pruning/keep_last_n: correctly handle the case where count > matching snaps

fixes #446

client/reset.go

@@ -1,88 +0,0 @@
-package client
-
-import (
-	"context"
-	"strconv"
-	"time"
-
-	"github.com/kr/pretty"
-	"github.com/pkg/errors"
-	"github.com/spf13/pflag"
-
-	"github.com/zrepl/zrepl/cli"
-	"github.com/zrepl/zrepl/config"
-	"github.com/zrepl/zrepl/daemon"
-	"github.com/zrepl/zrepl/daemon/job"
-)
-
-var resetCmdArgs struct {
-	verbose  bool
-	interval time.Duration
-	token    string
-}
-
-var ResetCmd = &cli.Subcommand{
-	Use:   "reset [-t TOKEN | JOB INVOCATION [replication|snapshotting|prune_sender|prune_receiver]]",
-	Short: "",
-	Run: func(ctx context.Context, subcommand *cli.Subcommand, args []string) error {
-		return runResetCmd(subcommand.Config(), args)
-	},
-	SetupFlags: func(f *pflag.FlagSet) {
-		f.BoolVarP(&resetCmdArgs.verbose, "verbose", "v", false, "verbose output")
-		f.DurationVarP(&resetCmdArgs.interval, "poll-interval", "i", 100*time.Millisecond, "poll interval")
-		f.StringVarP(&resetCmdArgs.token, "token", "t", "", "token produced by 'signal' subcommand")
-	},
-}
-
-func runResetCmd(config *config.Config, args []string) error {
-
-	httpc, err := controlHttpClient(config.Global.Control.SockPath)
-	if err != nil {
-		return err
-	}
-
-	var req daemon.ControlJobEndpointResetActiveRequest
-	if resetCmdArgs.token != "" {
-		var token TriggerToken
-		err := token.Decode(resetCmdArgs.token)
-		if err != nil {
-			return errors.Wrap(err, "cannot decode token")
-		}
-		req = token.ToReset()
-	} else {
-		jobName := args[0]
-
-		invocationId, err := strconv.ParseUint(args[1], 10, 64)
-		if err != nil {
-			return errors.Wrap(err, "parse invocation id")
-		}
-
-		// what := args[2]
-
-		// updated by subsequent requests
-		req = daemon.ControlJobEndpointResetActiveRequest{
-			Job: jobName,
-			ActiveSideResetRequest: job.ActiveSideResetRequest{
-				InvocationId: invocationId,
-			},
-		}
-	}
-
-	var res job.ActiveSideResetResponse
-	if resetCmdArgs.verbose {
-		pretty.Println("making request", req)
-	}
-	err = jsonRequestResponse(httpc, daemon.ControlJobEndpointResetActive,
-		req,
-		&res,
-	)
-	if err != nil {
-		return err
-	}
-
-	if resetCmdArgs.verbose {
-		pretty.Println("got response", res)
-	}
-
-	return nil
-}

client/signal.go

@@ -0,0 +1,42 @@
+package client
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+
+	"github.com/zrepl/zrepl/cli"
+	"github.com/zrepl/zrepl/config"
+	"github.com/zrepl/zrepl/daemon"
+)
+
+var SignalCmd = &cli.Subcommand{
+	Use:   "signal [wakeup|reset] JOB",
+	Short: "wake up a job from wait state or abort its current invocation",
+	Run: func(ctx context.Context, subcommand *cli.Subcommand, args []string) error {
+		return runSignalCmd(subcommand.Config(), args)
+	},
+}
+
+func runSignalCmd(config *config.Config, args []string) error {
+	if len(args) != 2 {
+		return errors.Errorf("Expected 2 arguments: [wakeup|reset] JOB")
+	}
+
+	httpc, err := controlHttpClient(config.Global.Control.SockPath)
+	if err != nil {
+		return err
+	}
+
+	err = jsonRequestResponse(httpc, daemon.ControlJobEndpointSignal,
+		struct {
+			Name string
+			Op   string
+		}{
+			Name: args[1],
+			Op:   args[0],
+		},
+		struct{}{},
+	)
+	return err
+}

client/status/client/client.go

@@ -11,7 +11,6 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/zrepl/zrepl/daemon"
-	"github.com/zrepl/zrepl/daemon/job"
 )
 
 type Client struct {
@@ -43,27 +42,21 @@ func (c *Client) StatusRaw() ([]byte, error) {
 	return r, nil
 }
 
-func (c *Client) signal(jobName, sig string) error {
-	return jsonRequestResponse(c.h, daemon.ControlJobEndpointTriggerActive,
+func (c *Client) signal(job, sig string) error {
+	return jsonRequestResponse(c.h, daemon.ControlJobEndpointSignal,
 		struct {
-			Job string
-			job.ActiveSideTriggerRequest
+			Name string
+			Op   string
 		}{
-			Job: jobName,
-			ActiveSideTriggerRequest: job.ActiveSideTriggerRequest{
-				What: sig,
-			},
+			Name: job,
+			Op:   sig,
 		},
 		struct{}{},
 	)
 }
 
-func (c *Client) SignalReplication(job string) error {
-	return c.signal(job, "replication")
-}
-
-func (c *Client) SignalSnapshot(job string) error {
-	return c.signal(job, "snapshot")
+func (c *Client) SignalWakeup(job string) error {
+	return c.signal(job, "wakeup")
 }
 
 func (c *Client) SignalReset(job string) error {

client/status/status.go

@@ -19,8 +19,7 @@ import (
 type Client interface {
 	Status() (daemon.Status, error)
 	StatusRaw() ([]byte, error)
-	SignalReplication(job string) error
-	SignalSnapshot(job string) error
+	SignalWakeup(job string) error
 	SignalReset(job string) error
 }
 
@@ -71,12 +70,16 @@ func runStatusV2Command(ctx context.Context, config *config.Config, args []strin
 
 	mode := statusv2Flags.Mode.Value().(statusv2Mode)
 
-	if !isatty.IsTerminal(os.Stdout.Fd()) && mode != StatusV2ModeDump {
-		usemode, err := statusv2Flags.Mode.InputForChoice(StatusV2ModeDump)
+	if !isatty.IsTerminal(os.Stdout.Fd()) && mode != StatusV2ModeDump && mode != StatusV2ModeRaw {
+		dumpmode, err := statusv2Flags.Mode.InputForChoice(StatusV2ModeDump)
 		if err != nil {
 			panic(err)
 		}
-		return errors.Errorf("error: stdout is not a tty, please use --mode %s", usemode)
+		rawmode, err := statusv2Flags.Mode.InputForChoice(StatusV2ModeRaw)
+		if err != nil {
+			panic(err)
+		}
+		return errors.Errorf("error: stdout is not a tty, please use --mode %s or --mode %s", dumpmode, rawmode)
 	}
 
 	switch mode {

client/status/status_interactive.go

@@ -281,8 +281,8 @@ func interactive(c Client, flag statusFlags) error {
 			if !ok {
 				return nil
 			}
-			signals := []string{"replication", "snapshot", "reset"}
-			clientFuncs := []func(job string) error{c.SignalReplication, c.SignalSnapshot, c.SignalReset}
+			signals := []string{"wakeup", "reset"}
+			clientFuncs := []func(job string) error{c.SignalWakeup, c.SignalReset}
 			sigMod := tview.NewModal()
 			sigMod.SetBackgroundColor(tcell.ColorDefault)
 			sigMod.SetBorder(true)

