diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9696a64b3..48e6d77ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,18 @@
+# 6.0.1
+
+SMP agent:
+- support changing user of the new connection.
+- do not start delivery workers when there are no messages to deliver.
+- enable notifications for all connections.
+- combine database transactions when subscribing.
+- store query errors, reduce slow query threshold to 1ms.
+
+SMP server:
+- safe compacting of store log.
+- fix possible race when creating client that might lead to memory leak.
+
+Dependencies: upgrade tls to 1.9
+
 # 6.0.0
 
 Version 6.0.0.8
diff --git a/package.yaml b/package.yaml
index 26cdcc51a..789e2e151 100644
--- a/package.yaml
+++ b/package.yaml
@@ -1,5 +1,5 @@
 name: simplexmq
-version: 6.0.0.8
+version: 6.0.1.0
 synopsis: SimpleXMQ message broker
 description: |
   This package includes <./docs/Simplex-Messaging-Server.html server>,
@@ -69,7 +69,7 @@ dependencies:
   - temporary == 1.3.*
   - time == 1.12.*
   - time-manager == 0.0.*
-  - tls >= 1.7.0 && < 1.8
+  - tls >= 1.9.0 && < 1.10
   - transformers == 0.6.*
   - unliftio == 0.2.*
   - unliftio-core == 0.2.*
diff --git a/simplexmq.cabal b/simplexmq.cabal
index d557ac509..d222352a1 100644
--- a/simplexmq.cabal
+++ b/simplexmq.cabal
@@ -5,7 +5,7 @@ cabal-version: 1.12
 -- see: https://github.com/sol/hpack
 
 name:           simplexmq
-version:        6.0.0.8
+version:        6.0.1.0
 synopsis:       SimpleXMQ message broker
 description:    This package includes <./docs/Simplex-Messaging-Server.html server>,
                 <./docs/Simplex-Messaging-Client.html client> and
@@ -258,7 +258,7 @@ library
     , temporary ==1.3.*
     , time ==1.12.*
     , time-manager ==0.0.*
-    , tls >=1.7.0 && <1.8
+    , tls >=1.9.0 && <1.10
     , transformers ==0.6.*
     , unliftio ==0.2.*
     , unliftio-core ==0.2.*
@@ -333,7 +333,7 @@ executable ntf-server
     , temporary ==1.3.*
     , time ==1.12.*
     , time-manager ==0.0.*
-    , tls >=1.7.0 && <1.8
+    , tls >=1.9.0 && <1.10
     , transformers ==0.6.*
     , unliftio ==0.2.*
     , unliftio-core ==0.2.*
@@ -412,7 +412,7 @@ executable smp-server
     , temporary ==1.3.*
     , time ==1.12.*
     , time-manager ==0.0.*
-    , tls >=1.7.0 && <1.8
+    , tls >=1.9.0 && <1.10
     , transformers ==0.6.*
     , unliftio ==0.2.*
     , unliftio-core ==0.2.*
@@ -490,7 +490,7 @@ executable xftp
     , temporary ==1.3.*
     , time ==1.12.*
     , time-manager ==0.0.*
-    , tls >=1.7.0 && <1.8
+    , tls >=1.9.0 && <1.10
     , transformers ==0.6.*
     , unliftio ==0.2.*
     , unliftio-core ==0.2.*
@@ -565,7 +565,7 @@ executable xftp-server
     , temporary ==1.3.*
     , time ==1.12.*
     , time-manager ==0.0.*
-    , tls >=1.7.0 && <1.8
+    , tls >=1.9.0 && <1.10
     , transformers ==0.6.*
     , unliftio ==0.2.*
     , unliftio-core ==0.2.*
@@ -681,7 +681,7 @@ test-suite simplexmq-test
     , time ==1.12.*
     , time-manager ==0.0.*
     , timeit ==2.0.*
-    , tls >=1.7.0 && <1.8
+    , tls >=1.9.0 && <1.10
     , transformers ==0.6.*
     , unliftio ==0.2.*
     , unliftio-core ==0.2.*
diff --git a/src/Simplex/Messaging/Agent.hs b/src/Simplex/Messaging/Agent.hs
index 672375aaf..176d33403 100644
--- a/src/Simplex/Messaging/Agent.hs
+++ b/src/Simplex/Messaging/Agent.hs
@@ -53,6 +53,7 @@ module Simplex.Messaging.Agent
     deleteConnectionAsync,
     deleteConnectionsAsync,
     createConnection,
+    changeConnectionUser,
     prepareConnectionToJoin,
     joinConnection,
     allowConnection,
@@ -131,6 +132,7 @@ import Data.Bifunctor (bimap, first)
 import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
 import Data.Composition ((.:), (.:.), (.::), (.::.))
+import Data.Containers.ListUtils (nubOrd)
 import Data.Either (isRight, rights)
 import Data.Foldable (foldl', toList)
 import Data.Functor (($>))
@@ -333,6 +335,11 @@ createConnection :: AgentClient -> UserId -> Bool -> SConnectionMode c -> Maybe
 createConnection c userId enableNtfs = withAgentEnv c .:: newConn c userId "" enableNtfs
 {-# INLINE createConnection #-}
 
