GlobalAccelerator

Question 1

Problem statement

Answer 1

Critical workloads, such as dynamic API delivery, gaming, and video/voice over IP require higher levels of availability and performance through the use of multi-Region architectures.

latency-sensitive applications

simplify the way traffic is routed across your applications in multiple AWS Regions. Global Accelerator provides several key features to help you distribute your traffic while improving the availability and performance of your application.

Question 2

AWS Global Accelerator

Answer 2

AWS Global Accelerator is a networking service that sends your user’s traffic through Amazon Web Service’s global network infrastructure, improving your internet user performance by up to 60%. When the internet is congested, Global Accelerator’s automatic routing optimizations will help keep your packet loss, jitter, and latency consistently low.

If local and global traffic to your application’s single Region is left on the public internet, it can be negatively impacted by internet congestion and local outages. Using Global Accelerator, your user’s traffic is moved off the internet and onto Amazon’s private global network through 80+ global edge locations, then directed to your application origins.

Question 3

Anycast

Answer 3

a network addressing and routing methodology in which a single destination address has multiple routing paths to two or more endpoint destinations. Routers will select the desired path on the basis of number of hops, distance, lowest cost, latency measurements or based on the least congested route. Anycast networks are widely used for content delivery network (CDN) products to bring their content closer to the end user.

Question 4

Unicast addressing

Answer 4

uses a one-to-one association between a sender and destination: each destination address uniquely identifies a single receiver endpoint.

One server holds one IP address

Question 5

Anycast addressing

Answer 5

a one-to-one-of-many association where datagrams are routed to any single member of a group of potential receivers that are all identified by the same destination address. The routing algorithm selects the single receiver from the group based on least-expensive routing metric. In practice, this means that packets are routed to the topologically-nearest member of an anycast group.

multiple servers have the same IP

Question 6

content delivery network, or content distribution network (CDN)

Answer 6

a geographically distributed network of proxy servers and their data centers. The goal is to provide high availability and performance by distributing the service spatially relative to end users. CDNs came into existence in the late 1990s as a means for alleviating the performance bottlenecks of the Internet, even as the Internet was starting to become a mission-critical medium for people and enterprises.

Question 7

Global Accelerator uses

Answer 7

Anycast IP concept to work

there’s going to be two of Anycast IPs that are going to be created for your application and they’re global.

Question 8

Global Accelerator works with

Answer 8

Elastic IP, EC2 instances, Application Load Balancer, Network Load Balancer and they can either be public or private.

With static IP addresses, you can now make changes to application infrastructure behind the scenes without having to update DNS records or your client applications.

Question 9

Static Anycast IPv4 addresses

Answer 9

When you deploy an accelerator, you are provided with two IPv4 static addresses that can be used as the interface to your application. Each IP address is served from edge locations containing network zones, each zone has infrastructure that is isolated from the infrastructure in the other zones, to provide redundancy. This allows client applications to retry if one IP address become unavailable due to network disruptions.

Question 10

Global traffic dials and Regional endpoint weights

Answer 10

When Global Accelerator is provisioned in front of multiple AWS Regions, by default requests are routed to the Region closest to your end users to provide the most optimal performance. To adjust how the traffic is routed, Global Accelerator provides traffic dials to shift traffic between the Regions configured behind your accelerator. These traffic dials come in handy when you need to redirect traffic from a Region that has exceeded its capacity, take a Region out of service for maintenance, or gradually ramp up traffic for a newly added Region. For even finer grained control of Regions containing multiple endpoints, you can use Global Accelerator’s endpoint weights to balance traffic across Network Load Balancers, Application Load Balancers, or Elastic IPs. Weighted endpoints can help you roll out new application changes when performing A/B testing or blue/green deployments.

Question 11

how it works

Answer 11

1. When a request is made to an accelerator static IP address, the request is first routed to a nearby Global Accelerator edge location over the public internet via the Anycast BGP protocol.
2. The accelerator accepts the request if there is a listener configured that matches the protocol and port, then determines the most optimal endpoint group based on:
   Geographic proximity to the edge location.
   Traffic dial settings
   Health of the endpoints in the endpoint group.
3. If the endpoint group closest to the edge location has the traffic dial configured to 100 percent and the endpoints in the Region are passing health checks, the request is forwarded over the AWS global network.
4. If the endpoint group closest to the Edge location has the traffic dial configured to less than 100 percent, the configured percentage of requests received by the edge location is sent to the closest endpoint group, and the remaining requests are distributed to other endpoint groups weighted by geographic proximity and the traffic dials settings. In all cases, endpoint groups must have healthy endpoints to receive requests.
5. For endpoint groups with multiple endpoints, Global Accelerator spreads the traffic across the endpoints using a 5 tuple hash based on protocol, source IP address, destination IP address, source port, and destination port. If endpoint weights are configured, Global Accelerator sends traffic to an endpoint based on the weight that you assign to it as a proportion of the total weight for all endpoints in the group. Note: Global Accelerator also provides client affinity capabilities for stateful application use cases.

Question 12

Global Accelerator constantly checks

Answer 12

the health of endpoints configured under an endpoint group to identify if an endpoint is healthy.