Fix some BlobDepot issues

32 files changed, 319 insertions, 152 deletions

diff --git a/ydb/core/base/blobstorage.h b/ydb/core/base/blobstorage.h
index bbbe1416098..42e27b391f2 100644
--- a/ydb/core/base/blobstorage.h
+++ b/ydb/core/base/blobstorage.h
@@ -875,6 +875,8 @@ struct TEvBlobStorage {
     static_assert(EvEnd < EventSpaceEnd(TKikimrEvents::ES_BLOBSTORAGE),
         "expect EvEnd < EventSpaceEnd(TKikimrEvents::ES_BLOBSTORAGE)");
 
+    struct TExecutionRelay {};
+
     struct TEvPutResult;
     struct TEvGetResult;
     struct TEvBlockResult;
@@ -914,6 +916,7 @@ struct TEvBlobStorage {
         mutable NLWTrace::TOrbit Orbit;
         ui32 RestartCounter = 0;
         std::vector<std::pair<ui64, ui32>> ExtraBlockChecks; // (TabletId, Generation) pairs
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvPut(const TLogoBlobID &id, TRcBuf &&buffer, TInstant deadline,
                NKikimrBlobStorage::EPutHandleClass handleClass = NKikimrBlobStorage::TabletLog,
@@ -986,6 +989,7 @@ struct TEvBlobStorage {
         TString ErrorReason;
         bool WrittenBeyondBarrier = false; // was this blob written beyond the barrier?
         mutable NLWTrace::TOrbit Orbit;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvPutResult(NKikimrProto::EReplyStatus status, const TLogoBlobID &id, const TStorageStatusFlags statusFlags,
                 ui32 groupId, float approximateFreeSpaceShare)
@@ -1064,6 +1068,7 @@ struct TEvBlobStorage {
         ui32 RestartCounter = 0;
         bool PhantomCheck = false;
         bool Decommission = false; // is it generated by decommission actor and should be handled by the underlying proxy?
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         struct TTabletData {
             TTabletData() = default;
@@ -1211,6 +1216,7 @@ struct TEvBlobStorage {
         TString DebugInfo;
         TString ErrorReason;
         mutable NLWTrace::TOrbit Orbit;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         // to measure blobstorage->client hop
         TInstant Sent;
@@ -1272,6 +1278,7 @@ struct TEvBlobStorage {
         const ui64 IssuerGuid = RandomNumber<ui64>() | 1;
         bool IsMonitored = true;
         ui32 RestartCounter = 0;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvBlock(ui64 tabletId, ui32 generation, TInstant deadline)
             : TabletId(tabletId)
@@ -1312,6 +1319,7 @@ struct TEvBlobStorage {
     struct TEvBlockResult : public TEventLocal<TEvBlockResult, EvBlockResult> {
         NKikimrProto::EReplyStatus Status;
         TString ErrorReason;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvBlockResult(NKikimrProto::EReplyStatus status)
             : Status(status)
@@ -1382,6 +1390,7 @@ struct TEvBlobStorage {
         const TInstant Deadline;
         mutable NLWTrace::TOrbit Orbit;
         ui32 RestartCounter = 0;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvPatch(ui32 originalGroupId, const TLogoBlobID &originalId, const TLogoBlobID &patchedId,
                 ui32 maskForCookieBruteForcing, TArrayHolder<TDiff> &&diffs, ui64 diffCount, TInstant deadline)
@@ -1508,6 +1517,7 @@ struct TEvBlobStorage {
         const float ApproximateFreeSpaceShare; // 0.f has special meaning 'data could not be obtained'
         TString ErrorReason;
         mutable NLWTrace::TOrbit Orbit;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvPatchResult(NKikimrProto::EReplyStatus status, const TLogoBlobID &id, TStorageStatusFlags statusFlags,
                 ui32 groupId, float approximateFreeSpaceShare)
@@ -1637,6 +1647,7 @@ struct TEvBlobStorage {
         const ui32 ForceBlockedGeneration;
         const bool FromLeader;
         ui32 RestartCounter = 0;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvDiscover(ui64 tabletId, ui32 minGeneration, bool readBody, bool discoverBlockedGeneration,
                 TInstant deadline, ui32 forceBlockedGeneration, bool fromLeader)
@@ -1683,6 +1694,7 @@ struct TEvBlobStorage {
         TString Buffer;
         ui32 BlockedGeneration;
         TString ErrorReason;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvDiscoverResult(NKikimrProto::EReplyStatus status, ui32 minGeneration, ui32 blockedGeneration)
             : Status(status)
@@ -1740,6 +1752,7 @@ struct TEvBlobStorage {
         ui32 ForceBlockedGeneration;
         ui32 RestartCounter = 0;
         bool Decommission = false;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvRange(ui64 tabletId, const TLogoBlobID &from, const TLogoBlobID &to, const bool mustRestoreFirst,
                 TInstant deadline, bool isIndexOnly = false, ui32 forceBlockedGeneration = 0)
@@ -1803,6 +1816,7 @@ struct TEvBlobStorage {
         TVector<TResponse> Responses;
         const ui32 GroupId;
         TString ErrorReason;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvRangeResult(NKikimrProto::EReplyStatus status, const TLogoBlobID &from, const TLogoBlobID &to, ui32 groupId)
             : Status(status)
@@ -1863,6 +1877,7 @@ struct TEvBlobStorage {
         bool Decommission = false;
 
         ui32 RestartCounter = 0;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvCollectGarbage(ui64 tabletId, ui32 recordGeneration, ui32 perGenerationCounter, ui32 channel,
                 bool collect, ui32 collectGeneration,
@@ -1972,6 +1987,7 @@ struct TEvBlobStorage {
         ui32 PerGenerationCounter;
         ui32 Channel;
         TString ErrorReason;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvCollectGarbageResult(NKikimrProto::EReplyStatus status, ui64 tabletId,
                 ui32 recordGeneration, ui32 perGenerationCounter, ui32 channel)
@@ -2005,6 +2021,7 @@ struct TEvBlobStorage {
     struct TEvStatus : public TEventLocal<TEvStatus, EvStatus> {
         const TInstant Deadline;
         ui32 RestartCounter = 0;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvStatus(TInstant deadline)
             : Deadline(deadline)
@@ -2035,6 +2052,7 @@ struct TEvBlobStorage {
         TStorageStatusFlags StatusFlags;
         float ApproximateFreeSpaceShare = 0.0f; // zero means absence of correct data
         TString ErrorReason;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvStatusResult(NKikimrProto::EReplyStatus status, TStorageStatusFlags statusFlags)
             : Status(status)
@@ -2064,6 +2082,7 @@ struct TEvBlobStorage {
         std::optional<std::tuple<ui64, ui8>> SkipBarriersUpTo;
         std::optional<TLogoBlobID> SkipBlobsUpTo;
         ui32 RestartCounter = 0;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvAssimilate(std::optional<ui64> skipBlocksUpTo, std::optional<std::tuple<ui64, ui8>> skipBarriersUpTo,
                 std::optional<TLogoBlobID> skipBlobsUpTo)
@@ -2181,6 +2200,7 @@ struct TEvBlobStorage {
         std::deque<TBlock> Blocks;
         std::deque<TBarrier> Barriers;
         std::deque<TBlob> Blobs;
+        std::shared_ptr<TExecutionRelay> ExecutionRelay;
 
         TEvAssimilateResult(NKikimrProto::EReplyStatus status, TString errorReason = {})
             : Status(status)
diff --git a/ydb/core/blob_depot/agent/agent_impl.h b/ydb/core/blob_depot/agent/agent_impl.h
index f9b9bb4ef0f..14b364cbebb 100644
--- a/ydb/core/blob_depot/agent/agent_impl.h
+++ b/ydb/core/blob_depot/agent/agent_impl.h
@@ -109,6 +109,9 @@ namespace NKikimr::NBlobDepot {
     protected:
         TBlobDepotAgent& Agent;
 
+        friend class TBlobDepotAgent;
+        std::set<std::weak_ptr<TEvBlobStorage::TExecutionRelay>, std::owner_less<std::weak_ptr<TEvBlobStorage::TExecutionRelay>>> SubrequestRelays;
+
     public:
         using TResponse = std::variant<
             // internal events
@@ -135,7 +138,8 @@ namespace NKikimr::NBlobDepot {
         TRequestSender(TBlobDepotAgent& agent);
         virtual ~TRequestSender();
         void ClearRequestsInFlight();
-        void OnRequestComplete(TRequestInFlight& requestInFlight, TResponse response);
+        void OnRequestComplete(TRequestInFlight& requestInFlight, TResponse response,
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay);
 
     protected:
         virtual void ProcessResponse(ui64 id, TRequestContext::TPtr context, TResponse response) = 0;
@@ -150,7 +154,7 @@ namespace NKikimr::NBlobDepot {
         , public TRequestSender
     {
         const ui32 VirtualGroupId;
-        const TActorId ProxyId;
+        TActorId ProxyId;
         const ui64 AgentInstanceId;
         ui64 TabletId = Max<ui64>();
         TActorId PipeId;
@@ -230,12 +234,14 @@ namespace NKikimr::NBlobDepot {
                     }
                 }
                 if (!info->GetTotalVDisksNum()) {
+                    // proxy finishes serving user requests
                     TActivationContext::Send(new IEventHandle(TEvents::TSystem::Poison, 0, ProxyId, {}, nullptr, 0));
-                    return;
+                    ProxyId = {};
                 }
             }
-
-            TActivationContext::Send(ev->Forward(ProxyId));
+            if (ProxyId) {
+                TActivationContext::Send(ev->Forward(ProxyId));
+            }
         }
 
         ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -249,7 +255,8 @@ namespace NKikimr::NBlobDepot {
         TRequestsInFlight OtherRequestInFlight;
 
         void RegisterRequest(ui64 id, TRequestSender *sender, TRequestContext::TPtr context,
-            TRequestInFlight::TCancelCallback cancelCallback, bool toBlobDepotTablet);
+            TRequestInFlight::TCancelCallback cancelCallback, bool toBlobDepotTablet,
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay = nullptr);
 
         template<typename TEvent>
         void HandleTabletResponse(TAutoPtr<TEventHandle<TEvent>> ev);
@@ -257,7 +264,8 @@ namespace NKikimr::NBlobDepot {
         template<typename TEvent>
         void HandleOtherResponse(TAutoPtr<TEventHandle<TEvent>> ev);
 
-        void OnRequestComplete(ui64 id, TRequestSender::TResponse response, TRequestsInFlight& map);
+        void OnRequestComplete(ui64 id, TRequestSender::TResponse response, TRequestsInFlight& map,
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay = nullptr);
         void DropTabletRequest(ui64 id);
 
         ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -312,6 +320,7 @@ namespace NKikimr::NBlobDepot {
             std::multimap<TMonotonic, TQuery*>::iterator QueryWatchdogMapIter;
             NLog::EPriority WatchdogPriority = NLog::PRI_WARN;
             bool Destroyed = false;
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> ExecutionRelay;
 
             static constexpr TDuration WatchdogDuration = TDuration::Seconds(10);
 
@@ -365,7 +374,9 @@ namespace NKikimr::NBlobDepot {
             TBlobStorageQuery(TBlobDepotAgent& agent, std::unique_ptr<IEventHandle> event)
                 : TQuery(agent, std::move(event))
                 , Request(*Event->Get<TEvent>())
-            {}
+            {
+                ExecutionRelay = std::move(Request.ExecutionRelay);
+            }
 
         protected:
             TEvent& Request;
diff --git a/ydb/core/blob_depot/agent/comm.cpp b/ydb/core/blob_depot/agent/comm.cpp
index a678898486d..2682683f4e6 100644
--- a/ydb/core/blob_depot/agent/comm.cpp
+++ b/ydb/core/blob_depot/agent/comm.cpp
@@ -134,7 +134,7 @@ namespace NKikimr::NBlobDepot {
         while (!TabletRequestInFlight.empty()) {
             auto node = TabletRequestInFlight.extract(TabletRequestInFlight.begin());
             auto& requestInFlight = node.value();
-            requestInFlight.Sender->OnRequestComplete(requestInFlight, TTabletDisconnected{});
+            requestInFlight.Sender->OnRequestComplete(requestInFlight, TTabletDisconnected{}, nullptr);
         }
 
         for (auto& [_, kind] : ChannelKinds) {
diff --git a/ydb/core/blob_depot/agent/proxy.cpp b/ydb/core/blob_depot/agent/proxy.cpp
index a38f53e66ee..e472b3d7919 100644
--- a/ydb/core/blob_depot/agent/proxy.cpp
+++ b/ydb/core/blob_depot/agent/proxy.cpp
@@ -4,13 +4,51 @@ namespace NKikimr::NBlobDepot {
 
     void TBlobDepotAgent::SendToProxy(ui32 groupId, std::unique_ptr<IEventBase> event, TRequestSender *sender,
             TRequestContext::TPtr context) {
+        auto executionRelay = std::make_shared<TEvBlobStorage::TExecutionRelay>();
+
+        switch (event->Type()) {
+            case TEvBlobStorage::EvPut:
+                static_cast<TEvBlobStorage::TEvPut&>(*event).ExecutionRelay = executionRelay;
+                break;
+
+            case TEvBlobStorage::EvGet:
+                static_cast<TEvBlobStorage::TEvGet&>(*event).ExecutionRelay = executionRelay;
+                break;
+        }
+
         const ui64 id = NextOtherRequestId++;
-        if (groupId == DecommitGroupId) {
+        auto getQueryId = [&] {
+            auto *p = dynamic_cast<TQuery*>(sender);
+            return p ? std::make_optional(p->GetQueryId()) : std::nullopt;
+        };
+        STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA46, "SendToProxy", (AgentId, LogId), (QueryId, getQueryId()),
+            (GroupId, groupId), (DecommitGroupId, DecommitGroupId), (Type, event->Type()), (Cookie, id));
+        if (groupId != DecommitGroupId) {
+            SendToBSProxy(SelfId(), groupId, event.release(), id);
+        } else if (ProxyId) {
             Send(ProxyId, event.release(), 0, id);
         } else {
-            SendToBSProxy(SelfId(), groupId, event.release(), id);
+            std::unique_ptr<IEventBase> response;
+            switch (const ui32 type = event->Type()) {
+                case TEvBlobStorage::EvGet: {
+                    response = static_cast<TEvBlobStorage::TEvGet&>(*event).MakeErrorResponse(NKikimrProto::OK,
+                        "proxy has vanished", groupId);
+                    event.reset(); // drop origin event to prevent extra refcounts on ExecutionRelay
+                    auto& r = static_cast<TEvBlobStorage::TEvGetResult&>(*response);
+                    for (size_t i = 0; i < r.ResponseSz; ++i) {
+                        r.Responses[i].Status = NKikimrProto::NODATA;
+                    }
+                    r.ExecutionRelay = executionRelay;
+                    break;
+                }
+
+                default:
+                    Y_FAIL("unexpected request type for decommission proxy Type# 0x%08" PRIx32, type);
+            }
+            Send(SelfId(), response.release(), 0, id);
         }
-        RegisterRequest(id, sender, std::move(context), {}, false);
+
+        RegisterRequest(id, sender, std::move(context), {}, false, std::move(executionRelay));
     }
 
 } // NKikimr::NBlobDepot
diff --git a/ydb/core/blob_depot/agent/query.cpp b/ydb/core/blob_depot/agent/query.cpp
index 495d9f09f45..947ea8b027c 100644
--- a/ydb/core/blob_depot/agent/query.cpp
+++ b/ydb/core/blob_depot/agent/query.cpp
@@ -159,6 +159,10 @@ namespace NKikimr::NBlobDepot {
         auto nh = Agent.QueryWatchdogMap.extract(QueryWatchdogMapIter);
         nh.key() = now + WatchdogDuration;
         QueryWatchdogMapIter = Agent.QueryWatchdogMap.insert(std::move(nh));
+        for (const auto& cookie : SubrequestRelays) {
+            Y_VERIFY_S(!cookie.expired(), "AgentId# " << Agent.LogId << " QueryId# " << GetQueryId()
+                << " subrequest got stuck");
+        }
     }
 
     void TBlobDepotAgent::TQuery::EndWithError(NKikimrProto::EReplyStatus status, const TString& errorReason) {
@@ -171,7 +175,9 @@ namespace NKikimr::NBlobDepot {
 #define XX(TYPE) \
             case TEvBlobStorage::TYPE: \
                 response = Event->Get<TEvBlobStorage::T##TYPE>()->MakeErrorResponse(status, errorReason, Agent.VirtualGroupId); \
-                break;
+                static_cast<TEvBlobStorage::T##TYPE##Result&>(*response).ExecutionRelay = std::move(ExecutionRelay); \
+                break; \
+            //
 
             ENUMERATE_INCOMING_EVENTS(XX)
 #undef XX
@@ -185,6 +191,16 @@ namespace NKikimr::NBlobDepot {
     void TBlobDepotAgent::TQuery::EndWithSuccess(std::unique_ptr<IEventBase> response) {
         STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA15, "query ends with success", (AgentId, Agent.LogId),
             (QueryId, GetQueryId()), (Response, response->ToString()), (Duration, TActivationContext::Monotonic() - StartTime));
+        switch (response->Type()) {
+#define XX(TYPE) \
+            case TEvBlobStorage::TYPE##Result: \
+                static_cast<TEvBlobStorage::T##TYPE##Result&>(*response).ExecutionRelay = std::move(ExecutionRelay); \
+                break; \
+            //
+
+            ENUMERATE_INCOMING_EVENTS(XX)
+#undef XX
+        }
         Agent.SelfId().Send(Event->Sender, response.release(), 0, Event->Cookie);
         OnDestroy(true);
         DoDestroy();
diff --git a/ydb/core/blob_depot/agent/read.cpp b/ydb/core/blob_depot/agent/read.cpp
index d367c21b56e..1f9816379e9 100644
--- a/ydb/core/blob_depot/agent/read.cpp
+++ b/ydb/core/blob_depot/agent/read.cpp
@@ -2,11 +2,15 @@
 
 namespace NKikimr::NBlobDepot {
 
-    struct TBlobDepotAgent::TQuery::TReadContext : TRequestContext {
+    struct TBlobDepotAgent::TQuery::TReadContext
+        : TRequestContext
+        , std::enable_shared_from_this<TReadContext>
+    {
         TReadArg ReadArg;
         const ui64 Size;
         TString Buffer;
         bool Terminated = false;
+        bool StopProcessingParts = false;
         ui32 NumPartsPending = 0;
         TLogoBlobID BlobWithoutData;
 
@@ -15,17 +19,27 @@ namespace NKikimr::NBlobDepot {
             , Size(size)
         {}
 