+-- | Changes the user id associated with a connection 
+changeConnectionUser :: AgentClient -> UserId -> ConnId -> UserId -> AE ()
+changeConnectionUser c oldUserId connId newUserId = withAgentEnv c $ changeConnectionUser' c oldUserId connId newUserId
+{-# INLINE changeConnectionUser #-}
+
 -- | Create SMP agent connection without queue (to be joined with joinConnection passing connection ID).
 -- This method is required to prevent race condition when confirmation from peer is received before
 -- the caller of joinConnection saves connection ID to the database.
@@ -741,6 +748,16 @@ newConn :: AgentClient -> UserId -> ConnId -> Bool -> SConnectionMode c -> Maybe
 newConn c userId connId enableNtfs cMode clientData pqInitKeys subMode =
   getSMPServer c userId >>= newConnSrv c userId connId False enableNtfs cMode clientData pqInitKeys subMode
 
+changeConnectionUser' :: AgentClient -> UserId -> ConnId -> UserId -> AM ()
+changeConnectionUser' c oldUserId connId newUserId = do
+  SomeConn _ conn <- withStore c (`getConn` connId)
+  case conn of
+    NewConnection {} -> updateConn
+    RcvConnection {} -> updateConn
+    _ -> throwE $ CMD PROHIBITED "changeConnectionUser: established connection"
+  where
+    updateConn = withStore' c $ \db -> setConnUserId db oldUserId connId newUserId
+
 newConnSrv :: AgentClient -> UserId -> ConnId -> Bool -> Bool -> SConnectionMode c -> Maybe CRClientData -> CR.InitialKeys -> SubscriptionMode -> SMPServerWithAuth -> AM (ConnId, ConnectionRequestUri c)
 newConnSrv c userId connId hasNewConn enableNtfs cMode clientData pqInitKeys subMode srv = do
   connId' <-
@@ -958,12 +975,12 @@ subscribeConnections' c connIds = do
   let (errs, cs) = M.mapEither id conns
       errs' = M.map (Left . storeError) errs
       (subRs, rcvQs) = M.mapEither rcvQueueOrResult cs
-  mapM_ (mapM_ (\(cData, sqs) -> mapM_ (lift . resumeMsgDelivery c cData) sqs) . sndQueue) cs
-  mapM_ (resumeConnCmds c) $ M.keys cs
+  resumeDelivery cs
+  lift $ resumeConnCmds c $ M.keys cs
   rcvRs <- lift $ connResults . fst <$> subscribeQueues c (concat $ M.elems rcvQs)
   ns <- asks ntfSupervisor
   tkn <- readTVarIO (ntfTkn ns)
-  when (instantNotifications tkn) . void . lift . forkIO . void . runExceptT $ sendNtfCreate ns rcvRs conns
+  lift $ when (instantNotifications tkn) . void . forkIO . void $ sendNtfCreate ns rcvRs cs
   let rs = M.unions ([errs', subRs, rcvRs] :: [Map ConnId (Either AgentErrorType ())])
   notifyResultError rs
   pure rs
@@ -995,15 +1012,20 @@ subscribeConnections' c connIds = do
         order (Active, _) = 2
         order (_, Right _) = 3
         order _ = 4
-    sendNtfCreate :: NtfSupervisor -> Map ConnId (Either AgentErrorType ()) -> Map ConnId (Either StoreError SomeConn) -> AM ()
-    sendNtfCreate ns rcvRs conns =
-      forM_ (M.assocs rcvRs) $ \case
-        (connId, Right _) -> forM_ (M.lookup connId conns) $ \case
-          Right (SomeConn _ conn) -> do
-            let cmd = if enableNtfs $ toConnData conn then NSCCreate else NSCDelete
-            atomically $ writeTBQueue (ntfSubQ ns) (connId, cmd)
-          _ -> pure ()
-        _ -> pure ()
+    sendNtfCreate :: NtfSupervisor -> Map ConnId (Either AgentErrorType ()) -> Map ConnId SomeConn -> AM' ()
+    sendNtfCreate ns rcvRs cs = do
+      -- TODO this needs to be batched end to end.
+      -- Currently, the only change is to ignore failed subscriptions.
+      let oks = M.keysSet $ M.filter (either temporaryAgentError $ const True) rcvRs
+      forM_ (M.restrictKeys cs oks) $ \case
+        SomeConn _ conn -> do
+          let cmd = if enableNtfs $ toConnData conn then NSCCreate else NSCDelete
+              ConnData {connId} = toConnData conn
+          atomically $ writeTBQueue (ntfSubQ ns) (connId, cmd)            
+    resumeDelivery :: Map ConnId SomeConn -> AM ()
+    resumeDelivery conns = do
+      conns' <- M.restrictKeys conns . S.fromList <$> withStore' c getConnectionsForDelivery
+      lift $ mapM_ (mapM_ (\(cData, sqs) -> mapM_ (resumeMsgDelivery c cData) sqs) . sndQueue) conns'
     sndQueue :: SomeConn -> Maybe (ConnData, NonEmpty SndQueue)
     sndQueue (SomeConn _ conn) = case conn of
       DuplexConnection cData _ sqs -> Just (cData, sqs)
@@ -1118,13 +1140,10 @@ resumeSrvCmds :: AgentClient -> Maybe SMPServer -> AM' ()
 resumeSrvCmds = void .: getAsyncCmdWorker False
 {-# INLINE resumeSrvCmds #-}
 
