diff --git a/model/thread.go b/model/thread.go
new file mode 100644
index 0000000000000..76707c5f19002
--- /dev/null
+++ b/model/thread.go
@@ -0,0 +1,24 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"encoding/json"
+)
+
+type Thread struct {
+	PostId       string      `json:"id"`
+	ReplyCount   int64       `json:"reply_count"`
+	LastReplyAt  int64       `json:"last_reply_at"`
+	Participants StringArray `json:"participants"`
+}
+
+func (o *Thread) ToJson() string {
+	b, _ := json.Marshal(o)
+	return string(b)
+}
+
+func (o *Thread) Etag() string {
+	return Etag(o.PostId, o.LastReplyAt)
+}
diff --git a/model/utils.go b/model/utils.go
index 47dd8c36b880a..3aed19da1576c 100644
--- a/model/utils.go
+++ b/model/utils.go
@@ -36,6 +36,26 @@ type StringInterface map[string]interface{}
 type StringMap map[string]string
 type StringArray []string
 
+func (sa StringArray) Remove(input string) StringArray {
+	for index := range sa {
+		if sa[index] == input {
+			ret := make(StringArray, 0, len(sa)-1)
+			ret = append(ret, sa[:index]...)
+			return append(ret, sa[index+1:]...)
+		}
+	}
+	return sa
+}
+
+func (sa StringArray) Contains(input string) bool {
+	for index := range sa {
+		if sa[index] == input {
+			return true
+		}
+	}
+
+	return false
+}
 func (sa StringArray) Equals(input StringArray) bool {
 
 	if len(sa) != len(input) {
diff --git a/store/opentracinglayer/opentracinglayer.go b/store/opentracinglayer/opentracinglayer.go
index ab2a101b91326..cf12ab949903a 100644
--- a/store/opentracinglayer/opentracinglayer.go
+++ b/store/opentracinglayer/opentracinglayer.go
@@ -45,6 +45,7 @@ type OpenTracingLayer struct {
 	SystemStore               store.SystemStore
 	TeamStore                 store.TeamStore
 	TermsOfServiceStore       store.TermsOfServiceStore
+	ThreadStore               store.ThreadStore
 	TokenStore                store.TokenStore
 	UploadSessionStore        store.UploadSessionStore
 	UserStore                 store.UserStore
@@ -161,6 +162,10 @@ func (s *OpenTracingLayer) TermsOfService() store.TermsOfServiceStore {
 	return s.TermsOfServiceStore
 }
 
+func (s *OpenTracingLayer) Thread() store.ThreadStore {
+	return s.ThreadStore
+}
+
 func (s *OpenTracingLayer) Token() store.TokenStore {
 	return s.TokenStore
 }
@@ -320,6 +325,11 @@ type OpenTracingLayerTermsOfServiceStore struct {
 	Root *OpenTracingLayer
 }
 
+type OpenTracingLayerThreadStore struct {
+	store.ThreadStore
+	Root *OpenTracingLayer
+}
+
 type OpenTracingLayerTokenStore struct {
 	store.TokenStore
 	Root *OpenTracingLayer
@@ -7584,6 +7594,96 @@ func (s *OpenTracingLayerTermsOfServiceStore) Save(termsOfService *model.TermsOf
 	return result, err
 }
 
+func (s *OpenTracingLayerThreadStore) Delete(postId string) error {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ThreadStore.Delete")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	err := s.ThreadStore.Delete(postId)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return err
+}
+
+func (s *OpenTracingLayerThreadStore) Get(id string) (*model.Thread, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ThreadStore.Get")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, err := s.ThreadStore.Get(id)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, err
+}
+
+func (s *OpenTracingLayerThreadStore) Save(thread *model.Thread) (*model.Thread, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ThreadStore.Save")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, err := s.ThreadStore.Save(thread)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, err
+}
+
+func (s *OpenTracingLayerThreadStore) SaveMultiple(thread []*model.Thread) ([]*model.Thread, int, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ThreadStore.SaveMultiple")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, resultVar1, err := s.ThreadStore.SaveMultiple(thread)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, resultVar1, err
+}
+
+func (s *OpenTracingLayerThreadStore) Update(thread *model.Thread) (*model.Thread, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ThreadStore.Update")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, err := s.ThreadStore.Update(thread)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, err
+}
+
 func (s *OpenTracingLayerTokenStore) Cleanup() {
 	origCtx := s.Root.Store.Context()
 	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "TokenStore.Cleanup")
@@ -9730,6 +9830,7 @@ func New(childStore store.Store, ctx context.Context) *OpenTracingLayer {
 	newStore.SystemStore = &OpenTracingLayerSystemStore{SystemStore: childStore.System(), Root: &newStore}
 	newStore.TeamStore = &OpenTracingLayerTeamStore{TeamStore: childStore.Team(), Root: &newStore}
 	newStore.TermsOfServiceStore = &OpenTracingLayerTermsOfServiceStore{TermsOfServiceStore: childStore.TermsOfService(), Root: &newStore}
+	newStore.ThreadStore = &OpenTracingLayerThreadStore{ThreadStore: childStore.Thread(), Root: &newStore}
 	newStore.TokenStore = &OpenTracingLayerTokenStore{TokenStore: childStore.Token(), Root: &newStore}
 	newStore.UploadSessionStore = &OpenTracingLayerUploadSessionStore{UploadSessionStore: childStore.UploadSession(), Root: &newStore}
 	newStore.UserStore = &OpenTracingLayerUserStore{UserStore: childStore.User(), Root: &newStore}
diff --git a/store/retrylayer/retrylayer.go b/store/retrylayer/retrylayer.go
index af57bb5f1898a..c896d5763e405 100644
--- a/store/retrylayer/retrylayer.go
+++ b/store/retrylayer/retrylayer.go
@@ -47,6 +47,7 @@ type RetryLayer struct {
 	SystemStore               store.SystemStore
 	TeamStore                 store.TeamStore
 	TermsOfServiceStore       store.TermsOfServiceStore
+	ThreadStore               store.ThreadStore
 	TokenStore                store.TokenStore
 	UploadSessionStore        store.UploadSessionStore
 	UserStore                 store.UserStore
@@ -163,6 +164,10 @@ func (s *RetryLayer) TermsOfService() store.TermsOfServiceStore {
 	return s.TermsOfServiceStore
 }
 
