Twenty years ago it would be common to have multiple data centers load balanced with specialized devices. The applications in multiple data centers would use the Domain Name System (DNS) to look up the application destination. The DNS system would be set up to with multiple data center locations. This would "round robin" the results between the data centers. If you have four data centers, the customers would get "round-robined" between each data center. Round Robin with DNS lookups was not really load balancing though. Architects needed tools that would balance traffic between multiple physical locations and move traffic away from overloaded data centers. They needed tools that would geographically load balance to get people to the closest data center. They needed resiliency options so that if a data center failed, the traffic would reroute. Global Server Load Balancers (GSLB) were created to add enhancements to DNS to move behind round-robin techniques. GSLBs would be primary DNS servers for the application's zone. The GSLB would normally be in one of the data centers, monitor the load with other data centers, and pass each customer query to the most appropriate, closest, and under-loaded data center. The GSLB would route around failed or overloaded data centers. GSLB would achieve resiliency with a primary and secondary GSLB in a different data center.
The traditional "GSLB in a data center" worked well in the "all data center" world. That has all changed in today's hybrid cloud and the edge-compute world.
Today's IT team must deploy and maintain applications all over the Internet. Applications continue to be in data centers. New applications get pushed into the cloud. Many of the applications are distributed on CDNs. In some cases, the organization will use multiple cloud operators. Other deployments will have a hybrid of data center and cloud. Other applications will use multiple CDNs.
Through all of this, the IT team must work with their peers to maintain a 99.999% customer SLAs. If they lose instances on cloud deployments, they have to ensure that it will fail over to the new instances. If there is an outage in a data center, they need to ensure that traffic swaps to the new data center. When they have a hybrid of data center and cloud deployments, they need to manage the load between the instances.
Load Balancing, Geographic Balancing, and Performance monitoring are all still required in this "modern Internet complexity." Today's requirements are more complicated. The traditional GSLB model inside of data center is stressed to match today's modern Internet complexity. It is only logical for the GSLB to move out of the data center into the cloud.
In the cloud, the GSLB function is decoupled from the physical data centers. In fact, an independent GSLB can be in an "overwatch" role separate from all the "hosted" locations of the applications. A cloud GSLB would be able to monitor the resiliency of the applications and services from outside in. Outside in better simulates the customer experience. An independent cloud GSLB can manage multiple cloud deployments. This allows the organization to pick the best cloud service for each unique application element (compute, storage, analytics, distribution, etc). A cloud GSLB allows for easier hybrid architectures using the best elements in various data centers and from various cloud providers.
GSLBs in the cloud is the solution needed for today's complicated Internet topology. For example, an IT Team might have the following requirements:
This type of geographic deployment is normal for today's Internet. The GSLB would be asked to support multiple protocols and services to support all the functions of the organization. Trying to run this GSLB function from inside the seven data centers places limits on the design. A cloud-based, globally deployed GSLB function provides the IT Team greater architectural flexibility.
Today Akamai has two solid, scalable, and robust GSLM services used by thousands of customer throughout the world. Most people do not think of Akamai as a global load balancing provider. Yet, the essence of Akamai's business is scaling the Internet. Moving the GSLM function into the cloud is a critical element for Akamai to help our customers scale their operations. With this, Akamai offers our customers two GSLB tools Global Traffic Management (GTM) for any traffic to any data center (e.g., API traffic shaping) and Application Load balancer (ALB) to optimize origin traffic flows and session affinity (e.g., original switching). GTM is a flexible multi-use, multi-protocol tool used by our customers to manage banking tools, databases, data centers, multiple-CDNs, and a surprising range of other options. ALB is an Akamai Cloudlet option that leverages our massive intelligent edge to move traffic management to layer 7. Both GTM and ALB follow Akamai's practice of maximized reliability, availability, and scale in all conditions independent of any underlying "stressors."
In future blogs, we'll provide a range of uses cases for GTM and ALB. The following provides a summary.
Akamai's GTM is a modern, highly reliable, dev-ops optimized, GSLB service that operates at the edge of the network across a diverse, distributed network of networks. Akamai's leading Information Security program governs with world-class controls and compliance and its Network Operations Command Center is on 24/7.
GTM allows for a range of load balancing, traffic routing, performance monitoring, geo-mapping, and fault monitoring. A global GTM deployment is an integral part of Akamai's Intelligent Edge Platform and provides organizations options to move services to optimal geographic locations. GTM services such as geo-mapping allow operations to deploy applications on multiple clouds and route user application connections to the geographically or topologically closest edge servers. Akamai's performance monitoring is an outside-in approach, setting up monitors worldwide. Akamai's GTM performance monitoring leverages the same monitoring used for Akamai's media, web, cloud, and security products that some the largest application, media, and network providers depend on every minute of every day.
ALB, Akamai's latest load balancing solution leverages the power of GTM, and additionally introduces layer 7 visibility and control when traffic is delivered through the Akamai platform, enhancing origin traffic routing options, and reducing risk to the user experience when expected outages occur. ALB introduces the following additional capabilities:
There will be many architectural situations where an organization will have GTM deployed to cover the resiliency for some functions and ALB deployed to cover specific applications. The combination of ALB and GTM provide devops, network architects, and system engineers with the flexibility to choose the optimal cloud-based GSLB solution. Some applications architects might need cloudlet ALB functionality to manage in-line experiences that Akamai delivers. At the same time, network architects for that same company might need to shape traffic between multiple cloud deployments and providers. With GTM and ALB, system engineers and application developers have full control - the power of AND.
GTM and ALB are an integral part of Akamai's Intelligent Edge Platform. Stay tuned to Akamai's blogs and subscribe to Akamai's Community to follow new updates, articles, and presentations as our solutions continually evolve to meet our customer's needs.