-resumeConnCmds :: AgentClient -> ConnId -> AM ()
-resumeConnCmds c connId =
-  unlessM connQueued $
-    withStore' c (`getPendingCommandServers` connId)
-      >>= mapM_ (lift . resumeSrvCmds c)
-  where
-    connQueued = atomically $ isJust <$> TM.lookupInsert connId True (connCmdsQueued c)
+resumeConnCmds :: AgentClient -> [ConnId] -> AM' ()
+resumeConnCmds c connIds = do
+  srvs <- nubOrd . concat . rights <$> withStoreBatch' c (\db -> fmap (getPendingCommandServers db) connIds)
+  mapM_ (resumeSrvCmds c) srvs
 
 getAsyncCmdWorker :: Bool -> AgentClient -> Maybe SMPServer -> AM' Worker
 getAsyncCmdWorker hasWork c server =
diff --git a/src/Simplex/Messaging/Agent/Client.hs b/src/Simplex/Messaging/Agent/Client.hs
index 23f0a98d1..fbdb53548 100644
--- a/src/Simplex/Messaging/Agent/Client.hs
+++ b/src/Simplex/Messaging/Agent/Client.hs
@@ -163,7 +163,7 @@ module Simplex.Messaging.Agent.Client
 where
 
 import Control.Applicative ((<|>))
-import Control.Concurrent (ThreadId, forkIO)
+import Control.Concurrent (ThreadId, killThread)
 import Control.Concurrent.Async (Async, uninterruptibleCancel)
 import Control.Concurrent.STM (retry)
 import Control.Exception (AsyncException (..), BlockedIndefinitelyOnSTM (..))
@@ -266,10 +266,11 @@ import Simplex.Messaging.Transport (SMPVersion, SessionId, THandleParams (sessio
 import Simplex.Messaging.Transport.Client (TransportHost (..))
 import Simplex.Messaging.Util
 import Simplex.Messaging.Version
-import System.Mem.Weak (Weak)
+import System.Mem.Weak (Weak, deRefWeak)
 import System.Random (randomR)
 import UnliftIO (mapConcurrently, timeout)
 import UnliftIO.Async (async)
+import UnliftIO.Concurrent (forkIO, mkWeakThreadId)
 import UnliftIO.Directory (doesFileExist, getTemporaryDirectory, removeFile)
 import qualified UnliftIO.Exception as E
 import UnliftIO.STM
@@ -313,7 +314,6 @@ data AgentClient = AgentClient
     workerSeq :: TVar Int,
     smpDeliveryWorkers :: TMap SndQAddr (Worker, TMVar ()),
     asyncCmdWorkers :: TMap (Maybe SMPServer) Worker,
-    connCmdsQueued :: TMap ConnId Bool,
     ntfNetworkOp :: TVar AgentOpState,
     rcvNetworkOp :: TVar AgentOpState,
     msgDeliveryOp :: TVar AgentOpState,
@@ -411,7 +411,7 @@ runWorkerAsync Worker {action} work =
     (atomically . tryPutTMVar action) -- if it was running (or if start crashes), put it back and unlock (don't lock if it was just started)
     (\a -> when (isNothing a) start) -- start worker if it's not running
   where
-    start = atomically . putTMVar action . Just =<< async work
+    start = atomically . putTMVar action . Just =<< mkWeakThreadId =<< forkIO work
 
 data AgentOperation = AONtfNetwork | AORcvNetwork | AOMsgDelivery | AOSndNetwork | AODatabase
   deriving (Eq, Show)
@@ -480,7 +480,6 @@ newAgentClient clientId InitialAgentServers {smp, ntf, xftp, netCfg} currentTs a
   workerSeq <- newTVarIO 0
   smpDeliveryWorkers <- TM.emptyIO
   asyncCmdWorkers <- TM.emptyIO
-  connCmdsQueued <- TM.emptyIO
   ntfNetworkOp <- newTVarIO $ AgentOpState False 0
   rcvNetworkOp <- newTVarIO $ AgentOpState False 0
   msgDeliveryOp <- newTVarIO $ AgentOpState False 0
@@ -519,7 +518,6 @@ newAgentClient clientId InitialAgentServers {smp, ntf, xftp, netCfg} currentTs a
         workerSeq,
         smpDeliveryWorkers,
         asyncCmdWorkers,
-        connCmdsQueued,
         ntfNetworkOp,
         rcvNetworkOp,
         msgDeliveryOp,
@@ -893,7 +891,6 @@ closeAgentClient c = do
   atomically (swapTVar (smpSubWorkers c) M.empty) >>= mapM_ cancelReconnect
   clearWorkers smpDeliveryWorkers >>= mapM_ (cancelWorker . fst)
   clearWorkers asyncCmdWorkers >>= mapM_ cancelWorker
-  clear connCmdsQueued
   atomically . RQ.clear $ activeSubs c
   atomically . RQ.clear $ pendingSubs c
   clear subscrConns
@@ -909,7 +906,7 @@ closeAgentClient c = do
 cancelWorker :: Worker -> IO ()
 cancelWorker Worker {doWork, action} = do
   noWorkToDo doWork
-  atomically (tryTakeTMVar action) >>= mapM_ (mapM_ uninterruptibleCancel)
+  atomically (tryTakeTMVar action) >>= mapM_ (mapM_ $ deRefWeak >=> mapM_ killThread)
 
