Backup Strategy: Identify Your Needs

Data loss is one of the biggest business risk in running modern software systems. And to be honest, it's rarely caused by infrastructure failures. In most real-life cases, it's a result of a buggy upgrade or a human mistake that accidentally corrupts the data.

That's why properly organized backups are the foundation of any disaster recovery plan (DR Strategies overview can be found there).

If you have a monolith app deployed on a single VM, the strategy is simple: just perform a full VM backup. But for microservice solutions with hundreds of services, different types of databases and other persistence storages, the task becomes non trivial.

To build your own backup strategy, you need to answer the following questions:

✏️ What type of data sources do you have? It can be databases, queues, file and blob storages, VMs and other infrastructure components.
✏️ What data is business critical? Classify data based on criticality, different type of data can have different requirements to RPO and even allow some data loss.
✏️ Is data primary or secondary? Some data can be reproduceable from other sources (search indexes, streaming data, deployment configuration, etc.) and it's cheaper to restore it from initial source than perform a backup and fix consistency issues.
✏️ What are the RPO and RTO requirements? According to that you will set up a backup frequency. For example, if RPO is 15 minutes then you’ll need to schedule backups at least every 15 minutes.
✏️ Are there any compliance rules? Some regulations require to keep the data for a specific period of time (e.g., billing and revenue data, personal data). That mostly impacts backup retentions policies and required hardware.

According to the answers you can choose suitable backup types, schedule, recovery and testing strategies. More about that in future posts 😉

#engineering #systemdesign #backups