metadb: add optional fast restart path that skips storage walk when (version + commit + storage config) matches metaDB stamp (#4026)

* chore(metadb): add writer version to interface Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * chore(metadb): add writer version to db mock Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * chore(metadb): implement writer version for bolt, redis, and dynamodb Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * feat(metadb): add optional fast restart path that skips storage walk when binary identity matches metaDB stamp binary identity is determined by the current release tag/commit and stored in metaDB after a successful storage parse. When fast restart is enabled, the next startup will skip the parse if the stored identity matches the current binary Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * chore(cli): serve: add a way to force reparse storage Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * refactor(meta): version: split to avoid global state mutation in tests Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * fix(meta): version: include commit in writerVersion to distinguish retags Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * chore(config): add IsFastRestartEnabled() test Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * fix(meta): skip writer-version stamp when storage parse is incomplete ParseStorage returns nil even when individual repos fail to parse or are only partially parsed (a missing manifest blob), so MaybeParseStorage would stamp a partially-populated metaDB as good. On the next restart fastRestart trusts the stamp, skips the storage walk, and never recovers. Track per-repo outcomes via parseStats and stamp only when the walk fully populated the metaDB, otherwise log and continue so the next restart reparses Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * fix(docs): readme: remove trailing comma from JSON config Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * fix(meta): dynamodb: use context.Background instead of context.TODO Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * fix(meta): invalidate fast restart on storage config changes Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * chore(meta): dynamodb: use context.Background() instead of context.TODO() Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * docs(meta): dynamodb: add comment about nil AttributeValue handling in GetWriterVersion Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * chore: rename writer-version stamp to fast-restart stamp also replaces the version/commit tracking to use BinaryVersion instead of WriterVersion This should make things more clear Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * fix(config): ensure FastRestart is on GlobalStorageConfig This is not a per-subpath setting Signed-off-by: Jacob McSwain <jacob@mcswain.dev> * fix(metadb): redis: tests: ensure clients are closed Signed-off-by: Jacob McSwain <jacob@mcswain.dev> --------- Signed-off-by: Jacob McSwain <jacob@mcswain.dev>
2026-06-17 21:17:58 +08:00 · 2026-06-09 12:47:20 -05:00
parent d480380ef7
commit 273b15364b
19 changed files with 1103 additions and 44 deletions
@@ -1,6 +1,8 @@
 package config

 import (
+	"crypto/sha256"
+	"encoding/hex"
 	"encoding/json"
 	"maps"
 	"os"
@@ -498,6 +500,14 @@ type GlobalStorageConfig struct {
 	StorageConfig `mapstructure:",squash"`

 	SubPaths map[string]StorageConfig
+
+	// FastRestart lets the controller skip the startup storage walk when neither
+	// the Zot binary nor the storage config has changed since the last run. This
+	// avoids re-reading all metadata from storage on every restart, at the cost
+	// of not detecting out-of-band changes to storage; any storage-config change
+	// forces a full reparse. It is a top-level storage setting only and is not
+	// honored under subPaths. Defaults to false.
+	FastRestart *bool `mapstructure:",omitempty"`
 }

 type AccessControlConfig struct {
@@ -1270,6 +1280,61 @@ func (c *Config) GetRealm() string {
 	return c.HTTP.Realm
 }

+// IsFastRestartEnabled reports whether the controller may skip the startup
+// storage walk when the metaDB fast-restart stamp matches the current binary
+// and storage config. Defaults to false when unset.
+func (c *Config) IsFastRestartEnabled() bool {
+	if c == nil {
+		return false
+	}
+
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	if c.Storage.FastRestart == nil {
+		return false
+	}
+
+	return *c.Storage.FastRestart
+}
+
+// StorageFingerprint returns a stable SHA-256 of the storage config that influences the
+// storage->metaDB walk. It is combined with this binary's identity (see meta.FastRestartStamp)
+// into the fast-restart stamp: when it changes, the metaDB may no longer match storage and a full
+// reparse is forced. FastRestart and the runtime-only GCMaxSchedulerDelay are excluded so
+// toggling them never spuriously invalidates the stamp.
+func (c *Config) StorageFingerprint() string {
+	if c == nil {
+		return ""
+	}
+
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	var norm GlobalStorageConfig
+	if err := DeepCopy(c.Storage, &norm); err != nil {
+		return ""
+	}
+
+	norm.FastRestart = nil
+	norm.GCMaxSchedulerDelay = 0
+
+	for name, subPath := range norm.SubPaths {
+		subPath.GCMaxSchedulerDelay = 0
+		norm.SubPaths[name] = subPath
+	}
+
+	// encoding/json sorts map keys, so the serialization is deterministic across restarts.
+	blob, err := json.Marshal(norm)
+	if err != nil {
+		return ""
+	}
+
+	sum := sha256.Sum256(blob)
+
+	return hex.EncodeToString(sum[:])
+}
+
 // GetCompat returns a copy of the compatibility config.
 func (c *Config) GetCompat() []compat.MediaCompatibility {
 	if c == nil {
@@ -13,6 +13,75 @@ import (
 	syncconf "zotregistry.dev/zot/v2/pkg/extensions/config/sync"
 )

