serves multiple tenants.

In recent years, multitenancy has become a common topic in our industry as many organizations provide service to multiple customers using the same infrastructure. Multitenancy usually becomes an issue in software architecture because tenants often expect a decent level of isolation from one another.

In this post, I will go over different known approaches for achieving multi-tenancy and discuss the approach we took to build Ariga's cloud platform. In addition, I will demonstrate how we added built-in support for multi-tenant environments in Atlas to overcome some of the challenges we faced.

With the release of v0.6.0, we introduced a workflow for managing changes to database schemas that we have called: Versioned Migration Authoring.

Today, we released the first version of the Atlas migration execution engine, that can apply migration files on your database. In this post, we will give a brief overview of the features and what to expect in the future.

With the release of v0.6.0, we are happy to announce official support for a style of workflow for managing changes to database schemas that we have been experimenting with in the past months: Versioned Migration Authoring.

TL;DR​

• Atlas supports a declarative workflow (similar to Terraform) where users provide the desired database schema in a simple data definition language and Atlas calculates a plan to get a target database to that state. This workflow is supported by the schema apply command.
• Many teams prefer a more imperative approach where each change to the database schema is checked-in to source control and reviewed during code-review. This type of workflow is commonly called versioned migrations (or change based migrations) and is supported by many established tools such as Flyway and Liquibase.
• The downside of the versioned migration approach is, of course, that it puts the burden of planning the migration on developers. As part of the Atlas project we advocate for a third combined approach that we call "Versioned Migration Authoring".
• Versioned Migration Authoring is an attempt to combine the simplicity and expressiveness of the declarative approach with the control and explicitness of versioned migrations.
• To use Versioned Migration Authoring today, use the atlas migrate diff command. See the Getting Started section below for instructions.