Create v2 GC settings

config/core/configmaps/gc.yaml

@@ -20,7 +20,7 @@ metadata:
   labels:
     serving.knative.dev/release: devel
   annotations:
-    knative.dev/example-checksum: "83219cc3"
+    knative.dev/example-checksum: "c675b489"
 data:
   _example: |
     ################################
@@ -47,10 +47,40 @@ data:
     # resync period (10 hours).
     stale-revision-timeout: "15h"
 
-    # Minimum number of generations of revisions to keep before considering
-    # them for GC
+    # Minimum number of generations of non-active revisions to keep before
+    # considering them for GC.
     stale-revision-minimum-generations: "20"
 
     # To avoid constant updates, we allow an existing annotation to be stale by this
     # amount before we update the timestamp.
     stale-revision-lastpinned-debounce: "5h"
+
+
+    # ---------------------------------------
+    # V2 Garbage Collector Settings
+    # ---------------------------------------
+    #
+    # These settings are enabled via the 'responsive-revision-gc' feature flag.
+    # ALPHA NOTE: This feature is still experimental and under active development.
+
+    # Duration since revision creation before considering it for GC.
+    retain-since-create-time: "48h"
+
+    # Duration since a route has pointed at the revision
+    # before considering it for GC.
+    retain-since-last-active-time: "15h"
+
+    # Minimum number of non-active revisions to retain.
+    min-stale-revisions: "20"
+
+    # Maximum number of non-active revisions to retain regardless of
+    # creation or staleness time-bounds.
+    #
+    # Instead of allowing revisions to become stale down to min-stale-revisions,
+    # this mode will keep around revisions up to this maximum limit. A value of 0
+    # will immediately delete any non-active revisions. The expected total number
+    # of revisions is the number of active plus this value.
+    #
+    # Set to -1 to disable this setting. Revisions will be eligible for gc as soon
+    # as they are considered stale as long as there are more than min-stale-revisions.
+    max-stale-revisions: "-1"

pkg/gc/config.go

@@ -37,18 +37,41 @@ type Config struct {
 	// Timeout since a revision lastPinned before it should be GC'd
 	// This must be longer than the controller resync period
 	StaleRevisionTimeout time.Duration
-	// Minimum number of generations of revisions to keep before considering for GC
+	// Minimum number of generations of revisions to keep before considering for GC.
 	StaleRevisionMinimumGenerations int64
 	// Minimum staleness duration before updating lastPinned
 	StaleRevisionLastpinnedDebounce time.Duration
+
+	// Duration from creation when a Revision should be considered active
+	// and exempt from GC. Note that GCMaxStaleRevision may override this if set.
+	RetainSinceCreateTime time.Duration
+	// Duration from last active when a Revision should be considered active
+	// and exempt from GC.Note that GCMaxStaleRevision may override this if set.
+	RetainSinceLastActiveTime time.Duration
+	// Minimum number of generations of revisions to keep before considering for GC.
+	// Set -1 to disable minimum and fill up to max.
+	// Either min or max must be set.
+	MinStaleRevisions int64
+	// Maximum number of stale revisions to keep before considering for GC.
+	// regardless of creation or staleness time-bounds
+	// Set -1 to disable this setting.
+	// Either min or max must be set.
+	MaxStaleRevisions int64
 }
 
 func defaultConfig() *Config {
 	return &Config{
+		// V1 GC Settings
 		StaleRevisionCreateDelay:        48 * time.Hour,
 		StaleRevisionTimeout:            15 * time.Hour,
 		StaleRevisionLastpinnedDebounce: 5 * time.Hour,
 		StaleRevisionMinimumGenerations: 20,
+
+		// V2 GC Settings
+		RetainSinceCreateTime:     48 * time.Hour,
+		RetainSinceLastActiveTime: 15 * time.Hour,
+		MinStaleRevisions:         20,
+		MaxStaleRevisions:         -1,
 	}
 }
 
@@ -62,18 +85,35 @@ func NewConfigFromConfigMapFunc(ctx context.Context) func(configMap *corev1.Conf
 			cm.AsDuration("stale-revision-create-delay", &c.StaleRevisionCreateDelay),
 			cm.AsDuration("stale-revision-timeout", &c.StaleRevisionTimeout),
 			cm.AsDuration("stale-revision-lastpinned-debounce", &c.StaleRevisionLastpinnedDebounce),
-
 			cm.AsInt64("stale-revision-minimum-generations", &c.StaleRevisionMinimumGenerations),
+
+			cm.AsDuration("retain-since-create-time", &c.RetainSinceCreateTime),
+			cm.AsDuration("retain-since-last-active-time", &c.RetainSinceLastActiveTime),
+			cm.AsInt64("min-stale-revisions", &c.MinStaleRevisions),
+			cm.AsInt64("max-stale-revisions", &c.MaxStaleRevisions),
 		); err != nil {
 			return nil, fmt.Errorf("failed to parse data: %w", err)
 		}
 
