Add crawler delay config + dynamic config values (#11018)

cmd/admin-handlers-config-kv.go

@@ -130,8 +130,8 @@ func (a adminAPIHandlers) SetConfigKVHandler(w http.ResponseWriter, r *http.Requ
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return
 	}
-
-	if _, err = cfg.ReadFrom(bytes.NewReader(kvBytes)); err != nil {
+	dynamic, err := cfg.ReadConfig(bytes.NewReader(kvBytes))
+	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return
 	}
@@ -158,6 +158,17 @@ func (a adminAPIHandlers) SetConfigKVHandler(w http.ResponseWriter, r *http.Requ
 		saveConfig(GlobalContext, objectAPI, backendEncryptedFile, backendEncryptedMigrationComplete)
 	}
 
+	// Apply dynamic values.
+	if err := applyDynamicConfig(GlobalContext, cfg); err != nil {
+		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
+		return
+	}
+	globalNotificationSys.SignalService(serviceReloadDynamic)
+
+	// If all values were dynamic, tell the client.
+	if dynamic {
+		w.Header().Set(madmin.ConfigAppliedHeader, madmin.ConfigAppliedTrue)
+	}
 	writeSuccessResponseHeadersOnly(w)
 }
 
@@ -266,7 +277,7 @@ func (a adminAPIHandlers) RestoreConfigHistoryKVHandler(w http.ResponseWriter, r
 		return
 	}
 
-	if _, err = cfg.ReadFrom(bytes.NewReader(kvBytes)); err != nil {
+	if _, err = cfg.ReadConfig(bytes.NewReader(kvBytes)); err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return
 	}
@@ -378,7 +389,7 @@ func (a adminAPIHandlers) SetConfigHandler(w http.ResponseWriter, r *http.Reques
 	}
 
 	cfg := newServerConfig()
-	if _, err = cfg.ReadFrom(bytes.NewReader(kvBytes)); err != nil {
+	if _, err = cfg.ReadConfig(bytes.NewReader(kvBytes)); err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return
 	}

cmd/admin-handlers.go

@@ -205,9 +205,10 @@ func (a adminAPIHandlers) ServiceHandler(w http.ResponseWriter, r *http.Request)
 	}
 
 	var objectAPI ObjectLayer
-	if serviceSig == serviceRestart {
+	switch serviceSig {
+	case serviceRestart:
 		objectAPI, _ = validateAdminReq(ctx, w, r, iampolicy.ServiceRestartAdminAction)
-	} else {
+	case serviceStop:
 		objectAPI, _ = validateAdminReq(ctx, w, r, iampolicy.ServiceStopAdminAction)
 	}
 	if objectAPI == nil {

cmd/admin-heal-ops.go

@@ -658,7 +658,9 @@ func (h *healSequence) healSequenceStart(objAPI ObjectLayer) {
 }
 
 func (h *healSequence) queueHealTask(source healSource, healType madmin.HealItemType) error {
+	globalHealConfigMu.Lock()
 	opts := globalHealConfig
+	globalHealConfigMu.Unlock()
 
 	// Send heal request
 	task := healTask{

cmd/common-main.go

@@ -64,10 +64,12 @@ func verifyObjectLayerFeatures(name string, objAPI ObjectLayer) {
 		}
 	}
 
+	globalCompressConfigMu.Lock()
 	if globalCompressConfig.Enabled && !objAPI.IsCompressionSupported() {
 		logger.Fatal(errInvalidArgument,
 			"Compression support is requested but '%s' does not support compression", name)
 	}
+	globalCompressConfigMu.Unlock()
 }
 
 // Check for updates and print a notification message

cmd/config-current.go

@@ -17,6 +17,7 @@
 package cmd
 
 import (
+	"context"
 	"fmt"
 	"strings"
 	"sync"
@@ -25,6 +26,7 @@ import (
 	"github.com/minio/minio/cmd/config/api"
 	"github.com/minio/minio/cmd/config/cache"
 	"github.com/minio/minio/cmd/config/compress"
+	"github.com/minio/minio/cmd/config/crawler"
 	"github.com/minio/minio/cmd/config/dns"
 	"github.com/minio/minio/cmd/config/etcd"
 	"github.com/minio/minio/cmd/config/heal"
@@ -57,6 +59,7 @@ func initHelp() {
 		config.LoggerWebhookSubSys:  logger.DefaultKVS,
 		config.AuditWebhookSubSys:   logger.DefaultAuditKVS,
 		config.HealSubSys:           heal.DefaultKVS,
+		config.CrawlerSubSys:        crawler.DefaultKVS,
 	}
 	for k, v := range notify.DefaultNotificationKVS {
 		kvs[k] = v
@@ -112,6 +115,10 @@ func initHelp() {
 			Key:         config.HealSubSys,
 			Description: "manage object healing frequency and bitrot verification checks",
 		},
+		config.HelpKV{
+			Key:         config.CrawlerSubSys,
+			Description: "manage crawling for usage calculation, lifecycle, healing and more",
+		},
 		config.HelpKV{
 			Key:             config.LoggerWebhookSubSys,
 			Description:     "send server logs to webhook endpoints",
@@ -192,6 +199,7 @@ func initHelp() {
 		config.CacheSubSys:          cache.Help,
 		config.CompressionSubSys:    compress.Help,
 		config.HealSubSys:           heal.Help,
+		config.CrawlerSubSys:        crawler.Help,
 		config.IdentityOpenIDSubSys: openid.Help,
 		config.IdentityLDAPSubSys:   xldap.Help,
 		config.PolicyOPASubSys:      opa.Help,
@@ -221,6 +229,9 @@ var (
 )
 