client/trigger.go

@@ -1,94 +0,0 @@
-package client
-
-import (
-	"context"
-	"encoding/json"
-	"fmt"
-
-	"github.com/pkg/errors"
-
-	"github.com/zrepl/zrepl/cli"
-	"github.com/zrepl/zrepl/config"
-	"github.com/zrepl/zrepl/daemon"
-	"github.com/zrepl/zrepl/daemon/job"
-)
-
-var TriggerCmd = &cli.Subcommand{
-	Use:   "trigger JOB [replication|snapshot]",
-	Short: "",
-	Run: func(ctx context.Context, subcommand *cli.Subcommand, args []string) error {
-		return runTriggerCmd(subcommand.Config(), args)
-	},
-}
-
-type TriggerToken struct {
-	// TODO version, daemon invocation id, etc.
-	Job          string
-	InvocationId uint64
-}
-
-func (t TriggerToken) Encode() string {
-	j, err := json.Marshal(t)
-	if err != nil {
-		panic(err)
-	}
-	return string(j)
-}
-
-func (t *TriggerToken) Decode(s string) error {
-	return json.Unmarshal([]byte(s), t)
-}
-
-func (t TriggerToken) ToReset() daemon.ControlJobEndpointResetActiveRequest {
-	return daemon.ControlJobEndpointResetActiveRequest{
-		Job: t.Job,
-		ActiveSideResetRequest: job.ActiveSideResetRequest{
-			InvocationId: t.InvocationId,
-		},
-	}
-}
-
-func (t TriggerToken) ToWait() daemon.ControlJobEndpointWaitActiveRequest {
-	return daemon.ControlJobEndpointWaitActiveRequest{
-		Job: t.Job,
-		ActiveSidePollRequest: job.ActiveSidePollRequest{
-			InvocationId: t.InvocationId,
-		},
-	}
-}
-
-func runTriggerCmd(config *config.Config, args []string) error {
-	if len(args) != 2 {
-		return errors.Errorf("Expected 2 arguments: [replication|reset|snapshot] JOB")
-	}
-
-	httpc, err := controlHttpClient(config.Global.Control.SockPath)
-	if err != nil {
-		return err
-	}
-
-	jobName := args[0]
-	what := args[1]
-
-	var res job.ActiveSideSignalResponse
-	err = jsonRequestResponse(httpc, daemon.ControlJobEndpointTriggerActive,
-		struct {
-			Job string
-			job.ActiveSideTriggerRequest
-		}{
-			Job: jobName,
-			ActiveSideTriggerRequest: job.ActiveSideTriggerRequest{
-				What: what,
-			},
-		},
-		&res,
-	)
-
-	token := TriggerToken{
-		Job:          jobName,
-		InvocationId: res.InvocationId,
-	}
-
-	fmt.Println(token.Encode())
-	return err
-}

client/wait.go

@@ -1,110 +0,0 @@
-package client
-
-import (
-	"context"
-	"fmt"
-	"strconv"
-	"time"
-
-	"github.com/kr/pretty"
-	"github.com/pkg/errors"
-	"github.com/spf13/pflag"
-
-	"github.com/zrepl/zrepl/cli"
-	"github.com/zrepl/zrepl/config"
-	"github.com/zrepl/zrepl/daemon"
-	"github.com/zrepl/zrepl/daemon/job"
-)
-
-var waitCmdArgs struct {
-	verbose  bool
-	interval time.Duration
-	token    string
-}
-
-var WaitCmd = &cli.Subcommand{
-	Use:   "wait [-t TOKEN | JOB INVOCATION [replication|snapshotting|prune_sender|prune_receiver]]",
-	Short: "",
-	Run: func(ctx context.Context, subcommand *cli.Subcommand, args []string) error {
-		return runWaitCmd(subcommand.Config(), args)
-	},
-	SetupFlags: func(f *pflag.FlagSet) {
-		f.BoolVarP(&waitCmdArgs.verbose, "verbose", "v", false, "verbose output")
-		f.DurationVarP(&waitCmdArgs.interval, "poll-interval", "i", 100*time.Millisecond, "poll interval")
-		f.StringVarP(&waitCmdArgs.token, "token", "t", "", "token produced by 'signal' subcommand")
-	},
-}
-
-func runWaitCmd(config *config.Config, args []string) error {
-
-	httpc, err := controlHttpClient(config.Global.Control.SockPath)
-	if err != nil {
-		return err
-	}
-
-	var req daemon.ControlJobEndpointWaitActiveRequest
-	if waitCmdArgs.token != "" {
-		var token TriggerToken
-		err := token.Decode(resetCmdArgs.token)
-		if err != nil {
-			return errors.Wrap(err, "cannot decode token")
-		}
-		req = token.ToWait()
-	} else {
-
-		jobName := args[0]
-
-		invocationId, err := strconv.ParseUint(args[1], 10, 64)
-		if err != nil {
-			return errors.Wrap(err, "parse invocation id")
-		}
-
-		// updated by subsequent requests
-		req = daemon.ControlJobEndpointWaitActiveRequest{
-			Job: jobName,
-			ActiveSidePollRequest: job.ActiveSidePollRequest{
-				InvocationId: invocationId,
-			},
-		}
-	}
-
-	doneErr := fmt.Errorf("done")
-
-	pollOnce := func() error {
-		var res job.ActiveSidePollResponse
-		if waitCmdArgs.verbose {
-			pretty.Println("making poll request", req)
-		}
-		err = jsonRequestResponse(httpc, daemon.ControlJobEndpointPollActive,
-			req,
-			&res,
-		)
-		if err != nil {
-			return err
-		}
-
-		if waitCmdArgs.verbose {
-			pretty.Println("got poll response", res)
-		}
-
-		if res.Done {
-			return doneErr
-		}
-
-		req.InvocationId = res.InvocationId
-
-		return nil
-	}
-
-	t := time.NewTicker(waitCmdArgs.interval)
-	for range t.C {
-		err := pollOnce()
-		if err == doneErr {
-			return nil
-		} else if err != nil {
-			return err
-		}
-	}
-
-	return err
-}

config/samples/quickstart_backup_to_external_disk.yml

@@ -40,7 +40,7 @@ jobs:
 
 # This job pushes to the local sink defined in job `backuppool_sink`.
 # We trigger replication manually from the command line / udev rules using
-#  `zrepl signal replication push_to_drive`
+#  `zrepl signal wakeup push_to_drive`
 - type: push
   name: push_to_drive
   connect:

daemon/control.go

@@ -73,29 +73,12 @@ func (j *controlJob) RegisterMetrics(registerer prometheus.Registerer) {
 }
 
 const (
-	ControlJobEndpointPProf         string = "/debug/pprof"
-	ControlJobEndpointVersion       string = "/version"
-	ControlJobEndpointStatus        string = "/status"
-	ControlJobEndpointTriggerActive string = "/signal/active"
-	ControlJobEndpointPollActive    string = "/poll/active"
-	ControlJobEndpointResetActive   string = "/reset/active"
+	ControlJobEndpointPProf   string = "/debug/pprof"
+	ControlJobEndpointVersion string = "/version"
+	ControlJobEndpointStatus  string = "/status"
+	ControlJobEndpointSignal  string = "/signal"
 )
 
-type ControlJobEndpointTriggerActiveRequest struct {
-	Job string
-	job.ActiveSideTriggerRequest
-}
-
-type ControlJobEndpointResetActiveRequest struct {
-	Job string
-	job.ActiveSideResetRequest
-}
-
-type ControlJobEndpointWaitActiveRequest struct {
-	Job string
-	job.ActiveSidePollRequest
-}
-
 func (j *controlJob) Run(ctx context.Context) {
 
 	log := job.GetLogger(ctx)
@@ -147,106 +130,29 @@ func (j *controlJob) Run(ctx context.Context) {
 			return s, nil
 		}})
 