+func (s *RetryLayer) Thread() store.ThreadStore {
+	return s.ThreadStore
+}
+
 func (s *RetryLayer) Token() store.TokenStore {
 	return s.TokenStore
 }
@@ -322,6 +327,11 @@ type RetryLayerTermsOfServiceStore struct {
 	Root *RetryLayer
 }
 
+type RetryLayerThreadStore struct {
+	store.ThreadStore
+	Root *RetryLayer
+}
+
 type RetryLayerTokenStore struct {
 	store.TokenStore
 	Root *RetryLayer
@@ -7192,6 +7202,106 @@ func (s *RetryLayerTermsOfServiceStore) Save(termsOfService *model.TermsOfServic
 
 }
 
+func (s *RetryLayerThreadStore) Delete(postId string) error {
+
+	tries := 0
+	for {
+		err := s.ThreadStore.Delete(postId)
+		if err == nil {
+			return nil
+		}
+		if !isRepeatableError(err) {
+			return err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return err
+		}
+	}
+
+}
+
+func (s *RetryLayerThreadStore) Get(id string) (*model.Thread, error) {
+
+	tries := 0
+	for {
+		result, err := s.ThreadStore.Get(id)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+	}
+
+}
+
+func (s *RetryLayerThreadStore) Save(thread *model.Thread) (*model.Thread, error) {
+
+	tries := 0
+	for {
+		result, err := s.ThreadStore.Save(thread)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+	}
+
+}
+
+func (s *RetryLayerThreadStore) SaveMultiple(thread []*model.Thread) ([]*model.Thread, int, error) {
+
+	tries := 0
+	for {
+		result, resultVar1, err := s.ThreadStore.SaveMultiple(thread)
+		if err == nil {
+			return result, resultVar1, nil
+		}
+		if !isRepeatableError(err) {
+			return result, resultVar1, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, resultVar1, err
+		}
+	}
+
+}
+
+func (s *RetryLayerThreadStore) Update(thread *model.Thread) (*model.Thread, error) {
+
+	tries := 0
+	for {
+		result, err := s.ThreadStore.Update(thread)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+	}
+
+}
+
 func (s *RetryLayerTokenStore) Cleanup() {
 
 	s.TokenStore.Cleanup()
@@ -8644,6 +8754,7 @@ func New(childStore store.Store) *RetryLayer {
 	newStore.SystemStore = &RetryLayerSystemStore{SystemStore: childStore.System(), Root: &newStore}
 	newStore.TeamStore = &RetryLayerTeamStore{TeamStore: childStore.Team(), Root: &newStore}
 	newStore.TermsOfServiceStore = &RetryLayerTermsOfServiceStore{TermsOfServiceStore: childStore.TermsOfService(), Root: &newStore}
+	newStore.ThreadStore = &RetryLayerThreadStore{ThreadStore: childStore.Thread(), Root: &newStore}
 	newStore.TokenStore = &RetryLayerTokenStore{TokenStore: childStore.Token(), Root: &newStore}
 	newStore.UploadSessionStore = &RetryLayerUploadSessionStore{UploadSessionStore: childStore.UploadSession(), Root: &newStore}
 	newStore.UserStore = &RetryLayerUserStore{UserStore: childStore.User(), Root: &newStore}
diff --git a/store/retrylayer/retrylayer_test.go b/store/retrylayer/retrylayer_test.go
index 5224057637d37..d48b7f67197d4 100644
--- a/store/retrylayer/retrylayer_test.go
+++ b/store/retrylayer/retrylayer_test.go
@@ -33,6 +33,7 @@ func genStore() *mocks.Store {
 	mock.On("OAuth").Return(&mocks.OAuthStore{})
 	mock.On("Plugin").Return(&mocks.PluginStore{})
 	mock.On("Post").Return(&mocks.PostStore{})
+	mock.On("Thread").Return(&mocks.ThreadStore{})
 	mock.On("Preference").Return(&mocks.PreferenceStore{})
 	mock.On("ProductNotices").Return(&mocks.ProductNoticesStore{})
 	mock.On("Reaction").Return(&mocks.ReactionStore{})
diff --git a/store/sqlstore/post_store.go b/store/sqlstore/post_store.go
index a737fdfb0d8ad..c4a6a8ce5b948 100644
--- a/store/sqlstore/post_store.go
+++ b/store/sqlstore/post_store.go
@@ -11,15 +11,15 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/mattermost/mattermost-server/v5/store/searchlayer"
-
 	sq "github.com/Masterminds/squirrel"
+	"github.com/mattermost/gorp"
 	"github.com/pkg/errors"
 
 	"github.com/mattermost/mattermost-server/v5/einterfaces"
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/store"
+	"github.com/mattermost/mattermost-server/v5/store/searchlayer"
 	"github.com/mattermost/mattermost-server/v5/utils"
 )
 
@@ -159,18 +159,34 @@ func (s *SqlPostStore) SaveMultiple(posts []*model.Post) ([]*model.Post, int, er
 		return nil, -1, errors.Wrap(err, "post_tosql")
 	}
 
-	if _, err := s.GetMaster().Exec(query, args...); err != nil {
+	transaction, err := s.GetMaster().Begin()
+	if err != nil {
+		return posts, -1, errors.Wrap(err, "begin_transaction")
+	}
+
+	defer finalizeTransaction(transaction)
+
+	if _, err = transaction.Exec(query, args...); err != nil {
 		return nil, -1, errors.Wrap(err, "failed to save Post")
 	}
 
