*: promote the boltdb-freelistType from experimental to official and set default type to hashmap

Documentation/op-guide/configuration.md

@@ -89,6 +89,11 @@ To start etcd automatically using custom settings at startup in Linux, using a [
 + default: 0
 + env variable: ETCD_BACKEND_BATCH_LIMIT
 
+### --backend-bbolt-freelist-type
++ The freelist type that etcd backend(bboltdb) uses (array and map are supported types).
++ default: map
++ env variable: ETCD_BACKEND_BBOLT_FREELIST_TYPE
+
 ### --backend-batch-interval
 + BackendBatchInterval is the maximum time before commit the backend transaction.
 + default: 0
@@ -436,11 +441,6 @@ Follow the instructions when using these flags.
 
 ## Experimental flags
 
-### --experimental-backend-bbolt-freelist-type
-+ The freelist type that etcd backend(bboltdb) uses (array and map are supported types).
-+ default: array
-+ env variable: ETCD_EXPERIMENTAL_BACKEND_BBOLT_FREELIST_TYPE
-
 ### --experimental-corrupt-check-time
 + Duration of time between cluster corruption check passes
 + default: 0s

embed/config.go

@@ -77,7 +77,7 @@ const (
 	// More details are listed in ../Documentation/tuning.md#time-parameters.
 	maxElectionMs = 50000
 	// backend freelist map type
-	freelistMapType = "map"
+	freelistArrayType = "array"
 )
 
 var (
@@ -171,10 +171,12 @@ type Config struct {
 	// BackendBatchInterval is the maximum time before commit the backend transaction.
 	BackendBatchInterval time.Duration `json:"backend-batch-interval"`
 	// BackendBatchLimit is the maximum operations before commit the backend transaction.
-	BackendBatchLimit int   `json:"backend-batch-limit"`
-	QuotaBackendBytes int64 `json:"quota-backend-bytes"`
-	MaxTxnOps         uint  `json:"max-txn-ops"`
-	MaxRequestBytes   uint  `json:"max-request-bytes"`
+	BackendBatchLimit int `json:"backend-batch-limit"`
+	// BackendFreelistType specifies the type of freelist that boltdb backend uses (array and map are supported types).
+	BackendFreelistType string `json:"backend-bbolt-freelist-type"`
+	QuotaBackendBytes   int64  `json:"quota-backend-bytes"`
+	MaxTxnOps           uint   `json:"max-txn-ops"`
+	MaxRequestBytes     uint   `json:"max-request-bytes"`
 
 	LPUrls, LCUrls []url.URL
 	APUrls, ACUrls []url.URL
@@ -276,8 +278,6 @@ type Config struct {
 	ExperimentalInitialCorruptCheck bool          `json:"experimental-initial-corrupt-check"`
 	ExperimentalCorruptCheckTime    time.Duration `json:"experimental-corrupt-check-time"`
 	ExperimentalEnableV2V3          string        `json:"experimental-enable-v2v3"`
-	// ExperimentalBackendFreelistType specifies the type of freelist that boltdb backend uses (array and map are supported types).
-	ExperimentalBackendFreelistType string `json:"experimental-backend-bbolt-freelist-type"`
 	// ExperimentalEnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
 	ExperimentalEnableLeaseCheckpoint bool `json:"experimental-enable-lease-checkpoint"`
 	ExperimentalCompactionBatchLimit  int  `json:"experimental-compaction-batch-limit"`
@@ -907,9 +907,9 @@ func (cfg *Config) getMetricsURLs() (ss []string) {
 }
 
 func parseBackendFreelistType(freelistType string) bolt.FreelistType {
-	if freelistType == freelistMapType {
-		return bolt.FreelistMapType
+	if freelistType == freelistArrayType {
+		return bolt.FreelistArrayType
 	}
 
-	return bolt.FreelistArrayType
+	return bolt.FreelistMapType
 }

embed/etcd.go

@@ -159,7 +159,7 @@ func StartEtcd(inCfg *Config) (e *Etcd, err error) {
 		return e, err
 	}
 
