How to Achieve Resilience and Scale with Global Server Load Balancing

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In the world of IT delivery, where the demands of high availability and scalability are constantly increasing, IT decision-makers and senior system administrators face the challenge of providing consistent, efficient and reliable service delivery for increasingly geographically spread businesses. One solution to these challenges is Global Server Load Balancing.

Many organizations now use a hybrid deployment model for their application servers and core server infrastructure. This involves deploying them across a combination of traditional private data centers, public cloud platforms and private cloud infrastructure provided by dedicated hosting companies. Many businesses require their IT systems to be available across geographic regions such as AMER, EMEA or APAC.

This global deployment scenario offers numerous benefits, such as optimized performance and low latency, as users access applications from the data center that is currently best placed to handle their requests. This blog explores how global server load balancing makes deploying applications across regions easier, how it works and how it boosts organizational resilience and scalability, as well as other benefits.

What is Global Server Load Balancing?

Global Server Load Balancing (GSLB) is an advanced method of distributing traffic across multiple servers situated in different geographical locations. GSLB optimizes resource use, maximizes throughput, minimizes response time and provides high availability of applications and services. GSLB extends the traditional load balancing concept beyond a single data center, enabling organizations to distribute their load across global infrastructures.

GSLB is crucial for organizations that operate globally, where server workloads often vary significantly based on location, time zone and local demand. GSLB routes user requests to the nearest or best-performing data center, thereby reducing latency and improving the overall user experience. Read more on GSLB and what load balancing is.

How Does Global Server Load Balancing Work?

GSLB works by managing traffic across multiple on-premises and cloud-based servers. It uses intelligent algorithms and policies to route user requests to the most suitable server based on geographic location, server health, current load and network latency.

In on-premises deployments, GSLB can distribute traffic among different servers across multiple data centers. This is beneficial for organizations with existing on-premises infrastructure looking to optimize server usage and improve failover capabilities. In cloud-based (and hybrid) deployments, GSLB allows for the seamless integration of cloud and on-premises resources by distributing traffic across cloud providers or between cloud and on-premises servers.

Simply put, GSLB enhances the load-balancing functionality used to share access requests and connections across a local server pool and extends it to multiple geographically spread server pools. These pools can be in the cloud or on-premise. Read more about how global server load balancing really works.

You can also watch a recording of a Progress Kemp LoadMaster webinar titled How to Achieve Resilience and Scale with Global Server Load Balancing.

How to Achieve Resilience and Scale with Global Service Load Balancing?

GSLB builds on and extends the core Kemp LoadMaster load balancer functionality.

DNS-based GSLB

DNS is a foundational component of GSLB. It allows LoadMaster GSLB to resolve domain names to IP addresses and use the Fully Qualified Domain Name (FQDN) for each site as the basis for traffic routing to the most suitable servers based on location and availability. When a site is unavailable, or the servers located within it are not performing correctly, requests using the application’s FQDN automatically get redirected to another site by modifying the FQDN in the requests. End-users or other application services then use the redirected IP address to establish a connection with the application server and communicate with it directly.

For GSLB DNS integration, you need to configure the following items:

  • Global DNS records: Configure dedicated DNS records (e.g., A records) with GSLB-enabled nameservers. These records point to GSLB virtual IP addresses instead of individual server IPs.
  • Intelligent DNS resolution: When users access an application, the GSLB name server analyzes their location, network conditions and real-time server health data. It then selects the optimal server and returns its IP address through the DNS response.
  • Geolocation routing: Advanced GSLB solutions leverage geolocation data to refine routing decisions further. This means users get preferentially directed to a server in the closest region, minimizing latency and improving user experience. They can still be directed to servers in more distant locations if those servers can handle the requests better.

LoadMaster GEO

LoadMaster GEO delivers GSLB on top of the core LoadMaster functionality. It takes LoadMaster beyond single data center capabilities, enabling high availability (HA) for multi-data centers. LoadMaster GEO allows intelligent traffic distribution across various data centers and cloud providers based on predefined policies and real-time data center performance. It helps deliver continuous service availability, even in the event of a data center or cloud provider outage, by automatically rerouting traffic to the best site available.

The features of LoadMaster GEO include:

  • Multi-data center configuration: Supports deployment of LoadMaster instances in each data center where application infrastructure resides. These LoadMaster instances form a collection, dynamically communicating and sharing server health information.
  • Global health checks: LoadMaster performs comprehensive health checks on all servers across global data centers, verifying their availability and responsiveness.
  • Automatic failover: If a server or data center has issues, LoadMaster GEO automatically redirects traffic to healthy servers in other locations. This provides rapid failover and minimizes downtime.
  • Global traffic management: LoadMaster GEO supports the advanced LoadMaster core traffic management features like session persistence, content switching and application-specific routing, delivering optimal performance and user experiences.


Benefits of GSLB

GSLB offers numerous benefits, key among them being:

  • An enhanced user experience: By routing traffic to the nearest or best-performing server, GSLB reduces latency and improves response times, improving end-user and customer experiences.
  • Improved scalability: GSLB enables organizations to scale their infrastructure horizontally across multiple global data centers, allowing them to handle increased traffic without compromising performance.
  • High availability and disaster recovery: GSLB provides an effective disaster recovery solution by automatically rerouting traffic away from unavailable servers or data centers, giving service continuity.
  • Optimized resource utilization: With GSLB, no single server or data center is overwhelmed with traffic, leading to optimized resource utilization and reduced operational costs.

How Customers Use GSLB

Organizations worldwide are using GSLB to improve the application experience for their staff and customers. By implementing GSLB, businesses maximize application availability and optimize performance across their global estate, regardless of their user’s locations. Global server load balancing benefits services such as e-commerce platforms, online gaming and streaming services, where latency and downtime can seriously impact user satisfaction and revenue.

It’s not just commercial organizations that benefit from using GSLB. Read how the Harris County District Attorney’s Office benefits from LoadMaster GEO GSLB in this High Availability and Multi-Resiliency Case Study.

Find Out More

Learn more about LoadMaster GEO GSLB implementation via our datasheet and Global Server Load Balancing (GSLB) web page. You can also start a free trial of LoadMaster and Contact Us to discuss your application delivery needs.

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Doug Barney

Doug Barney was the founding editor of Redmond Magazine, Redmond Channel Partner, Redmond Developer News and Virtualization Review. Doug has also served as Executive Editor of Network World, Editor in Chief of AmigaWorld and Editor in Chief of Network Computing.