The Logging and Bookkeeping service (LB) tracks jobs in terms of events (important points of job life, e.g. submission, finding a matching CE, starting execution etc.) gathered from various WMS components as well as CEs (all those have to be instrumented with LB calls).

The events are passed to a physically close component of the LB infrastructure (locallogger) in order to avoid network problems. This component stores them in a local disk file and takes over the responsibility to deliver them further.