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?
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!
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
Related
I am relatively experienced with many AWS services - but I do have a large gap around Aurora/RDS
I'm trying to create a multi-region multi-master (write replicas) setup
The purpose is to give low latency to users (if each read and write replica is in the user's region) and to give resilience (if there is a region outage, the users can have their requests routed to another region (the latency will be higher, but reduced service is better than no service))
I'm trying to learn about AWS Aurora and I've created a toy cluster to learn. It seems I can create a cluster that is served out of multiple regions (and Aurora replicates data between regions automatically). I've also read that it is possible to have a multi-master setup (in my toy cluster, it only had one write partition, I couldn't work out how to create another write partition in another region, which made me question if it's possible?)
Here is a diagram of what I'm thinking:
https://imgur.com/DzoSpHL
Thank you in advance!
The purpose is to give low latency to users (if each read and write replica is in the user's region)
I couldn't work out how to create another write partition in another region, which made me question if it's possible?
That is not possible (at least not currently) because of multi-master Aurora limitations.
all DB instances in a multi-master cluster must be in the same AWS Region.
and others such as
you can have a maximum of two DB instances in a multi-master cluster
You can't enable cross-Region replicas from multi-master clusters.
You can read more here
The best thing you can do in your scenario is to create single master and place read replicas into those additional regions (possibly with some caching in necessary).
As mentioned earlier it is not possible with Aurora.
However DynamoDB supports multi-active multi-region:
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GlobalTables.html
As others have said, with Amazon Aurora, you cannot deploy multi-Region and multi-master. However you can deploy multi-Region using Aurora Global Database. Then one writer endpoint would be in one Region, while reader endpoints would be available in all the other Regions. Then you can also use write forwarding (assuming you are using the MySQL flavor of Aurora) in the read-only Regions. I know latency is a concern for you, so note the write actually goes back to the primary Region, so writes will incur that extra latency.
There's a statement in AWS S3 documentation that objects in S3 are replicated and stored across at least three geographically-dispersed Availability Zones. However, on the Global Infrastructure page there are a few regions (Canada Central and Beijing) with only 2 Availability Zones available.
If I understand it right, the replication settings are region-specific and all objects will be replicated only across 2 Availability Zones. Does anybody have any insights on that?
Some regions have fewer than three availability zones accessible to customers, but none -- apparently -- have fewer than three where S3 is deployed.
Amazon S3 Standard, S3 Standard-Infrequent Access, and S3 Glacier storage classes replicate data across a minimum of three AZs to protect against the loss of one entire AZ. This remains true in Regions where fewer than three AZs are publicly available.
https://aws.amazon.com/s3/faqs/
In case of a disaster, when an entire AWS region fails and all its customers want to move their workloads to the next closest region in a disaster recovery scenario, is AWS ready for this?
I imagine millions of servers running in each region. Is AWS ready to provision them in another region the next day? Do they have that capacity at the ready?
AWS global infrastructure is using the concept of Availability Zones inside each region, to partition the resources, isolate the risks and ultimately reduce the blast radius of an eventual failure. AZs are groups of datacenter within a region that are designed to be independent of each others in terms of risks (i.e. different connection to the power grid, redundant and isolated network infrastructure, isolated in terms of geographical risks such as earthquake, fooding etc)
Some services are designed to automatically take advantage of this redundant infrastructure (Amazon S3, Amazon DynamoDB, ELB etc), customer do not need to configure anything, redundancy and failover at the regional level is handled by the service. Some other services are operating at AZ level (Amazon EC2, EBS, RDS etc) Fo these services, the best practice is to design for multiple AZ architecture and data replication.
In the very unlikely case a service would not be available in an AZ, a well architected architecture will transparently fail over to another AZ, without any noticeable customer impact.
Back to your question, the architecture is designed to avoid a region-wide failure of all services. This never happened since we launched AWS in 2006. And, yes, we have a lot of capacity. I propose you to watch this keynote from James Hamilton to learn more about it https://www.youtube.com/watch?v=AyOAjFNPAbA
What exactly is the region in AWS world?
I have to ask which region is the right region for my business.Which factors are important before selecting region in AWS?
An AWS Region is a physical cluster of data centers located in a specific geographic location.
So, the Sydney Region data centers are all located in Sydney and the Oregon Region has data centers all located in Oregon.
A region consists of multiple Availability Zones. An Availability Zone is one or more data centers that contain the physical infrastructure that provides AWS services (eg data, storage, networking). There are very high-speed connections between Availability Zones within a Region.
