diff --git a/asyncsearcher/async_searcher.go b/asyncsearcher/async_searcher.go
index eab092cf..538e066c 100644
--- a/asyncsearcher/async_searcher.go
+++ b/asyncsearcher/async_searcher.go
@@ -73,7 +73,12 @@ type AsyncSearcherConfig struct {
 	MaxSizePerRequest int
 }
 
-func MustStartAsync(config AsyncSearcherConfig, mp MappingProvider, fracs fracmanager.List) *AsyncSearcher {
+type fractionAcquirer interface {
+	Fractions() fracmanager.List
+	AcquireFraction(name string) (_ frac.Fraction, release func(), ok bool)
+}
+
+func MustStartAsync(config AsyncSearcherConfig, mp MappingProvider, fracs fractionAcquirer) *AsyncSearcher {
 	if config.DataDir == "" {
 		logger.Fatal("can't start async searcher: DataDir is empty")
 	}
@@ -154,10 +159,10 @@ type asyncSearchInfo struct {
 	infoSize *atomic.Int64
 }
 
-func newAsyncSearchInfo(r AsyncSearchRequest, list fracmanager.List) asyncSearchInfo {
-	fracsToSearch := make([]fracSearchState, 0, len(list))
-	for _, f := range list {
-		fracsToSearch = append(fracsToSearch, fracSearchState{Name: f.Info().Name()})
+func newAsyncSearchInfo(r AsyncSearchRequest, fracNames []string) asyncSearchInfo {
+	fracsToSearch := make([]fracSearchState, 0, len(fracNames))
+	for _, name := range fracNames {
+		fracsToSearch = append(fracsToSearch, fracSearchState{Name: name})
 	}
 	ctx, cancel := context.WithCancel(context.Background())
 	return asyncSearchInfo{
@@ -204,7 +209,7 @@ func (i *asyncSearchInfo) Status() AsyncSearchStatus {
 	return status
 }
 
-func (as *AsyncSearcher) StartSearch(r AsyncSearchRequest, fracs fracmanager.List) error {
+func (as *AsyncSearcher) StartSearch(r AsyncSearchRequest, fracs fractionAcquirer) error {
 	if as.readOnly.Load() {
 		return fmt.Errorf("cannot start search on read-only mode")
 	}
@@ -235,7 +240,8 @@ func (as *AsyncSearcher) StartSearch(r AsyncSearchRequest, fracs fracmanager.Lis
 		return fmt.Errorf("retention time should be less than %s, got %s", maxRetention, r.Retention)
 	}
 
-	if ok := as.saveSearchInfo(r, fracs); !ok {
+	fracNames := fracs.Fractions().FilterInRange(r.Params.From, r.Params.To).Names()
+	if ok := as.saveSearchInfo(r, fracNames); !ok {
 		// Request was saved previously, skip it
 		return nil
 	}
@@ -245,13 +251,13 @@ func (as *AsyncSearcher) StartSearch(r AsyncSearchRequest, fracs fracmanager.Lis
 	return nil
 }
 
-func (as *AsyncSearcher) saveSearchInfo(r AsyncSearchRequest, fracs fracmanager.List) bool {
+func (as *AsyncSearcher) saveSearchInfo(r AsyncSearchRequest, fracNames []string) bool {
 	as.requestsMu.Lock()
 	defer as.requestsMu.Unlock()
 	if _, ok := as.requests[r.ID]; ok {
 		return false
 	}
-	info := newAsyncSearchInfo(r, fracs)
+	info := newAsyncSearchInfo(r, fracNames)
 	as.storeSearchInfoLocked(r.ID, info)
 	return true
 }
@@ -295,7 +301,7 @@ func (as *AsyncSearcher) createDataDir() {
 	})
 }
 