 waitUntilActive :: AgentClient -> IO ()
 waitUntilActive AgentClient {active} = unlessM (readTVarIO active) $ atomically $ unlessM (readTVar active) retry
diff --git a/src/Simplex/Messaging/Agent/Env/SQLite.hs b/src/Simplex/Messaging/Agent/Env/SQLite.hs
index f57cf91e9..bc5e800c5 100644
--- a/src/Simplex/Messaging/Agent/Env/SQLite.hs
+++ b/src/Simplex/Messaging/Agent/Env/SQLite.hs
@@ -41,6 +41,7 @@ module Simplex.Messaging.Agent.Env.SQLite
   )
 where
 
+import Control.Concurrent (ThreadId)
 import Control.Monad.Except
 import Control.Monad.IO.Unlift
 import Control.Monad.Reader
@@ -76,8 +77,9 @@ import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Transport (SMPVersion, TLS, Transport (..))
 import Simplex.Messaging.Transport.Client (defaultSMPPort)
 import Simplex.Messaging.Util (allFinally, catchAllErrors, catchAllErrors', tryAllErrors, tryAllErrors')
+import System.Mem.Weak (Weak)
 import System.Random (StdGen, newStdGen)
-import UnliftIO (Async, SomeException)
+import UnliftIO (SomeException)
 import UnliftIO.STM
 
 type AM' a = ReaderT Env IO a
@@ -312,7 +314,7 @@ mkInternal = INTERNAL . show
 data Worker = Worker
   { workerId :: Int,
     doWork :: TMVar (),
-    action :: TMVar (Maybe (Async ())),
+    action :: TMVar (Maybe (Weak ThreadId)),
     restarts :: TVar RestartCount
   }
 
diff --git a/src/Simplex/Messaging/Agent/Store/SQLite.hs b/src/Simplex/Messaging/Agent/Store/SQLite.hs
index 20f382d40..69b1b07e9 100644
--- a/src/Simplex/Messaging/Agent/Store/SQLite.hs
+++ b/src/Simplex/Messaging/Agent/Store/SQLite.hs
@@ -57,6 +57,7 @@ module Simplex.Messaging.Agent.Store.SQLite
     getDeletedConns,
     getConnData,
     setConnDeleted,
+    setConnUserId,
     setConnAgentVersion,
     setConnPQSupport,
     getDeletedConnIds,
@@ -110,6 +111,7 @@ module Simplex.Messaging.Agent.Store.SQLite
     getSndMsgViaRcpt,
     updateSndMsgRcpt,
     getPendingQueueMsg,
+    getConnectionsForDelivery,
     updatePendingMsgRIState,
     deletePendingMsgs,
     getExpiredSndMessages,
@@ -1008,6 +1010,10 @@ updateSndMsgRcpt db connId sndMsgId MsgReceipt {agentMsgId, msgRcptStatus} =
     "UPDATE snd_messages SET rcpt_internal_id = ?, rcpt_status = ? WHERE conn_id = ? AND internal_snd_id = ?"
     (agentMsgId, msgRcptStatus, connId, sndMsgId)
 
+getConnectionsForDelivery :: DB.Connection -> IO [ConnId]
+getConnectionsForDelivery db =
+  map fromOnly <$> DB.query_ db "SELECT DISTINCT conn_id FROM snd_message_deliveries WHERE failed = 0"
+
 getPendingQueueMsg :: DB.Connection -> ConnId -> SndQueue -> IO (Either StoreError (Maybe (Maybe RcvQueue, PendingMsgData)))
 getPendingQueueMsg db connId SndQueue {dbQueueId} =
   getWorkItem "message" getMsgId getMsgData markMsgFailed
@@ -1909,9 +1915,11 @@ newQueueId_ (Only maxId : _) = DBQueueId (maxId + 1)
 
 getConn :: DB.Connection -> ConnId -> IO (Either StoreError SomeConn)
 getConn = getAnyConn False
+{-# INLINE getConn #-}
 
 getDeletedConn :: DB.Connection -> ConnId -> IO (Either StoreError SomeConn)
 getDeletedConn = getAnyConn True
+{-# INLINE getDeletedConn #-}
 
 getAnyConn :: Bool -> DB.Connection -> ConnId -> IO (Either StoreError SomeConn)
 getAnyConn deleted' dbConn connId =
@@ -1932,9 +1940,11 @@ getAnyConn deleted' dbConn connId =
 
 getConns :: DB.Connection -> [ConnId] -> IO [Either StoreError SomeConn]
 getConns = getAnyConns_ False
+{-# INLINE getConns #-}
 
 getDeletedConns :: DB.Connection -> [ConnId] -> IO [Either StoreError SomeConn]
 getDeletedConns = getAnyConns_ True
+{-# INLINE getDeletedConns #-}
 
 getAnyConns_ :: Bool -> DB.Connection -> [ConnId] -> IO [Either StoreError SomeConn]
 getAnyConns_ deleted' db connIds = forM connIds $ E.handle handleDBError . getAnyConn deleted' db
@@ -1967,6 +1977,10 @@ setConnDeleted db waitDelivery connId
   | otherwise =
       DB.execute db "UPDATE connections SET deleted = ? WHERE conn_id = ?" (True, connId)
 