So, which Region to choose? It should typically be the one closest to your customers (to provide faster response) or perhaps closest to your existing data center if you are connecting it to AWS.
You might want to use multiple data centers so that you have services closest to customers spread around the world, rather than having them all connect back to one location. Or, you might want to use multiple Regions for redundancy in case of failure. (Project Nimble: Region Evacuation Reimagined – Netflix TechBlog)
There might also be legal requirements of which Region to use (based on data governance, privacy laws, etc). You might even choose a Region based on a lower price (USA regions are generally lower cost than others, especially for Internet data transfer costs).
You might also choose a region based upon which services are available: Region Table
See also: Global Cloud Infrastructure | Regions & Availability Zones | AWS
The definition and documentation of AWS Region is stated in the above comments. In summary, AWS Region is a separate geographic area. AWS Region has Availability Zones which are isolated data centers. Availability Zones is used for high availability. There are 2 or more Availability Zones for each region.
Which factors are important before selecting region in AWS?
There are several factors to consider.
Latency - The faster your data center, the better your performance. This link can display the latency between ec2 instances. https://www.cloudping.co/
Cost - Different region has different cost. So far, North Virginia is the cheapest.
AWS Services to use - Not all AWS Services are available in all regions. This link can display the supported services per region. https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services/
There are a number of resources that can help you understand AWS regions, availability zones, and how to architect using them, including:
AWS: Regions and Availability Zones
AWS: Architecting for the Cloud: Best Practices
CloudAcademy: How to Pick the Best AWS Region for Your Workload
Our current server consisting of an 2x EC2 instances and RDS (Read/Write) database is in Mumbai Region. However I would like to copy everything (2x EC2 & RDS (R/W)) across to Sydney, and other to other regions.
Ideally I would like to replicate the contents in those instances as well.
Does anyone know a quick and easy way of doing this?
Edit 25/01/2019:
However I would like to copy everything including what ever is inside the instances (2x EC2s and the RDSs)
Edit 29/01/2019:
The purpose is to "scale/expand out". I want to have the same infrastructure replicated 1-to-1 (exactly/identically) across various regions.
It is simple!
- For EC2 - you need to create an AMI of those instances then right click on the AMI you've just created and choose "copy AMI" to the designated region.
For RDS
If you just wanna copy data to another region then take a snapshot then copy that snapshot to destination region
If you want to make the RDS replicate to another region continuously then you need to create a read-replica from your RDS instance.
Option for replicating environment depends on how much downtime can you tolerate.
If you are okay with downtime
1. Copy the AMI of EC2 instance and snapshot of RDS to another regions
2. Bring up your new environment.
This is perfect for non critial workload
If this is critical application
1. Copy the AMI of ec2 instance ( I am assuming this would be your web/app instnaces) For real time replication use rsync or robocopy .. or solution like cloudendure .
2. Create a new RDS instance in sydney
3. USE DMS migration tool .. create source and target relationship
4. once insync cut off the relation bring new environment in sydney
As suggested by previous answers for EC2 you can create AMIs and then move the AMI to a different region.
For RDS, you can either create read replicas (and read replicas of read replicas, but beware of latency), read replicas are used to mainly improve read performance of your app.
You can also create a Multi AZ backup which will act as a disaster recovery site. However, note that Multi-AZ is only used in case of a failover. Moreover, Multi-AZ involves Synchronous data copy and read replicas are asynchronous, so read replicas can demonstrate eventual consistency behavior.
But the real question here is - What are you trying to achieve?
Are you trying to "scale out" your infrastructure to support huge traffic to your application? Or are you simply trying to setup disaster recovery (DR)?
If your answer is DR, then the approach is pretty straight forward with Multi AZ and EC2 instance snapshots. But if the answer is scaling out and performance, you really need to be thinking of better strategies such as using Cloudfront (CDN) if it is a web app, using Elasticache in-memory cache for frequently read data, or RDS read replicas, using Elastic Load Balancers with Dynamic/Step scale-out/scale-in. Other, methods would be to evaluate the type of RDS storage subsystem used i.e. using Provisional IOPs vs. Using General Purpose SSD, checking if there are any NAT “instance” bottlenecks in your VPC and so on.
It may be tempting to spin up all these redundant copies of EC2 AMIs or RDS read replicas with a click of a button, but you really need to be thinking about the cost you are going to incur on a monthly basis for completely un-used resources.