-func (as *AsyncSearcher) processRequest(asyncSearchID string, fracs fracmanager.List) {
+func (as *AsyncSearcher) processRequest(asyncSearchID string, fracs fractionAcquirer) {
 	defer as.processWg.Done()
 
 	as.rateLimit <- struct{}{}
@@ -305,7 +311,7 @@ func (as *AsyncSearcher) processRequest(asyncSearchID string, fracs fracmanager.
 	asyncSearchActiveSearches.Add(-1)
 }
 
-func (as *AsyncSearcher) doSearch(id string, fracs fracmanager.List) {
+func (as *AsyncSearcher) doSearch(id string, fracs fractionAcquirer) {
 	qprPaths, err := as.findQPRs(id)
 	if err != nil {
 		panic(fmt.Errorf("can't find QPRs for id %q: %s", id, err))
@@ -340,11 +346,6 @@ func (as *AsyncSearcher) doSearch(id string, fracs fracmanager.List) {
 		info.Request.Params.AST = ast.Root
 	}
 
-	fracsByName := make(map[string]frac.Fraction)
-	for _, f := range fracs {
-		fracsByName[f.Info().Name()] = f
-	}
-
 	for _, fracInfo := range info.Fractions {
 		if _, ok := processedFracs[fracInfo.Name]; ok {
 			continue
@@ -352,13 +353,7 @@ func (as *AsyncSearcher) doSearch(id string, fracs fracmanager.List) {
 		if as.shouldStopSearch(id) {
 			break
 		}
-
-		f, ok := fracsByName[fracInfo.Name]
-		if !ok { // oldest fracs may already be removed
-			logger.Info("async search: skip missing fraction", zap.String("id", id), zap.String("frac", fracInfo.Name))
-			continue
-		}
-		if err := as.processFrac(f, info); err != nil {
+		if err := as.acquireAndProcessFrac(fracInfo, info, fracs); err != nil {
 			as.updateSearchInfo(id, func(info *asyncSearchInfo) {
 				info.Error = err.Error()
 			})
@@ -400,6 +395,21 @@ func compressQPR(qpr *seq.QPR, cb func(compressed []byte) error) error {
 	return nil
 }
 
+func (as *AsyncSearcher) acquireAndProcessFrac(fracInfo fracSearchState, searchInfo asyncSearchInfo, fracs fractionAcquirer) (err error) {
+	f, release, ok := fracs.AcquireFraction(fracInfo.Name)
+	defer release()
+
+	if !ok { // oldest fracs may already be removed
+		logger.Info(
+			"async search: skip missing fraction",
+			zap.String("id", searchInfo.Request.ID),
+			zap.String("frac", fracInfo.Name),
+		)
+		return
+	}
+	return as.processFrac(f, searchInfo)
+}
+
 func (as *AsyncSearcher) processFrac(f frac.Fraction, info asyncSearchInfo) (err error) {
 	defer func() {
 		if panicData := util.RecoverToError(recover(), asyncSearchPanics); panicData != nil {
diff --git a/asyncsearcher/async_searcher_test.go b/asyncsearcher/async_searcher_test.go
index f403aa44..8ef37bc3 100644
--- a/asyncsearcher/async_searcher_test.go
+++ b/asyncsearcher/async_searcher_test.go
@@ -11,6 +11,7 @@ import (
 	"github.com/ozontech/seq-db/frac"
 	"github.com/ozontech/seq-db/frac/common"
 	"github.com/ozontech/seq-db/frac/processor"
+	"github.com/ozontech/seq-db/fracmanager"
 	"github.com/ozontech/seq-db/mappingprovider"
 	"github.com/ozontech/seq-db/seq"
 )
@@ -25,6 +26,10 @@ func (f *fakeFrac) Info() *common.Info {
 	return &f.info
 }
 
+func (f *fakeFrac) IsIntersecting(from, to seq.MID) bool {
+	return true
+}
+
 func (f *fakeFrac) Search(context.Context, processor.SearchParams) (*seq.QPR, error) {
 	return &f.dp.qpr, nil
 }
@@ -33,6 +38,21 @@ type fakeDP struct {
 	qpr seq.QPR
 }
 
