The Process for Zero-Downtime Data Migration

Downtime is a dirty word.

98% of firms report that a single hour of it costs at least $100,000.

That sounds steep, but it’s the reality. When things aren’t running, businesses don’t make money – they lose it. Yes, there are times when processes must be halted for maintenance or due to external factors, but, even when downtime is planned, it has harsh effects on business productivity and profitability.

Over the previous few decades, data migration was one of the occurrences that tended to require at least some downtime. But, thanks to the technologies now available, that’s no longer the case.

Given the downsides of downtime, as you migrate data, it makes sense to try to avoid it. With that in mind, here’s how to achieve zero-downtime during data migration.

Why Migrate Data?

Before we get into the details of the process, let’s answer a basic question: Given the complexity of a data migration, why would you migrate in the first place?

There are a variety of answers. Sometimes databases become obsolete. Sometimes new environments are so cost-efficient that the migration becomes a no-brainer. Sometimes more or different accessibility of data is needed.

The bottom line is that data migration makes sense in two scenarios – when it’s more costly to maintain data in its current location than it is to move the data, or when the benefits of moving the data outweigh the costs of moving it.

If you’ve found yourself in one of these situations, it’s time to migrate. If you haven’t, migration may not be necessary.

The Process for Zero-Downtime Migration

If you’ve clarified that it’s time to migrate your data, you will want to minimize the costs associated with the migration. Achieving a zero-downtime migration is hugely impactful toward this end, especially if the resources you’re migrating are costly to stop for any extended period of time.

Here’s how to make it happen.

1. Scope Out the Migration

We’ve written before about the steps involved in a data migration; the first is to scope the process. This will involve assessing the source data and defining the destination(s). You’ll need to plan out how data ingestion will happen and how data will be delivered, and you’ll need to define the format data should take within the new environment.

You can read more about this process here.

2. Use Data Ingestion and Replication to Create a Test Environment

Once you’ve scoped out the migration, the next step in a zero-downtime solution is to create a test environment.

This is crucial.

In this test environment, you should create a replica of your database while you continue using the live database. This can be done over a period of time, or data ingestion can happen all at once.

StarQuest Data Replicator (SQDR), our software solution for data migration, creates the ideal test environment by creating a full copy of existing data that is migrated incrementally to the new environment – with sub-second latency if need be – so that the mirror stays accurate and current.

Zero-downtime solutions like SQDR are a good choice, because the more current the data, the more useful it tends to be. Because zero-downtime solutions use mirroring, data stays current.

The end result of this process should be a working replica of your current database in its new environment.

3. Test the New Environment

Once the database has been replicated to the new environment, the next step is to test it – robustly.

You should perform the same functions and queries on the replicated database that you will expect to perform in production. You should allow stakeholders access to the test environment to ensure that everyone knows how to use it; you may offer training during this stage, too.

Essentially, you should use this stage as the dress rehearsal to get your processes in order. When things are working exactly as you’d like them to in production, you can go live.

4. Flip the Switch

This is the big moment – but, if you’ve tested your new environment robustly, it should be completely seamless.

Start using the data in the new environment and stop using the data in the old environment. There should be no pause in processes; you’ve achieved a zero-downtime migration.

5. Audit the New Environment

Regardless, you should still take time to audit the new environment after the migration is accomplished. Ensure that processes are working smoothly, that monitoring is in place, and that data is in the places it needs to be and in the right formats.

If the migration was done in order to achieve some benefit, this is also the time to evaluate whether or not things have improved.

Auditing should continue to be conducted at regular intervals, but past this point, you can consider your zero-downtime data migration complete.

If you use SQDR for your migration, you can rest easy. The solution is so good at what it does that it effectively eliminates this step. It keeps track of new changes even when you’re in the middle of a data migration so that the process happens seamlessly.

Ready to Plan a Zero-Downtime Data Migration?

Hopefully, the information above has helped you to define your own plan as you consider how to enact a zero-downtime data migration. If you’re looking to take the first step toward a migration, let’s talk.

At StarQuest, we’re experts at data ingestion and management. Our powerful SQDR software can be utilized for replication and ingestion from an extensive range of data sources, ensuring that you have a mirrored database working perfectly before you flip the switch on the migration.

And, importantly, our customer service team is regarded as some of the best in the business, with clients calling us “The best vendor support I have ever encountered.”

If you’re looking for data ingestion that can power your zero-downtime migration, we can help.

Get in touch with us to discuss your data ingestion needs. We can set you up with a no-charge trial of our software using the DBMS of your choice, and help you take the first step toward a seamless transition.