-	mux.Handle(ControlJobEndpointPollActive, requestLogger{log: log, handler: jsonRequestResponder{log, func(decoder jsonDecoder) (v interface{}, err error) {
-		var req ControlJobEndpointWaitActiveRequest
-		if decoder(&req) != nil {
-			return nil, errors.Errorf("decode failed")
-		}
-
-		j.jobs.m.RLock()
-
-		jo, ok := j.jobs.jobs[req.Job]
-		if !ok {
-			j.jobs.m.RUnlock()
-			return struct{}{}, fmt.Errorf("unknown job name %q", req.Job)
-		}
-
-		ajo, ok := jo.(*job.ActiveSide)
-		if !ok {
-			v, err = struct{}{}, fmt.Errorf("job %q is not an active side (it's a %T)", jo.Name(), jo)
-			j.jobs.m.RUnlock()
-			return v, err
-		}
-
-		res, err := ajo.Poll(req.ActiveSidePollRequest)
-
-		j.jobs.m.RUnlock()
-
-		return res, err
-	}}})
-
-	mux.Handle(ControlJobEndpointTriggerActive,
-		requestLogger{log: log, handler: jsonRequestResponder{log, func(decoder jsonDecoder) (v interface{}, err error) {
+	mux.Handle(ControlJobEndpointSignal,
+		requestLogger{log: log, handler: jsonRequestResponder{log, func(decoder jsonDecoder) (interface{}, error) {
 			type reqT struct {
-				Job string
-				job.ActiveSideTriggerRequest
+				Name string
+				Op   string
 			}
 			var req reqT
 			if decoder(&req) != nil {
 				return nil, errors.Errorf("decode failed")
 			}
 
-			// FIXME dedup the following code with ControlJobEndpointPollActive
-
-			j.jobs.m.RLock()
-
-			jo, ok := j.jobs.jobs[req.Job]
-			if !ok {
-				j.jobs.m.RUnlock()
-				return struct{}{}, fmt.Errorf("unknown job name %q", req.Job)
+			var err error
+			switch req.Op {
+			case "wakeup":
+				err = j.jobs.wakeup(req.Name)
+			case "reset":
+				err = j.jobs.reset(req.Name)
+			default:
+				err = fmt.Errorf("operation %q is invalid", req.Op)
 			}
 
-			ajo, ok := jo.(*job.ActiveSide)
-			if !ok {
-				v, err = struct{}{}, fmt.Errorf("job %q is not an active side (it's a %T)", jo.Name(), jo)
-				j.jobs.m.RUnlock()
-				return v, err
-			}
-
-			res, err := ajo.Trigger(req.ActiveSideTriggerRequest)
-
-			j.jobs.m.RUnlock()
-
-			return res, err
-
+			return struct{}{}, err
 		}}})
-
-	mux.Handle(ControlJobEndpointResetActive,
-		requestLogger{log: log, handler: jsonRequestResponder{log, func(decoder jsonDecoder) (v interface{}, err error) {
-			type reqT struct {
-				Job string
-				job.ActiveSideResetRequest
-			}
-			var req reqT
-			if decoder(&req) != nil {
-				return nil, errors.Errorf("decode failed")
-			}
-
-			// FIXME dedup the following code with ControlJobEndpointPollActive
-
-			j.jobs.m.RLock()
-
-			jo, ok := j.jobs.jobs[req.Job]
-			if !ok {
-				j.jobs.m.RUnlock()
-				return struct{}{}, fmt.Errorf("unknown job name %q", req.Job)
-			}
-
-			ajo, ok := jo.(*job.ActiveSide)
-			if !ok {
-				v, err = struct{}{}, fmt.Errorf("job %q is not an active side (it's a %T)", jo.Name(), jo)
-				j.jobs.m.RUnlock()
-				return v, err
-			}
-
-			res, err := ajo.Reset(req.ActiveSideResetRequest)
-
-			j.jobs.m.RUnlock()
-
-			return res, err
-
-		}}})
-
 	server := http.Server{
 		Handler: mux,
 		// control socket is local, 1s timeout should be more than sufficient, even on a loaded system

daemon/daemon.go

@@ -20,6 +20,8 @@ import (
 
 	"github.com/zrepl/zrepl/config"
 	"github.com/zrepl/zrepl/daemon/job"
+	"github.com/zrepl/zrepl/daemon/job/reset"
+	"github.com/zrepl/zrepl/daemon/job/wakeup"
 	"github.com/zrepl/zrepl/daemon/logging"
 	"github.com/zrepl/zrepl/logger"
 	"github.com/zrepl/zrepl/version"
@@ -129,13 +131,17 @@ type jobs struct {
 	wg sync.WaitGroup
 
 	// m protects all fields below it
-	m    sync.RWMutex
-	jobs map[string]job.Job
+	m       sync.RWMutex
+	wakeups map[string]wakeup.Func // by Job.Name
+	resets  map[string]reset.Func  // by Job.Name
+	jobs    map[string]job.Job
 }
 
 func newJobs() *jobs {
 	return &jobs{
-		jobs: make(map[string]job.Job),
+		wakeups: make(map[string]wakeup.Func),
+		resets:  make(map[string]reset.Func),
+		jobs:    make(map[string]job.Job),
 	}
 }
 
@@ -184,6 +190,28 @@ func (s *jobs) status() map[string]*job.Status {
 	return ret
 }
 
+func (s *jobs) wakeup(job string) error {
+	s.m.RLock()
+	defer s.m.RUnlock()
+
+	wu, ok := s.wakeups[job]
+	if !ok {
+		return errors.Errorf("Job %s does not exist", job)
+	}
+	return wu()
+}
+
+func (s *jobs) reset(job string) error {
+	s.m.RLock()
+	defer s.m.RUnlock()
+
+	wu, ok := s.resets[job]
+	if !ok {
+		return errors.Errorf("Job %s does not exist", job)
+	}
+	return wu()
+}
+
 const (
 	jobNamePrometheus = "_prometheus"
 	jobNameControl    = "_control"
@@ -214,6 +242,10 @@ func (s *jobs) start(ctx context.Context, j job.Job, internal bool) {
 
 	s.jobs[jobName] = j
 	ctx = zfscmd.WithJobID(ctx, j.Name())
+	ctx, wakeup := wakeup.Context(ctx)
+	ctx, resetFunc := reset.Context(ctx)
+	s.wakeups[jobName] = wakeup
+	s.resets[jobName] = resetFunc
 
 	s.wg.Add(1)
 	go func() {

daemon/job/active.go

@@ -8,11 +8,14 @@ import (
 
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
 
 	"github.com/zrepl/zrepl/daemon/logging/trace"
 	"github.com/zrepl/zrepl/util/envconst"
 
 	"github.com/zrepl/zrepl/config"
+	"github.com/zrepl/zrepl/daemon/job/reset"
+	"github.com/zrepl/zrepl/daemon/job/wakeup"
 	"github.com/zrepl/zrepl/daemon/pruner"
 	"github.com/zrepl/zrepl/daemon/snapper"
 	"github.com/zrepl/zrepl/endpoint"
@@ -40,12 +43,8 @@ type ActiveSide struct {
 	promBytesReplicated   *prometheus.CounterVec   // labels: filesystem
 	promReplicationErrors prometheus.Gauge
 