+setConnUserId :: DB.Connection -> UserId -> ConnId -> UserId -> IO ()
+setConnUserId db oldUserId connId newUserId = 
+  DB.execute db "UPDATE connections SET user_id = ? WHERE conn_id = ? and user_id = ?" (newUserId, connId, oldUserId)
+
 setConnAgentVersion :: DB.Connection -> ConnId -> VersionSMPA -> IO ()
 setConnAgentVersion db connId aVersion =
   DB.execute db "UPDATE connections SET smp_agent_version = ? WHERE conn_id = ?" (aVersion, connId)
diff --git a/src/Simplex/Messaging/Server.hs b/src/Simplex/Messaging/Server.hs
index c5d067475..a70995d5e 100644
--- a/src/Simplex/Messaging/Server.hs
+++ b/src/Simplex/Messaging/Server.hs
@@ -175,7 +175,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
           $>>= endPreviousSubscriptions
           >>= liftIO . mapM_ unsub
       where
-        updateSubscribers :: TVar (IM.IntMap Client) -> STM (Maybe (QueueId, Client))
+        updateSubscribers :: TVar (IM.IntMap (Maybe Client)) -> STM (Maybe (QueueId, Client))
         updateSubscribers cls = do
           (qId, clnt, subscribed) <- readTQueue $ subQ s
           current <- IM.member (clientId clnt) <$> readTVar cls
@@ -412,7 +412,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
               CPClients -> withAdminRole $ do
                 active <- unliftIO u (asks clients) >>= readTVarIO
                 hPutStrLn h "clientId,sessionId,connected,createdAt,rcvActiveAt,sndActiveAt,age,subscriptions"
-                forM_ (IM.toList active) $ \(cid, Client {sessionId, connected, createdAt, rcvActiveAt, sndActiveAt, subscriptions}) -> do
+                forM_ (IM.toList active) $ \(cid, cl) -> forM_ cl $ \Client {sessionId, connected, createdAt, rcvActiveAt, sndActiveAt, subscriptions} -> do
                   connected' <- bshow <$> readTVarIO connected
                   rcvActiveAt' <- strEncode <$> readTVarIO rcvActiveAt
                   sndActiveAt' <- strEncode <$> readTVarIO sndActiveAt
@@ -507,7 +507,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
                   activeClients <- readTVarIO clients
                   hPutStrLn h $ "Clients: " <> show (IM.size activeClients)
                   when (r == CPRAdmin) $ do
-                    clQs <- clientTBQueueLengths activeClients
+                    clQs <- clientTBQueueLengths' activeClients
                     hPutStrLn h $ "Client queues (rcvQ, sndQ, msgQ): " <> show clQs
                     (smpSubCnt, smpSubCntByGroup, smpClCnt, smpClQs) <- countClientSubs subscriptions (Just countSMPSubs) activeClients
                     hPutStrLn h $ "SMP subscriptions (via clients): " <> show smpSubCnt
@@ -542,11 +542,12 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
                               | otherwise = (cl : cls, IS.insert clientId clSet)
                         countSubClients :: M.Map QueueId Client -> Int
                         countSubClients = IS.size . M.foldr' (IS.insert . clientId) IS.empty
-                    countClientSubs :: (Client -> TMap QueueId a) -> Maybe (M.Map QueueId a -> IO (Int, Int, Int, Int)) -> IM.IntMap Client -> IO (Int, (Int, Int, Int, Int), Int, (Natural, Natural, Natural))
+                    countClientSubs :: (Client -> TMap QueueId a) -> Maybe (M.Map QueueId a -> IO (Int, Int, Int, Int)) -> IM.IntMap (Maybe Client) -> IO (Int, (Int, Int, Int, Int), Int, (Natural, Natural, Natural))
                     countClientSubs subSel countSubs_ = foldM addSubs (0, (0, 0, 0, 0), 0, (0, 0, 0))
                       where
-                        addSubs :: (Int, (Int, Int, Int, Int), Int, (Natural, Natural, Natural)) -> Client -> IO (Int, (Int, Int, Int, Int), Int, (Natural, Natural, Natural))
-                        addSubs (!subCnt, cnts@(!c1, !c2, !c3, !c4), !clCnt, !qs) cl = do
+                        addSubs :: (Int, (Int, Int, Int, Int), Int, (Natural, Natural, Natural)) -> Maybe Client -> IO (Int, (Int, Int, Int, Int), Int, (Natural, Natural, Natural))
+                        addSubs acc Nothing = pure acc
+                        addSubs (!subCnt, cnts@(!c1, !c2, !c3, !c4), !clCnt, !qs) (Just cl) = do
                           subs <- readTVarIO $ subSel cl
                           cnts' <- case countSubs_ of
                             Nothing -> pure cnts
@@ -559,6 +560,8 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
                           pure (subCnt + cnt, cnts', clCnt', qs')
                     clientTBQueueLengths :: Foldable t => t Client -> IO (Natural, Natural, Natural)
                     clientTBQueueLengths = foldM addQueueLengths (0, 0, 0)
+                    clientTBQueueLengths' :: Foldable t => t (Maybe Client) -> IO (Natural, Natural, Natural)
+                    clientTBQueueLengths' = foldM (\acc -> maybe (pure acc) (addQueueLengths acc)) (0, 0, 0)
                     addQueueLengths (!rl, !sl, !ml) cl = do
                       (rl', sl', ml') <- queueLengths cl
                       pure (rl + rl', sl + sl', ml + ml')
@@ -619,15 +622,18 @@ runClientTransport h@THandle {params = thParams@THandleParams {thVersion, sessio
   ts <- liftIO getSystemTime
   active <- asks clients
   nextClientId <- asks clientSeq
-  c@Client {clientId} <- liftIO $ newClient nextClientId q thVersion sessionId ts
-  atomically $ modifyTVar' active $ IM.insert clientId c
-  s <- asks server
-  expCfg <- asks $ inactiveClientExpiration . config
-  th <- newMVar h -- put TH under a fair lock to interleave messages and command responses
-  labelMyThread . B.unpack $ "client $" <> encode sessionId
-  raceAny_ ([liftIO $ send th c, liftIO $ sendMsg th c, client thParams c s, receive h c] <> disconnectThread_ c expCfg)
-    `finally` clientDisconnected c
+  clientId <- atomically $ stateTVar nextClientId $ \next -> (next, next + 1)
+  atomically $ modifyTVar' active $ IM.insert clientId Nothing
+  c <- liftIO $ newClient clientId q thVersion sessionId ts
+  runClientThreads active c clientId `finally` clientDisconnected c
   where
+    runClientThreads active c clientId = do
+      atomically $ modifyTVar' active $ IM.insert clientId $ Just c
+      s <- asks server
+      expCfg <- asks $ inactiveClientExpiration . config
+      th <- newMVar h -- put TH under a fair lock to interleave messages and command responses
+      labelMyThread . B.unpack $ "client $" <> encode sessionId
+      raceAny_ $ [liftIO $ send th c, liftIO $ sendMsg th c, client thParams c s, receive h c] <> disconnectThread_ c expCfg
     disconnectThread_ c (Just expCfg) = [liftIO $ disconnectTransport h (rcvActiveAt c) (sndActiveAt c) expCfg (noSubscriptions c)]
     disconnectThread_ _ _ = []
     noSubscriptions c = atomically $ (&&) <$> TM.null (ntfSubscriptions c) <*> (not . hasSubs <$> readTVar (subscriptions c))
diff --git a/src/Simplex/Messaging/Server/Env/STM.hs b/src/Simplex/Messaging/Server/Env/STM.hs
index 84e664607..9b1dd9405 100644
--- a/src/Simplex/Messaging/Server/Env/STM.hs
+++ b/src/Simplex/Messaging/Server/Env/STM.hs
@@ -127,7 +127,7 @@ data Env = Env
     serverStats :: ServerStats,
     sockets :: SocketState,
     clientSeq :: TVar ClientId,
-    clients :: TVar (IntMap Client),
+    clients :: TVar (IntMap (Maybe Client)),
     proxyAgent :: ProxyAgent -- senders served on this proxy
   }
 
