Global server load balancing (GSLB) is the practice of distributing internet traffic amongst many connected servers
dispersed around the world. It’s a modern network technique designed to both ensure high availability in case
one of the origin severs or data centers becomes completely unavailable, and also enhance the performance of web
applications and web services with the help of the domain name system (DNS).
GSLB distributes the traffic by leveraging traffic responses on various factors, including geographic proximity,
server load, network latency, and other configurable parameters. This means that when a user sends a request for a
particular web application, it first gets directed to the DNS server. GSLB aims to provide the most suitable IP
address and ensures the user is directed to the respected data centers that can handle the request efficiently.
Global server load balancing (GSLB) offers a multitude of benefits, two of which are particularly noteworthy:
Performance Optimization: GSLB also plays a crucial role in enhancing performance. It does this
in two ways. Firstly, it distributes the load across multiple data centers, preventing any single data center from
becoming overwhelmed with traffic. This load
balancing ensures that all users receive a consistent level of service, even during periods of peak demand.
Secondly, GSLB improves response times by directing traffic to the fastest responding data center, i.e., the one
with the lowest round-trip delay. By minimizing the distance that data packets need to travel, GSLB can
significantly reduce latency, thereby providing users with a faster and more responsive experience.
High Availability (HA) and Disaster Recovery: GSLB significantly enhances the reliability of
your network. In the event of a major incident—such as a data center losing power or its internet
connection, or even becoming entirely unavailable—GSLB ensures that your services remain accessible. It
achieves this by automatically redirecting traffic to another operational data center within the GSLB network.
This seamless transition ensures uninterrupted service, effectively providing a robust disaster recovery solution.
These factors make GSLB a powerful tool that can increase the reliability and performance of your network, ensuring
high availability and optimal user experience.
Global server load balancing (GSLB) operates by distributing internet traffic across multiple servers, often located
in different geographic locations. The technical process of GSLB involves several steps:
DNS Interaction: The client’s request primarily reaches the Domain Name System (DNS)
server. The GSLB-enabled DNS server chooses the best IP address dynamically instead of returning a single IP
address.
Traffic Distribution: GSLB distributes the incoming traffic signals across multiple servers and
data centers, which helps to evenly divide the load. This helps provide faster response times by reducing latency
and request overloads.
Client Request: When a client makes a request, the GSLB evaluates the request, considering the
client’s IP address as well as the health and responsiveness of the servers at each location.
Server Selection: The GSLB then selects which location to send the client’s request to,
based on factors like country of origin, latency, proximity, and/or response time.
High Availability (HA): One of the key benefits of GSLB is its ability to provide high availability.
In the event of a server or even an entire data center becoming unavailable due to issues such as power loss or
internet connection failure, GSLB ensures that the service remains uninterrupted. It does this by redirecting the
client’s request to another operational server or data center within the network. This automatic failover
mechanism is a crucial aspect of disaster recovery strategies, ensuring that services remain available even in the
face of significant disruptions.
GSLB can be configured in two ways: active-active and active-passive configurations:
Active-Passive Configuration: In this setup, the active GSLB Service is bound. Another GSLB
Virtual Server is created with a passive GSLB Service and configured as a Backup Virtual Server. This means that
if the active origin server or data center fails, the passive service takes over, ensuring uninterrupted service.
Active-Active Configuration: In this setup, multiple GSLB Services are bound to the GSLB Virtual
Server, and a load balancing method (e.g., proximity) is configured. Site persistence is also configured to ensure
that a client’s requests are consistently directed to the same site.
These configurations ensure that GSLB can effectively manage and distribute traffic, ensuring optimal performance and
high availability.
Global Server Load Balancing enhances performance by intelligently distributing user requests across multiple servers located in different geographical regions. This distribution minimizes latency and optimizes response times, ensuring that users connect to the nearest or least congested server. By leveraging real-time data, GSLB can dynamically route traffic based on various factors, including server health, current load, and network conditions. Moreover, GSLB continuously monitors server performance and availability. If a server experiences issues, GSLB can reroute traffic to other operational servers, maintaining service continuity and improving fault tolerance. This proactive management not only enhances user experience during peak traffic periods but also ensures that applications remain responsive and reliable, even under heavy loads.
