14325: Clean up unsafe concurrency in tests.
[arvados.git] / lib / dispatchcloud / worker / worker.go
index 7828d4f69fc0b81645e9665dfe798a275b3ea07b..a75d2bbb88611225c709a98f151dded697b5974c 100644 (file)
@@ -5,7 +5,20 @@
 package worker
 
 import (
+       "bytes"
+       "fmt"
+       "strings"
+       "sync"
        "time"
+
+       "git.curoverse.com/arvados.git/lib/cloud"
+       "git.curoverse.com/arvados.git/sdk/go/arvados"
+       "github.com/sirupsen/logrus"
+)
+
+const (
+       // TODO: configurable
+       maxPingFailTime = 10 * time.Minute
 )
 
 // State indicates whether a worker is available to do work, and (if
@@ -15,22 +28,17 @@ type State int
 const (
        StateUnknown  State = iota // might be running a container already
        StateBooting               // instance is booting
-       StateRunning               // instance is running
+       StateIdle                  // instance booted, no containers are running
+       StateRunning               // instance is running one or more containers
        StateShutdown              // worker has stopped monitoring the instance
-       StateHold                  // running, but not available to run new containers
-)
-
-const (
-       // TODO: configurable
-       maxPingFailTime = 10 * time.Minute
 )
 
 var stateString = map[State]string{
        StateUnknown:  "unknown",
        StateBooting:  "booting",
+       StateIdle:     "idle",
        StateRunning:  "running",
        StateShutdown: "shutdown",
-       StateHold:     "hold",
 }
 
 // String implements fmt.Stringer.
@@ -43,3 +51,361 @@ func (s State) String() string {
 func (s State) MarshalText() ([]byte, error) {
        return []byte(stateString[s]), nil
 }
+
+// IdleBehavior indicates the behavior desired when a node becomes idle.
+type IdleBehavior string
+
+const (
+       IdleBehaviorRun   IdleBehavior = "run"   // run containers, or shutdown on idle timeout
+       IdleBehaviorHold               = "hold"  // don't shutdown or run more containers
+       IdleBehaviorDrain              = "drain" // shutdown immediately when idle
+)
+
+var validIdleBehavior = map[IdleBehavior]bool{
+       IdleBehaviorRun:   true,
+       IdleBehaviorHold:  true,
+       IdleBehaviorDrain: true,
+}
+
+type worker struct {
+       logger   logrus.FieldLogger
+       executor Executor
+       wp       *Pool
+
+       mtx          sync.Locker // must be wp's Locker.
+       state        State
+       idleBehavior IdleBehavior
+       instance     cloud.Instance
+       instType     arvados.InstanceType
+       vcpus        int64
+       memory       int64
+       appeared     time.Time
+       probed       time.Time
+       updated      time.Time
+       busy         time.Time
+       destroyed    time.Time
+       lastUUID     string
+       running      map[string]struct{} // remember to update state idle<->running when this changes
+       starting     map[string]struct{} // remember to update state idle<->running when this changes
+       probing      chan struct{}
+}
+
+// caller must have lock.
+func (wkr *worker) startContainer(ctr arvados.Container) {
+       logger := wkr.logger.WithFields(logrus.Fields{
+               "ContainerUUID": ctr.UUID,
+               "Priority":      ctr.Priority,
+       })
+       logger = logger.WithField("Instance", wkr.instance)
+       logger.Debug("starting container")
+       wkr.starting[ctr.UUID] = struct{}{}
+       wkr.state = StateRunning
+       go func() {
+               env := map[string]string{
+                       "ARVADOS_API_HOST":  wkr.wp.arvClient.APIHost,
+                       "ARVADOS_API_TOKEN": wkr.wp.arvClient.AuthToken,
+               }
+               stdout, stderr, err := wkr.executor.Execute(env, "crunch-run --detach '"+ctr.UUID+"'", nil)
+               wkr.mtx.Lock()
+               defer wkr.mtx.Unlock()
+               now := time.Now()
+               wkr.updated = now
+               wkr.busy = now
+               delete(wkr.starting, ctr.UUID)
+               wkr.running[ctr.UUID] = struct{}{}
+               wkr.lastUUID = ctr.UUID
+               if err != nil {
+                       logger.WithField("stdout", string(stdout)).
+                               WithField("stderr", string(stderr)).
+                               WithError(err).
+                               Error("error starting crunch-run process")
+                       // Leave uuid in wkr.running, though: it's
+                       // possible the error was just a communication
+                       // failure and the process was in fact
+                       // started.  Wait for next probe to find out.
+                       return
+               }
+               logger.Info("crunch-run process started")
+               wkr.lastUUID = ctr.UUID
+       }()
+}
+
+// ProbeAndUpdate conducts appropriate boot/running probes (if any)
+// for the worker's curent state. If a previous probe is still
+// running, it does nothing.