-	tasksMtx           sync.Mutex
-	tasks              activeSideTasks
-	nextInvocationId   uint64
-	activeInvocationId uint64 // 0 <=> inactive
-	trigger            chan struct{}
-	reset              chan uint64
+	tasksMtx sync.Mutex
+	tasks    activeSideTasks
 }
 
 //go:generate enumer -type=ActiveSideState
@@ -58,17 +57,18 @@ const (
 	ActiveSideDone // also errors
 )
 
-type activeSideReplicationAndTriggerRemotePruneSequence struct {
+type activeSideTasks struct {
 	state ActiveSideState
 
 	// valid for state ActiveSideReplicating, ActiveSidePruneSender, ActiveSidePruneReceiver, ActiveSideDone
 	replicationReport driver.ReportFunc
 	replicationCancel context.CancelFunc
-	replicationDone   *report.Report
 
 	// valid for state ActiveSidePruneSender, ActiveSidePruneReceiver, ActiveSideDone
-	pruneRemote *pruner.Pruner
-	pruneRemoteCancel context.CancelFunc
+	prunerSender, prunerReceiver *pruner.Pruner
+
+	// valid for state ActiveSidePruneReceiver, ActiveSideDone
+	prunerSenderCancel, prunerReceiverCancel context.CancelFunc
 }
 
 func (a *ActiveSide) updateTasks(u func(*activeSideTasks)) activeSideTasks {
@@ -89,7 +89,7 @@ type activeMode interface {
 	SenderReceiver() (logic.Sender, logic.Receiver)
 	Type() Type
 	PlannerPolicy() logic.PlannerPolicy
-	RunPeriodic(ctx context.Context, wakePeriodic <-chan struct{}, replicationCommon chan<- struct{})
+	RunPeriodic(ctx context.Context, wakeUpCommon chan<- struct{})
 	SnapperReport() *snapper.Report
 	ResetConnectBackoff()
 }
@@ -131,8 +131,8 @@ func (m *modePush) Type() Type { return TypePush }
 
 func (m *modePush) PlannerPolicy() logic.PlannerPolicy { return *m.plannerPolicy }
 
-func (m *modePush) RunPeriodic(ctx context.Context, wakePeriodic <-chan struct{}, replicationCommon chan<- struct{}) {
-	m.snapper.Run(ctx, replicationCommon)
+func (m *modePush) RunPeriodic(ctx context.Context, wakeUpCommon chan<- struct{}) {
+	m.snapper.Run(ctx, wakeUpCommon)
 }
 
 func (m *modePush) SnapperReport() *snapper.Report {
@@ -214,10 +214,10 @@ func (*modePull) Type() Type { return TypePull }
 
 func (m *modePull) PlannerPolicy() logic.PlannerPolicy { return *m.plannerPolicy }
 
-func (m *modePull) RunPeriodic(ctx context.Context, wakePeriodic <-chan struct{}, replicationCommon chan<- struct{}) {
+func (m *modePull) RunPeriodic(ctx context.Context, wakeUpCommon chan<- struct{}) {
 	if m.interval.Manual {
 		GetLogger(ctx).Info("manual pull configured, periodic pull disabled")
-		// "waiting for wakeup replications" is printed in common ActiveSide.do
+		// "waiting for wakeups" is printed in common ActiveSide.do
 		return
 	}
 	t := time.NewTicker(m.interval.Interval)
@@ -226,12 +226,12 @@ func (m *modePull) RunPeriodic(ctx context.Context, wakePeriodic <-chan struct{}
 		select {
 		case <-t.C:
 			select {
-			case replicationCommon <- struct{}{}:
+			case wakeUpCommon <- struct{}{}:
 			default:
 				GetLogger(ctx).
 					WithField("pull_interval", m.interval).
 					Warn("pull job took longer than pull interval")
-				replicationCommon <- struct{}{} // block anyways, to queue up the wakeup replication
+				wakeUpCommon <- struct{}{} // block anyways, to queue up the wakeup
 			}
 		case <-ctx.Done():
 			return
@@ -425,205 +425,50 @@ func (j *ActiveSide) Run(ctx context.Context) {
 
 	defer log.Info("job exiting")
 
-	type Activity interface {
-		Trigger() (interface{}, error)
-	}
-
-	var periodicActivity Activity
-	var replicationActivity Activity
-	
 	periodicDone := make(chan struct{})
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 	periodicCtx, endTask := trace.WithTask(ctx, "periodic")
 	defer endTask()
+	go j.mode.RunPeriodic(periodicCtx, periodicDone)
 
-	wakePeriodic := make(chan struct{})
-	go j.mode.RunPeriodic(periodicCtx, wakePeriodic, periodicDone)
-
-	j.trigger = make(chan struct{})
-	j.reset = make(chan uint64)
-	j.nextInvocationId = 1
-
-	type WaitTriggerResult interface {
-		
-	}
-	var t interface{
-		WaitForTrigger(context.Context) (context.Context, <-chan WaitTriggerResult)
-	}
-
+	invocationCount := 0
+outer:
 	for {
-		log.Info("wait for triggers")
+		log.Info("wait for wakeups")
+		select {
+		case <-ctx.Done():
+			log.WithError(ctx.Err()).Info("context")
+			break outer
 
-			// j.tasksMtx.Lock()
-		// j.activeInvocationId = j.nextInvocationId
-		// j.nextInvocationId++
-		// thisInvocation := j.activeInvocationId // stack-local, for use in reset-handler goroutine below
-		// j.tasksMtx.Unlock()
-		
-		// // setup the goroutine that waits for task resets
-		// // Task resets are converted into cancellations of the invocation context.
-		
-		invocationCtx, cancelInvocation := context.WithCancel(invocationCtx)
-		// waitForResetCtx, stopWaitForReset := context.WithCancel(ctx)
-		// var wg sync.WaitGroup
-		// wg.Add(1)
-		// go func() {
-		// 	defer wg.Done()
-		// 	select {
-		// 	case <-waitForResetCtx.Done():
-		// 		return
-		// 	case reqResetInvocation := <-j.reset:
-		// 		l := log.WithField("requested_invocation_id", reqResetInvocation).
-		// 			WithField("this_invocation_id", thisInvocation)
-		// 		if reqResetInvocation == thisInvocation {
-		// 			l.Info("reset received, cancelling current invocation")
-		// 			cancelInvocation()
-		// 		} else {
-		// 			l.Debug("received reset for invocation id that is not us, discarding request")
-		// 		}
-		// 	}
-		// }()
-
-		// j.tasksMtx.Lock()
-		// j.activeInvocationId = 0
-		// j.tasksMtx.Unlock()
-
-		invocationCtx, err := t.WaitForTrigger(ctx)
-		if err != nil {
-			log.WithError(ctx.Err()).Info("error waiting for trigger")
-			break
+		case <-wakeup.Wait(ctx):
+			j.mode.ResetConnectBackoff()
+		case <-periodicDone:
 		}
-
-		j.mode.ResetConnectBackoff()
-
-		// setup the invocation context
-		invocationCtx, endSpan := trace.WithSpan(invocationCtx, fmt.Sprintf("invocation-%d", j.nextInvocationId))
-		
-
+		invocationCount++
+		invocationCtx, endSpan := trace.WithSpan(ctx, fmt.Sprintf("invocation-%d", invocationCount))
 		j.do(invocationCtx)
-		stopWaitForReset()
-		wg.Wait()
-
-	
-
 		endSpan()
 	}
 }
 
