Event-Driven Implementation of Layer-7 Load Balancer

Abstract

A single-page application is a web application which is retrieved with a single page load, and has become popular recently. In such web applications, real-time interaction is offered by long polling of HTML requests, typically the Comet model. However, such communication between a client and a server is inefficient because of the TCP handshake and HTTP header overhead. In order to improve this kind of inefficiency, WebSocket is proposed as a web technology providing full-duplex communications between web browsers and servers. In this paper, we design and implement a load balancer suitable for Web applications using the WebSocket protocol, which enables us to get improved performance with respect to simultaneous connectability. Usually, load balancers handle TCP packets in the transport layer, or L4, of the network. Our load balancer is designed as a relay in the application layer, or L7, in order to provide a finer distribution of the network load. We implement the load balancer on an event-driven web application framework, Node.js. We evaluate the implementation of efficiency of the load balancer.KeywordsLoad BalancerConnection RequestServer PoolSession ObjectLoad Balancer ProcessThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.