+	if err = s.updateThreadsFromPosts(transaction, posts); err != nil {
+		mlog.Error("Error updating posts, thread update failed", mlog.Err(err))
+	}
+
+	if err = transaction.Commit(); err != nil {
+		// don't need to rollback here since the transaction is already closed
+		return posts, -1, errors.Wrap(err, "commit_transaction")
+	}
+
 	for channelId, count := range channelNewPosts {
-		if _, err := s.GetMaster().Exec("UPDATE Channels SET LastPostAt = GREATEST(:LastPostAt, LastPostAt), TotalMsgCount = TotalMsgCount + :Count WHERE Id = :ChannelId", map[string]interface{}{"LastPostAt": maxDateNewPosts[channelId], "ChannelId": channelId, "Count": count}); err != nil {
+		if _, err = s.GetMaster().Exec("UPDATE Channels SET LastPostAt = GREATEST(:LastPostAt, LastPostAt), TotalMsgCount = TotalMsgCount + :Count WHERE Id = :ChannelId", map[string]interface{}{"LastPostAt": maxDateNewPosts[channelId], "ChannelId": channelId, "Count": count}); err != nil {
 			mlog.Error("Error updating Channel LastPostAt.", mlog.Err(err))
 		}
 	}
 
 	for rootId := range rootIds {
-		if _, err := s.GetMaster().Exec("UPDATE Posts SET UpdateAt = :UpdateAt WHERE Id = :RootId", map[string]interface{}{"UpdateAt": maxDateRootIds[rootId], "RootId": rootId}); err != nil {
+		if _, err = s.GetMaster().Exec("UPDATE Posts SET UpdateAt = :UpdateAt WHERE Id = :RootId", map[string]interface{}{"UpdateAt": maxDateRootIds[rootId], "RootId": rootId}); err != nil {
 			mlog.Error("Error updating Post UpdateAt.", mlog.Err(err))
 		}
 	}
@@ -265,6 +281,7 @@ func (s *SqlPostStore) Update(newPost *model.Post, oldPost *model.Post) (*model.
 
 	if len(newPost.RootId) > 0 {
 		s.GetMaster().Exec("UPDATE Posts SET UpdateAt = :UpdateAt WHERE Id = :RootId AND UpdateAt < :UpdateAt", map[string]interface{}{"UpdateAt": time, "RootId": newPost.RootId})
+		s.GetMaster().Exec("UPDATE Threads SET LastReplyAt = :UpdateAt WHERE PostId = :RootId", map[string]interface{}{"UpdateAt": time, "RootId": newPost.RootId})
 	}
 
 	// mark the old post as deleted
@@ -296,6 +313,9 @@ func (s *SqlPostStore) OverwriteMultiple(posts []*model.Post) ([]*model.Post, in
 
 			return nil, idx, errors.Wrap(err, "failed to update Post")
 		}
+		if len(post.RootId) > 0 {
+			tx.Exec("UPDATE Threads SET LastReplyAt = :UpdateAt WHERE PostId = :RootId", map[string]interface{}{"UpdateAt": updateAt, "RootId": post.Id})
+		}
 	}
 	err = tx.Commit()
 	if err != nil {
@@ -495,19 +515,49 @@ func (s *SqlPostStore) Delete(postId string, time int64, deleteByID string) erro
 		return errors.Wrap(err, "failed to update Posts")
 	}
 
-	return nil
+	return s.cleanupThreads(post.Id, post.RootId, post.UserId)
 }
 
 func (s *SqlPostStore) permanentDelete(postId string) error {
-	_, err := s.GetMaster().Exec("DELETE FROM Posts WHERE Id = :Id OR RootId = :RootId", map[string]interface{}{"Id": postId, "RootId": postId})
-	if err != nil {
+	var post model.Post
+	err := s.GetReplica().SelectOne(&post, "SELECT * FROM Posts WHERE Id = :Id AND DeleteAt = 0", map[string]interface{}{"Id": postId})
+	if err != nil && err != sql.ErrNoRows {
+		if err != sql.ErrNoRows {
+			return errors.Wrapf(err, "failed to get Post with id=%s", postId)
+		}
+
+		if err = s.cleanupThreads(post.Id, post.RootId, post.UserId); err != nil {
+			return errors.Wrapf(err, "failed to cleanup threads for Post with id=%s", postId)
+		}
+	}
+
+	if _, err = s.GetMaster().Exec("DELETE FROM Posts WHERE Id = :Id OR RootId = :RootId", map[string]interface{}{"Id": postId, "RootId": postId}); err != nil {
 		return errors.Wrapf(err, "failed to delete Post with id=%s", postId)
 	}
+
 	return nil
 }
 
+type postIds struct {
+	Id     string
+	RootId string
+	UserId string
+}
+
 func (s *SqlPostStore) permanentDeleteAllCommentByUser(userId string) error {
-	_, err := s.GetMaster().Exec("DELETE FROM Posts WHERE UserId = :UserId AND RootId != ''", map[string]interface{}{"UserId": userId})
+	results := []postIds{}
+	_, err := s.GetMaster().Select(&results, "Select Id, RootId FROM Posts WHERE UserId = :UserId AND RootId != ''", map[string]interface{}{"UserId": userId})
+	if err != nil {
+		return errors.Wrapf(err, "failed to fetch Posts with userId=%s", userId)
+	}
+
+	for _, ids := range results {
+		if err = s.cleanupThreads(ids.Id, ids.RootId, userId); err != nil {
+			return err
+		}
+	}
+
+	_, err = s.GetMaster().Exec("DELETE FROM Posts WHERE UserId = :UserId AND RootId != ''", map[string]interface{}{"UserId": userId})
 	if err != nil {
 		return errors.Wrapf(err, "failed to delete Posts with userId=%s", userId)
 	}
@@ -551,6 +601,18 @@ func (s *SqlPostStore) PermanentDeleteByUser(userId string) error {
 }
 