-type ActiveSidePollRequest struct {
-	InvocationId uint64
-}
-
-type ActiveSidePollResponse struct {
-	Done         bool
-	InvocationId uint64
-}
-
-func (j *ActiveSide) Poll(req ActiveSidePollRequest) (*ActiveSidePollResponse, error) {
-	j.tasksMtx.Lock()
-	defer j.tasksMtx.Unlock()
-
-	waitForId := req.InvocationId
-	if req.InvocationId == 0 {
-		// handle the case where the client doesn't know what the current invocation id is
-		if j.activeInvocationId != 0 {
-			waitForId = j.activeInvocationId
-		} else {
-			waitForId = j.nextInvocationId
-		}
-	}
-
-	var done bool
-	if j.activeInvocationId == 0 {
-		done = waitForId < j.nextInvocationId
-	} else {
-		done = waitForId < j.activeInvocationId
-	}
-	res := &ActiveSidePollResponse{Done: done, InvocationId: waitForId}
-	return res, nil
-}
-
-type ActiveSideResetRequest struct {
-	InvocationId uint64
-}
-
-type ActiveSideResetResponse struct {
-	InvocationId uint64
-}
-
-func (j *ActiveSide) Reset(req ActiveSideResetRequest) (*ActiveSideResetResponse, error) {
-	j.tasksMtx.Lock()
-	defer j.tasksMtx.Unlock()
-
-	resetId := req.InvocationId
-	if req.InvocationId == 0 {
-		// handle the case where the client doesn't know what the current invocation id is
-		resetId = j.activeInvocationId
-	}
-
-	if resetId == 0 {
-		return nil, fmt.Errorf("no active invocation")
-	}
-
-	if resetId != j.activeInvocationId {
-		return nil, fmt.Errorf("active invocation (%d) is not the invocation requested for reset (%d); (active invocation '0' indicates no active invocation)", j.activeInvocationId, resetId)
-	}
-
-	// non-blocking send (.Run() must not hold mutex while waiting for resets)
-	select {
-	case j.reset <- resetId:
-	default:
-	}
-
-	return &ActiveSideResetResponse{InvocationId: resetId}, nil
-}
-
-type ActiveSideTriggerRequest struct {
-}
-
-type ActiveSideSignalResponse struct {
-	InvocationId uint64
-	
-}
-
-func (j *ActiveSide) Trigger(req ActiveSideTriggerRequest) (*ActiveSideSignalResponse, error) {
-	// switch req.What {
-	// case "replication":
-	// 	invocationId, err = j.jobs.doreplication(req.Name)
-	// case "reset":
-	// 	err = j.jobs.reset(req.Name)
-	// case "snapshot":
-	// 	err = j.jobs.dosnapshot(req.Name)
-	// default:
-	// 	err = fmt.Errorf("operation %q is invalid", req.Op)
-	// }
-
-	j.tasksMtx.Lock()
-	var invocationId uint64
-	if j.activeInvocationId != 0 {
-		invocationId = j.activeInvocationId
-	} else {
-		invocationId = j.nextInvocationId
-	}
-	// non-blocking send (.Run() must not hold mutex while waiting for signals)
-	select {
-	case j.trigger <- struct{}{}:
-	default:
-	}
-	j.tasksMtx.Unlock()
-	return &ActiveSideSignalResponse{InvocationId: invocationId}, nil
-}
-
-type ReplicationPlusRemotePruneSequence struct {
-
-}
-
 func (j *ActiveSide) do(ctx context.Context) {
 
 	j.mode.ConnectEndpoints(ctx, j.connecter)
 	defer j.mode.DisconnectEndpoints()
 
+	// allow cancellation of an invocation (this function)
+	ctx, cancelThisRun := context.WithCancel(ctx)
+	defer cancelThisRun()
+	go func() {
+		select {
+		case <-reset.Wait(ctx):
+			log.Info("reset received, cancelling current invocation")
+			cancelThisRun()
+		case <-ctx.Done():
+		}
+	}()
+
 	sender, receiver := j.mode.SenderReceiver()
 
 	{
@@ -647,11 +492,10 @@ func (j *ActiveSide) do(ctx context.Context) {
 		GetLogger(ctx).Info("start replication")
 		repWait(true) // wait blocking
 		repCancel()   // always cancel to free up context resources
+
 		replicationReport := j.tasks.replicationReport()
 		j.promReplicationErrors.Set(float64(replicationReport.GetFailedFilesystemsCountInLatestAttempt()))
-		j.updateTasks(func(tasks *activeSideTasks) {
-			tasks.replicationDone = replicationReport
-		})
+
 		endSpan()
 	}
 

daemon/job/job.go

@@ -19,7 +19,6 @@ func GetLogger(ctx context.Context) Logger {
 	return logging.GetLogger(ctx, logging.SubsysJob)
 }
 
-
 type Job interface {
 	Name() string
 	Run(ctx context.Context)

daemon/job/reset/reset.go

@@ -0,0 +1,35 @@
+package reset
+
+import (
+	"context"
+	"errors"
+)
+
+type contextKey int
+
+const contextKeyReset contextKey = iota
+
+func Wait(ctx context.Context) <-chan struct{} {
+	wc, ok := ctx.Value(contextKeyReset).(chan struct{})
+	if !ok {
+		wc = make(chan struct{})
+	}
+	return wc
+}
+
+type Func func() error
+
+var AlreadyReset = errors.New("already reset")
+
+func Context(ctx context.Context) (context.Context, Func) {
+	wc := make(chan struct{})
+	wuf := func() error {
+		select {
+		case wc <- struct{}{}:
+			return nil
+		default:
+			return AlreadyReset
+		}
+	}
+	return context.WithValue(ctx, contextKeyReset, wc), wuf
+}

daemon/job/snapjob.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/zrepl/zrepl/config"
 	"github.com/zrepl/zrepl/daemon/filters"
+	"github.com/zrepl/zrepl/daemon/job/wakeup"
 	"github.com/zrepl/zrepl/daemon/pruner"
 	"github.com/zrepl/zrepl/daemon/snapper"
 	"github.com/zrepl/zrepl/endpoint"
@@ -111,13 +112,13 @@ func (j *SnapJob) Run(ctx context.Context) {
 	invocationCount := 0
 outer:
 	for {
-		log.Info("wait for replications")
+		log.Info("wait for wakeups")
 		select {
 		case <-ctx.Done():
 			log.WithError(ctx.Err()).Info("context")
 			break outer
 
-		// case <-doreplication.Wait(ctx):
+		case <-wakeup.Wait(ctx):
 		case <-periodicDone:
 		}
 		invocationCount++

