observability for tablet starts (#6584)

Author: vporyadke

ydb/core/mind/hive/hive_impl.cpp

@@ -1688,6 +1688,14 @@ void THive::UpdateCounterNodesConnected(i64 nodesConnectedDiff) {
     }
 }
 
+void THive::UpdateCounterTabletsStarting(i64 tabletsStartingDiff) {
+    if (TabletCounters != nullptr) {
+        auto& counter = TabletCounters->Simple()[NHive::COUNTER_TABLETS_STARTING];
+        auto newValue = counter.Get() + tabletsStartingDiff;
+        counter.Set(newValue);
+    }
+}
+
 void THive::RecordTabletMove(const TTabletMoveInfo& moveInfo) {
     TabletMoveHistory.PushBack(moveInfo);
     TabletCounters->Cumulative()[NHive::COUNTER_TABLETS_MOVED].Increment(1);

ydb/core/mind/hive/hive_impl.h

@@ -649,6 +649,7 @@ TTabletInfo* FindTabletEvenInDeleting(TTabletId tabletId, TFollowerId followerId
     void UpdateCounterBootQueueSize(ui64 bootQueueSize);
     void UpdateCounterEventQueueSize(i64 eventQueueSizeDiff);
     void UpdateCounterNodesConnected(i64 nodesConnectedDiff);
+    void UpdateCounterTabletsStarting(i64 tabletsStartingDiff);
     void RecordTabletMove(const TTabletMoveInfo& info);
     bool DomainHasNodes(const TSubDomainKey &domainKey) const;
     void ProcessBootQueue();

ydb/core/mind/hive/tablet_info.h

@@ -162,6 +162,7 @@ struct TTabletInfo {
     TInstant PostponedStart;
     EBalancerPolicy BalancerPolicy;
     TNodeId FailedNodeId = 0; // last time we tried to start the tablet, we failed on this node
+    TInstant BootTime;
 
     TTabletInfo(ETabletRole role, THive& hive);
     TTabletInfo(const TTabletInfo&) = delete;

ydb/core/mind/hive/tx__start_tablet.cpp

@@ -10,6 +10,7 @@ class TTxStartTablet : public TTransactionBase<THive> {
     ui64 Cookie;
     bool External;
     TSideEffects SideEffects;
+    bool Success;
 
 public:
     TTxStartTablet(TFullTabletId tabletId, const TActorId& local, ui64 cookie, bool external, THive *hive)
@@ -23,10 +24,12 @@ class TTxStartTablet : public TTransactionBase<THive> {
     TTxType GetTxType() const override { return NHive::TXTYPE_START_TABLET; }
 
     bool Execute(TTransactionContext& txc, const TActorContext&) override {
+        Success = false;
         SideEffects.Reset(Self->SelfId());
         BLOG_D("THive::TTxStartTablet::Execute Tablet " << TabletId);
         TTabletInfo* tablet = Self->FindTablet(TabletId);
         if (tablet != nullptr) {
+            tablet->BootTime = TActivationContext::Now();
             // finish fast-move operation
             if (tablet->LastNodeId != 0 && tablet->LastNodeId != Local.NodeId()) {
                 TNodeInfo* lastNode = Self->FindNode(tablet->LastNodeId);
@@ -65,6 +68,7 @@ class TTxStartTablet : public TTransactionBase<THive> {
                                 new TEvLocal::TEvBootTablet(*leader.TabletStorageInfo, promotableFollowerId, leader.KnownGeneration),
                                 IEventHandle::FlagTrackDelivery | IEventHandle::FlagSubscribeOnSession,
                                 Cookie);
+                    Success = true;
                     return true;
                 } else {
                     BLOG_W("THive::TTxStartTablet::Execute, ignoring TEvBootTablet(" << leader.ToString() << ") - wrong state or node");
@@ -79,6 +83,7 @@ class TTxStartTablet : public TTransactionBase<THive> {
                              new TEvLocal::TEvBootTablet(*follower.LeaderTablet.TabletStorageInfo, follower.Id),
                              IEventHandle::FlagTrackDelivery | IEventHandle::FlagSubscribeOnSession,
                              Cookie);
+                    Success = true;
                     return true;
                 } else {
                     BLOG_W("THive::TTxStartTablet::Execute, ignoring TEvBootTablet(" << follower.ToString() << ") - wrong state or node");
@@ -108,6 +113,9 @@ class TTxStartTablet : public TTransactionBase<THive> {
     void Complete(const TActorContext& ctx) override {
         BLOG_D("THive::TTxStartTablet::Complete Tablet " << TabletId << " SideEffects: " << SideEffects);
         SideEffects.Complete(ctx);
+        if (Success) {
+            Self->UpdateCounterTabletsStarting(+1);
+        }
     }
 };
 

ydb/core/mind/hive/tx__update_tablet_status.cpp

@@ -80,6 +80,14 @@ class TTxUpdateTabletStatus : public TTransactionBase<THive> {
             if (Status == TEvLocal::TEvTabletStatus::StatusOk) {
                 tablet->Statistics.AddRestartTimestamp(now.MilliSeconds());
                 tablet->ActualizeTabletStatistics(now);
+                if (tablet->BootTime != TInstant()) {
+                    TDuration startTime = now - tablet->BootTime;
+                    if (startTime > TDuration::Seconds(30)) {
+                        BLOG_W("Tablet " << tablet->GetFullTabletId() << " was starting for " << startTime.Seconds() << " seconds");
+                    }
+                    Self->TabletCounters->Percentile()[NHive::COUNTER_TABLETS_START_TIME].IncrementFor(startTime.MilliSeconds());
+                    Self->UpdateCounterTabletsStarting(-1);
+                }
                 TNodeInfo* node = Self->FindNode(Local.NodeId());
                 if (node == nullptr) {
                     // event from IC about disconnection of the node could overtake events from the node itself because of Pipe Server

ydb/core/protos/counters_hive.proto

@@ -29,6 +29,7 @@ enum ESimpleCounters {
     COUNTER_IMBALANCED_OBJECTS = 19 [(CounterOpts) = {Name: "ImbalancedObjects"}];
     COUNTER_WORST_OBJECT_VARIANCE = 20 [(CounterOpts) = {Name: "WorstObjectVariance"}];
     COUNTER_STORAGE_SCATTER = 21 [(CounterOpts) = {Name: "StorageScatter"}];
+    COUNTER_TABLETS_STARTING = 22 [(CounterOpts) = {Name: "TabletsStarting"}];
 }
 
 enum ECumulativeCounters {
@@ -75,6 +76,21 @@ enum EPercentileCounters {
         Ranges: { Value: 95    Name: "95%"       },
         Ranges: { Value: 100   Name: "100%"      },
     }];
+
+    COUNTER_TABLETS_START_TIME = 2 [(CounterOpts) = {
+        Name: "TabletsStartTimeMs",
+        Ranges: { Value: 1                       }
+        Ranges: { Value: 5                       }
+        Ranges: { Value: 10                      }
+        Ranges: { Value: 50                      }
+        Ranges: { Value: 100                     }
+        Ranges: { Value: 500                     }
+        Ranges: { Value: 1000                    }
+        Ranges: { Value: 5000                    }
+        Ranges: { Value: 10000                   }
+        Ranges: { Value: 30000                   }
+        Ranges: { Value: 60000                   }
+    }];
 }
 
 enum ETxTypes {