 func validateConfig(s config.Config, setDriveCount int) error {
+	// We must have a global lock for this so nobody else modifies env while we do.
+	defer env.LockSetEnv()()
+
 	// Disable merging env values with config for validation.
 	env.SetEnvOff()
 
@@ -249,14 +260,25 @@ func validateConfig(s config.Config, setDriveCount int) error {
 		return err
 	}
 
-	if _, err := compress.LookupConfig(s[config.CompressionSubSys][config.Default]); err != nil {
+	compCfg, err := compress.LookupConfig(s[config.CompressionSubSys][config.Default])
+	if err != nil {
 		return err
 	}
+	objAPI := newObjectLayerFn()
+	if objAPI != nil {
+		if compCfg.Enabled && !objAPI.IsCompressionSupported() {
+			return fmt.Errorf("Backend does not support compression")
+		}
+	}
 
 	if _, err := heal.LookupConfig(s[config.HealSubSys][config.Default]); err != nil {
 		return err
 	}
 
+	if _, err := crawler.LookupConfig(s[config.CrawlerSubSys][config.Default]); err != nil {
+		return err
+	}
+
 	{
 		etcdCfg, err := etcd.LookupConfig(s[config.EtcdSubSys][config.Default], globalRootCAs)
 		if err != nil {
@@ -438,10 +460,6 @@ func lookupConfigs(s config.Config, setDriveCount int) {
 			}
 		}
 	}
-	globalHealConfig, err = heal.LookupConfig(s[config.HealSubSys][config.Default])
-	if err != nil {
-		logger.LogIf(ctx, fmt.Errorf("Unable to read heal config: %w", err))
-	}
 
 	kmsCfg, err := crypto.LookupConfig(s, globalCertsCADir.Get(), NewGatewayHTTPTransport())
 	if err != nil {
@@ -459,11 +477,6 @@ func lookupConfigs(s config.Config, setDriveCount int) {
 		logger.LogIf(ctx, fmt.Errorf("%s env is deprecated please migrate to using `mc encrypt` at bucket level", crypto.EnvKMSAutoEncryption))
 	}
 
-	globalCompressConfig, err = compress.LookupConfig(s[config.CompressionSubSys][config.Default])
-	if err != nil {
-		logger.LogIf(ctx, fmt.Errorf("Unable to setup Compression: %w", err))
-	}
-
 	globalOpenIDConfig, err = openid.LookupConfig(s[config.IdentityOpenIDSubSys][config.Default],
 		NewGatewayHTTPTransport(), xhttp.DrainBody)
 	if err != nil {
@@ -538,6 +551,68 @@ func lookupConfigs(s config.Config, setDriveCount int) {
 	if err != nil {
 		logger.LogIf(ctx, fmt.Errorf("Unable to initialize notification target(s): %w", err))
 	}
+
+	// Apply dynamic config values
+	logger.LogIf(ctx, applyDynamicConfig(ctx, s))
+}
+
+// applyDynamicConfig will apply dynamic config values.
+// Dynamic systems should be in config.SubSystemsDynamic as well.
+func applyDynamicConfig(ctx context.Context, s config.Config) error {
+	// Read all dynamic configs.
+	// API
+	apiConfig, err := api.LookupConfig(s[config.APISubSys][config.Default])
+	if err != nil {
+		logger.LogIf(ctx, fmt.Errorf("Invalid api configuration: %w", err))
+	}
+
+	// Compression
+	cmpCfg, err := compress.LookupConfig(s[config.CompressionSubSys][config.Default])
+	if err != nil {
+		return fmt.Errorf("Unable to setup Compression: %w", err)
+	}
+	objAPI := newObjectLayerFn()
+	if objAPI != nil {
+		if cmpCfg.Enabled && !objAPI.IsCompressionSupported() {
+			return fmt.Errorf("Backend does not support compression")
+		}
+	}
+
+	// Heal
+	healCfg, err := heal.LookupConfig(s[config.HealSubSys][config.Default])
+	if err != nil {
+		logger.LogIf(ctx, fmt.Errorf("Unable to apply heal config: %w", err))
+	}
+
+	// Crawler
+	crawlerCfg, err := crawler.LookupConfig(s[config.CrawlerSubSys][config.Default])
+	if err != nil {
+		return fmt.Errorf("Unable to apply crawler config: %w", err)
+	}
+
+	// Apply configurations.
+	// We should not fail after this.
+	globalAPIConfig.init(apiConfig, globalAPIConfig.setDriveCount)
+
+	globalCompressConfigMu.Lock()
+	globalCompressConfig = cmpCfg
+	globalCompressConfigMu.Unlock()
+
+	globalHealConfigMu.Lock()
+	globalHealConfig = healCfg
+	globalHealConfigMu.Unlock()
+
+	logger.LogIf(ctx, crawlerSleeper.Update(crawlerCfg.Delay, crawlerCfg.MaxWait))
+
+	// Update all dynamic config values in memory.
+	globalServerConfigMu.Lock()
+	defer globalServerConfigMu.Unlock()
+	if globalServerConfig != nil {
+		for k := range config.SubSystemsDynamic {
+			globalServerConfig[k] = s[k]
+		}
+	}
+	return nil
 }
 