+//
+// It should be called in a new goroutine.
+func (wkr *worker) ProbeAndUpdate() {
+       select {
+       case wkr.probing <- struct{}{}:
+               wkr.probeAndUpdate()
+               <-wkr.probing
+       default:
+               wkr.logger.Debug("still waiting for last probe to finish")
+       }
+}
+
+// probeAndUpdate calls probeBooted and/or probeRunning if needed, and
+// updates state accordingly.
+//
+// In StateUnknown: Call both probeBooted and probeRunning.
+// In StateBooting: Call probeBooted; if successful, call probeRunning.
+// In StateRunning: Call probeRunning.
+// In StateIdle: Call probeRunning.
+// In StateShutdown: Do nothing.
+//
+// If both probes succeed, wkr.state changes to
+// StateIdle/StateRunning.
+//
+// If probeRunning succeeds, wkr.running is updated. (This means
+// wkr.running might be non-empty even in StateUnknown, if the boot
+// probe failed.)
+//
+// probeAndUpdate should be called in a new goroutine.
+func (wkr *worker) probeAndUpdate() {
+       wkr.mtx.Lock()
+       updated := wkr.updated
+       initialState := wkr.state
+       wkr.mtx.Unlock()
+
+       var (
+               booted   bool
+               ctrUUIDs []string
+               ok       bool
+               stderr   []byte
+       )
+
+       switch initialState {
+       case StateShutdown:
+               return
+       case StateIdle, StateRunning:
+               booted = true
+       case StateUnknown, StateBooting:
+       default:
+               panic(fmt.Sprintf("unknown state %s", initialState))
+       }
+
+       if !booted {
+               booted, stderr = wkr.probeBooted()
+               if !booted {
+                       // Pretend this probe succeeded if another
+                       // concurrent attempt succeeded.
+                       wkr.mtx.Lock()
+                       booted = wkr.state == StateRunning || wkr.state == StateIdle
+                       wkr.mtx.Unlock()
+               } else {
+                       wkr.logger.Info("instance booted; will try probeRunning")
+               }
+       }
+       if booted || wkr.state == StateUnknown {
+               ctrUUIDs, ok, stderr = wkr.probeRunning()
+       }
+       logger := wkr.logger.WithField("stderr", string(stderr))
+       wkr.mtx.Lock()
+       defer wkr.mtx.Unlock()
+       if !ok || (!booted && len(ctrUUIDs) == 0 && len(wkr.running) == 0) {
+               if wkr.state == StateShutdown && wkr.updated.After(updated) {
+                       // Skip the logging noise if shutdown was
+                       // initiated during probe.
+                       return
+               }
+               dur := time.Since(wkr.probed)
+               logger := logger.WithFields(logrus.Fields{
+                       "Duration": dur,
+                       "State":    wkr.state,
+               })
+               if !booted {
+                       // While we're polling the VM to see if it's
+                       // finished booting, failures are not
+                       // noteworthy, so we log at Debug level.
+                       logger.Debug("new instance not responding")
+               } else {
+                       logger.Info("instance not responding")
+               }
+               wkr.shutdownIfBroken(dur)
+               return
+       }
+
+       updateTime := time.Now()
+       wkr.probed = updateTime
+
+       if updated != wkr.updated {
+               // Worker was updated after the probe began, so
+               // wkr.running might have a container UUID that was
+               // not yet running when ctrUUIDs was generated. Leave
+               // wkr.running alone and wait for the next probe to
+               // catch up on any changes.
+               return
+       }
+
+       if len(ctrUUIDs) > 0 {
+               wkr.busy = updateTime
+               wkr.lastUUID = ctrUUIDs[0]
+       } else if len(wkr.running) > 0 {
+               // Actual last-busy time was sometime between wkr.busy
+               // and now. Now is the earliest opportunity to take
+               // advantage of the non-busy state, though.
+               wkr.busy = updateTime
+       }
+       running := map[string]struct{}{}
+       changed := false
+       for _, uuid := range ctrUUIDs {
+               running[uuid] = struct{}{}
+               if _, ok := wkr.running[uuid]; !ok {
+                       changed = true
+               }
+       }
+       for uuid := range wkr.running {
+               if _, ok := running[uuid]; !ok {
+                       logger.WithField("ContainerUUID", uuid).Info("crunch-run process ended")
+                       wkr.wp.notifyExited(uuid, updateTime)
+                       changed = true
+               }
+       }
+       if booted && (wkr.state == StateUnknown || wkr.state == StateBooting) {
+               // Note: this will change again below if
+               // len(wkr.starting)+len(wkr.running) > 0.
