AWS MySQL RDS architecture in multi regions

Question

I am starting to plan a multi region (us-east & us-west) web app that involves AWS RDS MySQL db. i am going to put this in AWS. Can any aws guru clarify my concern?

I will have the multi AZ for redundancy/High Availibity. And the Read DB accross regions for faster READ request processing.

My concern/question: If the master DB instance is in US-west. and if the write request from instances/computes/app server in us-east are routed to db endpoint which is in us-west, does this cause lag in the app OR is it the way how many AWS users uses? The read instance local to the app servers are not for writes.

Answer 1

You can't defeat the speed of light.

Having a server write to the database that may be 80ms away may not result in acceptable performance. Only you can determine this.

You run into the same issue if you use MySQL replication across regions.

Now, if you just want to have read replicas across regions, with all writes directed to a single region, you can probably make that work.

If you really need a fast, globally distributed database, consider using something like DynamoDB.