+type fakeFractionProvider fracmanager.List
+
+func (fp fakeFractionProvider) AcquireFraction(name string) (frac.Fraction, func(), bool) {
+	for _, f := range fp {
+		if f.Info().Name() == name {
+			return f, func() {}, true
+		}
+	}
+	return nil, func() {}, false
+}
+
+func (fp fakeFractionProvider) Fractions() fracmanager.List {
+	return fracmanager.List(fp)
+}
+
 func TestAsyncSearcherMaintain(t *testing.T) {
 	r := require.New(t)
 
@@ -50,7 +70,8 @@ func TestAsyncSearcherMaintain(t *testing.T) {
 		Query:     "*",
 		Retention: time.Hour,
 	}
-	fracs := []frac.Fraction{
+
+	fracs := fakeFractionProvider{
 		&fakeFrac{info: common.Info{Path: "1"}},
 	}
 	r.NoError(as.StartSearch(req, fracs))
diff --git a/fracmanager/fracmanager.go b/fracmanager/fracmanager.go
index b35066a9..6b5b7c87 100644
--- a/fracmanager/fracmanager.go
+++ b/fracmanager/fracmanager.go
@@ -95,6 +95,10 @@ func New(ctx context.Context, cfg *Config, s3cli *s3.Client, skipMaskProvider sk
 	return &fm, stop, nil
 }
 
+func (fm *FracManager) AcquireFraction(name string) (frac.Fraction, func(), bool) {
+	return fm.lc.registry.AcquireFraction(name)
+}
+
 func (fm *FracManager) Fractions() List {
 	return fm.lc.registry.AllFractions()
 }
diff --git a/fracmanager/fraction_registry.go b/fracmanager/fraction_registry.go
index c8a12eef..0f79c28d 100644
--- a/fracmanager/fraction_registry.go
+++ b/fracmanager/fraction_registry.go
@@ -34,6 +34,7 @@ type fractionRegistry struct {
 	muAll  sync.RWMutex    // protects active, all, and oldestTotal fields
 	active *activeProxy    // currently active writable fraction
 	all    []frac.Fraction // all fractions in creation order (read-only view)
+	allMap map[string]frac.Fraction
 }
 
 // NewFractionRegistry creates and initializes a new fraction registry instance.
@@ -82,6 +83,14 @@ func (r *fractionRegistry) Active() *activeProxy {
 	return r.active
 }
 
+func (r *fractionRegistry) AcquireFraction(name string) (frac.Fraction, func(), bool) {
+	r.muAll.RLock()
+	defer r.muAll.RUnlock()
+
+	f, ok := r.allMap[name]
+	return f, func() {}, ok
+}
+
 // AllFractions returns a read-only view of all fractions in creation order.
 func (r *fractionRegistry) AllFractions() []frac.Fraction {
 	r.muAll.RLock()
@@ -215,6 +224,7 @@ func (r *fractionRegistry) addActive(a *activeProxy) {
 
 	r.active = a
 	r.all = append(r.all, a.proxy)
+	r.allMap[a.instance.Info().Name()] = a.proxy
 }
 
 // trimAll removes the oldest fractions from the complete fractions list.
@@ -223,6 +233,9 @@ func (r *fractionRegistry) trimAll(count int) {
 	r.muAll.Lock()
 	defer r.muAll.Unlock()
 
+	for _, f := range r.all[:count] {
+		delete(r.allMap, f.Info().Name())
+	}
 	r.all = r.all[count:]
 	r.updateOldestTotal()
 }
@@ -439,26 +452,34 @@ func (r *fractionRegistry) removeFromOffloading(sealed *sealedProxy) {
 // Expensive O(n) operation used when direct list modification is insufficient.
 func (r *fractionRegistry) rebuildAllFractions() {
 	all := make([]frac.Fraction, 0, len(r.all))
+	allMap := make(map[string]frac.Fraction, len(r.all))
+
+	add := func(f frac.Fraction) {
+		all = append(all, f)
+		allMap[f.Info().Name()] = f
+	}
 
