Product overview

Load Balancer is a software solution for distributing incoming client requests across servers. It boosts the performance of servers by directing TCP/IP session requests to different servers within a group of servers; in this way, it balances the requests among all the servers. This load balancing is transparent to users and other applications. Load Balancer is useful for applications such as e-mail servers, World Wide Web servers, distributed parallel database queries, and other TCP/IP applications.

When used with Web servers, Load Balancer can help maximize the potential of your site by providing a powerful, flexible, and scalable solution to peak-demand problems. If visitors to your site can not get through at times of greatest demand, use Load Balancer to automatically find the optimal server to handle incoming requests, thus enhancing your customers’ satisfaction and your profitability.

What are the advantages to using Load Balancer?

The number of users and networks connected to the global Internet is growing exponentially. This growth is causing scalability problems that can limit users’ access to popular sites. Currently, network administrators are using numerous methods to try to maximize access. With some of these methods, you can choose a different server at random if an earlier choice is slow or not responding. This approach is cumbersome, annoying, and inefficient. Another method is standard round-robin, in which the domain name server selects servers in turn to handle requests. This approach is better, but still inefficient because it forwards traffic without any consideration of the server workload. In addition, even if a server fails, requests continue to be sent to it. The need for a more powerful solution has resulted in Load Balancer. It offers numerous benefits over earlier and competing solutions:
  • Scalability: As the number of client requests increases, you can add servers dynamically, providing support for tens of millions of requests per day, on tens or even hundreds of servers.
  • Efficient use of equipment: Load balancing ensures that each group of servers makes optimum use of its hardware by minimizing the hot-spots that frequently occur with a standard round-robin method.
  • Easy integration: Load Balancer uses standard TCP/IP protocols. You can add it to your existing network without making any physical changes to the network. It is simple to install and configure.
  • Low overhead Using a simple MAC level forwarding method, the Dispatcher component looks at the inbound client-to-server flows only. It does not need to see the outbound server-to-client flows. This significantly reduces its impact on the application compared with other approaches and can result in improved network performance.
  • Content-based routing (using the CBR component) In conjunction with Caching Proxy, the CBR component has the ability to proxy HTTP and HTTPS (SSL) requests to specific servers based on the content requested. For example, if a request contains the string "/cgi-bin/" in the directory portion of the URL, and the server name is a local server, CBR can direct the request to the best server in a set of servers specifically allocated to handle cgi requests.
  • High availability: The Dispatcher component offers built-in high availability, utilizing a backup machine that remains ready at all times to take over load balancing if the primary server machine fails. When one of the servers fails, requests continue to be serviced by the other server. This process eliminates any server as a single point of failure and makes the site highly available.
  • Client to server affinity: The affinity feature maps a client IP address to a back-end server, providing a higher level of efficiency by decreasing the memory and CPU utilization when compared to traditional connection forwarding.
  • Load balancing a private network: You can set up Dispatcher and the TCP server machines using a private network. This configuration can reduce the contention on the public or external network that can affect performance.
  • Learn how you can manage servers using Load Balancer.

    Load Balancer balances traffic among your servers through a unique combination of load balancing and management software. All client requests sent to the Dispatcher machine are directed to the ″best″ server according to weights that are set dynamically. You can use the default values for those weights or change the values during the configuration process.

    Dispatcher can also detect a failed server and forward traffic around it. Dispatcher supports HTTP, FTP, SSL, SMTP, NNTP, IMAP, POP3, Telnet, SIP, and any other TCP based application.

Load Balancer is the key to stable, efficient management of a large, scalable network of servers. You can link many individual servers into what seems to be a single, virtual server. Your site is presented as a single IP address to the world. Dispatcher functions independently of a domain name server; all requests are sent to the IP address of the Dispatcher machine.

Dispatcher brings distinct advantages in balancing traffic load to clustered servers, resulting in stable and efficient management of your site.


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Timestamp icon Last updated: March 23, 2018 0:18
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