NetScaler intro – Server offload – Multiplexing
Need the multiplexing basics in less than 3 mins? Read on….
When a user asks for content from the data centre their request is passed to the application server through a dedicated connection from the load balancer which manages the delivery path. Once the server has completed the request, the connection is closed ready for
a new connection to be opened for the next request.
The number of connections a server can handle at any one time depends on several factors but in some cases an application server can have hundreds of these connections open, each of which takes computational resource to open, maintain and close. I often describe it as similar to picking up a phone, dialling a number, waiting to be connected, having a conversation and then hanging up again. The actual conversation is only a small part of the process.
As a direct result, this connection management requires the use of the server resources which leaves less compute power to produce the content that the server is there for in the first place. The rest of time and effort is spent opening and closing connections.
NetScaler is a traffic management device which understands which server the connection is destined for and the content of the communication so rather than having many individual connections open, NetScaler’s take the content of those communications and pass them to the server down a single connection.The result is the server has to open fewer connections to have the same amount of conversations. Fewer connections require less management by the processor which in turn leaves compute power to actually serve content, ultimately allowing more users faster access to the server – Al
Multiplexing is a primary tool in the Datastream feature for SQL environments which features in another post on this blog
© Al Taylor 14th Sept 2012