-        void EndWithError(TQuery *query, NKikimrProto::EReplyStatus status, TString errorReason) {
-            query->OnRead(ReadArg.Tag, status, errorReason);
-            Terminated = true;
-        }
-
         void Abort() {
             Terminated = true;
         }
 
         void EndWithSuccess(TQuery *query) {
+            Y_VERIFY(!Terminated);
             query->OnRead(ReadArg.Tag, NKikimrProto::OK, std::move(Buffer));
+            Abort();
+        }
+
+        void EndWithError(TQuery *query, NKikimrProto::EReplyStatus status, TString errorReason) {
+            Y_VERIFY(!Terminated);
+            Y_VERIFY(status != NKikimrProto::NODATA && status != NKikimrProto::OK);
+            query->OnRead(ReadArg.Tag, status, errorReason);
+            Abort();
+        }
+
+        void EndWithNoData(TQuery *query) {
+            Y_VERIFY(!Terminated);
+            query->OnRead(ReadArg.Tag, NKikimrProto::NODATA, {});
+            Abort();
         }
 
         ui64 GetTag() const {
@@ -44,7 +58,8 @@ namespace NKikimr::NBlobDepot {
 
     bool TBlobDepotAgent::TQuery::IssueRead(TReadArg&& arg, TString& error) {
         STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA34, "IssueRead", (AgentId, Agent.LogId), (QueryId, GetQueryId()),
-            (ReadId, arg.Tag), (Offset, arg.Offset), (Size, arg.Size), (Value, arg.Value));
+            (ReadId, arg.Tag), (Key, Agent.PrettyKey(arg.Key)), (Offset, arg.Offset), (Size, arg.Size),
+            (Value, arg.Value));
 
         ui64 outputOffset = 0;
 
@@ -69,7 +84,8 @@ namespace NKikimr::NBlobDepot {
             if (end <= begin || blobId.BlobSize() < end) {
                 error = "incorrect SubrangeBegin/SubrangeEnd pair";
                 STLOG(PRI_CRIT, BLOB_DEPOT_AGENT, BDA24, error, (AgentId, Agent.LogId), (QueryId, GetQueryId()),
-                    (ReadId, arg.Tag), (Offset, arg.Offset), (Size, arg.Size), (Value, arg.Value));
+                    (ReadId, arg.Tag), (Key, Agent.PrettyKey(arg.Key)), (Offset, arg.Offset), (Size, arg.Size),
+                    (Value, arg.Value));
                 return false;
             }
 
@@ -101,7 +117,8 @@ namespace NKikimr::NBlobDepot {
         if (size) {
             error = "incorrect offset/size provided";
             STLOG(PRI_ERROR, BLOB_DEPOT_AGENT, BDA25, error, (AgentId, Agent.LogId), (QueryId, GetQueryId()),
-                (ReadId, arg.Tag), (Offset, arg.Offset), (Size, arg.Size), (Value, arg.Value));
+                (ReadId, arg.Tag), (Key, Agent.PrettyKey(arg.Key)), (Offset, arg.Offset), (Size, arg.Size),
+                (Value, arg.Value));
             return false;
         }
 
@@ -128,14 +145,10 @@ namespace NKikimr::NBlobDepot {
                 partContext->Offsets.push_back(outputOffset);
             }
 
-            // when the TEvGet query is sent to the underlying proxy, MustRestoreFirst must be cleared, or else it may
-            // lead to ERROR due to impossibility of writes; all MustRestoreFirst should be handled by the TEvResolve
-            // query
-            auto event = std::make_unique<TEvBlobStorage::TEvGet>(q, sz, TInstant::Max(), context->ReadArg.GetHandleClass,
-                context->ReadArg.MustRestoreFirst && groupId != Agent.DecommitGroupId);
+            auto event = std::make_unique<TEvBlobStorage::TEvGet>(q, sz, TInstant::Max(), context->ReadArg.GetHandleClass);
             event->ReaderTabletData = context->ReadArg.ReaderTabletData;
             STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA39, "issuing TEvGet", (AgentId, Agent.LogId), (QueryId, GetQueryId()),
-                (ReadId, context->GetTag()), (GroupId, groupId), (Msg, *event));
+                (ReadId, context->GetTag()), (Key, Agent.PrettyKey(context->ReadArg.Key)), (GroupId, groupId), (Msg, *event));
             Agent.SendToProxy(groupId, std::move(event), this, std::move(partContext));
             ++context->NumPartsPending;
         }
@@ -148,57 +161,60 @@ namespace NKikimr::NBlobDepot {
     void TBlobDepotAgent::TQuery::HandleGetResult(const TRequestContext::TPtr& context, TEvBlobStorage::TEvGetResult& msg) {
         auto& partContext = context->Obtain<TReadContext::TPartContext>();
         auto& readContext = *partContext.Read;
-        STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA41, "HandleGetResult", (AgentId, Agent.LogId), (ReadId, readContext.GetTag()),
-            (Msg, msg));
-        if (readContext.Terminated) {
+        STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA41, "HandleGetResult", (AgentId, Agent.LogId), (QueryId, GetQueryId()),
+            (ReadId, readContext.GetTag()), (Key, Agent.PrettyKey(readContext.ReadArg.Key)), (Msg, msg),
+            (Terminated, readContext.Terminated));
+        if (readContext.Terminated || readContext.StopProcessingParts) {
             return; // just ignore this read
         }
 
-        if (msg.Status != NKikimrProto::OK) {
-            readContext.EndWithError(this, msg.Status, std::move(msg.ErrorReason));
-        } else {
-            Y_VERIFY(msg.ResponseSz == partContext.Offsets.size());
-
-            for (ui32 i = 0; i < msg.ResponseSz; ++i) {
-                auto& blob = msg.Responses[i];
-                if (blob.Status == NKikimrProto::NODATA) {
-                    NKikimrBlobDepot::TEvResolve resolve;
-                    auto *item = resolve.AddItems();
-                    item->SetExactKey(readContext.ReadArg.Key);
-                    Agent.Issue(std::move(resolve), this, partContext.Read);
-                    readContext.Abort();
-                    readContext.BlobWithoutData = blob.Id;
-                    return;
-                } else if (blob.Status != NKikimrProto::OK) {
-                    return readContext.EndWithError(this, blob.Status, TStringBuilder() << "failed to read BlobId# " << blob.Id);
-                }
+        Y_VERIFY(msg.ResponseSz == partContext.Offsets.size());
+
+        for (ui32 i = 0; i < msg.ResponseSz; ++i) {
+            auto& blob = msg.Responses[i];
+            if (blob.Status == NKikimrProto::NODATA) {
+                NKikimrBlobDepot::TEvResolve resolve;
+                auto *item = resolve.AddItems();
+                item->SetExactKey(readContext.ReadArg.Key);
+                item->SetMustRestoreFirst(readContext.ReadArg.MustRestoreFirst);
+                STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDAxx, "issuing extra resolve", (Agent, Agent.LogId), (QueryId, GetQueryId()),
+                    (ReadId, readContext.GetTag()), (Key, Agent.PrettyKey(readContext.ReadArg.Key)), (Msg, resolve));
+                Agent.Issue(std::move(resolve), this, readContext.shared_from_this());
+                readContext.StopProcessingParts = true;
+                readContext.BlobWithoutData = blob.Id;
+                return;
+            } else if (blob.Status != NKikimrProto::OK) {
+                return readContext.EndWithError(this, blob.Status, TStringBuilder() << "failed to read BlobId# " << blob.Id);
+            }
 
-                auto& buffer = readContext.Buffer;
-                const ui64 offset = partContext.Offsets[i];
+            auto& buffer = readContext.Buffer;
+            const ui64 offset = partContext.Offsets[i];
 
-                Y_VERIFY(offset < readContext.Size && blob.Buffer.size() <= readContext.Size - offset);
+            Y_VERIFY(offset < readContext.Size && blob.Buffer.size() <= readContext.Size - offset);
 
-                if (!buffer && !offset) {
-                    buffer = std::move(blob.Buffer);
-                    buffer.resize(readContext.Size);
-                } else {
-                    if (!buffer) {
-                        buffer = TString::Uninitialized(readContext.Size);
-                    }
-                    memcpy(buffer.Detach() + offset, blob.Buffer.data(), blob.Buffer.size());
+            if (!buffer && !offset) {
+                buffer = std::move(blob.Buffer);
+                buffer.resize(readContext.Size);
+            } else {
+                if (!buffer) {
+                    buffer = TString::Uninitialized(readContext.Size);
                 }
+                memcpy(buffer.Detach() + offset, blob.Buffer.data(), blob.Buffer.size());
             }
+        }
 