 func (s *SqlPostStore) PermanentDeleteByChannel(channelId string) error {
+	results := []postIds{}
+	_, err := s.GetMaster().Select(&results, "SELECT Id, RootId, UserId FROM Posts WHERE ChannelId = :ChannelId", map[string]interface{}{"ChannelId": channelId})
+	if err != nil {
+		return errors.Wrapf(err, "failed to fetch Posts with channelId=%s", channelId)
+	}
+
+	for _, ids := range results {
+		if err = s.cleanupThreads(ids.Id, ids.RootId, ids.UserId); err != nil {
+			return err
+		}
+	}
+
 	if _, err := s.GetMaster().Exec("DELETE FROM Posts WHERE ChannelId = :ChannelId", map[string]interface{}{"ChannelId": channelId}); err != nil {
 		return errors.Wrapf(err, "failed to delete Posts with channelId=%s", channelId)
 	}
@@ -1858,3 +1920,90 @@ func (s *SqlPostStore) GetOldestEntityCreationTime() (int64, error) {
 	}
 	return oldest, nil
 }
+
+func (s *SqlPostStore) cleanupThreads(postId, rootId, userId string) error {
+	if len(rootId) > 0 {
+		thread, err := s.Thread().Get(rootId)
+		if err != nil {
+			if err != sql.ErrNoRows {
+				return errors.Wrap(err, "failed to get a thread")
+			}
+		}
+		if thread != nil {
+			thread.ReplyCount -= 1
+			thread.Participants = thread.Participants.Remove(userId)
+			if _, err = s.Thread().Update(thread); err != nil {
+				return errors.Wrap(err, "failed to update thread")
+			}
+		}
+	}
+	_, err := s.GetMaster().Exec("DELETE FROM Threads WHERE PostId = :Id", map[string]interface{}{"Id": postId})
+	if err != nil {
+		return errors.Wrap(err, "failed to update Threads")
+	}
+	return nil
+}
+
+func (s *SqlPostStore) updateThreadsFromPosts(transaction *gorp.Transaction, posts []*model.Post) error {
+	postsByRoot := map[string][]*model.Post{}
+	var rootIds []string
+	for _, post := range posts {
+		// skip if post is not a part of a thread
+		if len(post.RootId) == 0 {
+			continue
+		}
+		rootIds = append(rootIds, post.RootId)
+		postsByRoot[post.RootId] = append(postsByRoot[post.RootId], post)
+	}
+	if len(rootIds) == 0 {
+		return nil
+	}
+	now := model.GetMillis()
+	threadsByRootsSql, threadsByRootsArgs, _ := s.getQueryBuilder().Select("*").From("Threads").Where(sq.Eq{"PostId": rootIds}).ToSql()
+	var threadsByRoots []*model.Thread
+	if _, err := transaction.Select(&threadsByRoots, threadsByRootsSql, threadsByRootsArgs...); err != nil {
+		return err
+	}
+
+	threadByRoot := map[string]*model.Thread{}
+	for _, thread := range threadsByRoots {
+		threadByRoot[thread.PostId] = thread
+	}
+
+	for rootId, posts := range postsByRoot {
+		if thread, found := threadByRoot[rootId]; !found {
+			// calculate participants
+			var participants model.StringArray
+			if _, err := transaction.Select(&participants, "SELECT DISTINCT UserId FROM Posts WHERE RootId=:RootId", map[string]interface{}{"RootId": rootId}); err != nil {
+				return err
+			}
+			// calculate reply count
+			count, err := transaction.SelectInt("SELECT COUNT(Id) FROM Posts WHERE RootId=:RootId", map[string]interface{}{"RootId": rootId})
+			if err != nil {
+				return err
+			}
+			// no metadata entry, create one
+			if err := transaction.Insert(&model.Thread{
+				PostId:       rootId,
+				ReplyCount:   count,
+				LastReplyAt:  now,
+				Participants: participants,
+			}); err != nil {
+				return err
+			}
+		} else {
+			// metadata exists, update it
+			thread.LastReplyAt = now
+			for _, post := range posts {
+				thread.ReplyCount += 1
+				if !thread.Participants.Contains(post.UserId) {
+					thread.Participants = append(thread.Participants, post.UserId)
+				}
+			}
+			if _, err := transaction.Update(thread); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
diff --git a/store/sqlstore/store.go b/store/sqlstore/store.go
index 21aadd05ce26c..bd24ce38ab537 100644
--- a/store/sqlstore/store.go
+++ b/store/sqlstore/store.go
@@ -75,6 +75,7 @@ type SqlStore interface {
 	Team() store.TeamStore
 	Channel() store.ChannelStore
 	Post() store.PostStore
+	Thread() store.ThreadStore
 	User() store.UserStore
 	Bot() store.BotStore
 	Audit() store.AuditStore
diff --git a/store/sqlstore/supplier.go b/store/sqlstore/supplier.go
index 8304d70a6130c..921a7fbfb1a0d 100644
--- a/store/sqlstore/supplier.go
+++ b/store/sqlstore/supplier.go
@@ -72,6 +72,7 @@ type SqlSupplierStores struct {
 	team                 store.TeamStore
 	channel              store.ChannelStore
 	post                 store.PostStore
+	thread               store.ThreadStore
 	user                 store.UserStore
 	bot                  store.BotStore
 	audit                store.AuditStore
@@ -160,6 +161,7 @@ func NewSqlSupplier(settings model.SqlSettings, metrics einterfaces.MetricsInter
 	supplier.stores.status = newSqlStatusStore(supplier)
 	supplier.stores.fileInfo = newSqlFileInfoStore(supplier, metrics)
 	supplier.stores.uploadSession = newSqlUploadSessionStore(supplier)
+	supplier.stores.thread = newSqlThreadStore(supplier)
 	supplier.stores.job = newSqlJobStore(supplier)
 	supplier.stores.userAccessToken = newSqlUserAccessTokenStore(supplier)
 	supplier.stores.channelMemberHistory = newSqlChannelMemberHistoryStore(supplier)
@@ -189,6 +191,7 @@ func NewSqlSupplier(settings model.SqlSettings, metrics einterfaces.MetricsInter
 	supplier.stores.team.(*SqlTeamStore).createIndexesIfNotExists()
 	supplier.stores.channel.(*SqlChannelStore).createIndexesIfNotExists()
 	supplier.stores.post.(*SqlPostStore).createIndexesIfNotExists()
+	supplier.stores.thread.(*SqlThreadStore).createIndexesIfNotExists()
 	supplier.stores.user.(*SqlUserStore).createIndexesIfNotExists()
 	supplier.stores.bot.(*SqlBotStore).createIndexesIfNotExists()
 	supplier.stores.audit.(*SqlAuditStore).createIndexesIfNotExists()
@@ -1163,6 +1166,10 @@ func (ss *SqlSupplier) Plugin() store.PluginStore {
 	return ss.stores.plugin
 }
 
