allow followers in non-primary piles (#25541)

6 files changed, 65 insertions, 3 deletions

diff --git a/ydb/core/mind/hive/follower_group.h b/ydb/core/mind/hive/follower_group.h
index 6d047cfb8cb..b1cf31b95c1 100644
--- a/ydb/core/mind/hive/follower_group.h
+++ b/ydb/core/mind/hive/follower_group.h
@@ -49,6 +49,9 @@ struct TFollowerGroup {
                 }
             }
         }
+        if (RequireAllDataCenters) {
+            NodeFilter.MustBePrimaryPile = false;
+        }
         LocalNodeOnly = followerGroup.GetLocalNodeOnly();
         RequireDifferentNodes = followerGroup.GetRequireDifferentNodes();
         FollowerCountPerDataCenter = followerGroup.GetFollowerCountPerDataCenter();
diff --git a/ydb/core/mind/hive/hive.cpp b/ydb/core/mind/hive/hive.cpp
index be3780246b1..ac5ee9e6d3e 100644
--- a/ydb/core/mind/hive/hive.cpp
+++ b/ydb/core/mind/hive/hive.cpp
@@ -108,7 +108,15 @@ bool TNodeFilter::IsAllowedDataCenter(TDataCenterId dc) const {
 }
 
 bool TNodeFilter::IsAllowedPile(TBridgePileId pile) const {
-    return Hive->IsAllowedPile(pile);
+    if (MustBePrimaryPile) {
+        return Hive->IsPrimaryPile(pile);
+    } else {
+        const auto* pileInfo = Hive->FindPile(pile);
+        if (!pileInfo) {
+            return false;
+        }
+        return pileInfo->State == NKikimrBridge::TClusterState::SYNCHRONIZED;
+    }
 }
 
 template <typename K, typename V>
diff --git a/ydb/core/mind/hive/hive.h b/ydb/core/mind/hive/hive.h
index 69a92e4e8d8..871a5db95cc 100644
--- a/ydb/core/mind/hive/hive.h
+++ b/ydb/core/mind/hive/hive.h
@@ -329,6 +329,7 @@ struct TNodeFilter {
     TVector<TDataCenterId> AllowedDataCenters;
     TSubDomainKey ObjectDomain;
     TTabletTypes::EType TabletType = TTabletTypes::TypeInvalid;
+    bool MustBePrimaryPile = true;
 
     const THive* Hive;
 
diff --git a/ydb/core/mind/hive/hive_impl.cpp b/ydb/core/mind/hive/hive_impl.cpp
index 8464cd3bbef..2874e5ed013 100644
--- a/ydb/core/mind/hive/hive_impl.cpp
+++ b/ydb/core/mind/hive/hive_impl.cpp
@@ -3015,7 +3015,7 @@ void THive::ProcessPendingResumeTablet() {
     }
 }
 
-bool THive::IsAllowedPile(TBridgePileId pile) const {
+bool THive::IsPrimaryPile(TBridgePileId pile) const {
     if (BridgeInfo->BeingPromotedPile) {
         return BridgeInfo->BeingPromotedPile->BridgePileId == pile;
     } else {
@@ -3028,6 +3028,14 @@ TBridgePileInfo& THive::GetPile(TBridgePileId pileId) {
     return it->second;
 }
 
+const TBridgePileInfo* THive::FindPile(TBridgePileId pileId) const {
+    auto it = BridgePiles.find(pileId);
+    if (it == BridgePiles.end()) {
+        return nullptr;
+    }
+    return &it->second;
+}
+
 void THive::UpdatePiles() {
     Execute(CreateUpdatePiles());
 }
diff --git a/ydb/core/mind/hive/hive_impl.h b/ydb/core/mind/hive/hive_impl.h
index d5d15d224c1..a5f80bda0f4 100644
--- a/ydb/core/mind/hive/hive_impl.h
+++ b/ydb/core/mind/hive/hive_impl.h
@@ -742,8 +742,9 @@ TTabletInfo* FindTabletEvenInDeleting(TTabletId tabletId, TFollowerId followerId
     void BlockStorageForDelete(TTabletId tabletId, TSideEffects& sideEffects);
     void ProcessPendingStopTablet();
     void ProcessPendingResumeTablet();
-    bool IsAllowedPile(TBridgePileId pile) const;
+    bool IsPrimaryPile(TBridgePileId pile) const; // NOTE: this counts promoted pile as primary
     TBridgePileInfo& GetPile(TBridgePileId pileId);
+    const TBridgePileInfo* FindPile(TBridgePileId pileId) const;
     void UpdatePiles();
 
     ui32 GetEventPriority(IEventHandle* ev);
diff --git a/ydb/core/mind/hive/hive_ut.cpp b/ydb/core/mind/hive/hive_ut.cpp
index e3bf7370103..dd9b1f0e76b 100644
--- a/ydb/core/mind/hive/hive_ut.cpp
+++ b/ydb/core/mind/hive/hive_ut.cpp
@@ -8818,6 +8818,47 @@ Y_UNIT_TEST_SUITE(THiveTest) {
         UNIT_ASSERT(!distribution[0].empty());
 
     }
+
+    Y_UNIT_TEST(TestBridgeFollowers) {
+        static constexpr ui32 NUM_NODES = 4;
+        TTestBasicRuntime runtime(NUM_NODES, 2u);
+        TDummyBridge bridge(runtime);
+        Setup(runtime, true);
+        const ui64 hiveTablet = MakeDefaultHiveID();
+        const ui64 testerTablet = MakeTabletID(false, 1);
+        CreateTestBootstrapper(runtime, CreateTestTabletInfo(hiveTablet, TTabletTypes::Hive), &CreateDefaultHive);
+        {
+            TDispatchOptions options;
+            options.FinalEvents.emplace_back(TEvLocal::EvSyncTablets, runtime.GetNodeCount());
+            runtime.DispatchEvents(options);
+        }
+        TTabletTypes::EType tabletType = TTabletTypes::Dummy;
+
+        THolder<TEvHive::TEvCreateTablet> create(new TEvHive::TEvCreateTablet(testerTablet, 100500, tabletType, BINDED_CHANNELS));
+        create->Record.SetObjectId(1);
+        auto* followerGroup = create->Record.AddFollowerGroups();
+        followerGroup->SetFollowerCount(1);
+        followerGroup->SetFollowerCountPerDataCenter(true);
+        followerGroup->SetRequireAllDataCenters(true);
+        ui64 tabletId = SendCreateTestTablet(runtime, hiveTablet, testerTablet, std::move(create), 0, true);
+        MakeSureTabletIsUp(runtime, tabletId, 0);
+
+        NTabletPipe::TClientConfig pipeConfig;
+        pipeConfig.ForceLocal = true;
+        pipeConfig.AllowFollower = true;
+        pipeConfig.ForceFollower = true;
+        ui32 followers = 0;
+        for (ui32 node = 0; node < NUM_NODES; ++node) {
+            bool leader;
+            if (CheckTabletIsUp(runtime, tabletId, node, &pipeConfig, &leader)) {
+                if (!leader) {
+                    followers++;
+                }
+            }
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(followers, 2); // followers in both piles
+    }
 }
 
 Y_UNIT_TEST_SUITE(THeavyPerfTest) {