Workload Management System (Resource Broker (RB))

The components of the Workload Management System (WMS) are responsible for accepting jobs, matching up job requirements with available resources and dispatching the jobs to those resources. The Resource Broker component (RB) of the LCG middleware provides these services using information from the BDII and RLS. The services provided by the resource broker are detailed following.

Network Server: accepts incoming jobs from the UI and provides job control functionality.
Workload Manager: the core component of the system - manages the jobs in the system.
Match-maker: (also called the resource broker) matches job requirements to the available resources.
Job Adaptor: prepares the environment of the job and its final description prior to passing it to the Job Controller.
Job Control Service: performs job management duties (submission, status, removal etc).
Logging and Bookeeping Service: logs all job management events.
Proxy Server: handles proxy certificate renewal. Consider that if a users proxy expires prior to the completion of the job, further attempts to access resources will fail due to unauthorised access. The proxy server provides the functionality to automatically renew a grid users proxy prior to its expiration.

The LCG-2 middleware allows for multiple Resource Brokers.