amazon web services - Durability

Question

Can you let me know if data on below AWS technology keeps data on Multiple Facilities? How many? Different Availability Zones?

S3, EBS, Dynamo DB

Also want to know in general what is the distance between two AZ, want to make sure that any catastrophe can destroy complete region?

Answer 1

Just to Start Point out All the above asked questions are easily answered in AWS Documentation.

What is Region and Availability-Zone ?

Refer This Documentation

Each region is a separate geographic area . Each region has multiple, isolated locations known as Availability Zones.

Also want to know in general what is the distance between two AZ ?

I don't think any one would know answer to that , Amazon Does not Publish such kind of Information about their Data Centers,they are secretive about it.

Now to Start with S3 , As Per AWS Documentation :

Although, by default, Amazon S3 stores your data across multiple geographically distant Availability Zones.

Now You can Also Enable Cross Region Replilcation as per AWS documentation but that will incur extra cost :

Cross-region replication is a bucket-level configuration that enables automatic, asynchronous copying of objects across buckets in different AWS Regions.

Now for EBS as per AWS Documentation :

Each Amazon EBS volume is automatically replicated within its Availability Zone to protect you from component failure, offering high availability and durability

Also As per Documentation You can Create Point In Time Snapshot and make it available in Another AWS Region and all the Snapshots are backed up on AWS S3.

Now for DyanamoDB as per AWS Documentation :

DynamoDB stores data in partitions. A partition is an allocation of storage for a table, backed by solid-state drives (SSDs) and automatically replicated across multiple Availability Zones within an AWS Region.

Now you can make it available across region for more details please refer to this AWS Documentation

Hope This Clears your Doubts!

Answer 2

By default all these services replicate the data in different AZ(availability zones) which are in the same AWS region.

But AWS also provided the mechanism to replicate the data across different region(which you can choose), so that you can have more fault tolerant and low latency for the users(you can serve your users from the servers which is in the same region).

However keep in mind that replicating data across multiple zones involves more cost.

You can read AWS doc http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.RegionsAndAvailabilityZones.html to know where all aws regions and AZ presents to figure out the where they are located.

Whole Idea to keep different AZ and region is to provide high availability, so you shouldn't bother about the distance and availability, if you are having replication across multi AZ or region.

Edit :- Thanks to Michael for pointing out that EBS volumes are only replicated (mirrored) within the AZ where the volume is created