@@ -183,9 +183,8 @@ newServer = do
   savingLock <- atomically createLock
   return Server {subscribedQ, subscribers, ntfSubscribedQ, notifiers, savingLock}
 
-newClient :: TVar ClientId -> Natural -> VersionSMP -> ByteString -> SystemTime -> IO Client
-newClient nextClientId qSize thVersion sessionId createdAt = do
-  clientId <- atomically $ stateTVar nextClientId $ \next -> (next, next + 1)
+newClient :: ClientId -> Natural -> VersionSMP -> ByteString -> SystemTime -> IO Client
+newClient clientId qSize thVersion sessionId createdAt = do
   subscriptions <- TM.emptyIO
   ntfSubscriptions <- TM.emptyIO
   rcvQ <- newTBQueueIO qSize
diff --git a/src/Simplex/Messaging/Server/StoreLog.hs b/src/Simplex/Messaging/Server/StoreLog.hs
index d1ce15ed6..94a340d94 100644
--- a/src/Simplex/Messaging/Server/StoreLog.hs
+++ b/src/Simplex/Messaging/Server/StoreLog.hs
@@ -36,7 +36,7 @@ import Simplex.Messaging.Protocol
 import Simplex.Messaging.Server.QueueStore (NtfCreds (..), QueueRec (..), ServerQueueStatus (..))
 import Simplex.Messaging.Transport.Buffer (trimCR)
 import Simplex.Messaging.Util (ifM)
-import System.Directory (doesFileExist)
+import System.Directory (doesFileExist, renameFile)
 import System.IO
 