 // Help - return sub-system level help

cmd/config/config.go

@@ -77,6 +77,7 @@ const (
 	LoggerWebhookSubSys  = "logger_webhook"
 	AuditWebhookSubSys   = "audit_webhook"
 	HealSubSys           = "heal"
+	CrawlerSubSys        = "crawler"
 
 	// Add new constants here if you add new fields to config.
 )
@@ -98,7 +99,7 @@ const (
 )
 
 // SubSystems - all supported sub-systems
-var SubSystems = set.CreateStringSet([]string{
+var SubSystems = set.CreateStringSet(
 	CredentialsSubSys,
 	RegionSubSys,
 	EtcdSubSys,
@@ -113,6 +114,7 @@ var SubSystems = set.CreateStringSet([]string{
 	PolicyOPASubSys,
 	IdentityLDAPSubSys,
 	IdentityOpenIDSubSys,
+	CrawlerSubSys,
 	HealSubSys,
 	NotifyAMQPSubSys,
 	NotifyESSubSys,
@@ -124,7 +126,15 @@ var SubSystems = set.CreateStringSet([]string{
 	NotifyPostgresSubSys,
 	NotifyRedisSubSys,
 	NotifyWebhookSubSys,
-}...)
+)
+
+// SubSystemsDynamic - all sub-systems that have dynamic config.
+var SubSystemsDynamic = set.CreateStringSet(
+	APISubSys,
+	CompressionSubSys,
+	CrawlerSubSys,
+	HealSubSys,
+)
 
 // SubSystemsSingleTargets - subsystems which only support single target.
 var SubSystemsSingleTargets = set.CreateStringSet([]string{
@@ -141,6 +151,7 @@ var SubSystemsSingleTargets = set.CreateStringSet([]string{
 	IdentityLDAPSubSys,
 	IdentityOpenIDSubSys,
 	HealSubSys,
+	CrawlerSubSys,
 }...)
 
 // Constant separators
@@ -309,25 +320,29 @@ func (c Config) DelFrom(r io.Reader) error {
 	return nil
 }
 
-// ReadFrom - implements io.ReaderFrom interface
-func (c Config) ReadFrom(r io.Reader) (int64, error) {
+// ReadConfig - read content from input and write into c.
+// Returns whether all parameters were dynamic.
+func (c Config) ReadConfig(r io.Reader) (dynOnly bool, err error) {
 	var n int
 	scanner := bufio.NewScanner(r)
+	dynOnly = true
 	for scanner.Scan() {
 		// Skip any empty lines, or comment like characters
 		text := scanner.Text()
 		if text == "" || strings.HasPrefix(text, KvComment) {
 			continue
 		}
-		if err := c.SetKVS(text, DefaultKVS); err != nil {
-			return 0, err
+		dynamic, err := c.SetKVS(text, DefaultKVS)
+		if err != nil {
+			return false, err
 		}
+		dynOnly = dynOnly && dynamic
 		n += len(text)
 	}
 	if err := scanner.Err(); err != nil {
-		return 0, err
+		return false, err
 	}
-	return int64(n), nil
+	return dynOnly, nil
 }
 
 type configWriteTo struct {
@@ -618,26 +633,27 @@ func (c Config) Clone() Config {
 }
 