 	// collect fractions in correct chronological order: from oldest (remote) to newest (active)
 	for _, remote := range r.remotes {
-		all = append(all, remote.proxy)
+		add(remote.proxy)
 	}
 	for _, offloaded := range r.offloading {
-		all = append(all, offloaded.proxy)
+		add(offloaded.proxy)
 	}
 	for _, sealed := range r.sealed {
-		all = append(all, sealed.proxy)
+		add(sealed.proxy)
 	}
 	for _, active := range r.sealing {
-		all = append(all, active.proxy)
+		add(active.proxy)
 	}
-	all = append(all, r.active.proxy)
+
+	add(r.active.proxy)
 
 	r.muAll.Lock()
 	defer r.muAll.Unlock()
 
 	r.all = all
+	r.allMap = allMap
 	r.updateOldestTotal()
 }
 
diff --git a/fracmanager/list.go b/fracmanager/list.go
index 078ed02d..dba6c37b 100644
--- a/fracmanager/list.go
+++ b/fracmanager/list.go
@@ -56,7 +56,7 @@ func (l List) Sort(order seq.DocsOrder) {
 }
 
 func (l List) FilterInRange(from, to seq.MID) List {
-	res := make(List, 0)
+	res := make(List, 0, len(l))
 	for _, f := range l {
 		if f.IsIntersecting(from, to) {
 			res = append(res, f)
@@ -71,3 +71,11 @@ func (l *List) Shift(n int) []frac.Fraction {
 	*l = (*l)[n:]
 	return res
 }
+
+func (l List) Names() []string {
+	res := make([]string, 0, len(l))
+	for _, f := range l {
+		res = append(res, f.Info().Name())
+	}
+	return res
+}
diff --git a/skipmaskmanager/skip_mask_manager.go b/skipmaskmanager/skip_mask_manager.go
index 055cca33..47522a91 100644
--- a/skipmaskmanager/skip_mask_manager.go
+++ b/skipmaskmanager/skip_mask_manager.go
@@ -44,6 +44,11 @@ type MappingProvider interface {
 	GetMapping() seq.Mapping
 }
 
+type fractionAcquirer interface {
+	Fractions() fracmanager.List
+	AcquireFraction(name string) (_ frac.Fraction, release func(), ok bool)
+}
+
 // Config holds configuration parameters for SkipMaskManager.
 type Config struct {
 	DataDir        string // Directory to store skip mask files
@@ -137,7 +142,7 @@ func New(
 //   - Begins asynchronous processing of all skip mask queries
 //
 // This method must be called before using the manager.
-func (smm *SkipMaskManager) Start(fracs fracmanager.List) {
+func (smm *SkipMaskManager) Start(fracs fractionAcquirer) {
 	smm.createDataDir()
 
 	err := smm.loadSkipMasks()
@@ -145,7 +150,7 @@ func (smm *SkipMaskManager) Start(fracs fracmanager.List) {
 		logger.Fatal("failed to load previous skip masks", zap.Error(err))
 	}
 
-	err = smm.buildQueue(fracs)
+	err = smm.buildQueue(fracs.Fractions())
 	if err != nil {
 		logger.Fatal("failed to build skip mask manager queue", zap.Error(err))
 	}
@@ -166,7 +171,7 @@ func (smm *SkipMaskManager) Start(fracs fracmanager.List) {
 			}
 			sm.ast = ast
 