+func TestStorageFingerprint(t *testing.T) {
+	newConf := func() *config.Config {
+		conf := config.New()
+		conf.Storage.RootDirectory = "/var/lib/registry"
+
+		return conf
+	}
+
+	Convey("StorageFingerprint", t, func() {
+		Convey("nil config yields an empty fingerprint", func() {
+			var nilConf *config.Config
+
+			So(nilConf.StorageFingerprint(), ShouldEqual, "")
+		})
+
+		Convey("identical storage config yields an identical, non-empty fingerprint", func() {
+			fingerprint := newConf().StorageFingerprint()
+
+			So(fingerprint, ShouldNotEqual, "")
+			So(newConf().StorageFingerprint(), ShouldEqual, fingerprint)
+		})
+
+		Convey("changing a storage field changes the fingerprint", func() {
+			base := newConf().StorageFingerprint()
+
+			dedupe := newConf()
+			dedupe.Storage.Dedupe = !dedupe.Storage.Dedupe
+			So(dedupe.StorageFingerprint(), ShouldNotEqual, base)
+
+			rootDir := newConf()
+			rootDir.Storage.RootDirectory = "/different"
+			So(rootDir.StorageFingerprint(), ShouldNotEqual, base)
+
+			driver := newConf()
+			driver.Storage.StorageDriver = map[string]any{"name": "s3"}
+			So(driver.StorageFingerprint(), ShouldNotEqual, base)
+
+			subPaths := newConf()
+			subPaths.Storage.SubPaths = map[string]config.StorageConfig{"/a": {RootDirectory: "/data/a"}}
+			So(subPaths.StorageFingerprint(), ShouldNotEqual, base)
+		})
+
+		Convey("changing a non-storage field keeps the fingerprint", func() {
+			base := newConf().StorageFingerprint()
+
+			port := newConf()
+			port.HTTP.Port = "9999"
+			So(port.StorageFingerprint(), ShouldEqual, base)
+
+			logLevel := newConf()
+			logLevel.Log = &config.LogConfig{Level: "debug"}
+			So(logLevel.StorageFingerprint(), ShouldEqual, base)
+		})
+
+		Convey("FastRestart and GCMaxSchedulerDelay are excluded from the fingerprint", func() {
+			base := newConf().StorageFingerprint()
+
+			enabled := true
+			fastRestart := newConf()
+			fastRestart.Storage.FastRestart = &enabled
+			So(fastRestart.StorageFingerprint(), ShouldEqual, base)
+
+			schedDelay := newConf()
+			schedDelay.Storage.GCMaxSchedulerDelay = 5 * time.Minute
+			So(schedDelay.StorageFingerprint(), ShouldEqual, base)
+		})
+	})
+}
+
 func TestConfig(t *testing.T) {
 	Convey("Test config utils", t, func() {
 		firstStorageConfig := config.StorageConfig{
@@ -605,6 +674,24 @@ func TestConfig(t *testing.T) {
 		So(conf.IsRetentionEnabled(), ShouldBeFalse)
 	})

+	Convey("Test IsFastRestartEnabled()", t, func() {
+		var nilConf *config.Config = nil
+
+		So(nilConf.IsFastRestartEnabled(), ShouldBeFalse)
+
+		// Default config leaves FastRestart unset
+		conf := config.New()
+		So(conf.IsFastRestartEnabled(), ShouldBeFalse)
+
+		disabled := false
+		conf.Storage.FastRestart = &disabled
+		So(conf.IsFastRestartEnabled(), ShouldBeFalse)
+
+		enabled := true
+		conf.Storage.FastRestart = &enabled
+		So(conf.IsFastRestartEnabled(), ShouldBeTrue)
+	})
+
 	Convey("Test IsEventRecorderEnabled()", t, func() {
 		conf := config.New()
 		extensionsConfig := conf.CopyExtensionsConfig()