daemon/job/trigger/trigger.go

@@ -1,184 +0,0 @@
-//
-//
-// Alternative Design (in "RustGo")
-//
-//	enum InternalMsg {
-//	    Trigger((), chan (TriggerResponse, error)),
-//	    Poll(PollRequest, chan PollResponse),
-//	    Reset(ResetRequest, chan (ResetResponse, error)),
-//	}
-//
-//	enum State {
-//	    Running{
-//	        invocationId: u32,
-//	        cancelCurrentInvocation: context.CancelFunc
-//	    }
-//	    Waiting{
-//	        nextInvocationId: u32,
-//	    }
-//	}
-//
-//	for msg := <- t.internalMsgs {
-//	    match (msg, state) {
-//	        ...
-//	    }
-//	}
-package trigger
-
-import (
-	"context"
-	"fmt"
-	"math"
-	"sync"
-)
-
-type T struct {
-	mtx sync.Mutex
-	cv  sync.Cond
-
-	nextInvocationId        uint64
-	activeInvocationId      uint64 // 0 <=> inactive
-	triggerPending          bool
-	contextDone             bool
-	reset                   chan uint64
-	stopWaitForReset        chan struct{}
-	cancelCurrentInvocation context.CancelFunc
-}
-
-func New() *T {
-	t := &T{
-		activeInvocationId: math.MaxUint64,
-		nextInvocationId:   1,
-	}
-	t.cv.L = &t.mtx
-	return t
-}
-
-func (t *T) WaitForTrigger(ctx context.Context) (rctx context.Context, err error) {
-	t.mtx.Lock()
-	defer t.mtx.Unlock()
-
-	if t.activeInvocationId == 0 {
-		return nil, fmt.Errorf("must be running when calling this function")
-	}
-	t.activeInvocationId = 0
-	t.cancelCurrentInvocation = nil
-
-	if t.contextDone == true {
-		panic("implementation error: this variable is only true while in WaitForTrigger, and that's a mutually exclusive function")
-	}
-	stopWaitingForDone := make(chan struct{})
-	go func() {
-		select {
-		case <-stopWaitingForDone:
-		case <-ctx.Done():
-			t.mtx.Lock()
-			t.contextDone = true
-			t.cv.Broadcast()
-			t.mtx.Unlock()
-		}
-	}()
-
-	defer func() {
-		t.triggerPending = false
-		t.contextDone = false
-	}()
-	for !t.triggerPending && !t.contextDone {
-		t.cv.Wait()
-	}
-	close(stopWaitingForDone)
-	if t.contextDone {
-		if ctx.Err() == nil {
-			panic("implementation error: contextDone <=> ctx.Err() != nil")
-		}
-		return nil, ctx.Err()
-	}
-
-	t.activeInvocationId = t.nextInvocationId
-	t.nextInvocationId++
-	rctx, t.cancelCurrentInvocation = context.WithCancel(ctx)
-
-	return rctx, nil
-}
-
-type TriggerResponse struct {
-	InvocationId uint64
-}
-
-func (t *T) Trigger() (TriggerResponse, error) {
-	t.mtx.Lock()
-	defer t.mtx.Unlock()
-	var invocationId uint64
-	if t.activeInvocationId != 0 {
-		invocationId = t.activeInvocationId
-	} else {
-		invocationId = t.nextInvocationId
-	}
-	// non-blocking send (.Run() must not hold mutex while waiting for signals)
-	t.triggerPending = true
-	t.cv.Broadcast()
-	return TriggerResponse{InvocationId: invocationId}, nil
-}
-
-type PollRequest struct {
-	InvocationId uint64
-}
-
-type PollResponse struct {
-	Done         bool
-	InvocationId uint64
-}
-
-func (t *T) Poll(req PollRequest) (res PollResponse) {
-	t.mtx.Lock()
-	defer t.mtx.Unlock()
-
-	waitForId := req.InvocationId
-	if req.InvocationId == 0 {
-		// handle the case where the client doesn't know what the current invocation id is
-		if t.activeInvocationId != 0 {
-			waitForId = t.activeInvocationId
-		} else {
-			waitForId = t.nextInvocationId
-		}
-	}
-
-	var done bool
-	if t.activeInvocationId == 0 {
-		done = waitForId < t.nextInvocationId
-	} else {
-		done = waitForId < t.activeInvocationId
-	}
-	return PollResponse{Done: done, InvocationId: waitForId}
-}
-
-type ResetRequest struct {
-	InvocationId uint64
-}
-
-type ResetResponse struct {
-	InvocationId uint64
-}
-
-func (t *T) Reset(req ResetRequest) (*ResetResponse, error) {
-	t.mtx.Lock()
-	defer t.mtx.Unlock()
-
-	resetId := req.InvocationId
-	if req.InvocationId == 0 {
-		// handle the case where the client doesn't know what the current invocation id is
-		resetId = t.activeInvocationId
-	}
-
-	if resetId == 0 {
-		return nil, fmt.Errorf("no active invocation")
-	}
-
-	if resetId != t.activeInvocationId {
-		return nil, fmt.Errorf("active invocation (%d) is not the invocation requested for reset (%d); (active invocation '0' indicates no active invocation)", t.activeInvocationId, resetId)
-	}
-
-	t.cancelCurrentInvocation()
-
-	return &ResetResponse{InvocationId: resetId}, nil
-}

