A load balancer, also known as Global Server Load Balancing (GSLB), is the method of splitting and distributing the incoming network traffic to multiple hosts—which can be located at different geo locations—within the organization network. This helps the network effectively manage network traffic and prevent any delays in network services.
With load balancing enabled in the hosts, the organization’s network services are faster and provide more reliable responses to clients. Network traffic distribution replies on the client’s location and the availability of the server for quick resolution of queries.
How DNS load balancing works
When an organization’s network is established around the globe, DNS queries from different geo locations will be received in the DNS server, which facilitates GSLB. Based on the information provided in the query requests, the server reaches for the authoritative host that is close to the client’s location and provides the IP address of the host. This way, network traffic is split across multiple hosts.
Splitting network traffic across multiple hosts increases response rates and prevents network latency and disruptions, providing clients with reliable network services.
GSLB uses load balancing algorithms to determine how network traffic gets distributed. ManageEngine CloudDNS provides three types of algorithms:
1. Standard mode
This is the basic algorithm where the GSLB will direct a client’s DNS query to an IP or an available host. When there is no available nameserver, load distribution won’t be implemented, and the client will receive an error message.
2. Round robin
In the round robin algorithm, the network traffic gets distributed to all the nameservers equally. The first request goes to the first server, the second request goes to the second server, and it continues to equally distribute the requests to all the nameservers.
3. Failover mode
The network traffic in failover mode gets distributed to backup IPs or hosts when the primary IP or host faces a failure. There are two failover mode types:
(a) Weight-based failover
Weight-based failover distributes the traffic to multiple IPs or hosts based on their weights. The IP or host with the highest weight will be considered the primary option for traffic distribution. But the distribution will be rotated between the main host and the backup ones.
(b) Priority-based failover
Priority-based failover allows the application to set priority for an IP or host, and the prioritized host will be considered first for directing queries; only when the prioritized host fails are queries directed to backups.
What are the benefits of load balancing?
DNS servers with GSLB enabled experience improved network services with reliable and faster responses for clients in the following ways:
Enhanced network performance
GSLB increases the response rate for clients by splitting traffic to the authoritative nameserver close to clients location, thus improving the network efficiency and performance.
Increased availability of servers
Distributing the network traffic across multiple hosts increases the availability for quick response to clients. Clients can access the organization’s website without any delay at anytime.
Scalability
With the help of GSLB, the organization can now expand the network by adding new servers in new locations near clients for seamless network services.
Better load distribution
GLBS ensures that all network traffic won’t get transferred to one server to avoid overloading that server with queries. This increases the reliability of the network services.
Better user experience
Faster responses from the nameserver near the clients’ locations streamlines DNS services and prevents network delay, providing an optimal network experience for clients.
Disaster recovery
When a server faces downtime, GSLB will immediately redirect the traffic to the next available host to ensure the availability of DNS services, so clients don’t experience any downtime.
How can you enable load balancing with CloudDNS?
ManageEngine CloudDNS offers filters and DNS monitoring features that help enable load balancing to implement streamlined network traffic distribution across global audiences.
Filters
CloudDNS filters out DNS queries and directs them to specific hosts based on the information given in the queries. These filters play a crucial role in directing queries to the respective hosts based on factors like geolocation, Autonomous System Number (ASN), and IP, providing clients quicker responses and enabling administrators to enforce operational policies.
CloudDNS provides three filters for these factors:
Geo Filters
Geo Filters narrow down the DNS queries based on clients’ geo locations. This filter helps reach clients from different locations by directing queries across multiple hosts. It also helps manage local hosts, geo restrictions, and response speed. This can prevent network latency and improve efficiency.
ASN Filters
ASN Filters use a 16-digit or 32-digit numerical values, referred to as distinct identifiers, that are assigned to each network of the internet. These filters help exclude networks of certain ISPs or CDNs, allowing administrators to direct clients of an ASN value to enter a specific network. ASN Filters help with complying to security policies, business agreements, and regulations.
IP Filters
IP Filters distribute traffic to different hosts based on the individual client’s IP address or its prefixes. These filters can be used to direct selective client IPs to the organization’s hosts, which helps with security.
DNS monitoring
DNS monitoring features in CloudDNS helps monitor the status, capacity, performance, and availability of the DNS hosts and records, as they are crucial for traffic distribution. DNS monitoring helps not only improve network efficiency and security, but it also reduces downtime.
Implement load balancing for streamlined traffic distribution with the help of CloudDNS
By leveraging GSLB and the robust features provided by ManageEngine CloudDNS, organizations can significantly improve the performance, reliability, and scalability of their network infrastructure. Load balancing helps distribute traffic efficiently across multiple servers, enhances the user experience, ensures higher availability, and mitigates risks associated with network failures.
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