kvserver: deflake TestConsistencyQueueRecomputeStats

The test manually adds voters and expects a leaseholder to be
established before forcing a stats re-computation (which runs on the
leaseholder). With leader leases, it might take an extra election
timeout for the leader lease to be established after adding the new
voters, so the test flaked if the re-computation ran (and failed)
before the leaseholder was ready.

This commit makes the test retry the re-computation until a leasholder
is established.

Fixes: #136596

Release note: None

pkg/kv/kvserver/consistency_queue_test.go

@@ -606,18 +606,25 @@ func testConsistencyQueueRecomputeStatsImpl(t *testing.T, hadEstimates bool) {
 		t.Fatal(err)
 	}
 
-	// Force a run of the consistency queue, otherwise it might take a while.
-	store := tc.GetFirstStoreFromServer(t, 0)
-	require.NoError(t, store.ForceConsistencyQueueProcess())
-
-	// The stats should magically repair themselves. We'll first do a quick check
-	// and then a full recomputation.
-	repl, _, err := tc.Servers[0].GetStores().(*kvserver.Stores).GetReplicaForRangeID(ctx, rangeID)
-	require.NoError(t, err)
-	ms := repl.GetMVCCStats()
-	if ms.SysCount >= sysCountGarbage {
-		t.Fatalf("still have a SysCount of %d", ms.SysCount)
-	}
+	// When running with leader leases, it might take an extra election interval
+	// for a lease to be established after adding the voters above because the
+	// leader needs to get store liveness support from the followers. The stats
+	// re-computation runs on the leaseholder and will fail if there isn't one.
+	testutils.SucceedsSoon(t, func() error {
+		// Force a run of the consistency queue, otherwise it might take a while.
+		store := tc.GetFirstStoreFromServer(t, 0)
+		require.NoError(t, store.ForceConsistencyQueueProcess())
+
+		// The stats should magically repair themselves. We'll first do a quick check
+		// and then a full recomputation.
+		repl, _, err := tc.Servers[0].GetStores().(*kvserver.Stores).GetReplicaForRangeID(ctx, rangeID)
+		require.NoError(t, err)
+		ms := repl.GetMVCCStats()
+		if ms.SysCount >= sysCountGarbage {
+			return errors.Newf("still have a SysCount of %d", ms.SysCount)
+		}
+		return nil
+	})
 
 	if delta := computeDelta(db0); delta != (enginepb.MVCCStats{}) {
 		t.Fatalf("stats still in need of adjustment: %+v", delta)