 // SetKVS - set specific key values per sub-system.
-func (c Config) SetKVS(s string, defaultKVS map[string]KVS) error {
+func (c Config) SetKVS(s string, defaultKVS map[string]KVS) (dynamic bool, err error) {
 	if len(s) == 0 {
-		return Errorf("input arguments cannot be empty")
+		return false, Errorf("input arguments cannot be empty")
 	}
 	inputs := strings.SplitN(s, KvSpaceSeparator, 2)
 	if len(inputs) <= 1 {
-		return Errorf("invalid number of arguments '%s'", s)
+		return false, Errorf("invalid number of arguments '%s'", s)
 	}
 	subSystemValue := strings.SplitN(inputs[0], SubSystemSeparator, 2)
 	if len(subSystemValue) == 0 {
-		return Errorf("invalid number of arguments %s", s)
+		return false, Errorf("invalid number of arguments %s", s)
 	}
 
 	if !SubSystems.Contains(subSystemValue[0]) {
-		return Errorf("unknown sub-system %s", s)
+		return false, Errorf("unknown sub-system %s", s)
 	}
 
 	if SubSystemsSingleTargets.Contains(subSystemValue[0]) && len(subSystemValue) == 2 {
-		return Errorf("sub-system '%s' only supports single target", subSystemValue[0])
+		return false, Errorf("sub-system '%s' only supports single target", subSystemValue[0])
 	}
+	dynamic = SubSystemsDynamic.Contains(subSystemValue[0])
 
 	tgt := Default
 	subSys := subSystemValue[0]
@@ -647,7 +663,7 @@ func (c Config) SetKVS(s string, defaultKVS map[string]KVS) error {
 
 	fields := madmin.KvFields(inputs[1], defaultKVS[subSys].Keys())
 	if len(fields) == 0 {
-		return Errorf("sub-system '%s' cannot have empty keys", subSys)
+		return false, Errorf("sub-system '%s' cannot have empty keys", subSys)
 	}
 
 	var kvs = KVS{}
@@ -670,7 +686,7 @@ func (c Config) SetKVS(s string, defaultKVS map[string]KVS) error {
 			kvs.Set(prevK, madmin.SanitizeValue(kv[1]))
 			continue
 		}
-		return Errorf("key '%s', cannot have empty value", kv[0])
+		return false, Errorf("key '%s', cannot have empty value", kv[0])
 	}
 
 	_, ok := kvs.Lookup(Enable)
@@ -720,11 +736,11 @@ func (c Config) SetKVS(s string, defaultKVS map[string]KVS) error {
 			// Return error only if the
 			// key is enabled, for state=off
 			// let it be empty.
-			return Errorf(
+			return false, Errorf(
 				"'%s' is not optional for '%s' sub-system, please check '%s' documentation",
 				hkv.Key, subSys, subSys)
 		}
 	}
 	c[subSys][tgt] = currKVS
-	return nil
+	return dynamic, nil
 }

cmd/config/crawler/crawler.go

@@ -0,0 +1,86 @@
+/*
+ * MinIO Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package crawler
+
+import (
+	"strconv"
+	"time"
+
+	"github.com/minio/minio/cmd/config"
+)
+
+// Compression environment variables
+const (
+	Delay   = "delay"
+	MaxWait = "max_wait"
+)
+
+// Config represents the heal settings.
+type Config struct {
+	// Delay is the sleep multiplier.
+	Delay float64 `json:"delay"`
+	// MaxWait is maximum wait time between operations
+	MaxWait time.Duration
+}
+
+var (
+	// DefaultKVS - default KV config for heal settings
+	DefaultKVS = config.KVS{
+		config.KV{
+			Key:   Delay,
+			Value: "10",
+		},
+		config.KV{
+			Key:   MaxWait,
+			Value: "15s",
+		},
+	}
+
+	// Help provides help for config values
+	Help = config.HelpKVS{
+		config.HelpKV{
+			Key:         Delay,
+			Description: `crawler delay multiplier, default 10`,
+			Optional:    true,
+			Type:        "float",
+		},
+		config.HelpKV{
+			Key:         MaxWait,
+			Description: `maximum wait time between operations, default 15s`,
+			Optional:    true,
+			Type:        "duration",
+		},
+	}
+)
+
+// LookupConfig - lookup config and override with valid environment settings if any.
+func LookupConfig(kvs config.KVS) (cfg Config, err error) {
+	if err = config.CheckValidKeys(config.CrawlerSubSys, kvs, DefaultKVS); err != nil {
+		return cfg, err
+	}
+	delay := kvs.Get(Delay)
+	cfg.Delay, err = strconv.ParseFloat(delay, 64)
+	if err != nil {
+		return cfg, err
+	}
+	wait := kvs.Get(MaxWait)
+	cfg.MaxWait, err = time.ParseDuration(wait)
+	if err != nil {
+		return cfg, err
+	}
+	return cfg, nil
+}

cmd/data-crawler.go

@@ -21,11 +21,12 @@ import (
 	"context"
 	"encoding/binary"
 	"errors"
+	"math"
 	"math/rand"
 	"os"
 	"path"
-	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/minio/minio/cmd/config"
@@ -43,7 +44,6 @@ import (
 
 const (
 	dataCrawlSleepPerFolder  = time.Millisecond // Time to wait between folders.
-	dataCrawlSleepDefMult    = 10.0             // Default multiplier for waits between operations.
 	dataCrawlStartDelay      = 5 * time.Minute  // Time to wait on startup and between cycles.
 	dataUsageUpdateDirCycles = 16               // Visit all folders every n cycles.
 