+func (ss *SqlSupplier) Thread() store.ThreadStore {
+	return ss.stores.thread
+}
+
 func (ss *SqlSupplier) Role() store.RoleStore {
 	return ss.stores.role
 }
diff --git a/store/sqlstore/thread_store.go b/store/sqlstore/thread_store.go
new file mode 100644
index 0000000000000..3254076a7a112
--- /dev/null
+++ b/store/sqlstore/thread_store.go
@@ -0,0 +1,108 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package sqlstore
+
+import (
+	"database/sql"
+	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/store"
+	"github.com/pkg/errors"
+
+	sq "github.com/Masterminds/squirrel"
+)
+
+type SqlThreadStore struct {
+	SqlStore
+}
+
+func (s *SqlThreadStore) ClearCaches() {
+}
+
+func newSqlThreadStore(sqlStore SqlStore) store.ThreadStore {
+	s := &SqlThreadStore{
+		SqlStore: sqlStore,
+	}
+
+	for _, db := range sqlStore.GetAllConns() {
+		table := db.AddTableWithName(model.Thread{}, "Threads").SetKeys(false, "PostId")
+		table.ColMap("PostId").SetMaxSize(26)
+		table.ColMap("Participants").SetMaxSize(0)
+	}
+
+	return s
+}
+
+func threadSliceColumns() []string {
+	return []string{"PostId", "LastReplyAt", "ReplyCount", "Participants"}
+}
+
+func threadToSlice(thread *model.Thread) []interface{} {
+	return []interface{}{
+		thread.PostId,
+		thread.LastReplyAt,
+		thread.ReplyCount,
+		thread.Participants,
+	}
+}
+
+func (s *SqlThreadStore) createIndexesIfNotExists() {
+	s.CreateIndexIfNotExists("idx_threads_last_reply_at", "Threads", "LastReplyAt")
+	s.CreateIndexIfNotExists("idx_threads_post_id", "Threads", "PostId")
+}
+
+func (s *SqlThreadStore) SaveMultiple(threads []*model.Thread) ([]*model.Thread, int, error) {
+	builder := s.getQueryBuilder().Insert("Threads").Columns(threadSliceColumns()...)
+	for _, thread := range threads {
+		builder = builder.Values(threadToSlice(thread)...)
+	}
+	query, args, err := builder.ToSql()
+	if err != nil {
+		return nil, -1, errors.Wrap(err, "thread_tosql")
+	}
+
+	if _, err := s.GetMaster().Exec(query, args...); err != nil {
+		return nil, -1, errors.Wrap(err, "failed to save Post")
+	}
+
+	return threads, -1, nil
+}
+
+func (s *SqlThreadStore) Save(thread *model.Thread) (*model.Thread, error) {
+	threads, _, err := s.SaveMultiple([]*model.Thread{thread})
+	if err != nil {
+		return nil, err
+	}
+	return threads[0], nil
+}
+
+func (s *SqlThreadStore) Update(thread *model.Thread) (*model.Thread, error) {
+	if _, err := s.GetMaster().Update(thread); err != nil {
+		return nil, errors.Wrapf(err, "failed to update thread with id=%s", thread.PostId)
+	}
+
+	return thread, nil
+}
+
+func (s *SqlThreadStore) Get(id string) (*model.Thread, error) {
+	var thread model.Thread
+	query, args, _ := s.getQueryBuilder().Select("*").From("Threads").Where(sq.Eq{"PostId": id}).ToSql()
+	err := s.GetReplica().SelectOne(&thread, query, args...)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, store.NewErrNotFound("Thread", id)
+		}
+
+		return nil, errors.Wrapf(err, "failed to get thread with id=%s", id)
+	}
+	return &thread, nil
+}
+
+func (s *SqlThreadStore) Delete(threadId string) error {
+	query, args, _ := s.getQueryBuilder().Delete("Threads").Where(sq.Eq{"PostId": threadId}).ToSql()
+	if _, err := s.GetMaster().Exec(query, args...); err != nil {
+		return errors.Wrap(err, "failed to update threads")
+	}
+
+	return nil
+}
diff --git a/store/sqlstore/thread_store_test.go b/store/sqlstore/thread_store_test.go
new file mode 100644
index 0000000000000..82b399b3cbd69
--- /dev/null
+++ b/store/sqlstore/thread_store_test.go
@@ -0,0 +1,14 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package sqlstore
+
+import (
+	"testing"
+
+	"github.com/mattermost/mattermost-server/v5/store/storetest"
+)
+
+func TestThreadStore(t *testing.T) {
+	StoreTestWithSqlSupplier(t, storetest.TestThreadStore)
+}
diff --git a/store/store.go b/store/store.go
index 20d81f60d3239..81e050da901c2 100644
--- a/store/store.go
+++ b/store/store.go
@@ -24,6 +24,7 @@ type Store interface {
 	Team() TeamStore
 	Channel() ChannelStore
 	Post() PostStore
+	Thread() ThreadStore
 	User() UserStore
 	Bot() BotStore
 	Audit() AuditStore
@@ -245,6 +246,13 @@ type ChannelMemberHistoryStore interface {
 	GetUsersInChannelDuring(startTime int64, endTime int64, channelId string) ([]*model.ChannelMemberHistoryResult, error)
 	PermanentDeleteBatch(endTime int64, limit int64) (int64, error)
 }
+type ThreadStore interface {
+	SaveMultiple(thread []*model.Thread) ([]*model.Thread, int, error)
+	Save(thread *model.Thread) (*model.Thread, error)
+	Update(thread *model.Thread) (*model.Thread, error)
+	Get(id string) (*model.Thread, error)
+	Delete(postId string) error
+}
 
 type PostStore interface {
 	SaveMultiple(posts []*model.Post) ([]*model.Post, int, error)
diff --git a/store/storetest/mocks/SqlStore.go b/store/storetest/mocks/SqlStore.go
index db6c129331324..629308fbcc432 100644
--- a/store/storetest/mocks/SqlStore.go
+++ b/store/storetest/mocks/SqlStore.go
@@ -782,6 +782,22 @@ func (_m *SqlStore) TermsOfService() store.TermsOfServiceStore {
 	return r0
 }
 
+// Thread provides a mock function with given fields:
+func (_m *SqlStore) Thread() store.ThreadStore {
+	ret := _m.Called()
+
+	var r0 store.ThreadStore
+	if rf, ok := ret.Get(0).(func() store.ThreadStore); ok {
+		r0 = rf()
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(store.ThreadStore)
+		}
+	}
+
+	return r0
+}
+
 // Token provides a mock function with given fields:
 func (_m *SqlStore) Token() store.TokenStore {
 	ret := _m.Called()
diff --git a/store/storetest/mocks/Store.go b/store/storetest/mocks/Store.go
index cdfb63221eee7..45ed48e2a9ad2 100644
--- a/store/storetest/mocks/Store.go
+++ b/store/storetest/mocks/Store.go
@@ -549,6 +549,22 @@ func (_m *Store) TermsOfService() store.TermsOfServiceStore {
 	return r0
 }
 
