The Research Of Adaptive Dynamic Load Balancing Based On Common Object Request Broker Architecture

CORBA (Common Object Request Broker Architecture) is widely used to develop and integrate distributed systems as a kind of important middleware. In order to promote performance of the distributed systems based on CORBA, it is necessary to do research on load balancing based on CORBA.Traditional load balancing technologies designed for distributed systems based on CORBA have several deficiencies. They distribute load among servers when systems start and they cannot adapt load among multiple servers fairly according to current load conditions. They provide so single load metric and load balancing policy that they cannot be used in deferent environments.The adaptive dynamic load balancing system model is brought forward after the design principle and the load balancing layer and the load balancing policies are decided. In the system, Monitor is used to sample data about the system resource of the host. Analyzer is used to analysis load information and to decide which server will receive next client request. Alarm is used to force the server to refuse or to accept the client request according to the server's load status. Redirector is used to forward client request to the server which analyzer has choose to use. Load Manager is used to integrate and manage all the components.That the portable interceptor and LOCATION_FORWARD mechanism of CORBA are used to develop the adaptive dynamic load balancing system based on CORBA makes the adaptive dynamic load balancing system portable and transparent. Components of the system use event service to communicate in pull mode or push mode. That the system provide several load metrics and load balancing policies which users can choose to use make the system can adapt to deferent environments. All the components work together to make the system adaptive and dynamic.The test result proves that the adaptive dynamic load balancing system can distribute load among servers fairly and can promote the performance of distributed systems based on CORBA efficiently.