@@ -54,7 +54,11 @@ const (
 
 var (
 	globalHealConfig   heal.Config
+	globalHealConfigMu sync.Mutex
+
 	dataCrawlerLeaderLockTimeout = newDynamicTimeout(30*time.Second, 10*time.Second)
+	// Sleeper values are updated when config is loaded.
+	crawlerSleeper = newDynamicSleeper(10, 10*time.Second)
 )
 
 // initDataCrawler will start the crawler unless disabled.
@@ -141,7 +145,6 @@ type folderScanner struct {
 	newCache   dataUsageCache
 	withFilter *bloomFilter
 
-	dataUsageCrawlMult  float64
 	dataUsageCrawlDebug bool
 	healFolderInclude   uint32 // Include a clean folder one in n cycles.
 	healObjectSelect    uint32 // Do a heal check on an object once every n cycles. Must divide into healFolderInclude
@@ -172,11 +175,6 @@ func crawlDataFolder(ctx context.Context, basePath string, cache dataUsageCache,
 		return cache, errors.New("internal error: root scan attempted")
 	}
 
-	delayMult, err := strconv.ParseFloat(env.Get(envDataUsageCrawlDelay, "10.0"), 64)
-	if err != nil {
-		logger.LogIf(ctx, err)
-		delayMult = dataCrawlSleepDefMult
-	}
 	s := folderScanner{
 		root:                basePath,
 		getSize:             getSize,
@@ -184,7 +182,6 @@ func crawlDataFolder(ctx context.Context, basePath string, cache dataUsageCache,
 		newCache:            dataUsageCache{Info: cache.Info},
 		newFolders:          nil,
 		existingFolders:     nil,
-		dataUsageCrawlMult:  delayMult,
 		dataUsageCrawlDebug: intDataUpdateTracker.debug,
 		healFolderInclude:   0,
 		healObjectSelect:    0,
@@ -386,7 +383,7 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 				}
 			}
 		}
-		sleepDuration(dataCrawlSleepPerFolder, f.dataUsageCrawlMult)
+		crawlerSleeper.Sleep(ctx, dataCrawlSleepPerFolder)
 
 		cache := dataUsageEntry{}
 
@@ -435,7 +432,7 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 			}
 
 			// Dynamic time delay.
-			t := UTCNow()
+			wait := crawlerSleeper.Timer(ctx)
 
 			// Get file size, ignore errors.
 			item := crawlItem{
@@ -450,7 +447,7 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 			}
 			size, err := f.getSize(item)
 
-			sleepDuration(time.Since(t), f.dataUsageCrawlMult)
+			wait()
 			if err == errSkipFile {
 				return nil
 			}
@@ -506,8 +503,7 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 			}
 
 			// Dynamic time delay.
-			t := UTCNow()
-
+			wait := crawlerSleeper.Timer(ctx)
 			resolver.bucket = bucket
 
 			foundObjs := false
@@ -535,8 +531,8 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 						logger.Info(color.Green("healObjects:")+" got partial, %d agreed, errs: %v", nAgreed, errs)
 					}
 					// Sleep and reset.
-					sleepDuration(time.Since(t), f.dataUsageCrawlMult)
-					t = UTCNow()
+					wait()
+					wait = crawlerSleeper.Timer(ctx)
 					entry, ok := entries.resolve(&resolver)
 					if !ok {
 						for _, err := range errs {
@@ -572,8 +568,8 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 					}
 					for _, ver := range fiv.Versions {
 						// Sleep and reset.
-						sleepDuration(time.Since(t), f.dataUsageCrawlMult)
-						t = UTCNow()
+						wait()
+						wait = crawlerSleeper.Timer(ctx)
 						err := bgSeq.queueHealTask(healSource{
 							bucket:    bucket,
 							object:    fiv.Name,
@@ -605,6 +601,9 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 				// If we have quorum, found directories, but no objects, issue heal to delete the dangling.
 				objAPI.HealObjects(ctx, bucket, prefix, madmin.HealOpts{Recursive: true, Remove: true},
 					func(bucket, object, versionID string) error {
+						// Wait for each heal as per crawler frequency.
+						wait()
+						wait = crawlerSleeper.Timer(ctx)
 						return bgSeq.queueHealTask(healSource{
 							bucket:    bucket,
 							object:    object,
@@ -613,7 +612,7 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 					})
 			}
 
-			sleepDuration(time.Since(t), f.dataUsageCrawlMult)
+			wait()
 