-            if (!--readContext.NumPartsPending) {
-                readContext.EndWithSuccess(this);
-            }
+        if (!--readContext.NumPartsPending) {
+            readContext.EndWithSuccess(this);
         }
     }
 
     void TBlobDepotAgent::TQuery::HandleResolveResult(const TRequestContext::TPtr& context, TEvBlobDepot::TEvResolveResult& msg) {
         auto& readContext = context->Obtain<TReadContext>();
+        if (readContext.Terminated) {
+            return;
+        }
         STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA42, "HandleResolveResult", (AgentId, Agent.LogId), (QueryId, GetQueryId()),
-            (ReadId, readContext.GetTag()), (Msg, msg.Record));
+            (ReadId, readContext.GetTag()), (Key, Agent.PrettyKey(readContext.ReadArg.Key)), (Msg, msg.Record));
         if (msg.Record.GetStatus() != NKikimrProto::OK) {
             readContext.EndWithError(this, msg.Record.GetStatus(), msg.Record.GetErrorReason());
         } else if (msg.Record.ResolvedKeysSize() == 1) {
@@ -210,18 +226,19 @@ namespace NKikimr::NBlobDepot {
                     readContext.EndWithError(this, NKikimrProto::ERROR, TStringBuilder() << "failed to restart read Error# " << error);
                 }
             } else if (!item.GetReliablyWritten()) { // this was unassimilated value and we got NODATA for it
-                readContext.EndWithError(this, NKikimrProto::NODATA, {});
+                readContext.EndWithNoData(this);
             } else {
-                Y_VERIFY_DEBUG_S(false, "data is lost AgentId# " << Agent.LogId << " QueryId# " << GetQueryId()
+                STLOG(PRI_CRIT, BLOB_DEPOT_AGENT, BDA40, "failed to read blob: data seems to be lost", (AgentId, Agent.LogId),
+                    (QueryId, GetQueryId()), (ReadId, readContext.GetTag()), (Key, Agent.PrettyKey(readContext.ReadArg.Key)),
+                    (BlobId, readContext.BlobWithoutData));
+                Y_VERIFY_DEBUG_S(false, "data seems to be lost AgentId# " << Agent.LogId << " QueryId# " << GetQueryId()
                     << " ReadId# " << readContext.GetTag() << " BlobId# " << readContext.BlobWithoutData);
-                STLOG(PRI_CRIT, BLOB_DEPOT_AGENT, BDA40, "failed to read blob -- data is lost", (AgentId, Agent.LogId),
-                    (QueryId, GetQueryId()), (ReadId, readContext.GetTag()), (BlobId, readContext.BlobWithoutData));
                 readContext.EndWithError(this, NKikimrProto::ERROR, TStringBuilder() << "failed to read BlobId# "
-                    << readContext.BlobWithoutData << ": data is lost");
+                    << readContext.BlobWithoutData << ": data seems to be lost");
             }
         } else {
             Y_VERIFY(!msg.Record.ResolvedKeysSize());
-            readContext.EndWithError(this, NKikimrProto::NODATA, {});
+            readContext.EndWithNoData(this);
         }
     }
 
diff --git a/ydb/core/blob_depot/agent/request.cpp b/ydb/core/blob_depot/agent/request.cpp
index dc830f5cecd..621d5be545d 100644
--- a/ydb/core/blob_depot/agent/request.cpp
+++ b/ydb/core/blob_depot/agent/request.cpp
@@ -36,7 +36,12 @@ namespace NKikimr::NBlobDepot {
         });
     }
 
-    void TRequestSender::OnRequestComplete(TRequestInFlight& requestInFlight, TResponse response) {
+    void TRequestSender::OnRequestComplete(TRequestInFlight& requestInFlight, TResponse response,
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay) {
+        if (executionRelay) {
+            const size_t num = SubrequestRelays.erase(executionRelay);
+            Y_VERIFY(num);
+        }
         requestInFlight.Unlink();
         ProcessResponse(requestInFlight.Id, std::move(requestInFlight.Context), std::move(response));
     }
@@ -63,11 +68,15 @@ namespace NKikimr::NBlobDepot {
     // TBlobDepotAgent machinery
 
     void TBlobDepotAgent::RegisterRequest(ui64 id, TRequestSender *sender, TRequestContext::TPtr context,
-            TRequestInFlight::TCancelCallback cancelCallback, bool toBlobDepotTablet) {
+            TRequestInFlight::TCancelCallback cancelCallback, bool toBlobDepotTablet,
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay) {
         TRequestsInFlight& map = toBlobDepotTablet ? TabletRequestInFlight : OtherRequestInFlight;
         const bool inserted = map.emplace(id, sender, std::move(context), std::move(cancelCallback),
             toBlobDepotTablet).second;
         Y_VERIFY(inserted);
+        if (executionRelay) {
+            sender->SubrequestRelays.emplace(executionRelay);
+        }
     }
 
     template<typename TEvent>
@@ -91,18 +100,20 @@ namespace NKikimr::NBlobDepot {
 
     template<typename TEvent>
     void TBlobDepotAgent::HandleOtherResponse(TAutoPtr<TEventHandle<TEvent>> ev) {
-        STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA17, "HandleOtherResponse", (AgentId, LogId),
-            (Id, ev->Cookie), (Type, TypeName<TEvent>()));
-        OnRequestComplete(ev->Cookie, ev->Get(), OtherRequestInFlight);
+        STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA17, "HandleOtherResponse", (AgentId, LogId), (Id, ev->Cookie),
+            (Type, TypeName<TEvent>()), (Msg, *ev->Get()));
+        Y_VERIFY(ev->Get()->ExecutionRelay);
+        OnRequestComplete(ev->Cookie, ev->Get(), OtherRequestInFlight, std::move(ev->Get()->ExecutionRelay));
     }
 
     template void TBlobDepotAgent::HandleOtherResponse(TEvBlobStorage::TEvGetResult::TPtr ev);
     template void TBlobDepotAgent::HandleOtherResponse(TEvBlobStorage::TEvPutResult::TPtr ev);
 
-    void TBlobDepotAgent::OnRequestComplete(ui64 id, TResponse response, TRequestsInFlight& map) {
+    void TBlobDepotAgent::OnRequestComplete(ui64 id, TResponse response, TRequestsInFlight& map,
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay) {
         if (auto node = map.extract(id)) {
             auto& requestInFlight = node.value();
-            requestInFlight.Sender->OnRequestComplete(requestInFlight, std::move(response));
+            requestInFlight.Sender->OnRequestComplete(requestInFlight, std::move(response), std::move(executionRelay));
         }
     }
 
diff --git a/ydb/core/blob_depot/agent/storage_get.cpp b/ydb/core/blob_depot/agent/storage_get.cpp
index 4e97c34738b..697dfb2d495 100644
--- a/ydb/core/blob_depot/agent/storage_get.cpp
+++ b/ydb/core/blob_depot/agent/storage_get.cpp
@@ -103,7 +103,7 @@ namespace NKikimr::NBlobDepot {
             }
 
             void OnRead(ui64 tag, NKikimrProto::EReplyStatus status, TString buffer) override {
-                STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA35, "OnRead", (AgentId, Agent.LogId),
+                STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA35, "OnRead", (AgentId, Agent.LogId), (QueryId, GetQueryId()),
                     (Tag, tag), (Status, status), (Buffer.size, status == NKikimrProto::OK ? buffer.size() : 0),
                     (ErrorReason, status != NKikimrProto::OK ? buffer : ""));
 
diff --git a/ydb/core/blob_depot/agent/storage_range.cpp b/ydb/core/blob_depot/agent/storage_range.cpp
index 70e50a56f17..d9a2b049f6b 100644
--- a/ydb/core/blob_depot/agent/storage_range.cpp
+++ b/ydb/core/blob_depot/agent/storage_range.cpp
@@ -11,7 +11,6 @@ namespace NKikimr::NBlobDepot {
 
             std::unique_ptr<TEvBlobStorage::TEvRangeResult> Response;
             ui32 ReadsInFlight = 0;
-            ui32 ResolvesInFlight = 0;
             std::map<TLogoBlobID, TString> FoundBlobs;
             std::vector<TRead> Reads;
             bool Reverse = false;
@@ -27,10 +26,7 @@ namespace NKikimr::NBlobDepot {
                 Response = std::make_unique<TEvBlobStorage::TEvRangeResult>(NKikimrProto::OK, Request.From, Request.To,
                     Agent.VirtualGroupId);
 
-                IssueResolve();
-            }
-
-            void IssueResolve() {
+                // issue resolve query
                 TString from = Request.From.AsBinaryString();
                 TString to = Request.To.AsBinaryString();
                 Reverse = Request.To < Request.From;
@@ -50,18 +46,6 @@ namespace NKikimr::NBlobDepot {
                 item->SetMustRestoreFirst(Request.MustRestoreFirst);
 
                 Agent.Issue(std::move(resolve), this, nullptr);
-                ++ResolvesInFlight;
-            }
-
-            void IssueResolve(ui64 tag) {
-                NKikimrBlobDepot::TEvResolve resolve;
-                auto *item = resolve.AddItems();
-                item->SetExactKey(Reads[tag].Id.AsBinaryString());
-                item->SetMustRestoreFirst(Request.MustRestoreFirst);
-                item->SetCookie(tag);
-
-                Agent.Issue(std::move(resolve), this, nullptr);
-                ++ResolvesInFlight;
             }
 
             void ProcessResponse(ui64 id, TRequestContext::TPtr context, TResponse response) override {
@@ -81,7 +65,8 @@ namespace NKikimr::NBlobDepot {
             }
 
             void HandleResolveResult(ui64 id, TRequestContext::TPtr context, NKikimrBlobDepot::TEvResolveResult& msg) {
-                --ResolvesInFlight;
+                STLOG(PRI_DEBUG, BLOB_DEPOT_AGENT, BDA47, "HandleResolveResult", (AgentId, Agent.LogId),
+                    (QueryId, GetQueryId()), (Msg, msg));
 
                 if (msg.GetStatus() != NKikimrProto::OK && msg.GetStatus() != NKikimrProto::OVERRUN) {
                     return EndWithError(msg.GetStatus(), msg.GetErrorReason());
@@ -139,7 +124,8 @@ namespace NKikimr::NBlobDepot {
                     case NKikimrProto::OK: {
                         Y_VERIFY(dataOrErrorReason.size() == read.Id.BlobSize());
                         const bool inserted = FoundBlobs.try_emplace(read.Id, std::move(dataOrErrorReason)).second;
-                        Y_VERIFY(inserted);
+                        Y_VERIFY_S(inserted, "AgentId# " << Agent.LogId << " QueryId# " << GetQueryId()
+                            << " duplicate BlobId# " << read.Id << " received");
                         break;
                     }
 
