Load balancing is the process of distributing service requests across a cluster of servers. There are many benefits to this process, these include

• Improves performance - The highest performance is achieved when the processing power of servers is used intelligently. Advanced server load balancing products can direct end-user service requests to the servers that are least busy and therefore capable of providing the fastest response times.
• Creates Resilience - high-availability pairs for load balancer resilience, and creates fault-tolerance for back-end servers.
• Adds Intelligence - Content inspection rules allow sending requests for certain web pages to specific groups of servers.
• Improves Reliability - By continually monitoring the health of back-end servers, failed servers are automatically detected and removed from the cluster until they recover.
• Ease of Use - Easy to install and configure, and include a secure, web-based graphical user interface which provides you with visual alerting, health monitoring and cluster diagnostics.
• One-Click Session Persistence - If sticky sessions are required for web application, just turn on session affinity with one click.
• Improved flexibility and scalability - Many content intensive applications have scaled beyond the point where a single server can provide adequate processing power. Both enterprises and service providers need the flexibility to deploy additional servers quickly and transparently to end-users.
• Enhanced availability - server load balancing is its ability to improve application availability. If an application or server fails, load balancing can automatically redistribute end-user service requests to other servers within a server farm or to servers in another location.
• Less disruption - Server load balancing also prevents planned outages for software or hardware maintenance from disrupting service to end users.

Cisco Ace Load Balancer

The Cisco ACE Application Control Engine Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers is a next-generation load-balancing and application-delivery solution.
• Helps ensure business continuity by increasing application availability
• Improves business productivity by accelerating application and server performance
• Reduces data centre power, space, and cooling needs through a virtualized architecture
• Helps lower operational costs associated with application provisioning and scaling
It achieves these goals through intelligent load-balancing and content-switching technologies integrated with acceleration and security capabilities. A virtualized architecture and role-based administration helps to provision and deliver multiple applications from a single module to increase data centre scalability