+// Thread provides a mock function with given fields:
+func (_m *Store) Thread() store.ThreadStore {
+	ret := _m.Called()
+
+	var r0 store.ThreadStore
+	if rf, ok := ret.Get(0).(func() store.ThreadStore); ok {
+		r0 = rf()
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(store.ThreadStore)
+		}
+	}
+
+	return r0
+}
+
 // Token provides a mock function with given fields:
 func (_m *Store) Token() store.TokenStore {
 	ret := _m.Called()
diff --git a/store/storetest/mocks/ThreadStore.go b/store/storetest/mocks/ThreadStore.go
new file mode 100644
index 0000000000000..5050c688305cf
--- /dev/null
+++ b/store/storetest/mocks/ThreadStore.go
@@ -0,0 +1,128 @@
+// Code generated by mockery v1.0.0. DO NOT EDIT.
+
+// Regenerate this file using `make store-mocks`.
+
+package mocks
+
+import (
+	model "github.com/mattermost/mattermost-server/v5/model"
+	mock "github.com/stretchr/testify/mock"
+)
+
+// ThreadStore is an autogenerated mock type for the ThreadStore type
+type ThreadStore struct {
+	mock.Mock
+}
+
+// Delete provides a mock function with given fields: postId
+func (_m *ThreadStore) Delete(postId string) error {
+	ret := _m.Called(postId)
+
+	var r0 error
+	if rf, ok := ret.Get(0).(func(string) error); ok {
+		r0 = rf(postId)
+	} else {
+		r0 = ret.Error(0)
+	}
+
+	return r0
+}
+
+// Get provides a mock function with given fields: id
+func (_m *ThreadStore) Get(id string) (*model.Thread, error) {
+	ret := _m.Called(id)
+
+	var r0 *model.Thread
+	if rf, ok := ret.Get(0).(func(string) *model.Thread); ok {
+		r0 = rf(id)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*model.Thread)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(string) error); ok {
+		r1 = rf(id)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// Save provides a mock function with given fields: thread
+func (_m *ThreadStore) Save(thread *model.Thread) (*model.Thread, error) {
+	ret := _m.Called(thread)
+
+	var r0 *model.Thread
+	if rf, ok := ret.Get(0).(func(*model.Thread) *model.Thread); ok {
+		r0 = rf(thread)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*model.Thread)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(*model.Thread) error); ok {
+		r1 = rf(thread)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// SaveMultiple provides a mock function with given fields: thread
+func (_m *ThreadStore) SaveMultiple(thread []*model.Thread) ([]*model.Thread, int, error) {
+	ret := _m.Called(thread)
+
+	var r0 []*model.Thread
+	if rf, ok := ret.Get(0).(func([]*model.Thread) []*model.Thread); ok {
+		r0 = rf(thread)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]*model.Thread)
+		}
+	}
+
+	var r1 int
+	if rf, ok := ret.Get(1).(func([]*model.Thread) int); ok {
+		r1 = rf(thread)
+	} else {
+		r1 = ret.Get(1).(int)
+	}
+
+	var r2 error
+	if rf, ok := ret.Get(2).(func([]*model.Thread) error); ok {
+		r2 = rf(thread)
+	} else {
+		r2 = ret.Error(2)
+	}
+
+	return r0, r1, r2
+}
+
+// Update provides a mock function with given fields: thread
+func (_m *ThreadStore) Update(thread *model.Thread) (*model.Thread, error) {
+	ret := _m.Called(thread)
+
+	var r0 *model.Thread
+	if rf, ok := ret.Get(0).(func(*model.Thread) *model.Thread); ok {
+		r0 = rf(thread)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*model.Thread)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(*model.Thread) error); ok {
+		r1 = rf(thread)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
diff --git a/store/storetest/store.go b/store/storetest/store.go
index 43beb2d0d88e7..1889d707c81d9 100644
--- a/store/storetest/store.go
+++ b/store/storetest/store.go
@@ -33,6 +33,7 @@ type Store struct {
 	LicenseStore              mocks.LicenseStore
 	TokenStore                mocks.TokenStore
 	EmojiStore                mocks.EmojiStore
+	ThreadStore               mocks.ThreadStore
 	StatusStore               mocks.StatusStore
 	FileInfoStore             mocks.FileInfoStore
 	UploadSessionStore        mocks.UploadSessionStore
@@ -72,6 +73,7 @@ func (s *Store) Preference() store.PreferenceStore                 { return &s.P
 func (s *Store) License() store.LicenseStore                       { return &s.LicenseStore }
 func (s *Store) Token() store.TokenStore                           { return &s.TokenStore }
 func (s *Store) Emoji() store.EmojiStore                           { return &s.EmojiStore }
+func (s *Store) Thread() store.ThreadStore                         { return &s.ThreadStore }
 func (s *Store) Status() store.StatusStore                         { return &s.StatusStore }
 func (s *Store) FileInfo() store.FileInfoStore                     { return &s.FileInfoStore }
 func (s *Store) UploadSession() store.UploadSessionStore           { return &s.UploadSessionStore }
@@ -133,6 +135,7 @@ func (s *Store) AssertExpectations(t mock.TestingT) bool {
 		&s.PluginStore,
 		&s.RoleStore,
 		&s.SchemeStore,
+		&s.ThreadStore,
 		&s.ProductNoticesStore,
 	)
 }
diff --git a/store/storetest/thread_store.go b/store/storetest/thread_store.go
new file mode 100644
index 0000000000000..62edf5e2c195d
--- /dev/null
+++ b/store/storetest/thread_store.go
@@ -0,0 +1,200 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package storetest
+
+import (
+	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/store"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestThreadStore(t *testing.T, ss store.Store, s SqlSupplier) {
+	t.Run("ThreadStorePopulation", func(t *testing.T) { testThreadStorePopulation(t, ss) })
+}
+
+func testThreadStorePopulation(t *testing.T, ss store.Store) {
+	makeSomePosts := func() []*model.Post {
+		o1 := model.Post{}
+		o1.ChannelId = model.NewId()
+		o1.UserId = model.NewId()
+		o1.RootId = model.NewId()
+		o1.Message = "zz" + model.NewId() + "b"
+
+		o2 := model.Post{}
+		o2.ChannelId = model.NewId()
+		o2.UserId = model.NewId()
+		o2.RootId = o1.RootId
+		o2.Message = "zz" + model.NewId() + "b"
+
+		o3 := model.Post{}
+		o3.ChannelId = model.NewId()
+		o3.UserId = model.NewId()
+		o3.RootId = model.NewId()
+		o3.Message = "zz" + model.NewId() + "b"
+
+		o4 := model.Post{}
+		o4.ChannelId = model.NewId()
+		o4.UserId = model.NewId()
+		o4.Message = "zz" + model.NewId() + "b"
+
+		newPosts, errIdx, err := ss.Post().SaveMultiple([]*model.Post{&o1, &o2, &o3, &o4})