daemon/job/trigger/trigger_test.go

@@ -1,205 +0,0 @@
-package trigger_test
-
-import (
-	"context"
-	"net/http"
-	"sync"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-	"github.com/zrepl/zrepl/daemon/job/trigger"
-	"github.com/zrepl/zrepl/daemon/logging/trace"
-	"github.com/zrepl/zrepl/replication"
-	"github.com/zrepl/zrepl/replication/driver"
-	"github.com/zrepl/zrepl/replication/logic"
-)
-
-func TestBasics(t *testing.T) {
-
-	var wg sync.WaitGroup
-	defer wg.Wait()
-
-	tr := trigger.New()
-
-	triggered := make(chan int)
-	waitForTriggerError := make(chan error)
-	waitForResetCallToBeMadeByMainGoroutine := make(chan struct{})
-	postResetAssertionsDone := make(chan struct{})
-
-	taskCtx := context.Background()
-	taskCtx, cancelTaskCtx := context.WithCancel(taskCtx)
-
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-
-		taskCtx := context.WithValue(taskCtx, "mykey", "myvalue")
-
-		triggers := 0
-
-	outer:
-		for {
-			invocationCtx, err := tr.WaitForTrigger(taskCtx)
-			if err != nil {
-				waitForTriggerError <- err
-				return
-			}
-			require.Equal(t, invocationCtx.Value("mykey"), "myvalue")
-
-			triggers++
-			triggered <- triggers
-
-			switch triggers {
-			case 1:
-				continue outer
-			case 2:
-				<-waitForResetCallToBeMadeByMainGoroutine
-				require.Equal(t, context.Canceled, invocationCtx.Err(), "Reset() cancels invocation context")
-				require.Nil(t, taskCtx.Err(), "Reset() does not cancel task context")
-				close(postResetAssertionsDone)
-			}
-
-		}
-
-	}()
-
-	t.Logf("trigger 1")
-	_, err := tr.Trigger()
-	require.NoError(t, err)
-	v := <-triggered
-	require.Equal(t, 1, v)
-
-	t.Logf("trigger 2")
-	triggerResponse, err := tr.Trigger()
-	require.NoError(t, err)
-	v = <-triggered
-	require.Equal(t, 2, v)
-
-	t.Logf("reset")
-	resetResponse, err := tr.Reset(trigger.ResetRequest{InvocationId: triggerResponse.InvocationId})
-	require.NoError(t, err)
-	t.Logf("reset response: %#v", resetResponse)
-	close(waitForResetCallToBeMadeByMainGoroutine)
-	<-postResetAssertionsDone
-
-	t.Logf("cancel the context")
-	cancelTaskCtx()
-	wfte := <-waitForTriggerError
-	require.Equal(t, taskCtx.Err(), wfte)
-
-}
-
-type PushJob struct {
-	snap *Snapshotter
-	repl *ReplicationAndTriggerRemotePruningSequence
-}
-
-func (j *PushJob) Handle(w http.ResponseWriter, r *http.Request) {
-	panic("unimplemented")
-}
-
-func (j *PushJob) HandleTrigger(w http.ResponseWriter, r *http.Request) {
-	panic("unimplemented")
-}
-
-func (j *PushJob) Run(ctx context.Context) {
-
-}
-
-type SnapshotSequence struct {
-
-}
-
-type ReplicationAndTriggerRemotePruningSequence struct {
-
-}
-
-func (s ReplicationAndTriggerRemotePruningSequence) Run(ctx context.Context) {
-
-	j.mode.ConnectEndpoints(ctx, j.connecter)
-	defer j.mode.DisconnectEndpoints()
-
-	sender, receiver := j.mode.SenderReceiver()
-
-	{
-		select {
-		case <-ctx.Done():
-			return
-		default:
-		}
-		ctx, endSpan := trace.WithSpan(ctx, "replication")
-		ctx, repCancel := context.WithCancel(ctx)
-		var repWait driver.WaitFunc
-		j.updateTasks(func(tasks *activeSideTasks) {
-			// reset it
-			*tasks = activeSideTasks{}
-			tasks.replicationCancel = func() { repCancel(); endSpan() }
-			tasks.replicationReport, repWait = replication.Do(
-				ctx, j.replicationDriverConfig, logic.NewPlanner(j.promRepStateSecs, j.promBytesReplicated, sender, receiver, j.mode.PlannerPolicy()),
-			)
-			tasks.state = ActiveSideReplicating
-		})
-		GetLogger(ctx).Info("start replication")
-		repWait(true) // wait blocking
-		repCancel()   // always cancel to free up context resources
-		replicationReport := j.tasks.replicationReport()
-		j.promReplicationErrors.Set(float64(replicationReport.GetFailedFilesystemsCountInLatestAttempt()))
-		j.updateTasks(func(tasks *activeSideTasks) {
-			tasks.replicationDone = replicationReport
-		})
-		endSpan()
-	}
-
-	{
-		select {
-		case <-ctx.Done():
-			return
-		default:
-		}
-		ctx, endSpan := trace.WithSpan(ctx, "prune_sender")
-		ctx, senderCancel := context.WithCancel(ctx)
-		tasks := j.updateTasks(func(tasks *activeSideTasks) {
-			tasks.prunerSender = j.prunerFactory.BuildSenderPruner(ctx, sender, sender)
-			tasks.prunerSenderCancel = func() { senderCancel(); endSpan() }
-			tasks.state = ActiveSidePruneSender
-		})
-		GetLogger(ctx).Info("start pruning sender")
-		tasks.prunerSender.Prune()
-		GetLogger(ctx).Info("finished pruning sender")
-		senderCancel()
-		endSpan()
-	}
-	{
-		select {
-		case <-ctx.Done():
-			return
-		default:
-		}
-		ctx, endSpan := trace.WithSpan(ctx, "prune_recever")
-		ctx, receiverCancel := context.WithCancel(ctx)
-		tasks := j.updateTasks(func(tasks *activeSideTasks) {
-			tasks.prunerReceiver = j.prunerFactory.BuildReceiverPruner(ctx, receiver, sender)
-			tasks.prunerReceiverCancel = func() { receiverCancel(); endSpan() }
-			tasks.state = ActiveSidePruneReceiver
-		})
-		GetLogger(ctx).Info("start pruning receiver")
-		tasks.prunerReceiver.Prune()
-		GetLogger(ctx).Info("finished pruning receiver")
-		receiverCancel()
-		endSpan()
-	}
-
-	j.updateTasks(func(tasks *activeSideTasks) {
-		tasks.state = ActiveSideDone
-	})
-
-}
-
-
-func TestUseCase(t *testing.T) {
-
-	var as ActiveSide
-
-	as.
-	
-}

daemon/job/wakeup/wakeup.go

@@ -0,0 +1,35 @@
+package wakeup
+
+import (
+	"context"
+	"errors"
+)
+
+type contextKey int
+
+const contextKeyWakeup contextKey = iota
+
+func Wait(ctx context.Context) <-chan struct{} {
+	wc, ok := ctx.Value(contextKeyWakeup).(chan struct{})
+	if !ok {
+		wc = make(chan struct{})
+	}
+	return wc
+}
+
+type Func func() error
+
+var AlreadyWokenUp = errors.New("already woken up")
+
+func Context(ctx context.Context) (context.Context, Func) {
+	wc := make(chan struct{})
+	wuf := func() error {
+		select {
+		case wc <- struct{}{}:
+			return nil
+		default:
+			return AlreadyWokenUp
+		}
+	}
+	return context.WithValue(ctx, contextKeyWakeup, wc), wuf
+}

daemon/snapper/snapper.go

@@ -210,10 +210,6 @@ func syncUp(a args, u updater) state {
 		return u(func(s *Snapper) {
 			s.state = Planning
 		}).sf()
-	// case <-dosnapshot.Wait(a.ctx):
-	// 	return u(func(s *Snapper) {
-	// 		s.state = Planning
-	// 	}).sf()
 	case <-a.ctx.Done():
 		return onMainCtxDone(a.ctx, u)
 	}
@@ -382,10 +378,6 @@ func wait(a args, u updater) state {
 		return u(func(snapper *Snapper) {
 			snapper.state = Planning
 		}).sf()
-	// case <-dosnapshot.Wait(a.ctx):
-	// 	return u(func(snapper *Snapper) {
-	// 		snapper.state = Planning
-	// 	}).sf()
 	case <-a.ctx.Done():
 		return onMainCtxDone(a.ctx, u)
 	}

daemon/snapper/snapper_all.go

@@ -18,9 +18,9 @@ type PeriodicOrManual struct {
 	s *Snapper
 }
 
-func (s *PeriodicOrManual) Run(ctx context.Context, replicationCommon chan<- struct{}) {
+func (s *PeriodicOrManual) Run(ctx context.Context, wakeUpCommon chan<- struct{}) {
 	if s.s != nil {
-		s.s.Run(ctx, replicationCommon)
+		s.s.Run(ctx, wakeUpCommon)
 	}
 }
 

docs/changelog.rst

@@ -32,7 +32,6 @@ We use the following annotations for classifying changes:
 0.4.0
 -----
 
-* |break| Change syntax to trigger a job replication, rename ``zrepl signal wakeup JOB`` to ``zrepl signal replication JOB``
 * |feature| support setting zfs send / recv flags in the config (send: ``-wLcepbS`` , recv: ``-ox`` ).
   Config docs :ref:`here <job-send-options>` and :ref:`here <job-recv-options>` .
 * |feature| parallel replication is now configurable (disabled by default, :ref:`config docs here <replication-option-concurrency>` ).

docs/configuration/jobs.rst

@@ -78,7 +78,7 @@ Job Type ``pull``
         ``$root_fs/$source_path``
     * - ``interval``
       - | Interval at which to pull from the source job (e.g. ``10m``).
-        | ``manual`` disables periodic pulling, replication then only happens on :ref:`replication <cli-signal-replication>`.
+        | ``manual`` disables periodic pulling, replication then only happens on :ref:`wakeup <cli-signal-wakeup>`.
     * - ``pruning``
       - |pruning-spec|
 

docs/configuration/snapshotting.rst

@@ -15,7 +15,7 @@ A filesystem that does not have snapshots by the snapshotter has lower priority
 
 For ``push`` jobs, replication is automatically triggered after all filesystems have been snapshotted.
 
-Note that the ``zrepl signal replication JOB`` subcommand does not trigger snapshotting.
+Note that the ``zrepl signal wakeup JOB`` subcommand does not trigger snapshotting.
 
 
 ::
@@ -38,7 +38,7 @@ There is also a ``manual`` snapshotting type, which covers the following use cas
 * Existing infrastructure for automatic snapshots: you only want to use this zrepl job for replication.
 * Handling snapshotting through a separate ``snap`` job.
 