-			smm.processSkipMask(sm, fracs.FilterInRange(sm.params.From, sm.params.To))
+			smm.processSkipMask(sm, fracs)
 		}
 	}()
 }
@@ -434,17 +439,7 @@ func (smm *SkipMaskManager) buildQueue(fracs fracmanager.List) error {
 // It processes each fraction with a .queue file, running search queries in parallel
 // (limited by the rate limiter). Each successful search writes results to a .skipmask
 // file. The skip mask status is set to Done when all fractions are processed.
-func (smm *SkipMaskManager) processSkipMask(skipMask *SkipMask, fracs fracmanager.List) {
-	if len(fracs) == 0 {
-		skipMask.setStatus(StatusDone)
-		return
-	}
-
-	fracsByName := make(map[string]frac.Fraction)
-	for _, f := range fracs {
-		fracsByName[f.Info().Name()] = f
-	}
-
+func (smm *SkipMaskManager) processSkipMask(skipMask *SkipMask, fracs fractionAcquirer) {
 	skipMaskDes, err := os.ReadDir(skipMask.dirPath)
 	if err != nil {
 		panic(fmt.Errorf("BUG: reading directory must be successful: %s", err))
@@ -453,11 +448,6 @@ func (smm *SkipMaskManager) processSkipMask(skipMask *SkipMask, fracs fracmanage
 	inProgress.Add(1)
 
 	processFracInQueue := func(name string) error {
-		f, ok := fracsByName[fracNameFromFilePath(name)]
-		if !ok { // skip missing fracs
-			return nil
-		}
-
 		select {
 		case <-smm.ctx.Done():
 			return nil
@@ -466,6 +456,13 @@ func (smm *SkipMaskManager) processSkipMask(skipMask *SkipMask, fracs fracmanage
 			go func() {
 				defer skipMask.processWg.Done()
 				defer func() { <-smm.rateLimit }()
+
+				f, release, ok := fracs.AcquireFraction(fracNameFromFilePath(name))
+				defer release()
+				if !ok { // skip missing fracs
+					return
+				}
+
 				if err := smm.processFrac(f, skipMask); err != nil {
 					if errors.Is(err, context.Canceled) {
 						logger.Info("skip mask manager refresh frac context cancelled")
diff --git a/storeapi/grpc_async_search.go b/storeapi/grpc_async_search.go
index 518ed19f..6f0310d4 100644
--- a/storeapi/grpc_async_search.go
+++ b/storeapi/grpc_async_search.go
@@ -46,8 +46,7 @@ func (g *GrpcV1) StartAsyncSearch(
 		Retention: r.Retention.AsDuration(),
 		WithDocs:  r.WithDocs,
 	}
-	fracs := g.fracManager.Fractions().FilterInRange(seq.MillisToMID(uint64(r.From)), seq.MillisToMID(uint64(r.To)))
-	if err := g.asyncSearcher.StartSearch(req, fracs); err != nil {
+	if err := g.asyncSearcher.StartSearch(req, g.fracManager); err != nil {
 		return nil, err
 	}
 
diff --git a/storeapi/grpc_v1.go b/storeapi/grpc_v1.go
index b9246998..3471b3f0 100644
--- a/storeapi/grpc_v1.go
+++ b/storeapi/grpc_v1.go
@@ -114,10 +114,7 @@ func NewGrpcV1(cfg APIConfig, fracManager *fracmanager.FracManager, mappingProvi
 		fetchData: fetchData{
 			docFetcher: fracmanager.NewFetcher(config.FetchWorkers),
 		},
-		asyncSearcher: asyncsearcher.MustStartAsync(
-			cfg.Search.Async, mappingProvider,
-			fracManager.Fractions(),
-		),
+		asyncSearcher: asyncsearcher.MustStartAsync(cfg.Search.Async, mappingProvider, fracManager),
 	}
 
 	return g
diff --git a/storeapi/store.go b/storeapi/store.go
index 5ea0c5a7..dd53079e 100644
--- a/storeapi/store.go
+++ b/storeapi/store.go
@@ -72,7 +72,7 @@ func NewStore(
 		return nil, fmt.Errorf("loading fractions error: %w", err)
 	}
 
-	skipMaskManager.Start(fracManager.Fractions())
+	skipMaskManager.Start(fracManager)
 
 	return &Store{
 		Config: c,