+		if c.MaxStaleRevisions >= 0 && c.MinStaleRevisions > c.MaxStaleRevisions {
+			return nil, fmt.Errorf(
+				"min-stale-revisions(%d) must be <= max-stale-revisions(%d)",
+				c.MinStaleRevisions, c.MaxStaleRevisions)
+		}
+		if c.MinStaleRevisions < 0 {
+			return nil, fmt.Errorf("min-stale-revisions must be non-negative, was: %d", c.MinStaleRevisions)
+		}
+		if c.MaxStaleRevisions < -1 {
+			return nil, fmt.Errorf("max-stale-revisions must be >= -1, was: %d", c.MaxStaleRevisions)
+		}
+
 		if c.StaleRevisionMinimumGenerations < 0 {
 			return nil, fmt.Errorf("stale-revision-minimum-generations must be non-negative, was: %d", c.StaleRevisionMinimumGenerations)
 		}
 
 		if c.StaleRevisionTimeout-c.StaleRevisionLastpinnedDebounce < minRevisionTimeout {
-			logger.Warnf("Got revision timeout of %v, minimum supported value is %v", c.StaleRevisionTimeout, minRevisionTimeout+c.StaleRevisionLastpinnedDebounce)
+			logger.Warnf("Got revision timeout of %v, minimum supported value is %v",
+				c.StaleRevisionTimeout, minRevisionTimeout+c.StaleRevisionLastpinnedDebounce)
 			c.StaleRevisionTimeout = minRevisionTimeout + c.StaleRevisionLastpinnedDebounce
 		}
 		return c, nil

pkg/gc/config_test.go

@@ -51,12 +51,20 @@ func TestOurConfig(t *testing.T) {
 			StaleRevisionTimeout:            14 * time.Hour,
 			StaleRevisionMinimumGenerations: 10,
 			StaleRevisionLastpinnedDebounce: 2*time.Hour + 30*time.Minute + 44*time.Second,
+			RetainSinceCreateTime:           17 * time.Hour,
+			RetainSinceLastActiveTime:       16 * time.Hour,
+			MinStaleRevisions:               5,
+			MaxStaleRevisions:               500,
 		},
 		data: map[string]string{
 			"stale-revision-create-delay":        "15h",
 			"stale-revision-timeout":             "14h",
 			"stale-revision-minimum-generations": "10",
 			"stale-revision-lastpinned-debounce": "2h30m44s",
+			"retain-since-create-time":           "17h",
+			"retain-since-last-active-time":      "16h",
+			"min-stale-revisions":                "5",
+			"max-stale-revisions":                "500",
 		},
 	}, {
 		name: "Invalid duration",
@@ -72,6 +80,28 @@ func TestOurConfig(t *testing.T) {
 		data: map[string]string{
 			"stale-revision-minimum-generations": "-1",
 		},
+	}, {
+		name: "Invalid negative minimum generation v2",
+		fail: true,
+		want: nil,
+		data: map[string]string{
+			"min-stale-revisions": "-1",
+		},
+	}, {
+		name: "Invalid negative maximum generation",
+		fail: true,
+		want: nil,
+		data: map[string]string{
+			"max-stale-revisions": "-2",
+		},
+	}, {
+		name: "Invalid max less than min",
+		fail: true,
+		want: nil,
+		data: map[string]string{
+			"min-stale-revisions": "20",
+			"max-stale-revisions": "10",
+		},
 	}, {
 		name: "Invalid minimum generation",
 		fail: true,
@@ -85,13 +115,16 @@ func TestOurConfig(t *testing.T) {
 		want: &Config{
 			StaleRevisionCreateDelay:        15 * time.Hour,
 			StaleRevisionTimeout:            15 * time.Hour,
-			StaleRevisionMinimumGenerations: 10,
+			StaleRevisionMinimumGenerations: 20,
 			StaleRevisionLastpinnedDebounce: 5 * time.Hour,
+			RetainSinceCreateTime:           48 * time.Hour,
+			RetainSinceLastActiveTime:       15 * time.Hour,
+			MinStaleRevisions:               20,
+			MaxStaleRevisions:               -1,
 		},
 		data: map[string]string{
-			"stale-revision-create-delay":        "15h",
-			"stale-revision-minimum-generations": "10",
-			"stale-revision-timeout":             "1h",
+			"stale-revision-create-delay": "15h",
+			"stale-revision-timeout":      "1h",
 		},
 	}} {
 		t.Run(tt.name, func(t *testing.T) {