 			// Add unless healing returned an error.
 			if foundObjs {
@@ -651,12 +650,12 @@ func (f *folderScanner) deepScanFolder(ctx context.Context, folder cachedFolder)
 			dirStack = append(dirStack, entName)
 			err := readDirFn(path.Join(dirStack...), addDir)
 			dirStack = dirStack[:len(dirStack)-1]
-			sleepDuration(dataCrawlSleepPerFolder, f.dataUsageCrawlMult)
+			crawlerSleeper.Sleep(ctx, dataCrawlSleepPerFolder)
 			return err
 		}
 
 		// Dynamic time delay.
-		t := UTCNow()
+		wait := crawlerSleeper.Timer(ctx)
 
 		// Get file size, ignore errors.
 		dirStack = append(dirStack, entName)
@@ -686,8 +685,8 @@ func (f *folderScanner) deepScanFolder(ctx context.Context, folder cachedFolder)
 				heal:       hashPath(path.Join(prefix, entName)).mod(f.oldCache.Info.NextCycle, f.healObjectSelect/folder.objectHealProbDiv),
 			})
 
-		// Don't sleep for really small amount of time
-		sleepDuration(time.Since(t), f.dataUsageCrawlMult)
+		// Wait to throttle IO
+		wait()
 
 		if err == errSkipFile {
 			return nil
@@ -910,21 +909,6 @@ func (i *crawlItem) objectPath() string {
 	return path.Join(i.prefix, i.objectName)
 }
 
-// sleepDuration multiplies the duration d by x
-// and sleeps if is more than 100 micro seconds.
-// Sleep is limited to max 15 seconds.
-func sleepDuration(d time.Duration, x float64) {
-	const maxWait = 15 * time.Second
-	const minWait = 100 * time.Microsecond
-	// Don't sleep for really small amount of time
-	if d := time.Duration(float64(d) * x); d > minWait {
-		if d > maxWait {
-			d = maxWait
-		}
-		time.Sleep(d)
-	}
-}
-
 // healReplication will heal a scanned item that has failed replication.
 func (i *crawlItem) healReplication(ctx context.Context, o ObjectLayer, meta actionMeta) {
 	if meta.oi.DeleteMarker || !meta.oi.VersionPurgeStatus.Empty() {
@@ -967,3 +951,126 @@ func (i *crawlItem) healReplicationDeletes(ctx context.Context, o ObjectLayer, m
 		})
 	}
 }
+
+type dynamicSleeper struct {
+	mu sync.RWMutex
+
+	// Sleep factor
+	factor float64
+
+	// maximum sleep cap,
+	// set to <= 0 to disable.
+	maxSleep time.Duration
+
+	// Don't sleep at all, if time taken is below this value.
+	// This is to avoid too small costly sleeps.
+	minSleep time.Duration
+
+	// cycle will be closed
+	cycle chan struct{}
+}
+
+// newDynamicSleeper
+func newDynamicSleeper(factor float64, maxWait time.Duration) *dynamicSleeper {
+	return &dynamicSleeper{
+		factor:   factor,
+		cycle:    make(chan struct{}),
+		maxSleep: maxWait,
+		minSleep: 100 * time.Microsecond,
+	}
+}
+
+// Timer returns a timer that has started.
+// When the returned function is called it will wait.
+func (d *dynamicSleeper) Timer(ctx context.Context) func() {
+	t := time.Now()
+	return func() {
+		doneAt := time.Now()
+		for {
+			// Grab current values
+			d.mu.RLock()
+			minWait, maxWait := d.minSleep, d.maxSleep
+			factor := d.factor
+			cycle := d.cycle
+			d.mu.RUnlock()
+			elapsed := doneAt.Sub(t)
+			// Don't sleep for really small amount of time
+			wantSleep := time.Duration(float64(elapsed) * factor)
+			if wantSleep <= minWait {
+				return
+			}
+			if maxWait > 0 && wantSleep > maxWait {
+				wantSleep = maxWait
+			}
+			timer := time.NewTimer(wantSleep)
+			select {
+			case <-ctx.Done():
+				if !timer.Stop() {
+					<-timer.C
+				}
+				return
+			case <-timer.C:
+				return
+			case <-cycle:
+				if !timer.Stop() {
+					// We expired.
+					<-timer.C
+					return
+				}
+			}
+		}
+	}
+}
+
+// Sleep sleeps the specified time multiplied by the sleep factor.
+// If the factor is updated the sleep will be done again with the new factor.
+func (d *dynamicSleeper) Sleep(ctx context.Context, base time.Duration) {
+	for {
+		// Grab current values
+		d.mu.RLock()
+		minWait, maxWait := d.minSleep, d.maxSleep
+		factor := d.factor
+		cycle := d.cycle
+		d.mu.RUnlock()
+		// Don't sleep for really small amount of time
+		wantSleep := time.Duration(float64(base) * factor)
+		if wantSleep <= minWait {
+			return
+		}
+		if maxWait > 0 && wantSleep > maxWait {
+			wantSleep = maxWait
+		}
+		timer := time.NewTimer(wantSleep)
+		select {
+		case <-ctx.Done():
+			if !timer.Stop() {
+				<-timer.C
+			}
+			return
+		case <-timer.C:
+			return
+		case <-cycle:
+			if !timer.Stop() {
+				// We expired.
+				<-timer.C
+				return
+			}
+		}
+	}
+}
+
+// Update the current settings and cycle all waiting.
+// Parameters are the same as in the contructor.
+func (d *dynamicSleeper) Update(factor float64, maxWait time.Duration) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if math.Abs(d.factor-factor) < 1e-10 && d.maxSleep == maxWait {
+		return nil
+	}
+	// Update values and cycle waiting.
+	close(d.cycle)
+	d.factor = factor
+	d.maxSleep = maxWait
+	d.cycle = make(chan struct{})
+	return nil
+}