GSLB employs several methods to effectively manage and distribute traffic across servers. Some of the most common techniques include:
- DNS Load Balancing: This method uses the Domain Name System (DNS) to direct user requests to different servers based on predefined rules. It can implement strategies like round-robin, where requests are distributed evenly across servers, or more sophisticated methods that consider server load and response times.
- Geolocation-Based Routing: This technique routes traffic based on the geographic location of the user. By directing requests to the nearest server, it reduces latency and improves load times, providing a better user experience.
- Anycast Routing: In this method, multiple servers share the same IP address. The network routes user requests to the nearest server based on the shortest path, enhancing speed and reliability.
- Health Checks and Failover: GSLB systems perform regular health checks on servers to ensure they are operational. If a server fails, traffic is automatically redirected to healthy servers, ensuring high availability and minimal disruption.
GSLB offers a range of benefits, including:
Enhanced Operational Resilience
Implementing GSLB significantly enhances operational resilience and ensures high availability by intelligently
directing user traffic to the most suitable servers based on real-time data. This means that even if a server or an
entire data center becomes unavailable, the GSLB function can reroute the traffic to another available server,
ensuring uninterrupted service.
Moreover, GSLB facilitates efficient disaster recovery strategies. In cases where an entire Point of Presence (PoP)
shuts down, GSLB swiftly redirects traffic to another operational PoP. This ability to switch user traffic instantly
and seamlessly to an alternative data center in the event of an unexpected outage improves the resilience and
availability of key applications.
Optimized Performance
GSLB optimizes performance by intelligently distributing traffic to the most suitable servers based on real-time
data. By taking the heavy traffic signal as the input and redistributing it to other places, GSLB enables users to
experience optimal performance even at peak traffic. It also reduces latency by providing the data centers to the
users who are geographically closest to them. This helps reduce the distance the data packets travel, thereby
enhancing the user experience by providing a faster response.
Regulatory Compliance
GSLB contributes to regulatory compliance by enabling data localization and customized content delivery across
different geographic regions. Many countries or supranational bodies like the EU have regulations on data and how it
can be stored and transferred. GSLB can be configured to adhere to these regulations to ensure that users within a
particular jurisdiction do not connect to servers on sites where they should not store their data.
Advanced Security Features with Radware's GSLB Solutions
Radware’s GSLB solutions, such as Alteon Application
Switches, provide all the above benefits along with advanced security features. These solutions ensure
protection against a broad spectrum of cyber threats, thereby enhancing the security of your IT infrastructure.
Radware’s GSLB solutions are designed to deliver a high-quality, reliable experience for users, no matter where
they are in the world and no matter where their applications and data are located.
Global Server Load Balancing and Local Load Balancing (LLB) are two key techniques used to manage and distribute
network traffic. While they share a common goal of ensuring efficient and reliable data delivery, they operate at
different levels and serve distinct roles.
Global Server Load Balancing (GSLB)
GSLB takes the concept of LLB further by operating across multiple geographically dispersed data centers or cloud
regions. It manages load distribution across multiple data centers or locations, making it a crucial component for
global applications. GSLB operates by leveraging DNS (Domain Name System) to intelligently direct incoming user
requests. It not only manages traffic distribution across these broader areas but also incorporates site health
checks, geographic considerations, and compliance requirements into its routing decisions.
Radware’s Expertise
Radware, as a leading provider of cybersecurity and application delivery solutions, has expertise in integrating
both GSLB and LLB solutions. Our solutions offer a holistic approach to traffic management, ensuring an optimal
user experience regardless of scale or location. Radware’s GSLB solutions, such as Alteon Application
Switches, provide all the benefits of GSLB along with advanced security features. These solutions ensure
protection against a broad spectrum of cyber threats, thereby enhancing the security of your IT infrastructure.
Local Load Balancing (LLB)
LLB operates within a single data center or cloud region, distributing traffic among a pool of servers to ensure
efficiency and reliability. It is designed to manage massive workloads so that no one server becomes overwhelmed by
requests, which can increase latency and cause downtime. Different load balancing techniques may be used to achieve
this purpose: for example, a load balancer may evaluate server load or geographical distance before deciding where to
direct traffic. If a server goes offline, the load balancer redirects incoming traffic to another available server in
a process called failover.