 -- | opaque container for file handle with a type-safe IOMode
@@ -140,10 +140,12 @@ logDeleteNotifier s = writeStoreLogRecord s . DeleteNotifier
 
 readWriteStoreLog :: FilePath -> IO (Map RecipientId QueueRec, StoreLog 'WriteMode)
 readWriteStoreLog f = do
-  qs <- ifM (doesFileExist f) (readQueues f) (pure M.empty)
+  qs <- ifM (doesFileExist f) readQS (pure M.empty)
   s <- openWriteStoreLog f
   writeQueues s qs
   pure (qs, s)
+  where
+    readQS = readQueues f <* renameFile f (f <> ".bak")
 
 writeQueues :: StoreLog 'WriteMode -> Map RecipientId QueueRec -> IO ()
 writeQueues s = mapM_ $ \q -> when (active q) $ logCreateQueue s q
diff --git a/src/Simplex/Messaging/Transport.hs b/src/Simplex/Messaging/Transport.hs
index 58843b7f5..3386f82f3 100644
--- a/src/Simplex/Messaging/Transport.hs
+++ b/src/Simplex/Messaging/Transport.hs
@@ -113,6 +113,7 @@ import Simplex.Messaging.Transport.Buffer
 import Simplex.Messaging.Util (bshow, catchAll, catchAll_, liftEitherWith)
 import Simplex.Messaging.Version
 import Simplex.Messaging.Version.Internal
+import System.IO.Error (isEOFError)
 import UnliftIO.Exception (Exception)
 import qualified UnliftIO.Exception as E
 import UnliftIO.STM
@@ -339,11 +340,12 @@ instance Transport TLS where
 
   getLn :: TLS -> IO ByteString
   getLn TLS {tlsContext, tlsBuffer} = do
-    getLnBuffered tlsBuffer (T.recvData tlsContext) `E.catch` handleEOF
+    getLnBuffered tlsBuffer (T.recvData tlsContext) `E.catches` [E.Handler handleTlsEOF, E.Handler handleEOF]
     where
-      handleEOF = \case
-        T.Error_EOF -> E.throwIO TEBadBlock
+      handleTlsEOF = \case
+        T.PostHandshake T.Error_EOF -> E.throwIO TEBadBlock
         e -> E.throwIO e
+      handleEOF e = if isEOFError e then E.throwIO TEBadBlock else E.throwIO e
 
 -- * SMP transport
 
diff --git a/src/Simplex/Messaging/Transport/WebSockets.hs b/src/Simplex/Messaging/Transport/WebSockets.hs
index 0883fcc28..866d0d197 100644
--- a/src/Simplex/Messaging/Transport/WebSockets.hs
+++ b/src/Simplex/Messaging/Transport/WebSockets.hs
@@ -25,6 +25,7 @@ import Simplex.Messaging.Transport
     withTlsUnique,
   )
 import Simplex.Messaging.Transport.Buffer (trimCR)
+import System.IO.Error (isEOFError)
 
 data WS = WS
   { wsPeer :: TransportPeer,
@@ -108,9 +109,11 @@ makeTLSContextStream cxt =
   S.makeStream readStream writeStream
   where
     readStream :: IO (Maybe ByteString)
-    readStream =
-      (Just <$> T.recvData cxt) `E.catch` \case
-        T.Error_EOF -> pure Nothing
-        e -> E.throwIO e
+    readStream = (Just <$> T.recvData cxt) `E.catches` [E.Handler handleTlsEOF, E.Handler handleEOF]
+      where
+        handleTlsEOF = \case
+          T.PostHandshake T.Error_EOF -> pure Nothing
+          e -> E.throwIO e
+        handleEOF e = if isEOFError e then pure Nothing else E.throwIO e
     writeStream :: Maybe LB.ByteString -> IO ()
     writeStream = maybe (closeTLS cxt) (T.sendData cxt)
diff --git a/src/Simplex/RemoteControl/Client.hs b/src/Simplex/RemoteControl/Client.hs
index de0cbce3b..381397c6e 100644
--- a/src/Simplex/RemoteControl/Client.hs
+++ b/src/Simplex/RemoteControl/Client.hs
@@ -305,7 +305,7 @@ connectRCCtrl_ drg pairing'@RCCtrlPairing {caKey, caCert} inv@RCInvitation {ca,
 
 catchRCError :: ExceptT RCErrorType IO a -> (RCErrorType -> ExceptT RCErrorType IO a) -> ExceptT RCErrorType IO a
 catchRCError = catchAllErrors $ \e -> case fromException e of
-  Just (TLS.Terminated _ _ (TLS.Error_Protocol (_, _, TLS.UnknownCa))) -> RCEIdentity
+  Just (TLS.Terminated _ _ (TLS.Error_Protocol _ TLS.UnknownCa)) -> RCEIdentity
   _ -> RCEException $ show e
 {-# INLINE catchRCError #-}
 