cmd/data-usage.go

@@ -28,7 +28,6 @@ import (
 
 const (
 	envDataUsageCrawlConf  = "MINIO_DISK_USAGE_CRAWL_ENABLE"
-	envDataUsageCrawlDelay = "MINIO_DISK_USAGE_CRAWL_DELAY"
 	envDataUsageCrawlDebug = "MINIO_DISK_USAGE_CRAWL_DEBUG"
 
 	dataUsageRoot   = SlashSeparator

cmd/globals.go

@@ -20,6 +20,7 @@ import (
 	"crypto/x509"
 	"net/http"
 	"os"
+	"sync"
 	"time"
 
 	"github.com/minio/minio-go/v7/pkg/set"
@@ -245,6 +246,7 @@ var (
 	globalAutoEncryption bool
 
 	// Is compression enabled?
+	globalCompressConfigMu sync.Mutex
 	globalCompressConfig   compress.Config
 
 	// Some standard object extensions which we strictly dis-allow for compression.

cmd/handler-api.go

@@ -35,6 +35,7 @@ type apiConfig struct {
 	listQuorum       int
 	extendListLife   time.Duration
 	corsAllowOrigins []string
+	setDriveCount    int
 }
 
 func (t *apiConfig) init(cfg api.Config, setDriveCount int) {
@@ -43,6 +44,7 @@ func (t *apiConfig) init(cfg api.Config, setDriveCount int) {
 
 	t.clusterDeadline = cfg.ClusterDeadline
 	t.corsAllowOrigins = cfg.CorsAllowOrigin
+	t.setDriveCount = setDriveCount
 
 	var apiRequestsMaxPerNode int
 	if cfg.RequestsMax <= 0 {
@@ -62,8 +64,14 @@ func (t *apiConfig) init(cfg api.Config, setDriveCount int) {
 			apiRequestsMaxPerNode /= len(globalEndpoints.Hostnames())
 		}
 	}
-
+	if cap(t.requestsPool) < apiRequestsMaxPerNode {
+		// Only replace if needed.
+		// Existing requests will use the previous limit,
+		// but new requests will use the new limit.
+		// There will be a short overlap window,
+		// but this shouldn't last long.
 		t.requestsPool = make(chan struct{}, apiRequestsMaxPerNode)
+	}
 	t.requestsDeadline = cfg.RequestsDeadline
 	t.listQuorum = cfg.GetListQuorum()
 	t.extendListLife = cfg.ExtendListLife
@@ -76,6 +84,13 @@ func (t *apiConfig) getListQuorum() int {
 	return t.listQuorum
 }
 
+func (t *apiConfig) getSetDriveCount() int {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+
+	return t.setDriveCount
+}
+
 func (t *apiConfig) getExtendListLife() time.Duration {
 	t.mu.RLock()
 	defer t.mu.RUnlock()

cmd/object-api-utils.go

@@ -436,7 +436,10 @@ func (o ObjectInfo) GetActualSize() (int64, error) {
 // Using compression and encryption together enables room for side channel attacks.
 // Eliminate non-compressible objects by extensions/content-types.
 func isCompressible(header http.Header, object string) bool {
-	if crypto.IsRequested(header) || excludeForCompression(header, object, globalCompressConfig) {
+	globalCompressConfigMu.Lock()
+	cfg := globalCompressConfig
+	globalCompressConfigMu.Unlock()
+	if !cfg.Enabled || crypto.IsRequested(header) || excludeForCompression(header, object, cfg) {
 		return false
 	}
 	return true

cmd/peer-rest-server.go

@@ -786,6 +786,17 @@ func (s *peerRESTServer) SignalServiceHandler(w http.ResponseWriter, r *http.Req
 		globalServiceSignalCh <- signal
 	case serviceStop:
 		globalServiceSignalCh <- signal
+	case serviceReloadDynamic:
+		srvCfg, err := getValidConfig(newObjectLayerFn())
+		if err != nil {
+			s.writeErrorResponse(w, err)
+			return
+		}
+		err = applyDynamicConfig(r.Context(), srvCfg)
+		if err != nil {
+			s.writeErrorResponse(w, err)
+		}
+		return
 	default:
 		s.writeErrorResponse(w, errUnsupportedSignal)
 		return

cmd/server-main.go

@@ -475,7 +475,7 @@ func serverMain(ctx *cli.Context) {
 
 	logger.SetDeploymentID(globalDeploymentID)
 
