Research And Implemention Of Lightweight Instant Messaging System

This thesis relies on the enterprise cooperation project named"Social application platform for the elderly".Because of the requirement for the funcation of instant messaging,it needs to develop an instant messaging system.But general design of instant messaging system is for large enterprises with large-scale users and has many drawbacks,such as hight development cost,deployment difficulty and heavy maintenance work.The platform has the features of small user scale and small user concurrency.The general design is not suitable for this platform,so it needs to develop a lightweight instant messaging system.At the same time for the core technical problems in instant messaging system,such as load balancing,routing strategy and data synchronization,current solutions used by general instant messaging system are too complex and large,not suitable for lightweight instant messaging system,so it is necessary to study new solution that is more suitable for lightweight scenes.The message forwarding mechanism used in general instant messaging system has many problems such as cumbersome message processing and large memory consumption,so it needs to study a new message forwarding mechanism to solve these problems.On the basis of studying the design of general instant messaging system,this thesis designed and implemented a lightweight instant messaging system named pushd.This system can effectively reduce the cost of development and reduce the pressure of system deployment and system maintenance work in the case of meeting the current user scale of the platform.This thesis analysed the present development of instant messaging system and the significance of studying lightweight instant messaging system,made a thorough study about the general design of the instant messaging system and the relevant open source technology,studied the requirements of the lightweight instant messaging system on the system function,performance and lightweight.By studying the drawback of general messaging mechanism,this thesis proposed a topic-oriented message forwarding mechanism named publish-subscribe mechanism.This mechanism can speed up message forwarding and save more system memory.And this thesis has designed and implemented five basic system functions:message forwarding,off-line message,off-line push,system monitoring and phone SDK.Finally,this thesis made function test and performance test to the system.The data from test proved the availability of the system after analyzing.