cmd/jobrun: repeat strategies as part of jobrun

cmd/config.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"github.com/jinzhu/copier"
 	"github.com/mitchellh/mapstructure"
+	"github.com/zrepl/zrepl/jobrun"
 	"github.com/zrepl/zrepl/rpc"
 	"github.com/zrepl/zrepl/sshbytestream"
 	. "github.com/zrepl/zrepl/util"
@@ -13,6 +14,7 @@ import (
 	"io"
 	"io/ioutil"
 	"strings"
+	"time"
 )
 
 type Pool struct {
@@ -42,12 +44,15 @@ type Push struct {
 	To                *Pool
 	Filter            zfs.DatasetMapping
 	InitialReplPolicy rpc.InitialReplPolicy
+	RepeatStrategy    jobrun.RepeatStrategy
 }
 type Pull struct {
 	From              *Pool
 	Mapping           zfs.DatasetMapping
 	InitialReplPolicy rpc.InitialReplPolicy
+	RepeatStrategy    jobrun.RepeatStrategy
 }
+
 type ClientMapping struct {
 	From    string
 	Mapping zfs.DatasetMapping
@@ -171,6 +176,7 @@ func parsePushs(v interface{}, pl poolLookup) (p []Push, err error) {
 		To                string
 		Filter            map[string]string
 		InitialReplPolicy string
+		Repeat            map[string]string
 	}, 0)
 
 	if err = mapstructure.Decode(v, &asList); err != nil {
@@ -197,6 +203,10 @@ func parsePushs(v interface{}, pl poolLookup) (p []Push, err error) {
 			return
 		}
 
+		if push.RepeatStrategy, err = parseRepeatStrategy(e.Repeat); err != nil {
+			return
+		}
+
 		p[i] = push
 	}
 
@@ -209,6 +219,7 @@ func parsePulls(v interface{}, pl poolLookup) (p []Pull, err error) {
 		From              string
 		Mapping           map[string]string
 		InitialReplPolicy string
+		Repeat            map[string]string
 	}, 0)
 
 	if err = mapstructure.Decode(v, &asList); err != nil {
@@ -241,6 +252,9 @@ func parsePulls(v interface{}, pl poolLookup) (p []Pull, err error) {
 		if pull.InitialReplPolicy, err = parseInitialReplPolicy(e.InitialReplPolicy, rpc.DEFAULT_INITIAL_REPL_POLICY); err != nil {
 			return
 		}
+		if pull.RepeatStrategy, err = parseRepeatStrategy(e.Repeat); err != nil {
+			return
+		}
 
 		p[i] = pull
 	}
@@ -272,6 +286,25 @@ err:
 	return
 }
 
+func parseRepeatStrategy(r map[string]string) (s jobrun.RepeatStrategy, err error) {
+
+	if r == nil {
+		return jobrun.NoRepeatStrategy{}, nil
+	}
+
+	if repeatStr, ok := r["interval"]; ok {
+		d, err := time.ParseDuration(repeatStr)
+		if err != nil {
+			return nil, err
+		}
+		s = &jobrun.PeriodicRepeatStrategy{d}
+		return s, err
+	} else {
+		return nil, fmt.Errorf("attribute 'interval' not found but required in repeat specification")
+	}
+
+}
+
 func expectList(v interface{}) (asList []interface{}, err error) {
 	var ok bool
 	if asList, ok = v.([]interface{}); !ok {

cmd/main.go

@@ -158,9 +158,8 @@ func cmdRun(c *cli.Context) error {
 	i := 0
 	for _, pull := range conf.Pulls {
 		jobs[i] = jobrun.Job{
-			Name:     fmt.Sprintf("pull%d", i),
-			Interval: time.Duration(5 * time.Second),
-			Repeats:  true,
+			Name:           fmt.Sprintf("pull.%d", i),
+			RepeatStrategy: pull.RepeatStrategy,
 			RunFunc: func(log jobrun.Logger) error {
 				log.Printf("doing pull: %v", pull)
 				return jobPull(pull, c, log)
@@ -170,9 +169,8 @@ func cmdRun(c *cli.Context) error {
 	}
 	for _, push := range conf.Pushs {
 		jobs[i] = jobrun.Job{
-			Name:     fmt.Sprintf("push%d", i),
-			Interval: time.Duration(5 * time.Second),
-			Repeats:  true,
+			Name:           fmt.Sprintf("push.%d", i),
+			RepeatStrategy: push.RepeatStrategy,
 			RunFunc: func(log jobrun.Logger) error {
 				log.Printf("doing push: %v", push)
 				return jobPush(push, c, log)

