(HTTP Load Balancing is only available in OctaGate Switch Enterprise Edition)

• Improve site performance by spreading load over multiple servers
• Avoid site downtime through server failover
• Combine Load Balancing and SSL Encryption on one machine

Load Balancing is a method of improving site performance and site up time by distributing the load of a site over several servers. At $950 OctaGate Switch is an extremely competetively priced Load Balancing product.

OctaGate Switch offers HTTP Load Balancing, which will let you speed up your web applications by simply adding another server to your site. OctaGate Switch will determine which server currently has the lightest load, and new connections will be forwarded to that server. Several load balanced servers are called a load balanced cluster, or simply a cluster.

OctaGate Switch is an extremely cost effective method of improving performance of a web application or web site that's running slowly. For instance, if you have to choose between a complete re-write of a system, or simply adding a few more servers, the choice is easy to make!

See this demo for an example of load balancing.

If one server suddenly dies, OctaGate Switch will stop redirecting to it and instead favor the servers that are still working. Once the server is working again, OctaGate Switch will again include it in the cluster. This can radically improve your site uptime, because even if a server dies, the site stays active and responsive but with less capacity.

OctaGate Switch will frequently (currently every 10 seconds) poll all load balancing servers to verify if they are online or offline. This means that a failed server will be detected within, on average, 5 seconds.

Once a user has connected to your site, he has a persistent session. This means that OctaGate Switch will redirected him to the same server for the duration of his visit - so server side persistence will work just as it did before.

The most important features of HTTP Load Balancing are:

• Speed up slow web application by adding more hardware and let OctaGate Switch divide the load between the servers
• Failover broken servers to servers that are still working
• Process more transactions faster
• Improved up-time for your site

Currently OctaGate Switch supports two main methods for Session identification;

• IP Number based session identification
• Browser cookie based session identification

IP Number based session identification means that the IP number of the incoming request is used to identify the user and the session. If you have a number of users behind a NAT router that method will break down. This is because they will all appear to have the same IP number.

Instead you can use browser cookie base session identification. This means that OctaGate Switch will add a cookie to the communication between the server and the browsers. This cookie will be used to identify the user throughout the session. This method requires that cookies are enabled on all browsing computers, though, otherwise it will not work.

For internet applications and external web sites, we recommend that you use IP number based session identification, because you can't guarantee that all users have cookies enabled. For intranets and extranets you may use browser cookie based session identification, just make sure that all browsers accept cookies.

Which you prefer will depend on your network topology though - do you use NAT routers or not?

Many Load Balancing solutions don't take the server capacity into account. This means that if you add a new server that is two times faster than your old server, the old server will still get as many requests as the new server. In that situation, it's better do simply remove the old server completely. OctaGate Switch will instead make sure that the new server get two times as many connections / requests as the old server. This means that the old server will actually help instead of hinder the site. The choice for which server a new connection is forwarded to is based on up to date information about the servers current load.

This also means that old hardware will get a new lease on life, because OctaGate Switch will make sure that they all work to the top of their capacity.

You typically only need one cluster for your site, but OctaGate Switch can easily handle multiple clusters.

You can use HTTP Load Balancing for performing Soft Roll out.

You can also use HTTP Load Balancing for SOAP Load Balancing.