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SQL Azure - Improve restoring time of BACPAC during load tests

SQL Azure is a great service when you need a location to store a relational database and you don't want to manage the infrastructure that is behind it. In only a few minutes, you can get a powerful database ready for your needs.

In almost all projects life cycles, there is a moment in time when need to run one or more Load Tests. For each scenario, you may need a different database setup.
In the above example, we have 3 different scenarios that we want to test. This means that, we need to load 3 different bacpac files. If the database is relatively small (10MB) than we will not have any kind of problems.
But with a large database, the restoring process can take some time. Behind the scene, a database restoring process is complex and CPU intensive, because of this it will require time and CPU.
This will not be a problem for a database of type P1 or P2, where the restoring process is fast. But, for a S0 or S1, we may need to wait for even a few hours, until our backup is restored and our database is ready to run another load test scenario.

What we could do in this case? What we can do to reduce the waiting time between Load Tests?
Better databases
One possible solution would be to upgrade our database to a better one. Unfortunately this is not a solution. When you run a load test you want to run with the same configuration like in production. Running with a better database may affect your load tests results.

Different databases
Another solution is to prepare multiple databases, with different configuration. In this way you can have for each scenario a different database instance. From your application you could specify what database you want to use.
This could work for small/medium solutions. But this could increase the load test setup if your system use 15 different databases for example. Also, the costs of running the load tests may be impacted.

Better databases only when we restore a bacpac
Using this approach, we would run the load test with the database type that we want. Only during the load test setup, we would upgrade our database instance to a better type. In this way we can minimize the time that is needed to restore a specific bacpac and we would also reduce the costs of the load tests.

It is important to know that changing the type of a database takes only a few minutes. In this way we can easily play with different types.

In conclusion we could say that the best approach in this situation is to use the same database, but to change the type of the database when a database restore is done. This would allow us to keep the time and the costs to minimal and well-balanced.


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