cmd/sampleconf/zrepl.yml

@@ -23,6 +23,8 @@ pulls:
   # local replication, only allowed in pull mode
   # the from name 'local' is reserved for this purpose
   - from: local
+    repeat:
+      interval: 15m
     mapping: {
       "tank/usr/home":"mirrorpool/foo/bar"
     }

jobrun/jobrun.go

@@ -19,12 +19,24 @@ func (l jobLogger) Printf(format string, v ...interface{}) {
 }
 
 type Job struct {
-	Name      string
-	RunFunc   func(log Logger) (err error)
-	LastStart time.Time
-	LastError error
-	Interval  time.Duration
-	Repeats   bool
+	Name           string
+	RunFunc        func(log Logger) (err error)
+	LastStart      time.Time
+	LastError      error
+	DueAt          time.Time
+	RepeatStrategy RepeatStrategy
+}
+
+type JobRunResult struct {
+	Start  time.Time
+	Finish time.Time
+	Error  error
+}
+
+func (r JobRunResult) RunTime() time.Duration { return r.Finish.Sub(r.Start) }
+
+type RepeatStrategy interface {
+	ShouldReschedule(lastResult JobRunResult) (nextDue time.Time, reschedule bool)
 }
 
 type JobRunner struct {
@@ -78,15 +90,20 @@ loop:
 
 	case finishedJob := <-r.finishedJobChan:
 
-		runTime := time.Since(finishedJob.LastStart)
+		delete(r.running, finishedJob.Name)
 
-		r.logger.Printf("[%s] finished after %v\n", finishedJob.Name, runTime)
-		if runTime > finishedJob.Interval {
-			r.logger.Printf("[%s] job exceeded interval of %v\n", finishedJob.Name, finishedJob.Interval)
+		res := JobRunResult{
+			Start:  finishedJob.LastStart,
+			Finish: time.Now(),
+			Error:  finishedJob.LastError,
 		}
 
-		delete(r.running, finishedJob.Name)
-		if finishedJob.Repeats {
+		r.logger.Printf("[%s] finished after %s\n", finishedJob.Name, res.RunTime())
+
+		dueTime, resched := finishedJob.RepeatStrategy.ShouldReschedule(res)
+		if resched {
+			r.logger.Printf("[%s] rescheduling to %s", dueTime)
+			finishedJob.DueAt = dueTime
 			r.pending[finishedJob.Name] = finishedJob
 		}
 
@@ -108,11 +125,9 @@ loop:
 
 	for jobName, job := range r.pending {
 
-		jobDueTime := job.LastStart.Add(job.Interval)
-
-		if jobDueTime.After(time.Now()) {
-			if jobDueTime.Before(nextJobDue) {
-				nextJobDue = jobDueTime
+		if job.DueAt.After(time.Now()) {
+			if job.DueAt.Before(nextJobDue) {
+				nextJobDue = job.DueAt
 			}
 			jobPending = true
 			continue

jobrun/repeat_strategies.go

@@ -0,0 +1,25 @@
+package jobrun
+
+import (
+	"time"
+)
+
+type NoRepeatStrategy struct{}
+
+func (s NoRepeatStrategy) ShouldReschedule(lastResult JobRunResult) (time.Time, bool) {
+	return time.Time{}, false
+}
+
+type PeriodicRepeatStrategy struct {
+	Interval time.Duration
+}
+
+func (s *PeriodicRepeatStrategy) ShouldReschedule(lastResult JobRunResult) (next time.Time, shouldRun bool) {
+	// Don't care about the result
+	shouldRun = true
+	next = lastResult.Start.Add(s.Interval)
+	if next.Before(time.Now()) {
+		next = time.Now()
+	}
+	return
+}