redis

When you start your business and you have only a few Customers you are in an easy situation from performance perspective. I mean, you should provide some resources to your Customers for the right and acceptable performance.

Then your business is growing, you must serve your customers need, and increase system performance. Sometimes this is easy, sometimes not.

For this there is a quite common solution which helps you to provide a fast and reliable service. This is the Redis Cache which is available for almost every solutions in the cloud.

Redis is a great solution. You can find more information for the bigest hyperscalers’ offer:

• Azure Cache for Redis
• Memorystore for Redis (GCP)
• Amazon ElastiCache for Redis

All of them are great, reliable, easy to use and fast. Nevertheless Today I would like to draw your attention for a brand new feature which allows you to replicate your Redis Cache data among different regions. Is it cool, isn’t it?

I am sure you know the AWS ElasticCache for Redis

From now AWS offers cross-region replication for this cache service.

How it helps?

This solution could be useful if the geolocal performance is important for you, or from disaster recovery point of view.

How it works?

1. When you have an existing Redis cluster (or you build a new one) somewhere the Global Datastores are supported. This will be the primary (active)
   

   

2. After some configuration steps AWS provisions the secondary (passive) Redis clusters to the selected regions. (You can create maximum 2 passive clusters)

Limitations

As you can see above there are several limitation of this feature.

• You only can add READ caches for your primary cluster
• Maximum number of replicas: 2
• Global Datastore is available only some regions
• ElastiCache doesn’t support autofailover from one AWS Region to another.

The full list of limitations you can find here: Prerequisites and Limitations

Finally you can find the detailed information AWS Documentation page: Replication Across AWS Regions Using Global Datastore

If you feel this could be a great opportunity to increase your business performance in the near future. My suggestion to start to discover this new feature.