@@ -157,7 +143,7 @@ namespace NKikimr::NBlobDepot {
             }
 
             void CheckAndFinish() {
-                if (!ReadsInFlight && !ResolvesInFlight && !Finished) {
+                if (!ReadsInFlight && !Finished) {
                     for (auto& [id, buffer] : FoundBlobs) {
                         Y_VERIFY_S(buffer.size() == Request.IsIndexOnly ? 0 : id.BlobSize(), "Id# " << id << " Buffer.size# " << buffer.size());
                         Response->Responses.emplace_back(id, std::move(buffer));
diff --git a/ydb/core/blob_depot/data.cpp b/ydb/core/blob_depot/data.cpp
index 0ce533696a6..5251191bd47 100644
--- a/ydb/core/blob_depot/data.cpp
+++ b/ydb/core/blob_depot/data.cpp
@@ -454,7 +454,7 @@ namespace NKikimr::NBlobDepot {
             };
 
             STLOG(PRI_DEBUG, BLOB_DEPOT, BDT13, "Trim", (Id, Self->GetLogId()), (AgentId, agent.Connection->NodeId),
-                (Id, ev->Cookie), (Channel, channelIndex), (InvalidatedStep, invalidatedStep),
+                (Id, ev->Cookie), (Channel, int(channelIndex)), (InvalidatedStep, invalidatedStep),
                 (GivenIdRanges, channel.GivenIdRanges),
                 (Agent.GivenIdRanges, agent.GivenIdRanges[channelIndex]),
                 (WritesInFlight, makeWritesInFlight()));
diff --git a/ydb/core/blob_depot/data.h b/ydb/core/blob_depot/data.h
index 7231cc8226c..463b6979c7c 100644
--- a/ydb/core/blob_depot/data.h
+++ b/ydb/core/blob_depot/data.h
@@ -379,6 +379,9 @@ namespace NKikimr::NBlobDepot {
             ui64 MaxKeys = 0;
             ui32 PrechargeRows = 0;
             ui64 PrechargeBytes = 0;
+#ifndef NDEBUG
+            std::set<TKey> KeysInRange = {}; // runtime state
+#endif
         };
 
     private:
@@ -490,9 +493,8 @@ namespace NKikimr::NBlobDepot {
                 }
                 while (rowset.IsValid()) {
                     TKey key = TKey::FromBinaryKey(rowset.GetKey(), Data->Self->Config);
-                    STLOG(PRI_DEBUG, BLOB_DEPOT, BDT46, "ScanRange.Load", (Id, Data->Self->GetLogId()), (Left, left),
+                    STLOG(PRI_TRACE, BLOB_DEPOT, BDT46, "ScanRange.Load", (Id, Data->Self->GetLogId()), (Left, left),
                         (Right, right), (Key, key));
-                    LastProcessedKey.emplace(key);
                     if (left < key && key < right) {
                         TValue* const value = Data->AddDataOnLoad(key, rowset.template GetValue<Schema::Data::Value>(),
                             rowset.template GetValueOrDefault<Schema::Data::UncertainWrite>());
@@ -504,18 +506,16 @@ namespace NKikimr::NBlobDepot {
                                 Processing = Range.Flags & EScanFlags::INCLUDE_END ? key <= Range.End : key < Range.End;
                             }
                         }
-                        Processing = Processing && callback(std::move(key), *value);
+                        Processing = Processing && callback(key, *value);
                         *Progress = true;
                     } else {
                         Y_VERIFY_DEBUG(key == left || key == right);
                     }
+                    LastProcessedKey.emplace(std::move(key));
                     if (!rowset.Next()) {
                         return false; // we break iteration anyway, because we can't read more data
                     }
                 }
-                if (!LastProcessedKey || (Range.Flags & EScanFlags::REVERSE ? left < *LastProcessedKey : *LastProcessedKey < right)) {
-                    LastProcessedKey.emplace(Range.Flags & EScanFlags::REVERSE ? left : right);
-                }
                 return Processing;
             };
         };
@@ -526,7 +526,7 @@ namespace NKikimr::NBlobDepot {
 
         template<typename TCallback>
         bool ScanRange(TScanRange& range, NTabletFlatExecutor::TTransactionContext *txc, bool *progress, TCallback&& callback) {
-            STLOG(PRI_DEBUG, BLOB_DEPOT, BDT76, "ScanRange", (Id, Self->GetLogId()), (Begin, range.Begin), (End, range.End),
+            STLOG(PRI_TRACE, BLOB_DEPOT, BDT76, "ScanRange", (Id, Self->GetLogId()), (Begin, range.Begin), (End, range.End),
                 (Flags, range.Flags), (MaxKeys, range.MaxKeys));
 
             const bool reverse = range.Flags & EScanFlags::REVERSE;
@@ -534,11 +534,13 @@ namespace NKikimr::NBlobDepot {
 
             bool res = true;
 
-            auto issue = [&](TKey&& key, const TValue& value) {
+            auto issue = [&](const TKey& key, const TValue& value) {
                 Y_VERIFY_DEBUG(range.Flags & EScanFlags::INCLUDE_BEGIN ? range.Begin <= key : range.Begin < key);
                 Y_VERIFY_DEBUG(range.Flags & EScanFlags::INCLUDE_END ? key <= range.End : key < range.End);
-
-                if (!callback(key, value) || (range.MaxKeys && !--range.MaxKeys)) {
+#ifndef NDEBUG
+                Y_VERIFY(range.KeysInRange.insert(key).second); // ensure that the generated key is unique
+#endif
+                if (!callback(key, value) || !--range.MaxKeys) {
                     return false; // scan aborted by user or finished scanning the required range
                 } else {
                     // remove already scanned items from the range query
@@ -549,7 +551,7 @@ namespace NKikimr::NBlobDepot {
             const auto& from = reverse ? TKey::Min() : range.Begin;
             const auto& to = reverse ? range.End : TKey::Max();
             LoadedKeys.EnumInRange(from, to, reverse, [&](const TKey& left, const TKey& right, bool isRangeLoaded) {
-                STLOG(PRI_DEBUG, BLOB_DEPOT, BDT83, "ScanRange.Step", (Id, Self->GetLogId()), (Left, left), (Right, right),
+                STLOG(PRI_TRACE, BLOB_DEPOT, BDT83, "ScanRange.Step", (Id, Self->GetLogId()), (Left, left), (Right, right),
                     (IsRangeLoaded, isRangeLoaded), (From, from), (To, to));
                 if (!isRangeLoaded) {
                     // we have to load range (left, right), not including both ends
@@ -565,7 +567,7 @@ namespace NKikimr::NBlobDepot {
                             break;
                         } else if (range.Flags & EScanFlags::INCLUDE_BEGIN ? key < range.Begin : key <= range.Begin) {
                             return false; // just left the left side of the range
-                        } else if ((key != range.End || range.Flags & EScanFlags::INCLUDE_END) && !issue(TKey(key), value)) {
+                        } else if ((key != range.End || range.Flags & EScanFlags::INCLUDE_END) && !issue(key, value)) {
                             return false; // enough keys processed
                         }
                     }
@@ -576,11 +578,15 @@ namespace NKikimr::NBlobDepot {
                         const auto& [key, value] = *it;
                         if (range.Flags & EScanFlags::INCLUDE_END ? range.End < key : range.End <= key) {
                             return false; // just left the right side of the range
-                        } else if ((key != range.Begin || range.Flags & EScanFlags::INCLUDE_BEGIN) && !issue(TKey(key), value)) {
+                        } else if ((key != range.Begin || range.Flags & EScanFlags::INCLUDE_BEGIN) && !issue(key, value)) {
                             return false; // enough keys processed
                         }
                     }
                 }
+                if (!loader.LastProcessedKey || (reverse & EScanFlags::REVERSE ? left < *loader.LastProcessedKey :
+                        *loader.LastProcessedKey < right)) {
+                    loader.LastProcessedKey.emplace(reverse ? left : right);
+                }
                 return true;
             });
 
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy.h b/ydb/core/blobstorage/dsproxy/dsproxy.h
index ab8820c93b2..c40dc750612 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy.h
+++ b/ydb/core/blobstorage/dsproxy/dsproxy.h
@@ -131,6 +131,33 @@ NActors::NLog::EPriority PriorityForStatusOutbound(NKikimrProto::EReplyStatus st
 NActors::NLog::EPriority PriorityForStatusResult(NKikimrProto::EReplyStatus status);
 NActors::NLog::EPriority PriorityForStatusInbound(NKikimrProto::EReplyStatus status);
 
