Global Server Load Balancing

Most businesses use digital means to connect, market and run businesses. They use data servers to get end-user requests and process them as they solve their pains.

However, if the servers are overcrowded, they can’t work efficiently and can slow down the process of sharing data and information on servers.

In this article, you will learn more about how you can share data between different servers globally to lighten the load and make online surfing and browsing fast. In addition, you will learn more about global server balancing, what it is, how it works, and its configuration and benefits.


  1. What is Global Server Load Balancing
  2. How GSLB Works
  3. Global Server Load Balancing Configurations
  4. Benefits of GSLB
  5. Disaster Recovery
  6. FAQ
  7. Conclusion

What is Global Server Load Balancing?

GSLB (Global Server Load Balancing) is the distribution of the internet to different servers to increase the user experience and offer a faster transfer of information and data across other servers worldwide. Here is a simple screenshot to see how the whole system operates.

The diagram shows a global server load balancing setup where
traffic is distributed across multiple servers in different locations. This allows for efficient distribution
of traffic to the application servers.

Source: AVI Networks

How GSLB Works

Global server load balancing internet network traffic from different data centers. Once a customer makes request, the GSLB evaluates what the customer wants and then considers the customer's IP address alongside the health and responsiveness of different servers in various locations. The customer request is then sent to the most appropriate data center site.

The GSLB chooses the location to send the customer request to based on factors like:

  • Latency
  • Server response time and proximity
  • Country of origin
  • Bandwidth utilization
  • Network costs
  • Bandwidth thresholds

Here is example of how global server load balancing works when an end user sends a request to the servers.

GSLB Principle of Operation Scheme

Source: Flowmon

Global Server Load Balancing Configurations

The configuration for GLSB has various entities on each appliance for the GSLB configuration.

  • DNS VIPs
  • Content switching virtual servers
  • ADNS services
  • GSLB virtual servers
  • GSLB sites

Active-Passive or Primary Backup Configuration

For this configuration, one of the server locations is set to be active, and the other servers are passive for that service. When the active location stops working, one of the passive servers becomes active, and the end-user requests are redirected to that server. This type of configuration is ideal for disaster recovery. See how it works.

In the diagram, Site 1 is active and Site 2 is passive, with
the same configuration as Site 1. If Site 1 goes offline, Site 2 becomes operational.

Source: Citrix

After configuring the primary data server, the same setup is replicated for the passive data servers by designating a GSLB virtual server as a backup server in case of failover.

For example, when a customer requests an order, it is sent to servers in site one, and if, in the process, the server crashes or is affected, the GSLB system sends that request to the other site 2, activating it. It ensures the end-user still gets a solution to their request even if the server has failed.

Active-Active Configuration

In this case, all the servers are active. Therefore the end users' requests are shared among the servers, and their requests are addressed by the servers based on their proximity and where the client is located.

In this configuration, all the services for a given domain or application are connected to the same GSLB virtual server. For this configuration, different websites exchange essential metrics through the metrics exchange protocol (MEP)

Here is how the configuration works:

In the diagram, Site 1 and Site 2 are both active
GLSB sites. When a client sends a DNS request, it is directed to one of the active sites.

Source: Citrix

The above sites are GSLB active. Therefore, once an end-user sends an order, it lands on one of those sites.

For instance, if site 2 receives an end-user request, its GSLB virtual server chooses the load balancing, sends the site IP address to the DNS server, and then sends it to the end user.

With the new virtual server, the end user resends their orders to it through the new IP address created. Since both sites are active, the GSLB algorithms consider the best server to send the end-user request.

Benefits of GSLB

Improves Network Latency

With global load servers, customers can access data on information that is close to their network. This minimizes the delays in processing and presenting information when customers request it. Once an end user makes a request, it’s easily processed, and the customer gets their orders faster.

Deliver Localized and Customized Content

When an end user sends a request over GSLB, one of the checks they do is country of origin and geographic location. The servers then can present the end user with localized and customized information based on their location and user preference.

Increase Content Delivery Speeds

With global load balancers, you can share the Internet traffic to different servers, which increases the loading speeds of servers and end users accessing the information. The end user can access the information they want from the closest DNS server at faster speeds.

High Availability of Key Applications

Since the servers are distributed and configured to give end users solutions to their requests, GSLB can monitor key applications and have the best-performing applications to give the end user the best experience based on their locations.

Due to the high availability of data servers and storage systems, the end user can still get the best solution to their requests even when the data server is affected as the traffic is redirected to the nearest server.

Improve End-user Experience

Customers make requests online through the servers because they are looking for a solution to help them solve their pain points. A great global server balancer system helps customers have a great experience in their search.

Compliance With Rules

The forwarding preferences for the global load server balancers make it possible to customize the settings with a given location. So a business can customize its work to adhere to the government or country-specific regulations.

Disaster Recovery

As you run your business, challenges can affect your business operation or information delivery to your end users.

GSLB helps with disaster recovery and management. Global server load balancing helps monitor data centers for threats.

When it notices any failure or problems with a data server, it redirects the traffic to another server to prevent a total breakdown that can affect business operations.

GSLB also allows data migration and system upgrading without affecting the end user request. Since the system can share the data to the nearest and redirect the customer request to the servers, the end user can get the desired results without interference.


1. Is GSLB open source?

Businesses can find solutions for open-source GSLB online. However, you can integrate the best-performing services for GSLB with application delivery solutions that need commercial support.

2. What load-balancing methods does GSLB use?

  • Round robin
  • Least connections
  • Round trip time

3. What are the main features of GSLB?

  • Failover and disaster recovery
  • Network costs
  • Server and bandwidth utilization
  • DNS layer ¾ load balancing

4. How can GSLB choose the optimal server for an end user at any time and in any place?

  • Measuring the server response time
  • Calculating the shortest distance between networks
  • By measuring server load for CPU and RAM


Having a great and faster internet connection is essential for effective online marketing. GSLB is a system that ensures a safe and faster Network connection improves user experience and drives more business activities for brands.

Ensure that you use global server load balancing to make the business running process effective.