diff --git a/tests/AgentTests/FunctionalAPITests.hs b/tests/AgentTests/FunctionalAPITests.hs
index 4d61d8463..f0a25b758 100644
--- a/tests/AgentTests/FunctionalAPITests.hs
+++ b/tests/AgentTests/FunctionalAPITests.hs
@@ -283,6 +283,9 @@ functionalAPITests t = do
     testPQMatrix3 t $ runAgentClientContactTestPQ3 True
   it "should support rejecting contact request" $
     withSmpServer t testRejectContactRequest
+  describe "Changing connection user id" $ do
+    it "should change user id for new connections" $ do
+      withSmpServer t testUpdateConnectionUserId
   describe "Establishing connection asynchronously" $ do
     it "should connect with initiating client going offline" $
       withSmpServer t testAsyncInitiatingOffline
@@ -912,6 +915,25 @@ testRejectContactRequest =
     rejectContact alice addrConnId invId
     liftIO $ noMessages bob "nothing delivered to bob"
 
+testUpdateConnectionUserId :: HasCallStack => IO ()
+testUpdateConnectionUserId =
+  withAgentClients2 $ \alice bob -> runRight_ $ do
+    (connId, qInfo) <- createConnection alice 1 True SCMInvitation Nothing SMSubscribe
+    newUserId <- createUser alice [noAuthSrvCfg testSMPServer] [noAuthSrvCfg testXFTPServer]
+    _ <- changeConnectionUser alice 1 connId newUserId
+    aliceId <- A.prepareConnectionToJoin bob 1 True qInfo PQSupportOn
+    (aliceId', sqSecured') <- A.joinConnection bob 1 (Just aliceId) True qInfo "bob's connInfo" PQSupportOn SMSubscribe
+    liftIO $ do
+      aliceId' `shouldBe` aliceId
+      sqSecured' `shouldBe` True
+    ("", _, A.CONF confId pqSup' _ "bob's connInfo") <- get alice
+    liftIO $ pqSup' `shouldBe` PQSupportOn
+    allowConnection alice connId confId "alice's connInfo"
+    let pqEnc = CR.pqSupportToEnc PQSupportOn
+    get alice ##> ("", connId, A.CON pqEnc)
+    get bob ##> ("", aliceId, A.INFO PQSupportOn "alice's connInfo")
+    get bob ##> ("", aliceId, A.CON pqEnc)
+
 testAsyncInitiatingOffline :: HasCallStack => IO ()
 testAsyncInitiatingOffline =
   withAgent 2 agentCfg initAgentServers testDB2 $ \bob -> runRight_ $ do
diff --git a/tests/AgentTests/NotificationTests.hs b/tests/AgentTests/NotificationTests.hs
index cc79faeca..012da704d 100644
--- a/tests/AgentTests/NotificationTests.hs
+++ b/tests/AgentTests/NotificationTests.hs
@@ -508,6 +508,7 @@ testNotificationSubscriptionExistingConnection APNSMockServer {apnsQ} baseId ali
   suspendAgent alice 0
   closeSQLiteStore store
   threadDelay 1000000
+  print "before opening the database from another agent"
 
   -- aliceNtf client doesn't have subscription and is allowed to get notification message
   withAgent 3 aliceCfg initAgentServers testDB $ \aliceNtf -> runRight_ $ do
@@ -515,6 +516,7 @@ testNotificationSubscriptionExistingConnection APNSMockServer {apnsQ} baseId ali
     pure ()
 
   threadDelay 1000000
+  print "after closing the database in another agent"
   reopenSQLiteStore store
   foregroundAgent alice
   threadDelay 500000
diff --git a/tests/AgentTests/SQLiteTests.hs b/tests/AgentTests/SQLiteTests.hs
index 39a4b1b95..95096e800 100644
--- a/tests/AgentTests/SQLiteTests.hs
+++ b/tests/AgentTests/SQLiteTests.hs
@@ -114,6 +114,8 @@ storeTests = do
           testDeleteRcvConn
           testDeleteSndConn
           testDeleteDuplexConn
+        describe "setConnUserId" $ do
+          testSetConnUserIdNewConn
         describe "upgradeRcvConnToDuplex" $ do
           testUpgradeRcvConnToDuplex
         describe "upgradeSndConnToDuplex" $ do
@@ -336,6 +338,21 @@ testGetRcvConn =
     getRcvConn db smpServer recipientId
       `shouldReturn` Right (rq, SomeConn SCRcv (RcvConnection cData1 rq))
 
+testSetConnUserIdNewConn :: SpecWith SQLiteStore
+testSetConnUserIdNewConn =
+  it "should set user id for new connection" . withStoreTransaction $ \db -> do
+    g <- C.newRandom
+    Right connId <- createNewConn db g cData1 {connId = ""} SCMInvitation
+    newUserId <- createUserRecord db
+    _ <- setConnUserId db 1 connId newUserId
+    connResult <- getConn db connId
+    case connResult of
+      Right (SomeConn SCNew (NewConnection connData)) -> do
+        let ConnData {userId} = connData
+        userId `shouldBe` newUserId
+      _ -> do
+         expectationFailure "Failed to get connection"
+
 testDeleteRcvConn :: SpecWith SQLiteStore
 testDeleteRcvConn =
   it "should create RcvConnection and delete it" . withStoreTransaction $ \db -> do