-	go initDataCrawler(GlobalContext, newObject)
+	initDataCrawler(GlobalContext, newObject)
 
 	// Enable background operations for erasure coding
 	if globalIsErasure {

cmd/service.go

@@ -29,6 +29,7 @@ type serviceSignal int
 const (
 	serviceRestart       serviceSignal = iota // Restarts the server.
 	serviceStop                               // Stops the server.
+	serviceReloadDynamic                      // Reload dynamic config values.
 	// Add new service requests here.
 )
 

cmd/xl-storage.go

@@ -336,7 +336,10 @@ func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCac
 	if objAPI == nil {
 		return cache, errServerNotInitialized
 	}
-	opts := globalHealConfig
+
+	globalHealConfigMu.Lock()
+	healOpts := globalHealConfig
+	globalHealConfigMu.Unlock()
 
 	dataUsageInfo, err := crawlDataFolder(ctx, s.diskPath, cache, func(item crawlItem) (int64, error) {
 		// Look for `xl.meta/xl.json' at the leaf.
@@ -375,7 +378,7 @@ func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCac
 			})
 			if !version.Deleted {
 				// Bitrot check local data
-				if size > 0 && item.heal && opts.Bitrot {
+				if size > 0 && item.heal && healOpts.Bitrot {
 					// HealObject verifies bitrot requirement internally
 					res, err := objAPI.HealObject(ctx, item.bucket, item.objectPath(), oi.VersionID, madmin.HealOpts{
 						Remove:   healDeleteDangling,

cmd/xl-storage_test.go

@@ -1693,7 +1693,7 @@ func TestXLStorageVerifyFile(t *testing.T) {
 	reader := bytes.NewReader(data)
 	for {
 		// Using io.CopyBuffer instead of this loop will not work for us as io.CopyBuffer
-		// will use bytes.Buffer.ReadFrom() which will not do shardSize'ed writes causing error.
+		// will use bytes.Buffer.ReadConfig() which will not do shardSize'ed writes causing error.
 		n, err := reader.Read(shard)
 		w.Write(shard[:n])
 		if err == nil {

pkg/env/env.go

@@ -24,10 +24,19 @@ import (
 
 var (
 	privateMutex sync.RWMutex
+	lockEnvMutex sync.Mutex
 	envOff       bool
 )
 
+// LockSetEnv locks modifications to environment.
+// Call returned function to unlock.
+func LockSetEnv() func() {
+	lockEnvMutex.Lock()
+	return lockEnvMutex.Unlock
+}
+
 // SetEnvOff - turns off env lookup
+// A global lock above this MUST ensure that
 func SetEnvOff() {
 	privateMutex.Lock()
 	defer privateMutex.Unlock()

pkg/madmin/config-kv-commands.go

@@ -50,11 +50,19 @@ func (adm *AdminClient) DelConfigKV(ctx context.Context, k string) (err error) {
 	return nil
 }
 
+const (
+	// ConfigAppliedHeader is the header indicating whether the config was applied without requiring a restart.
+	ConfigAppliedHeader = "x-minio-config-applied"
+
+	// ConfigAppliedTrue is the value set in header if the config was applied.
+	ConfigAppliedTrue = "true"
+)
+
 // SetConfigKV - set key value config to server.
-func (adm *AdminClient) SetConfigKV(ctx context.Context, kv string) (err error) {
+func (adm *AdminClient) SetConfigKV(ctx context.Context, kv string) (restart bool, err error) {
 	econfigBytes, err := EncryptData(adm.getSecretKey(), []byte(kv))
 	if err != nil {
-		return err
+		return false, err
 	}
 
 	reqData := requestData{
@@ -67,14 +75,14 @@ func (adm *AdminClient) SetConfigKV(ctx context.Context, kv string) (err error)
 
 	defer closeResponse(resp)
 	if err != nil {
-		return err
+		return false, err
 	}
 
 	if resp.StatusCode != http.StatusOK {
-		return httpRespToErrorResponse(resp)
+		return false, httpRespToErrorResponse(resp)
 	}
 
-	return nil
+	return resp.Header.Get(ConfigAppliedHeader) != ConfigAppliedTrue, nil
 }
 
 // GetConfigKV - returns the key, value of the requested key, incoming data is encrypted.