+		require.Nil(t, err, "couldn't save item")
+		require.Equal(t, -1, errIdx)
+		require.Len(t, newPosts, 4)
+		require.Equal(t, int64(2), newPosts[0].ReplyCount)
+		require.Equal(t, int64(2), newPosts[1].ReplyCount)
+		require.Equal(t, int64(1), newPosts[2].ReplyCount)
+		require.Equal(t, int64(0), newPosts[3].ReplyCount)
+		return newPosts
+	}
+	t.Run("Save replies creates a thread", func(t *testing.T) {
+		newPosts := makeSomePosts()
+		thread, err := ss.Thread().Get(newPosts[0].RootId)
+		require.Nil(t, err, "couldn't get thread")
+		require.NotNil(t, thread)
+		require.Equal(t, int64(2), thread.ReplyCount)
+		require.ElementsMatch(t, model.StringArray{newPosts[0].UserId, newPosts[1].UserId}, thread.Participants)
+
+		o5 := model.Post{}
+		o5.ChannelId = model.NewId()
+		o5.UserId = model.NewId()
+		o5.RootId = newPosts[0].RootId
+		o5.Message = "zz" + model.NewId() + "b"
+
+		_, _, err = ss.Post().SaveMultiple([]*model.Post{&o5})
+		require.Nil(t, err, "couldn't save item")
+
+		thread, err = ss.Thread().Get(newPosts[0].RootId)
+		require.Nil(t, err, "couldn't get thread")
+		require.NotNil(t, thread)
+		require.Equal(t, int64(3), thread.ReplyCount)
+		require.ElementsMatch(t, model.StringArray{newPosts[0].UserId, newPosts[1].UserId, o5.UserId}, thread.Participants)
+	})
+
+	t.Run("Delete a reply updates count on a thread", func(t *testing.T) {
+		newPosts := makeSomePosts()
+		thread, err := ss.Thread().Get(newPosts[0].RootId)
+		require.Nil(t, err, "couldn't get thread")
+		require.NotNil(t, thread)
+		require.Equal(t, int64(2), thread.ReplyCount)
+		require.ElementsMatch(t, model.StringArray{newPosts[0].UserId, newPosts[1].UserId}, thread.Participants)
+
+		err = ss.Post().Delete(newPosts[1].Id, 1234, model.NewId())
+		require.Nil(t, err, "couldn't delete post")
+
+		thread, err = ss.Thread().Get(newPosts[0].RootId)
+		require.Nil(t, err, "couldn't get thread")
+		require.NotNil(t, thread)
+		require.Equal(t, int64(1), thread.ReplyCount)
+		require.ElementsMatch(t, model.StringArray{newPosts[0].UserId}, thread.Participants)
+	})
+
+	t.Run("Update reply should update the UpdateAt of the thread", func(t *testing.T) {
+		rootPost := model.Post{}
+		rootPost.RootId = model.NewId()
+		rootPost.ChannelId = model.NewId()
+		rootPost.UserId = model.NewId()
+		rootPost.Message = "zz" + model.NewId() + "b"
+
+		replyPost := model.Post{}
+		replyPost.ChannelId = rootPost.ChannelId
+		replyPost.UserId = model.NewId()
+		replyPost.Message = "zz" + model.NewId() + "b"
+		replyPost.RootId = rootPost.RootId
+
+		newPosts, _, err := ss.Post().SaveMultiple([]*model.Post{&rootPost, &replyPost})
+		require.Nil(t, err)
+
+		thread1, err := ss.Thread().Get(newPosts[0].RootId)
+		require.Nil(t, err)
+
+		rrootPost, err := ss.Post().GetSingle(rootPost.Id)
+		require.Nil(t, err)
+		require.Equal(t, rrootPost.UpdateAt, rootPost.UpdateAt)
+
+		replyPost2 := model.Post{}
+		replyPost2.ChannelId = rootPost.ChannelId
+		replyPost2.UserId = model.NewId()
+		replyPost2.Message = "zz" + model.NewId() + "b"
+		replyPost2.RootId = rootPost.Id
+
+		replyPost3 := model.Post{}
+		replyPost3.ChannelId = rootPost.ChannelId
+		replyPost3.UserId = model.NewId()
+		replyPost3.Message = "zz" + model.NewId() + "b"
+		replyPost3.RootId = rootPost.Id
+
+		_, _, err = ss.Post().SaveMultiple([]*model.Post{&replyPost2, &replyPost3})
+		require.Nil(t, err)
+
+		rrootPost2, err := ss.Post().GetSingle(rootPost.Id)
+		require.Nil(t, err)
+		require.Greater(t, rrootPost2.UpdateAt, rrootPost.UpdateAt)
+
+		thread2, err := ss.Thread().Get(rootPost.Id)
+		require.Nil(t, err)
+		require.Greater(t, thread2.LastReplyAt, thread1.LastReplyAt)
+	})
+
+	t.Run("Deleting reply should update the thread", func(t *testing.T) {
+		rootPost := model.Post{}
+		rootPost.RootId = model.NewId()
+		rootPost.ChannelId = model.NewId()
+		rootPost.UserId = model.NewId()
+		rootPost.Message = "zz" + model.NewId() + "b"
+
+		replyPost := model.Post{}
+		replyPost.ChannelId = rootPost.ChannelId
+		replyPost.UserId = model.NewId()
+		replyPost.Message = "zz" + model.NewId() + "b"
+		replyPost.RootId = rootPost.RootId
+
+		newPosts, _, err := ss.Post().SaveMultiple([]*model.Post{&rootPost, &replyPost})
+		require.Nil(t, err)
+
+		thread1, err := ss.Thread().Get(newPosts[0].RootId)
+		require.Nil(t, err)
+		require.EqualValues(t, thread1.ReplyCount, 2)
+		require.Len(t, thread1.Participants, 2)
+
+		err = ss.Post().Delete(replyPost.Id, 123, model.NewId())
+		require.Nil(t, err)
+
+		thread2, err := ss.Thread().Get(rootPost.RootId)
+		require.Nil(t, err)
+		require.EqualValues(t, thread2.ReplyCount, 1)
+		require.Len(t, thread2.Participants, 1)
+	})
+
+	t.Run("Deleting root post should delete the thread", func(t *testing.T) {
+		rootPost := model.Post{}
+		rootPost.ChannelId = model.NewId()
+		rootPost.UserId = model.NewId()
+		rootPost.Message = "zz" + model.NewId() + "b"
+
+		newPosts1, _, err := ss.Post().SaveMultiple([]*model.Post{&rootPost})
+		require.Nil(t, err)
+
+		replyPost := model.Post{}
+		replyPost.ChannelId = rootPost.ChannelId
+		replyPost.UserId = model.NewId()
+		replyPost.Message = "zz" + model.NewId() + "b"
+		replyPost.RootId = newPosts1[0].Id
+
+		_, _, err = ss.Post().SaveMultiple([]*model.Post{&replyPost})
+		require.Nil(t, err)
+
+		thread1, err := ss.Thread().Get(newPosts1[0].Id)
+		require.Nil(t, err)
+		require.EqualValues(t, thread1.ReplyCount, 1)
+		require.Len(t, thread1.Participants, 1)
+
+		err = ss.Post().Delete(rootPost.Id, 123, model.NewId())
+		require.Nil(t, err)
+
+		thread2, _ := ss.Thread().Get(rootPost.Id)
+		require.Nil(t, thread2)
+	})
+}
diff --git a/store/timerlayer/timerlayer.go b/store/timerlayer/timerlayer.go
index 9344c1a610ab2..da0cde93eccea 100644
--- a/store/timerlayer/timerlayer.go
+++ b/store/timerlayer/timerlayer.go
@@ -45,6 +45,7 @@ type TimerLayer struct {
 	SystemStore               store.SystemStore
 	TeamStore                 store.TeamStore
 	TermsOfServiceStore       store.TermsOfServiceStore
+	ThreadStore               store.ThreadStore
 	TokenStore                store.TokenStore
 	UploadSessionStore        store.UploadSessionStore
 	UserStore                 store.UserStore
@@ -161,6 +162,10 @@ func (s *TimerLayer) TermsOfService() store.TermsOfServiceStore {
 	return s.TermsOfServiceStore
 }
 
