Hands-On Software Engineering with Golang

Running a new job

Once the worker receives a new job assignment from the master, it calls the coordinator's constructor and then invokes its RunJob method, which blocks until the job either completes or an error occurs:

func (c *workerJobCoordinator) RunJob() error {    // ...}

Let's break down the RunJob implementation into smaller chunks and go through each one:

execFactory := newWorkerExecutorFactory(c.cfg.serializer, c.barrier)executor, err := c.cfg.jobRunner.StartJob(c.cfg.jobDetails, execFactory)if err != nil {    c.cancelJobCtx()    return xerrors.Errorf("unable to start job on worker: %w", err)}graph := executor.Graph()graph.RegisterRelayer(bspgraph.RelayerFunc(c.relayNonLocalMessage))

The very first thing that RunJob does is to create a ...