Home Resource Center Glossary Load Balancing

Load balancing is an important networking feature generally performed by multiple dedicated hardware devices known as Application Delivery Controllers (ADCs). These load balancing devices distribute large amounts of inbound traffic among a group of back-end servers hosting the same application content.  

There are a variety of methods that dictate how back-end servers are selected by the load balancing device. These include:

  • Round Robin
  • Least Connections
  • Weighted Round Robin
  • Weighted Lease Connections
  • Fastest Response

In addition to choosing which server receives a specific transaction request, the load balancing device is responsible for maintaining and monitoring server connections. This includes monitoring specific data—such as IP addresses—of incoming transaction requests so that any future requests are routed to the same server.  

While traditional load balancers satisfied an organization’s requirements two decades ago, they can’t keep up with modern availability, acceleration, and security demands. Application delivery controllers have bridged the gap by providing load balancing plus new content delivery features.

The Thunder Series advanced server load balancing and flexible health monitoring capabilities provide application availability and reliability.

The core of A10 ADC platform covers a wide range of options for load balancing methods and health checks. Comprehensive IPv4 and IPv6 support across all models maximizes options for current and future deployment.

Key Features

Advanced Layer 4/Layer 7 Server Load Balancing
Fast TCP, Fast UDP, Fast HTTP, Full HTTP Proxy

  • High-performance, template-based, Layer 7 URL and URL hash switching
  • Header, URL and domain manipulation
  • Comprehensive Layer 7 application persistence support
  • aFleX technology for deep packet inspection and traffic manipulation

Comprehensive load balancing methods for server selection

  • Round Robin
  • Least Connections
  • Weighted Round Robin
  • Weighted Least Connections
  • Fastest Response

Advanced Health Monitoring to ensure servers and applications are responding as expected, and to remove unresponsive servers load balancing server pools.

  • Comprehensive protocol support - ICMP, TCP, UDP, HTTP, HTTPS, FTP, RTSP, SMTP, POP3, SNMP, DNS, RADIUS, LDAP, SIP
  • TCL scriptable health check support

The Thunder Series and AX Series comprehensive traffic manipulation features, load balancing methods and health checks, coupled with flexible deployment methods, make the Thunder Series and AX series ideal for a wide variety of deployment scenarios.