Documentation
¶
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type DoTaskArgs ¶
type DoTaskArgs struct { JobName string File string // only for map, the input file Phase jobPhase // are we in mapPhase or reducePhase? TaskNumber int // this task's index in the current phase // NumOtherPhase is the total number of tasks in other phase; mappers // need this to compute the number of output bins, and reducers needs // this to know how many input files to collect. NumOtherPhase int }
DoTaskArgs holds the arguments that are passed to a worker when a job is scheduled on it.
type KeyValue ¶
KeyValue is a type used to hold the key/value pairs passed to the map and reduce functions.
type Master ¶
Master holds all the state that the master needs to keep track of.
func Distributed ¶
Distributed schedules map and reduce tasks on workers that register with the master over RPC.
func Sequential ¶
func Sequential(jobName string, files []string, nreduce int, mapF func(string, string) []KeyValue, reduceF func(string, []string) string, ) (mr *Master)
Sequential runs map and reduce tasks sequentially, waiting for each task to complete before running the next.
func (*Master) CleanupFiles ¶
func (mr *Master) CleanupFiles()
CleanupFiles removes all intermediate files produced by running mapreduce.
func (*Master) Register ¶
func (mr *Master) Register(args *RegisterArgs, _ *struct{}) error
Register is an RPC method that is called by workers after they have started up to report that they are ready to receive tasks.
type Parallelism ¶
type Parallelism struct {
// contains filtered or unexported fields
}
track whether workers executed in parallel.
type RegisterArgs ¶
type RegisterArgs struct {
Worker string // the worker's UNIX-domain socket name, i.e. its RPC address
}
RegisterArgs is the argument passed when a worker registers with the master.
type ShutdownReply ¶
type ShutdownReply struct {
Ntasks int
}
ShutdownReply is the response to a WorkerShutdown. It holds the number of tasks this worker has processed since it was started.
type Worker ¶
type Worker struct { sync.Mutex Map func(string, string) []KeyValue Reduce func(string, []string) string // contains filtered or unexported fields }
Worker holds the state for a server waiting for DoTask or Shutdown RPCs
func (*Worker) DoTask ¶
func (wk *Worker) DoTask(arg *DoTaskArgs, _ *struct{}) error
DoTask is called by the master when a new task is being scheduled on this worker.
func (*Worker) Shutdown ¶
func (wk *Worker) Shutdown(_ *struct{}, res *ShutdownReply) error
Shutdown is called by the master when all work has been completed. We should respond with the number of tasks we have processed.