add option to continue booting tablets when a node hits MaxTabletsScheduled KIKIMR-18947

ydb/core/mind/hive/hive_impl.cpp

@@ -1215,6 +1215,7 @@ THive::TBestNodeResult THive::FindBestNode(const TTabletInfo& tablet) {
     }
 
     TVector<TSelectedNode> selectedNodes;
+    bool thereAreNodesWithManyStarts = false;
 
     for (auto itCandidateNodes = candidateGroups.begin(); itCandidateNodes != candidateGroups.end(); ++itCandidateNodes) {
         const std::vector<TNodeInfo*>& candidateNodes(*itCandidateNodes);
@@ -1240,8 +1241,11 @@ THive::TBestNodeResult THive::FindBestNode(const TTabletInfo& tablet) {
                     }
                 } else {
                     BLOG_TRACE("[FBN] Tablet " << tablet.ToString() << " node " << nodeInfo.Id << " is not able to schedule the tablet");
-                    tablet.BootState = BootStateTooManyStarting;
-                    return TBestNodeResult(false);
+                    thereAreNodesWithManyStarts = true;
+                    if (GetBootStrategy() == NKikimrConfig::THiveConfig::HIVE_BOOT_STRATEGY_BALANCED) {
+                        tablet.BootState = BootStateTooManyStarting;
+                        return TBestNodeResult(false);
+                    }
                 }
             } else {
                 BLOG_TRACE("[FBN] Node " << nodeInfo.Id << " is not allowed"
@@ -1256,6 +1260,10 @@ THive::TBestNodeResult THive::FindBestNode(const TTabletInfo& tablet) {
         }
     }
     BLOG_TRACE("[FBN] Tablet " << tablet.ToString() << " selected nodes count " << selectedNodes.size());
+    if (selectedNodes.empty() && thereAreNodesWithManyStarts) {
+        BLOG_TRACE("[FBN] Tablet " << tablet.ToString() << " all available nodes are booting too many tablets");
+        return TBestNodeResult(false);
+    }
 
     TNodeInfo* selectedNode = nullptr;
     if (!selectedNodes.empty()) {

ydb/core/mind/hive/hive_impl.h

@@ -830,6 +830,10 @@ public:
         return CurrentConfig.GetNodeRestartsToIgnoreInWarmup();
     }
 
+    NKikimrConfig::THiveConfig::EHiveBootStrategy GetBootStrategy() const {
+        return CurrentConfig.GetBootStrategy();
+    }
+
     static void ActualizeRestartStatistics(google::protobuf::RepeatedField<google::protobuf::uint64>& restartTimestamps, ui64 barrier);
     static bool IsSystemTablet(TTabletTypes::EType type);
 

ydb/core/mind/hive/hive_ut.cpp

@@ -5532,6 +5532,33 @@ Y_UNIT_TEST_SUITE(THiveTest) {
         UNIT_ASSERT_VALUES_EQUAL(nodeTablets[4], 0);
         UNIT_ASSERT_VALUES_EQUAL(nodeTablets[5], NUM_TABLETS);
     }
+
+    Y_UNIT_TEST(TestProgressWithMaxTabletsScheduled) {
+        TTestBasicRuntime runtime(2, false);
+
+        Setup(runtime, true, 1, [](TAppPrepare& app) {
+            app.HiveConfig.SetMaxTabletsScheduled(1);
+            app.HiveConfig.SetBootStrategy(NKikimrConfig::THiveConfig::HIVE_BOOT_STRATEGY_FAST);
+        });
+
+        const ui64 hiveTablet = MakeDefaultHiveID(0);
+        const ui64 testerTablet = MakeDefaultHiveID(1);
+
+        CreateTestBootstrapper(runtime, CreateTestTabletInfo(hiveTablet, TTabletTypes::Hive), &CreateDefaultHive);
+
+        TTabletTypes::EType tabletType = TTabletTypes::Dummy;
+        TVector<ui64> tablets;
+        for (int i = 0; i < 10; ++i) {
+            THolder<TEvHive::TEvCreateTablet> ev(new TEvHive::TEvCreateTablet(testerTablet, 100500 + i, tabletType, BINDED_CHANNELS));
+            ui64 tabletId = SendCreateTestTablet(runtime, hiveTablet, testerTablet, std::move(ev), 0, true);
+            tablets.emplace_back(tabletId);
+        };
+
+        SendKillLocal(runtime, 0);
+        for (auto tablet : tablets) {
+            WaitForTabletIsUp(runtime, tablet, 1);
+        }
+    }
 }
 
 }

ydb/core/protos/config.proto

@@ -1666,6 +1666,11 @@ message THiveConfig {
         HIVE_NODE_SELECT_STRATEGY_RANDOM = 3;
     }
 
+    enum EHiveBootStrategy {
+        HIVE_BOOT_STRATEGY_BALANCED = 0;
+        HIVE_BOOT_STRATEGY_FAST = 1;
+    }
+
     optional uint64 MaxTabletsScheduled = 2 [default = 100];
     optional uint64 MaxResourceCounter = 3 [default = 100000000];
     optional uint64 MaxResourceCPU = 4 [default = 10000000];
@@ -1723,6 +1728,7 @@ message THiveConfig {
     optional uint64 MaxMovementsOnEmergencyBalancer = 57 [default = 2];
     optional bool ContinueEmergencyBalancer = 58 [default = true];
     optional double MinPeriodBetweenEmergencyBalance = 59 [default = 0.1]; // seconds
+    optional EHiveBootStrategy BootStrategy = 60 [default = HIVE_BOOT_STRATEGY_BALANCED];
 }
 
 message TDataShardConfig {