+inline void SetExecutionRelay(IEventBase& ev, std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay) {
+    switch (const ui32 type = ev.Type()) {
+#define XX(T) \
+        case TEvBlobStorage::Ev##T: \
+            static_cast<TEvBlobStorage::TEv##T&>(ev).ExecutionRelay = std::move(executionRelay); \
+            break; \
+        case TEvBlobStorage::Ev##T##Result: \
+            static_cast<TEvBlobStorage::TEv##T##Result&>(ev).ExecutionRelay = std::move(executionRelay); \
+            break; \
+        //
+
+        XX(Put)
+        XX(Get)
+        XX(Block)
+        XX(Discover)
+        XX(Range)
+        XX(CollectGarbage)
+        XX(Status)
+        XX(Patch)
+        XX(Assimilate)
+#undef XX
+
+        default:
+            Y_FAIL("unexpected event Type# 0x%08" PRIx32, type);
+    }
+}
+
 template<typename TDerived>
 class TBlobStorageGroupRequestActor : public TActor<TBlobStorageGroupRequestActor<TDerived>> {
 public:
@@ -141,7 +168,8 @@ public:
     TBlobStorageGroupRequestActor(TIntrusivePtr<TBlobStorageGroupInfo> info, TIntrusivePtr<TGroupQueues> groupQueues,
             TIntrusivePtr<TBlobStorageGroupProxyMon> mon, const TActorId& source, ui64 cookie, NWilson::TTraceId traceId,
             NKikimrServices::EServiceKikimr logComponent, bool logAccEnabled, TMaybe<TGroupStat::EKind> latencyQueueKind,
-            TInstant now, TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters, ui32 restartCounter, TString name)
+            TInstant now, TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters, ui32 restartCounter, TString name,
+            std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay)
         : TActor<TBlobStorageGroupRequestActor<TDerived>>(&TThis::InitialStateFunc, TDerived::ActorActivityType())
         , Info(std::move(info))
         , GroupQueues(std::move(groupQueues))
@@ -155,6 +183,7 @@ public:
         , LatencyQueueKind(latencyQueueKind)
         , RequestStartTime(now)
         , RacingDomains(&Info->GetTopology())
+        , ExecutionRelay(std::move(executionRelay))
     {
         TDerived::ActiveCounter(Mon)->Inc();
         Span
@@ -272,6 +301,9 @@ public:
         // make NodeWarden restart the query just after proxy reconfiguration
         Y_VERIFY_DEBUG(RestartCounter < 100);
         auto q = self.RestartQuery(RestartCounter + 1);
+        if (q->Type() != TEvBlobStorage::EvBunchOfEvents) {
+            SetExecutionRelay(*q, std::exchange(ExecutionRelay, {}));
+        }
         ++*Mon->NodeMon->RestartHisto[Min<size_t>(Mon->NodeMon->RestartHisto.size() - 1, RestartCounter)];
         const TActorId& proxyId = MakeBlobStorageProxyID(Info->GroupID);
         TActivationContext::Send(new IEventHandle(nodeWardenId, Source, q.release(), 0, Cookie, &proxyId, Span.GetTraceId()));
@@ -414,6 +446,9 @@ public:
     }
 
     void PassAway() override {
+        // ensure we didn't keep execution relay on occasion
+        Y_VERIFY_DEBUG_S(!ExecutionRelay, LogCtx.RequestPrefix << " actor died without properly sending response");
+
         // ensure that we are dying for the first time
         Y_VERIFY(!std::exchange(Dead, true));
         TDerived::ActiveCounter(Mon)->Dec();
@@ -452,6 +487,13 @@ public:
 #undef XX
         }
 
+        if (ExecutionRelay) {
+            SetExecutionRelay(*ev, std::exchange(ExecutionRelay, {}));
+            ExecutionRelayUsed = true;
+        } else {
+            Y_VERIFY(!ExecutionRelayUsed);
+        }
+
         // ensure that we are dying for the first time
         Y_VERIFY(!Dead);
         if (RequestHandleClass && PoolCounters) {
@@ -543,6 +585,8 @@ private:
     std::deque<std::unique_ptr<IEventHandle>> PostponedQ;
     TBlobStorageGroupInfo::TGroupFailDomains RacingDomains; // a set of domains we've received RACE from
     TActorId ProxyActorId;
+    std::shared_ptr<TEvBlobStorage::TExecutionRelay> ExecutionRelay;
+    bool ExecutionRelayUsed = false;
 };
 
 void Encrypt(char *destination, const char *source, size_t shift, size_t sizeBytes, const TLogoBlobID &id,
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_assimilate.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_assimilate.cpp
index 15138025e56..3e76e63db80 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_assimilate.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_assimilate.cpp
@@ -268,7 +268,7 @@ public:
             NWilson::TTraceId traceId, TInstant now, TIntrusivePtr<TStoragePoolCounters>& storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
             NKikimrServices::BS_PROXY_ASSIMILATE, false, {}, now, storagePoolCounters, ev->RestartCounter,
-            "DSProxy.Assimilate")
+            "DSProxy.Assimilate", std::move(ev->ExecutionRelay))
         , SkipBlocksUpTo(ev->SkipBlocksUpTo)
         , SkipBarriersUpTo(ev->SkipBarriersUpTo)
         , SkipBlobsUpTo(ev->SkipBlobsUpTo)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_block.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_block.cpp
index f381d505a7d..117b9f65886 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_block.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_block.cpp
@@ -139,7 +139,7 @@ public:
             TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_BLOCK, false, {}, now, storagePoolCounters, ev->RestartCounter,
-                "DSProxy.Block")
+                "DSProxy.Block", std::move(ev->ExecutionRelay))
         , TabletId(ev->TabletId)
         , Generation(ev->Generation)
         , Deadline(ev->Deadline)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_collect.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_collect.cpp
index d5875e70955..de0d07e30c5 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_collect.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_collect.cpp
@@ -111,7 +111,7 @@ class TBlobStorageGroupCollectGarbageRequest : public TBlobStorageGroupRequestAc
         auto result = std::make_unique<TEvBlobStorage::TEvCollectGarbageResult>(status, TabletId, RecordGeneration,
             PerGenerationCounter, Channel);
         result->ErrorReason = ErrorReason;
-        A_LOG_LOG_S(true, PriorityForStatusOutbound(status), "DSPC02", "Result# " << result->Print(false));
+        A_LOG_LOG_S(true, status == NKikimrProto::OK ? NLog::PRI_INFO : NLog::PRI_NOTICE, "DSPC02", "Result# " << result->Print(false));
         SendResponseAndDie(std::move(result));
     }
 
@@ -147,7 +147,7 @@ public:
             NWilson::TTraceId traceId, TInstant now, TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_COLLECT, false, {}, now, storagePoolCounters, ev->RestartCounter,
-                "DSProxy.CollectGarbage")
+                "DSProxy.CollectGarbage", std::move(ev->ExecutionRelay))
         , TabletId(ev->TabletId)
         , RecordGeneration(ev->RecordGeneration)
         , PerGenerationCounter(ev->PerGenerationCounter)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_discover.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_discover.cpp
index b9201f16922..ca296d76ad3 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_discover.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_discover.cpp
@@ -886,7 +886,7 @@ public:
             TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_DISCOVER, true, {}, now, storagePoolCounters, ev->RestartCounter,
-                "DSProxy.Discover")
+                "DSProxy.Discover", std::move(ev->ExecutionRelay))
         , TabletId(ev->TabletId)
         , MinGeneration(ev->MinGeneration)
         , ReadBody(ev->ReadBody)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3dc.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3dc.cpp
index 9a5c04380ef..31ceba6c386 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3dc.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3dc.cpp
@@ -464,7 +464,7 @@ public:
             TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(std::move(info), std::move(state), std::move(mon), source, cookie,
                 std::move(traceId), NKikimrServices::BS_PROXY_DISCOVER, false, {}, now, storagePoolCounters,
-                ev->RestartCounter, "DSProxy.Discover(mirror-3-dc)")
+                ev->RestartCounter, "DSProxy.Discover(mirror-3-dc)", std::move(ev->ExecutionRelay))
         , TabletId(ev->TabletId)
         , MinGeneration(ev->MinGeneration)
         , StartTime(now)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3of4.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3of4.cpp
index 2b350fe8a6c..4e7ff9c2ce7 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3of4.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_discover_m3of4.cpp
@@ -36,7 +36,7 @@ public:
             TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(std::move(info), std::move(state), std::move(mon), source, cookie,
                 std::move(traceId), NKikimrServices::BS_PROXY_DISCOVER, false, {}, now, storagePoolCounters,
-                ev->RestartCounter, "DSProxy.Discover(mirror-3of4)")
+                ev->RestartCounter, "DSProxy.Discover(mirror-3of4)", std::move(ev->ExecutionRelay))
         , TabletId(ev->TabletId)
         , MinGeneration(ev->MinGeneration)
         , StartTime(now)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_get.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_get.cpp
index 0b89004dd24..bd5ed008eab 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_get.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_get.cpp
@@ -465,6 +465,7 @@ class TBlobStorageGroupGetRequest : public TBlobStorageGroupRequestActor<TBlobSt
         LWPROBE(DSProxyRequestDuration, TEvBlobStorage::EvGet, requestSize, duration.SecondsFloat() * 1000.0, tabletId,
                 evResult->GroupId, channel, NKikimrBlobStorage::EGetHandleClass_Name(GetImpl.GetHandleClass()),
                 success);
+        A_LOG_LOG_S(true, success ? NLog::PRI_INFO : NLog::PRI_NOTICE, "BPG68", "Result# " << evResult->Print(false));
         return SendResponseAndDie(std::unique_ptr<TEvBlobStorage::TEvGetResult>(evResult.Release()));
     }
 
