Hands-On Software Engineering with Golang

Implementing the job runner for master nodes

Let's begin by examining the rather trivial StartJob method implementation for the master node:

func (n *MasterNode) StartJob(_ job.Details, execFactory bspgraph.ExecutorFactory) (*bspgraph.Executor, error) {
    if err := n.calculator.Graph().Reset(); err != nil {
        return nil, err
    }

    n.jobStartedAt = n.cfg.Clock.Now()
    n.calculator.SetExecutorFactory(execFactory)
    return n.calculator.Executor(), nil
}

The StartJob method records the time when the job was started and performs the following three tasks:

1. It resets the graph's internal state. This is important as the calculator component instance is re-used between subsequent job runs.
2. It overrides the calculator component's executor factory with the version ...