diff --git a/internal/vkgo/rpc/handlers.go b/internal/vkgo/rpc/handlers.go
index cac0cc1d5..0a9614162 100644
--- a/internal/vkgo/rpc/handlers.go
+++ b/internal/vkgo/rpc/handlers.go
@@ -43,7 +43,7 @@ func (s *Server) collectStats(localAddr net.Addr) map[string]string {
 	requestMem, _ := s.reqMemSem.Observe()
 	responseMem, _ := s.respMemSem.Observe()
 
-	workersTotal := s.workerPool.Created()
+	workersTotal, _ := s.workerPool.Created()
 
 	gc := srvfunc.GetGCStats()
 	gcPausesMs, _ := json.Marshal(gc.LastPausesMs)
diff --git a/internal/vkgo/rpc/rpc.go b/internal/vkgo/rpc/rpc.go
index b06dca85b..278334955 100644
--- a/internal/vkgo/rpc/rpc.go
+++ b/internal/vkgo/rpc/rpc.go
@@ -102,7 +102,13 @@ func (err *tagError) Error() string {
 	if err == nil {
 		return "<nil>"
 	}
-	return err.msg
+	if len(err.msg) != 0 {
+		return err.msg
+	}
+	if err.err != nil {
+		return err.err.Error()
+	}
+	return ""
 }
 
 func (err *tagError) Unwrap() error {
diff --git a/internal/vkgo/rpc/server.go b/internal/vkgo/rpc/server.go
index d806bff05..63c58514a 100644
--- a/internal/vkgo/rpc/server.go
+++ b/internal/vkgo/rpc/server.go
@@ -174,6 +174,7 @@ type Server struct {
 	statRequestsCurrent    atomic.Int64
 	statRPS                atomic.Int64
 	statHostname           string
+	statLongPollsWaiting   atomic.Int64
 
 	opts ServerOptions
 
@@ -1100,6 +1101,22 @@ func (s *Server) RequestsCurrent() int64 {
 	return s.statRequestsCurrent.Load()
 }
 
+func (s *Server) WorkersPoolSize() (current int, total int) {
+	return s.workerPool.Created()
+}
+
+func (s *Server) LongPollsWaiting() int64 {
+	return s.statLongPollsWaiting.Load()
+}
+
+func (s *Server) RequestsMemory() (current int64, total int64) {
+	return s.reqMemSem.Observe()
+}
+
+func (s *Server) ResponsesMemory() (current int64, total int64) {
+	return s.respMemSem.Observe()
+}
+
 func (s *Server) RPS() int64 {
 	return s.statRPS.Load()
 }
diff --git a/internal/vkgo/rpc/server_conn.go b/internal/vkgo/rpc/server_conn.go
index d57b068c7..4b0edd9aa 100644
--- a/internal/vkgo/rpc/server_conn.go
+++ b/internal/vkgo/rpc/server_conn.go
@@ -95,6 +95,7 @@ func (sc *serverConn) push(hctx *HandlerContext, isLongpoll bool) {
 			sc.mu.Unlock()
 			return // already released
 		}
+		sc.server.statLongPollsWaiting.Dec()
 		delete(sc.longpollResponses, resp.hctx.queryID)
 	}
 	if sc.closedFlag || hctx.noResult {
@@ -309,6 +310,7 @@ func (sc *serverConn) makeLongpollResponse(hctx *HandlerContext, canceller Hijac
 		sc.server.rareLog(&sc.server.lastHijackWarningLog, "[rpc.Server] - invariant violation, hijack response queryID collision")
 		return
 	}
+	sc.server.statLongPollsWaiting.Inc()
 	sc.longpollResponses[queryID] = hijackedResponse{canceller: canceller, hctx: hctx}
 	if debugTrace {
 		sc.server.addTrace(fmt.Sprintf("makeLongpollResponse %p %d", hctx, hctx.queryID))
@@ -331,6 +333,7 @@ func (sc *serverConn) cancelLongpollResponse(queryID int64) {
 	if debugPrint {
 		fmt.Printf("longpollResponses cancel %d\n", queryID)
 	}
+	sc.server.statLongPollsWaiting.Dec()
 	delete(sc.longpollResponses, queryID)
 	if debugTrace {
 		sc.server.addTrace(fmt.Sprintf("cancelLongpollResponse %p %d", resp.hctx, queryID))
@@ -344,6 +347,7 @@ func (sc *serverConn) cancelAllLongpollResponses() {
 	sc.mu.Lock()
 	longpollResponses := sc.longpollResponses
 	sc.longpollResponses = nil // If makeLongpollResponse is called, we'll panic. But this must be impossible if SyncHandler follows protocol
+	sc.server.statLongPollsWaiting.Sub(int64(len(longpollResponses)))
 	if debugTrace {
 		sc.server.addTrace("cancelAllLongpollResponses")
 	}
diff --git a/internal/vkgo/rpc/server_options.go b/internal/vkgo/rpc/server_options.go
index 272341308..7db12cd45 100644
--- a/internal/vkgo/rpc/server_options.go
+++ b/internal/vkgo/rpc/server_options.go
@@ -287,8 +287,7 @@ func ServerWithRequestHandler(fn RequestHandlerFunc) ServerOptionsFunc {
 	}
 }
 
-// TODO: rename ServerWithResponseHandler
-func ServerWithRequestEndHandler(fn ResponseHandlerFunc) ServerOptionsFunc {
+func ServerWithResponseHandler(fn ResponseHandlerFunc) ServerOptionsFunc {
 	return func(opts *ServerOptions) {
 		opts.ResponseHandler = fn
 	}
diff --git a/internal/vkgo/rpc/server_workerpool.go b/internal/vkgo/rpc/server_workerpool.go
index f462ac40d..3aa3c86ae 100644
--- a/internal/vkgo/rpc/server_workerpool.go
+++ b/internal/vkgo/rpc/server_workerpool.go
@@ -70,10 +70,10 @@ func (t *workerPool) Close() {
 	t.cond.Broadcast()
 }
 
-func (t *workerPool) Created() int {
+func (t *workerPool) Created() (current int, total int) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
-	return t.created
+	return t.created, t.create
 }
 
 func (t *workerPool) Get(wg *WaitGroup) (*worker, bool) {