+               wkr.state = StateIdle
+               changed = true
+       } else if wkr.state == StateUnknown && len(running) != len(wkr.running) {
+               logger.WithFields(logrus.Fields{
+                       "RunningContainers": len(running),
+                       "State":             wkr.state,
+               }).Info("crunch-run probe succeeded, but boot probe is still failing")
+       }
+       if !changed {
+               return
+       }
+
+       wkr.running = running
+       if wkr.state == StateIdle && len(wkr.starting)+len(wkr.running) > 0 {
+               wkr.state = StateRunning
+       } else if wkr.state == StateRunning && len(wkr.starting)+len(wkr.running) == 0 {
+               wkr.state = StateIdle
+       }
+       wkr.updated = updateTime
+       if booted && (initialState == StateUnknown || initialState == StateBooting) {
+               logger.WithFields(logrus.Fields{
+                       "RunningContainers": len(running),
+                       "State":             wkr.state,
+               }).Info("probes succeeded, instance is in service")
+       }
+       go wkr.wp.notify()
+}
+
+func (wkr *worker) probeRunning() (running []string, ok bool, stderr []byte) {
+       cmd := "crunch-run --list"
+       stdout, stderr, err := wkr.executor.Execute(nil, cmd, nil)
+       if err != nil {
+               wkr.logger.WithFields(logrus.Fields{
+                       "Command": cmd,
+                       "stdout":  string(stdout),
+                       "stderr":  string(stderr),
+               }).WithError(err).Warn("probe failed")
+               return nil, false, stderr
+       }
+       stdout = bytes.TrimRight(stdout, "\n")
+       if len(stdout) == 0 {
+               return nil, true, stderr
+       }
+       return strings.Split(string(stdout), "\n"), true, stderr
+}
+
+func (wkr *worker) probeBooted() (ok bool, stderr []byte) {
+       cmd := wkr.wp.bootProbeCommand
+       if cmd == "" {
+               cmd = "true"
+       }
+       stdout, stderr, err := wkr.executor.Execute(nil, cmd, nil)
+       logger := wkr.logger.WithFields(logrus.Fields{
+               "Command": cmd,
+               "stdout":  string(stdout),
+               "stderr":  string(stderr),
+       })
+       if err != nil {
+               logger.WithError(err).Debug("boot probe failed")
+               return false, stderr
+       }
+       logger.Info("boot probe succeeded")
+       return true, stderr
+}
+
+// caller must have lock.
+func (wkr *worker) shutdownIfBroken(dur time.Duration) {
+       if wkr.idleBehavior == IdleBehaviorHold {
+               return
+       }
+       label, threshold := "", wkr.wp.timeoutProbe
+       if wkr.state == StateUnknown || wkr.state == StateBooting {
+               label, threshold = "new ", wkr.wp.timeoutBooting
+       }
+       if dur < threshold {
+               return
+       }
+       wkr.logger.WithFields(logrus.Fields{
+               "Duration": dur,
+               "Since":    wkr.probed,
+               "State":    wkr.state,
+       }).Warnf("%sinstance unresponsive, shutting down", label)
+       wkr.shutdown()
+}
+
+// caller must have lock.
+func (wkr *worker) shutdownIfIdle() bool {
+       if wkr.idleBehavior == IdleBehaviorHold {
+               return false
+       }
+       if !(wkr.state == StateIdle || (wkr.state == StateBooting && wkr.idleBehavior == IdleBehaviorDrain)) {
+               return false
+       }
+       age := time.Since(wkr.busy)
+       if wkr.idleBehavior != IdleBehaviorDrain && age < wkr.wp.timeoutIdle {
+               return false
+       }
+       wkr.logger.WithFields(logrus.Fields{
+               "Age":          age,
+               "IdleBehavior": wkr.idleBehavior,
+       }).Info("shutdown idle worker")
+       wkr.shutdown()
+       return true
+}
+
+// caller must have lock.
+func (wkr *worker) shutdown() {
+       now := time.Now()
+       wkr.updated = now
+       wkr.destroyed = now
+       wkr.state = StateShutdown
+       go wkr.wp.notify()
+       go func() {
+               err := wkr.instance.Destroy()
+               if err != nil {
+                       wkr.logger.WithError(err).Warn("shutdown failed")
+                       return
+               }
+       }()
+}
+
+// Save worker tags to cloud provider metadata, if they don't already
+// match. Caller must have lock.
+func (wkr *worker) saveTags() {
+       instance := wkr.instance
+       have := instance.Tags()
+       want := cloud.InstanceTags{
+               tagKeyInstanceType: wkr.instType.Name,
+               tagKeyIdleBehavior: string(wkr.idleBehavior),
+       }
+       go func() {
+               for k, v := range want {
+                       if v == have[k] {
+                               continue
+                       }
+                       err := instance.SetTags(want)
+                       if err != nil {
+                               wkr.wp.logger.WithField("Instance", instance).WithError(err).Warnf("error updating tags")
+                       }
+                       break
+
+               }
+       }()
+}