@@ -493,7 +494,8 @@ public:
             TInstant now, TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters, bool isVMultiPutMode)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_GET, ev->IsVerboseNoDataEnabled || ev->CollectDebugInfo,
-                latencyQueueKind, now, storagePoolCounters, ev->RestartCounter, "DSProxy.Get")
+                latencyQueueKind, now, storagePoolCounters, ev->RestartCounter, "DSProxy.Get",
+                std::move(ev->ExecutionRelay))
         , GetImpl(info, state, ev, std::move(nodeLayout), LogCtx.RequestPrefix)
         , Orbit(std::move(ev->Orbit))
         , Deadline(ev->Deadline)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_get_impl.h b/ydb/core/blobstorage/dsproxy/dsproxy_get_impl.h
index 5a80f045d55..81198774537 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_get_impl.h
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_get_impl.h
@@ -124,14 +124,15 @@ public:
 
     TString DumpQuery() const {
         TStringStream str;
-        str << "{";
+        str << '{';
+        str << "MustRestoreFirst# " << MustRestoreFirst;
         for (ui32 i = 0; i < QuerySize; ++i) {
-            str << (i ? " " : "")
+            str << ' '
                 << Queries[i].Id
-                << "@" << Queries[i].Shift
-                << ":" << Queries[i].Size;
+                << '@' << Queries[i].Shift
+                << ':' << Queries[i].Size;
         }
-        str << "}";
+        str << '}';
         return str.Str();
     }
 
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_impl.h b/ydb/core/blobstorage/dsproxy/dsproxy_impl.h
index 47d60411f30..8e46ae6c369 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_impl.h
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_impl.h
@@ -285,6 +285,7 @@ class TBlobStorageGroupProxy : public TActorBootstrapped<TBlobStorageGroupProxy>
             ? NKikimrProto::ERROR
             : NKikimrProto::NO_GROUP;
         auto response = ev->Get()->MakeErrorResponse(status, ErrorDescription, GroupId);
+        SetExecutionRelay(*response, std::move(ev->Get()->ExecutionRelay));
         NActors::NLog::EPriority priority = CheckPriorityForErrorState();
         LOG_LOG_S(*TlsActivationContext, priority, NKikimrServices::BS_PROXY, ExtraLogInfo << "Group# " << GroupId
                 << " HandleError ev# " << ev->Get()->Print(false)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_indexrestoreget.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_indexrestoreget.cpp
index 82499e11089..c15adde2177 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_indexrestoreget.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_indexrestoreget.cpp
@@ -35,7 +35,7 @@ class TBlobStorageGroupIndexRestoreGetRequest
     THashMap<TLogoBlobID, std::pair<bool, bool>> KeepFlags;
 
     void ReplyAndDie(NKikimrProto::EReplyStatus status) {
-        A_LOG_DEBUG_S("DSPI14", "ReplyAndDie"
+        A_LOG_INFO_S("DSPI14", "ReplyAndDie"
             << " Reply with status# " << NKikimrProto::EReplyStatus_Name(status)
             << " PendingResult# " << (PendingResult ? PendingResult->ToString().data() : "nullptr"));
         if (status != NKikimrProto::OK) {
@@ -270,7 +270,7 @@ public:
             TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_INDEXRESTOREGET, false, latencyQueueKind, now, storagePoolCounters,
-                ev->RestartCounter, "DSProxy.IndexRestoreGet")
+                ev->RestartCounter, "DSProxy.IndexRestoreGet", std::move(ev->ExecutionRelay))
         , QuerySize(ev->QuerySize)
         , Queries(ev->Queries.Release())
         , Deadline(ev->Deadline)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_multicollect.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_multicollect.cpp
index 28d623e7d77..e16fb06f16f 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_multicollect.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_multicollect.cpp
@@ -97,7 +97,7 @@ public:
             NWilson::TTraceId traceId, TInstant now, TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_MULTICOLLECT, false, {}, now, storagePoolCounters, 0,
-                "DSProxy.MultiCollect")
+                "DSProxy.MultiCollect", std::move(ev->ExecutionRelay))
         , TabletId(ev->TabletId)
         , RecordGeneration(ev->RecordGeneration)
         , PerGenerationCounter(ev->PerGenerationCounter)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_multiget.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_multiget.cpp
index e5d734c9d78..eba8d52a259 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_multiget.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_multiget.cpp
@@ -97,7 +97,7 @@ public:
             TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_MULTIGET, false, latencyQueueKind, now, storagePoolCounters, 0,
-                "DSProxy.MultiGet")
+                "DSProxy.MultiGet", std::move(ev->ExecutionRelay))
         , QuerySize(ev->QuerySize)
         , Queries(ev->Queries.Release())
         , Deadline(ev->Deadline)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_patch.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_patch.cpp
index b067f4a5f65..8950f18d7d3 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_patch.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_patch.cpp
@@ -108,7 +108,7 @@ public:
             bool useVPatch = false)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_PATCH, false, {}, now, storagePoolCounters,
-                ev->RestartCounter, "DSProxy.Patch")
+                ev->RestartCounter, "DSProxy.Patch", std::move(ev->ExecutionRelay))
         , OriginalGroupId(ev->OriginalGroupId)
         , OriginalId(ev->OriginalId)
         , PatchedId(ev->PatchedId)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_put.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_put.cpp
index 5c682482e68..a9ce350f309 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_put.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_put.cpp
@@ -329,7 +329,7 @@ class TBlobStorageGroupPutRequest : public TBlobStorageGroupRequestActor<TBlobSt
 
     void SendReply(std::unique_ptr<TEvBlobStorage::TEvPutResult> &putResult, ui64 blobIdx) {
         NKikimrProto::EReplyStatus status = putResult->Status;
-        A_LOG_LOG_S(false, status == NKikimrProto::OK ? NLog::PRI_DEBUG : NLog::PRI_NOTICE, "BPP21",
+        A_LOG_LOG_S(false, status == NKikimrProto::OK ? NLog::PRI_INFO : NLog::PRI_NOTICE, "BPP21",
             "SendReply putResult# " << putResult->ToString() << " ResponsesSent# " << ResponsesSent
             << " PutImpl.Blobs.size# " << PutImpl.Blobs.size()
             << " Last# " << (ResponsesSent + 1 == PutImpl.Blobs.size() ? "true" : "false"));
@@ -353,6 +353,7 @@ class TBlobStorageGroupPutRequest : public TBlobStorageGroupRequestActor<TBlobSt
         LWTRACK(DSProxyPutReply, PutImpl.Blobs[blobIdx].Orbit);
         putResult->Orbit = std::move(PutImpl.Blobs[blobIdx].Orbit);
         putResult->WrittenBeyondBarrier = PutImpl.WrittenBeyondBarrier[blobIdx];
+        putResult->ExecutionRelay = std::move(PutImpl.Blobs[blobIdx].ExecutionRelay);
         if (!IsManyPuts) {
             SendResponse(std::move(putResult), TimeStatsEnabled ? &TimeStats : nullptr);
         } else {
@@ -402,6 +403,7 @@ class TBlobStorageGroupPutRequest : public TBlobStorageGroupRequestActor<TBlobSt
                 item.Span.GetTraceId()
             ));
             put->RestartCounter = counter;
+            put->ExecutionRelay = std::move(item.ExecutionRelay);
         }
         return ev;
     }
@@ -429,7 +431,7 @@ public:
             bool enableRequestMod3x3ForMinLatecy)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_PUT, false, latencyQueueKind, now, storagePoolCounters,
-                ev->RestartCounter, "DSProxy.Put")
+                ev->RestartCounter, "DSProxy.Put", nullptr)
         , PutImpl(info, state, ev, mon, enableRequestMod3x3ForMinLatecy, source, cookie, Span.GetTraceId())
         , WaitingVDiskResponseCount(info->GetTotalVDisksNum())
         , Deadline(ev->Deadline)
@@ -472,7 +474,7 @@ public:
             bool enableRequestMod3x3ForMinLatecy)
         : TBlobStorageGroupRequestActor(info, state, mon, TActorId(), 0, NWilson::TTraceId(),
                 NKikimrServices::BS_PROXY_PUT, false, latencyQueueKind, now, storagePoolCounters,
-                MaxRestartCounter(events), "DSProxy.Put")
+                MaxRestartCounter(events), "DSProxy.Put", nullptr)
         , PutImpl(info, state, events, mon, handleClass, tactic, enableRequestMod3x3ForMinLatecy)
         , WaitingVDiskResponseCount(info->GetTotalVDisksNum())
         , IsManyPuts(true)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_put_impl.h b/ydb/core/blobstorage/dsproxy/dsproxy_put_impl.h
index 2695ea1ea83..52d22ffec5e 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_put_impl.h
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_put_impl.h
@@ -55,9 +55,11 @@ private:
         bool Replied = false;
         std::vector<std::pair<ui64, ui32>> ExtraBlockChecks;
         NWilson::TSpan Span;
+        std::shared_ptr<TEvBlobStorage::TExecutionRelay> ExecutionRelay;
 