-	backendFreelistType := parseBackendFreelistType(cfg.ExperimentalBackendFreelistType)
+	backendFreelistType := parseBackendFreelistType(cfg.BackendFreelistType)
 
 	srvcfg := etcdserver.ServerConfig{
 		Name:                       cfg.Name,

etcdmain/config.go

@@ -155,6 +155,7 @@ func newConfig() *config {
 	fs.UintVar(&cfg.ec.ElectionMs, "election-timeout", cfg.ec.ElectionMs, "Time (in milliseconds) for an election to timeout.")
 	fs.BoolVar(&cfg.ec.InitialElectionTickAdvance, "initial-election-tick-advance", cfg.ec.InitialElectionTickAdvance, "Whether to fast-forward initial election ticks on boot for faster election.")
 	fs.Int64Var(&cfg.ec.QuotaBackendBytes, "quota-backend-bytes", cfg.ec.QuotaBackendBytes, "Raise alarms when backend size exceeds the given quota. 0 means use the default quota.")
+	fs.StringVar(&cfg.ec.BackendFreelistType, "backend-bbolt-freelist-type", cfg.ec.BackendFreelistType, "BackendFreelistType specifies the type of freelist that boltdb backend uses(array and map are supported types)")
 	fs.DurationVar(&cfg.ec.BackendBatchInterval, "backend-batch-interval", cfg.ec.BackendBatchInterval, "BackendBatchInterval is the maximum time before commit the backend transaction.")
 	fs.IntVar(&cfg.ec.BackendBatchLimit, "backend-batch-limit", cfg.ec.BackendBatchLimit, "BackendBatchLimit is the maximum operations before commit the backend transaction.")
 	fs.UintVar(&cfg.ec.MaxTxnOps, "max-txn-ops", cfg.ec.MaxTxnOps, "Maximum number of operations permitted in a transaction.")
@@ -253,7 +254,6 @@ func newConfig() *config {
 	fs.BoolVar(&cfg.ec.ExperimentalInitialCorruptCheck, "experimental-initial-corrupt-check", cfg.ec.ExperimentalInitialCorruptCheck, "Enable to check data corruption before serving any client/peer traffic.")
 	fs.DurationVar(&cfg.ec.ExperimentalCorruptCheckTime, "experimental-corrupt-check-time", cfg.ec.ExperimentalCorruptCheckTime, "Duration of time between cluster corruption check passes.")
 	fs.StringVar(&cfg.ec.ExperimentalEnableV2V3, "experimental-enable-v2v3", cfg.ec.ExperimentalEnableV2V3, "v3 prefix for serving emulated v2 state.")
-	fs.StringVar(&cfg.ec.ExperimentalBackendFreelistType, "experimental-backend-bbolt-freelist-type", cfg.ec.ExperimentalBackendFreelistType, "ExperimentalBackendFreelistType specifies the type of freelist that boltdb backend uses(array and map are supported types)")
 	fs.BoolVar(&cfg.ec.ExperimentalEnableLeaseCheckpoint, "experimental-enable-lease-checkpoint", false, "Enable to persist lease remaining TTL to prevent indefinite auto-renewal of long lived leases.")
 	fs.IntVar(&cfg.ec.ExperimentalCompactionBatchLimit, "experimental-compaction-batch-limit", cfg.ec.ExperimentalCompactionBatchLimit, "Sets the maximum revisions deleted in each compaction batch.")
 

etcdmain/help.go

@@ -69,6 +69,8 @@ Member:
     Maximum number of wal files to retain (0 is unlimited).
   --quota-backend-bytes '0'
     Raise alarms when backend size exceeds the given quota (0 defaults to low space quota).
+  --backend-bbolt-freelist-type 'map'
+    BackendFreelistType specifies the type of freelist that boltdb backend uses(array and map are supported types).
   --backend-batch-interval ''
     BackendBatchInterval is the maximum time before commit the backend transaction.
   --backend-batch-limit '0'
@@ -200,8 +202,6 @@ Experimental feature:
     Duration of time between cluster corruption check passes.
   --experimental-enable-v2v3 ''
     Serve v2 requests through the v3 backend under a given prefix.
-  --experimental-backend-bbolt-freelist-type 'array'
-    ExperimentalBackendFreelistType specifies the type of freelist that boltdb backend uses(array and map are supported types).
   --experimental-enable-lease-checkpoint 'false'
     ExperimentalEnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
   --experimental-compaction-batch-limit 1000