+func (s *TimerLayer) Thread() store.ThreadStore {
+	return s.ThreadStore
+}
+
 func (s *TimerLayer) Token() store.TokenStore {
 	return s.TokenStore
 }
@@ -320,6 +325,11 @@ type TimerLayerTermsOfServiceStore struct {
 	Root *TimerLayer
 }
 
+type TimerLayerThreadStore struct {
+	store.ThreadStore
+	Root *TimerLayer
+}
+
 type TimerLayerTokenStore struct {
 	store.TokenStore
 	Root *TimerLayer
@@ -6846,6 +6856,86 @@ func (s *TimerLayerTermsOfServiceStore) Save(termsOfService *model.TermsOfServic
 	return result, err
 }
 
+func (s *TimerLayerThreadStore) Delete(postId string) error {
+	start := timemodule.Now()
+
+	err := s.ThreadStore.Delete(postId)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("ThreadStore.Delete", success, elapsed)
+	}
+	return err
+}
+
+func (s *TimerLayerThreadStore) Get(id string) (*model.Thread, error) {
+	start := timemodule.Now()
+
+	result, err := s.ThreadStore.Get(id)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("ThreadStore.Get", success, elapsed)
+	}
+	return result, err
+}
+
+func (s *TimerLayerThreadStore) Save(thread *model.Thread) (*model.Thread, error) {
+	start := timemodule.Now()
+
+	result, err := s.ThreadStore.Save(thread)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("ThreadStore.Save", success, elapsed)
+	}
+	return result, err
+}
+
+func (s *TimerLayerThreadStore) SaveMultiple(thread []*model.Thread) ([]*model.Thread, int, error) {
+	start := timemodule.Now()
+
+	result, resultVar1, err := s.ThreadStore.SaveMultiple(thread)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("ThreadStore.SaveMultiple", success, elapsed)
+	}
+	return result, resultVar1, err
+}
+
+func (s *TimerLayerThreadStore) Update(thread *model.Thread) (*model.Thread, error) {
+	start := timemodule.Now()
+
+	result, err := s.ThreadStore.Update(thread)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("ThreadStore.Update", success, elapsed)
+	}
+	return result, err
+}
+
 func (s *TimerLayerTokenStore) Cleanup() {
 	start := timemodule.Now()
 
@@ -8800,6 +8890,7 @@ func New(childStore store.Store, metrics einterfaces.MetricsInterface) *TimerLay
 	newStore.SystemStore = &TimerLayerSystemStore{SystemStore: childStore.System(), Root: &newStore}
 	newStore.TeamStore = &TimerLayerTeamStore{TeamStore: childStore.Team(), Root: &newStore}
 	newStore.TermsOfServiceStore = &TimerLayerTermsOfServiceStore{TermsOfServiceStore: childStore.TermsOfService(), Root: &newStore}
+	newStore.ThreadStore = &TimerLayerThreadStore{ThreadStore: childStore.Thread(), Root: &newStore}
 	newStore.TokenStore = &TimerLayerTokenStore{TokenStore: childStore.Token(), Root: &newStore}
 	newStore.UploadSessionStore = &TimerLayerUploadSessionStore{UploadSessionStore: childStore.UploadSession(), Root: &newStore}
 	newStore.UserStore = &TimerLayerUserStore{UserStore: childStore.User(), Root: &newStore}