make subnet subsys dynamic and simplify callhome (#15927)

cmd/callhome.go

@@ -25,7 +25,6 @@ import (
 
 	"github.com/minio/madmin-go"
 	"github.com/minio/minio/internal/logger"
-	uatomic "go.uber.org/atomic"
 )
 
 const (
@@ -34,9 +33,6 @@ const (
 
 	// callhomeSchemaVersion is current callhome schema version.
 	callhomeSchemaVersion = callhomeSchemaVersion1
-
-	// callhomeCycleDefault is the default interval between two callhome cycles (24hrs)
-	callhomeCycleDefault = 24 * time.Hour
 )
 
 // CallhomeInfo - Contains callhome information
@@ -45,26 +41,14 @@ type CallhomeInfo struct {
 	AdminInfo     madmin.InfoMessage `json:"admin_info"`
 }
 
-var (
-	enableCallhome            = uatomic.NewBool(false)
-	callhomeLeaderLockTimeout = newDynamicTimeout(30*time.Second, 10*time.Second)
-	callhomeFreq              = uatomic.NewDuration(callhomeCycleDefault)
-)
-
-func updateCallhomeParams(ctx context.Context, objAPI ObjectLayer) {
-	alreadyEnabled := enableCallhome.Load()
-	enableCallhome.Store(globalCallhomeConfig.Enable)
-	callhomeFreq.Store(globalCallhomeConfig.Frequency)
-
-	// If callhome was disabled earlier and has now been enabled,
-	// initialize the callhome process again.
-	if !alreadyEnabled && enableCallhome.Load() {
-		initCallhome(ctx, objAPI)
-	}
-}
+var callhomeLeaderLockTimeout = newDynamicTimeout(30*time.Second, 10*time.Second)
 
 // initCallhome will start the callhome task in the background.
 func initCallhome(ctx context.Context, objAPI ObjectLayer) {
+	if !globalCallhomeConfig.Enabled() {
+		return
+	}
+
 	go func() {
 		r := rand.New(rand.NewSource(time.Now().UnixNano()))
 		// Leader node (that successfully acquires the lock inside runCallhome)
@@ -72,54 +56,63 @@ func initCallhome(ctx context.Context, objAPI ObjectLayer) {
 		// the lock will be released and another node will acquire it and take over
 		// because of this loop.
 		for {
-			runCallhome(ctx, objAPI)
-			if !enableCallhome.Load() {
+			if !globalCallhomeConfig.Enabled() {
+				return
+			}
+
+			if !runCallhome(ctx, objAPI) {
+				// callhome was disabled or context was canceled
 				return
 			}
 
 			// callhome running on a different node.
 			// sleep for some time and try again.
-			duration := time.Duration(r.Float64() * float64(callhomeFreq.Load()))
+			duration := time.Duration(r.Float64() * float64(globalCallhomeConfig.FrequencyDur()))
 			if duration < time.Second {
 				// Make sure to sleep atleast a second to avoid high CPU ticks.
 				duration = time.Second
 			}
 			time.Sleep(duration)
-
-			if !enableCallhome.Load() {
-				return
-			}
 		}
 	}()
 }
 
-func runCallhome(ctx context.Context, objAPI ObjectLayer) {
+func runCallhome(ctx context.Context, objAPI ObjectLayer) bool {
 	// Make sure only 1 callhome is running on the cluster.
 	locker := objAPI.NewNSLock(minioMetaBucket, "callhome/runCallhome.lock")
 	lkctx, err := locker.GetLock(ctx, callhomeLeaderLockTimeout)
 	if err != nil {
-		return
+		// lock timedout means some other node is the leader,
+		// cycle back return 'true'
+		return true
 	}
 
 	ctx = lkctx.Context()
 	defer locker.Unlock(lkctx.Cancel)
 
-	callhomeTimer := time.NewTimer(callhomeFreq.Load())
+	callhomeTimer := time.NewTimer(globalCallhomeConfig.FrequencyDur())
 	defer callhomeTimer.Stop()
 
 	for {
+		if !globalCallhomeConfig.Enabled() {
+			// Stop the processing as callhome got disabled
+			return false
+		}
+
 		select {
 		case <-ctx.Done():
-			return
+			// indicates that we do not need to run callhome anymore
+			return false
 		case <-callhomeTimer.C:
-			if !enableCallhome.Load() {
+			if !globalCallhomeConfig.Enabled() {
 				// Stop the processing as callhome got disabled
-				return
+				return false
 			}
+
 			performCallhome(ctx)
 
 			// Reset the timer for next cycle.
-			callhomeTimer.Reset(callhomeFreq.Load())
+			callhomeTimer.Reset(globalCallhomeConfig.FrequencyDur())
 		}
 	}
 }