GSLB plays a crucial role in various practical scenarios, ensuring seamless user experiences, managing traffic for
multinational platforms, providing robust content delivery networks (CDN), and more.
Ensuring Seamless User Experiences for Global Online Services
GSLB is instrumental in enhancing user experiences for global online services. It intelligently distributes
internet or corporate network traffic across servers in multiple locations, anywhere in the world. This
distribution allows users to be automatically directed to content from servers located in their own geographic
region, reducing response times, and decreasing the use of expensive international data connections.
Providing Robust Content Delivery Networks (CDN)
In the context of CDN, GSLB plays a vital role in distributing the incoming traffic signals across multiple
servers and data centers, which helps to evenly divide the load. This distribution provides faster response times
by reducing latency and request overloads, ensuring a seamless user experience even during peak traffic scenarios.
The Role of GSLB in Disaster Recovery
GSLB plays a critical role in disaster recovery by routing traffic to backup sites and other alternate resources,
helping organizations avoid costly downtime. In the event of a disaster that causes the primary active data center
to be inactive, the standby data center becomes operational.
Radware’s GSLB Solutions
Radware’s GSLB solutions are tailored to meet these diverse needs, ensuring scalability, reliability, and
optimal performance across global digital infrastructures, which not only enhance the user experience but also
improve the resilience and availability of key applications.
Managing Traffic for Multinational
E-commerce Platforms
For multinational e-commerce platforms, GSLB is essential in managing traffic. It ensures that end-user traffic
is directed to the Point of Presence (PoP) with the lowest latency, providing a speedy service and enhancing user
satisfaction.
The Importance of GSLB in Cloud-Bursting Scenarios
In cloud-bursting scenarios, where there are sudden traffic spikes, GSLB helps in handling these spikes by
dynamically allocating resources across cloud environments. It ensures that no single location is handling so many
requests that it causes delay.
When choosing a global server load balancer (GSLB) for your organization, there are several factors to consider:
High Availability and Fault Tolerance: GSLB should increase fault tolerance and availability by
allowing multi-site content and service deployment, guarding against failures in the event of local or regional
network outages, power outages, or natural disasters.
Performance and User Experience: GSLB should enhance the performance and user experience by
efficiently distributing incoming traffic across multiple servers or data centers.
Geographic Redundancy and Improved Performance: GSLB should provide geographic redundancy and
improved performance by directing users to the data centers closest to them.
Scalability and Flexibility: GSLB should offer scalability and flexibility to handle increasing
traffic loads and adapt to changing business needs.
Disaster Recovery and Business Continuity: GSLB should support disaster recovery and business
continuity strategies by rerouting traffic to backup sites and other alternate resources.
Efficient Resource Utilization and Cost Savings: GSLB should enable efficient resource
utilization and cost savings by balancing the load evenly across multiple servers.
Regulatory Compliance and Data Localization: Data privacy and protection regulations vary widely
from one country or region to another. GSLB can play a crucial role in ensuring regulatory compliance by detecting the
geo-location of both the client and the server. This allows GSLB to keep data localized within the same country or
continent, as required by local laws and regulations. This ability to respect data sovereignty requirements not only
helps organizations avoid hefty fines and legal complications but also builds trust with users by demonstrating a
commitment to protecting their personal data.
When choosing a GSLB for your organization, it’s important to consider these seven key factors to ensure you
select a solution that best fits your organization’s specific needs and requirements.
Radware’s Range of GSLB Solutions
Radware offers a range of solutions that implement Global Server Load Balancing (GSLB). Apart from Alteon Application
Switches, Radware’s other solutions also use GSLB to direct user requests to the “best site” to
service the requests using three criteria: Site health, Site proximity, and Response time required to retrieve
specified content.
These solutions are not limited to HTTP; Radware’s GSLB solutions are versatile and adaptable to various application environments—any service
that can be load balanced with Radware’s solutions can operate with GSLB. These solutions ensure scalability,
reliability, and optimal performance across global digital infrastructures. They not only enhance the user experience
but also improve the resilience and availability of key applications.