         TBlobInfo(TLogoBlobID id, TRope&& buffer, TActorId recipient, ui64 cookie, NWilson::TTraceId traceId,
-                NLWTrace::TOrbit&& orbit, std::vector<std::pair<ui64, ui32>> extraBlockChecks, bool single)
+                NLWTrace::TOrbit&& orbit, std::vector<std::pair<ui64, ui32>> extraBlockChecks, bool single,
+                std::shared_ptr<TEvBlobStorage::TExecutionRelay> executionRelay)
             : BlobId(id)
             , Buffer(std::move(buffer))
             , BufferSize(Buffer.size())
@@ -66,6 +68,7 @@ private:
             , Orbit(std::move(orbit))
             , ExtraBlockChecks(std::move(extraBlockChecks))
             , Span(single ? NWilson::TSpan() : NWilson::TSpan(TWilson::BlobStorage, std::move(traceId), "DSProxy.Put.Blob"))
+            , ExecutionRelay(std::move(executionRelay))
         {}
 
         void Output(IOutputStream& s) const {
@@ -118,7 +121,7 @@ public:
         , Tactic(ev->Tactic)
     {
         Blobs.emplace_back(ev->Id, TRope(ev->Buffer), recipient, cookie, std::move(traceId), std::move(ev->Orbit),
-            std::move(ev->ExtraBlockChecks), true);
+            std::move(ev->ExtraBlockChecks), true, std::move(ev->ExecutionRelay));
 
         auto& blob = Blobs.back();
         LWPROBE(DSProxyBlobPutTactics, blob.BlobId.TabletID(), Info->GroupID, blob.BlobId.ToString(), Tactic,
@@ -147,7 +150,7 @@ public:
             Y_VERIFY(msg.HandleClass == putHandleClass);
             Y_VERIFY(msg.Tactic == tactic);
             Blobs.emplace_back(msg.Id, TRope(msg.Buffer), ev->Sender, ev->Cookie, std::move(ev->TraceId),
-                std::move(msg.Orbit), std::move(msg.ExtraBlockChecks), false);
+                std::move(msg.Orbit), std::move(msg.ExtraBlockChecks), false, std::move(msg.ExecutionRelay));
             Deadline = Max(Deadline, msg.Deadline);
 
             auto& blob = Blobs.back();
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_range.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_range.cpp
index fbcf7312169..d1783af11f8 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_range.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_range.cpp
@@ -299,7 +299,7 @@ class TBlobStorageGroupRangeRequest : public TBlobStorageGroupRequestActor<TBlob
         if (To < From) {
             std::reverse(result->Responses.begin(), result->Responses.end());
         }
-        A_LOG_LOG_S(true, PriorityForStatusOutbound(status), "DSR05", "Result# " << result->Print(false));
+        A_LOG_LOG_S(true, NLog::PRI_INFO, "DSR05", "Result# " << result->Print(false));
         SendReply(result);
     }
 
@@ -307,7 +307,7 @@ class TBlobStorageGroupRangeRequest : public TBlobStorageGroupRequestActor<TBlob
         std::unique_ptr<TEvBlobStorage::TEvRangeResult> result(new TEvBlobStorage::TEvRangeResult(
                     status, From, To, Info->GroupID));
         result->ErrorReason = ErrorReason;
-        A_LOG_LOG_S(true, PriorityForStatusOutbound(status), "DSR06", "Result# " << result->Print(false));
+        A_LOG_LOG_S(true, NLog::PRI_NOTICE, "DSR06", "Result# " << result->Print(false));
         SendReply(result);
     }
 
@@ -342,7 +342,7 @@ public:
             TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_RANGE, false, {}, now, storagePoolCounters,
-                ev->RestartCounter, "DSProxy.Range")
+                ev->RestartCounter, "DSProxy.Range", std::move(ev->ExecutionRelay))
         , TabletId(ev->TabletId)
         , From(ev->From)
         , To(ev->To)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_request.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_request.cpp
index 87b4d72b5df..6a622b7b7a2 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_request.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_request.cpp
@@ -91,6 +91,7 @@ namespace NKikimr {
             std::unique_ptr<TEvBlobStorage::TEvPutResult> result(
                     new TEvBlobStorage::TEvPutResult(NKikimrProto::ERROR, ev->Get()->Id, 0, GroupId, 0.f));
             result->ErrorReason = str.Str();
+            result->ExecutionRelay = std::move(ev->Get()->ExecutionRelay);
             LOG_ERROR_S(*TlsActivationContext, NKikimrServices::BS_PROXY,
                     "HandleNormal ev# " << ev->Get()->Print(false)
                     << " result# " << result->Print(false)
diff --git a/ydb/core/blobstorage/dsproxy/dsproxy_status.cpp b/ydb/core/blobstorage/dsproxy/dsproxy_status.cpp
index dfbe247be85..8ddf88414f2 100644
--- a/ydb/core/blobstorage/dsproxy/dsproxy_status.cpp
+++ b/ydb/core/blobstorage/dsproxy/dsproxy_status.cpp
@@ -90,7 +90,7 @@ public:
             ui64 cookie, NWilson::TTraceId traceId, TInstant now, TIntrusivePtr<TStoragePoolCounters> &storagePoolCounters)
         : TBlobStorageGroupRequestActor(info, state, mon, source, cookie, std::move(traceId),
                 NKikimrServices::BS_PROXY_STATUS, false, {}, now, storagePoolCounters,
-                ev->RestartCounter, "DSProxy.Status")
+                ev->RestartCounter, "DSProxy.Status", std::move(ev->ExecutionRelay))
         , Deadline(ev->Deadline)
         , Requests(0)
         , Responses(0)
diff --git a/ydb/core/blobstorage/dsproxy/mock/dsproxy_mock.cpp b/ydb/core/blobstorage/dsproxy/mock/dsproxy_mock.cpp
index b9404a73b12..4917dad2724 100644
--- a/ydb/core/blobstorage/dsproxy/mock/dsproxy_mock.cpp
+++ b/ydb/core/blobstorage/dsproxy/mock/dsproxy_mock.cpp
@@ -15,43 +15,50 @@ namespace NKikimr {
 
             void Handle(TEvBlobStorage::TEvPut::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM01, "TEvPut", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, Model->Handle(ev->Get()),0, ev->Cookie);
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), Model->Handle(ev->Get())), 0, ev->Cookie);
             }
 
             void Handle(TEvBlobStorage::TEvGet::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM02, "TEvGet", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, Model->Handle(ev->Get()), 0, ev->Cookie);
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), Model->Handle(ev->Get())), 0, ev->Cookie);
             }
 
             void Handle(TEvBlobStorage::TEvBlock::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM03, "TEvBlock", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, Model->Handle(ev->Get()), 0, ev->Cookie);
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), Model->Handle(ev->Get())), 0, ev->Cookie);
             }
 
             void Handle(TEvBlobStorage::TEvDiscover::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM04, "TEvDiscover", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, Model->Handle(ev->Get()), 0, ev->Cookie);
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), Model->Handle(ev->Get())), 0, ev->Cookie);
             }
 
             void Handle(TEvBlobStorage::TEvRange::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM05, "TEvRange", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, Model->Handle(ev->Get()), 0, ev->Cookie);
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), Model->Handle(ev->Get())), 0, ev->Cookie);
             }
 
             void Handle(TEvBlobStorage::TEvCollectGarbage::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM06, "TEvCollectGarbage", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, Model->Handle(ev->Get()), 0, ev->Cookie);
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), Model->Handle(ev->Get())), 0, ev->Cookie);
             }
 
             void Handle(TEvBlobStorage::TEvStatus::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM07, "TEvStatus", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, new TEvBlobStorage::TEvStatusResult(NKikimrProto::OK, Model->GetStorageStatusFlags()), 0,
-                        ev->Cookie);
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), new TEvBlobStorage::TEvStatusResult(NKikimrProto::OK,
+                    Model->GetStorageStatusFlags())), 0, ev->Cookie);
             }
 
             void Handle(TEvBlobStorage::TEvAssimilate::TPtr& ev) {
                 STLOG(PRI_DEBUG, BS_PROXY, BSPM09, "TEvAssimilate", (Msg, ev->Get()->ToString()));
-                Send(ev->Sender, new TEvBlobStorage::TEvAssimilateResult(NKikimrProto::ERROR, "not implemented"));
+                Send(ev->Sender, CopyExecutionRelay(ev->Get(), new TEvBlobStorage::TEvAssimilateResult(NKikimrProto::ERROR,
+                    "not implemented")), 0, ev->Cookie);
+            }
+
+            template<typename TOut, typename TIn>
+            TOut *CopyExecutionRelay(TIn *in, TOut *out) {
+                out->ExecutionRelay = std::move(in->ExecutionRelay);
+                return out;
             }
 
             void HandlePoison(TEvents::TEvPoisonPill::TPtr& ev) {
diff --git a/ydb/core/mind/bscontroller/virtual_group.cpp b/ydb/core/mind/bscontroller/virtual_group.cpp
index 5e25b1d46b2..80de996e32f 100644
--- a/ydb/core/mind/bscontroller/virtual_group.cpp
+++ b/ydb/core/mind/bscontroller/virtual_group.cpp
@@ -338,8 +338,10 @@ namespace NKikimr::NBsController {
         void OnPipeError(TActorId clientId) {
             if (clientId == HivePipeId) {
                 HivePipeId = {};
+                Bootstrap();
             } else if (clientId == BlobDepotPipeId) {
                 BlobDepotPipeId = {};
+                Bootstrap();
             }
         }
 
@@ -371,13 +373,12 @@ namespace NKikimr::NBsController {
             }
 
             NTabletPipe::CloseAndForgetClient(SelfId(), HivePipeId);
+            ConfigureBlobDepot();
         }
 
         void Handle(TEvHive::TEvTabletCreationResult::TPtr ev) {
             STLOG(PRI_INFO, BS_CONTROLLER, BSCVG05, "received TEvTabletCreationResult", (TabletId, Self->TabletID()),
                 (Msg, ev->Get()->Record));
-
-            ConfigureBlobDepot();
         }
 
         void ConfigureBlobDepot() {