-Note that you will have to trigger replication manually using the ``zrepl signal replication JOB`` subcommand in that case.
+Note that you will have to trigger replication manually using the ``zrepl signal wakeup JOB`` subcommand in that case.
 
 ::
 

docs/quickstart.rst

@@ -55,8 +55,8 @@ Watch it Work
 =============
 
 Run ``zrepl status`` on the active side of the replication setup to monitor snaphotting, replication and pruning activity.
-To re-trigger replication (snapshots are separate!), use ``zrepl signal replication JOBNAME``.
-(refer to the example use case document if you are uncertain which job you want to start replication).
+To re-trigger replication (snapshots are separate!), use ``zrepl signal wakeup JOBNAME``.
+(refer to the example use case document if you are uncertain which job you want to wake up).
 
 You can also use basic UNIX tools to inspect see what's going on.
 If you like tmux, here is a handy script that works on FreeBSD: ::

docs/usage.rst

@@ -13,7 +13,7 @@ CLI Overview
     The zrepl binary is self-documenting:
     run ``zrepl help`` for an overview of the available subcommands or ``zrepl SUBCOMMAND --help`` for information on available flags, etc.
 
-.. _cli-signal-replication:
+.. _cli-signal-wakeup:
 
 .. list-table::
     :widths: 30 70
@@ -29,7 +29,7 @@ CLI Overview
       - show job activity, or with ``--raw`` for JSON output
     * - ``zrepl stdinserver``
       - see :ref:`transport-ssh+stdinserver`
-    * - ``zrepl signal replication JOB``
+    * - ``zrepl signal wakeup JOB``
       - manually trigger replication + pruning of JOB
     * - ``zrepl signal reset JOB``
       - manually abort current replication + pruning of JOB

main.go

@@ -11,9 +11,7 @@ import (
 func init() {
 	cli.AddSubcommand(daemon.DaemonCmd)
 	cli.AddSubcommand(status.Subcommand)
-	cli.AddSubcommand(client.TriggerCmd)
-	cli.AddSubcommand(client.ResetCmd)
-	cli.AddSubcommand(client.WaitCmd)
+	cli.AddSubcommand(client.SignalCmd)
 	cli.AddSubcommand(client.StdinserverCmd)
 	cli.AddSubcommand(client.ConfigcheckCmd)
 	cli.AddSubcommand(client.VersionCmd)

pruning/keep_last_n.go

@@ -57,6 +57,11 @@ func (k KeepLastN) KeepRule(snaps []Snapshot) (destroyList []Snapshot) {
 		// then lexicographically descending (e.g. b, a)
 		return strings.Compare(matching[i].Name(), matching[j].Name()) == 1
 	})
-	destroyList = append(destroyList, matching[k.n:]...)
+
+	n := k.n
+	if n > len(matching) {
+		n = len(matching)
+	}
+	destroyList = append(destroyList, matching[n:]...)
 	return destroyList
 }

pruning/keep_last_n_test.go

@@ -83,6 +83,19 @@ func TestKeepLastN(t *testing.T) {
 				"b1": true,
 			},
 		},
+		"keep_more_than_matching": {
+			inputs: []Snapshot{
+				stubSnap{"a1", false, o(10)},
+				stubSnap{"b1", false, o(11)},
+				stubSnap{"a2", false, o(12)},
+			},
+			rules: []KeepRule{
+				MustKeepLastN(3, "a"),
+			},
+			expDestroy: map[string]bool{
+				"b1": true,
+			},
+		},
 	}
 
 	testTable(tcs, t)

zfs/zfs.go

@@ -26,11 +26,6 @@ import (
 	"github.com/zrepl/zrepl/zfs/zfscmd"
 )
 
-var (
-	ZFSSendPipeCapacityHint = int(envconst.Int64("ZFS_SEND_PIPE_CAPACITY_HINT", 1<<25))
-	ZFSRecvPipeCapacityHint = int(envconst.Int64("ZFS_RECV_PIPE_CAPACITY_HINT", 1<<25))
-)
-
 type DatasetPath struct {
 	comps []string
 }
@@ -328,8 +323,8 @@ func absVersion(fs string, v *ZFSSendArgVersion) (full string, err error) {
 }
 
 func pipeWithCapacityHint(capacity int) (r, w *os.File, err error) {
-	if capacity <= 0 {
-		panic(fmt.Sprintf("capacity must be positive %v", capacity))
+	if capacity < 0 {
+		panic(fmt.Sprintf("capacity must be non-negative, got %v", capacity))
 	}
 	stdoutReader, stdoutWriter, err := os.Pipe()
 	if err != nil {
@@ -858,7 +853,7 @@ func ZFSSend(ctx context.Context, sendArgs ZFSSendArgsValidated) (*SendStream, e
 	ctx, cancel := context.WithCancel(ctx)
 
 	// setup stdout with an os.Pipe to control pipe buffer size
-	stdoutReader, stdoutWriter, err := pipeWithCapacityHint(ZFSSendPipeCapacityHint)
+	stdoutReader, stdoutWriter, err := pipeWithCapacityHint(getPipeCapacityHint("ZFS_SEND_PIPE_CAPACITY_HINT"))
 	if err != nil {
 		cancel()
 		return nil, err
@@ -1160,7 +1155,7 @@ func ZFSRecv(ctx context.Context, fs string, v *ZFSSendArgVersion, stream io.Rea
 
 	stderr := bytes.NewBuffer(make([]byte, 0, RecvStderrBufSiz))
 
-	stdin, stdinWriter, err := pipeWithCapacityHint(ZFSRecvPipeCapacityHint)
+	stdin, stdinWriter, err := pipeWithCapacityHint(getPipeCapacityHint("ZFS_RECV_PIPE_CAPACITY_HINT"))
 	if err != nil {
 		return err
 	}

zfs/zfs_pipe.go

@@ -7,10 +7,14 @@ import (
 	"sync"
 )
 
+func getPipeCapacityHint(envvar string) int {
+	return 0 // not supported
+}
+
 var zfsPipeCapacityNotSupported sync.Once
 
 func trySetPipeCapacity(p *os.File, capacity int) {
-	if debugEnabled {
+	if debugEnabled && capacity != 0 {
 		zfsPipeCapacityNotSupported.Do(func() {
 			debug("trySetPipeCapacity error: OS does not support setting pipe capacity")
 		})

zfs/zfs_pipe_linux.go

@@ -3,11 +3,33 @@ package zfs
 import (
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
+	"strconv"
+	"strings"
 
 	"golang.org/x/sys/unix"
+
+	"github.com/zrepl/zrepl/util/envconst"
 )
 
+func getPipeCapacityHint(envvar string) int {
+	var capacity int64 = 1 << 25
+
+	// Work around a race condition in Linux >= 5.8 related to pipe resizing.
+	// https://github.com/zrepl/zrepl/issues/424#issuecomment-800370928
+	// https://bugzilla.kernel.org/show_bug.cgi?id=212295
+	if _, err := os.Stat("/proc/sys/fs/pipe-max-size"); err == nil {
+		if dat, err := ioutil.ReadFile("/proc/sys/fs/pipe-max-size"); err == nil {
+			if capacity, err = strconv.ParseInt(strings.TrimSpace(string(dat)), 10, 64); err != nil {
+				capacity = 1 << 25
+			}
+		}
+	}
+
+	return int(envconst.Int64(envvar, capacity))
+}
+
 func trySetPipeCapacity(p *os.File, capacity int) {
 	res, err := unix.FcntlInt(p.Fd(), unix.F_SETPIPE_SZ, capacity)
 	if err != nil {