update PRIMARY handling and error messages

Signed-off-by: Stephen Baker <[email protected]>

Author: sbaker617

go/vt/vttablet/tabletmanager/tm_init.go

@@ -383,24 +383,26 @@ func (tm *TabletManager) Start(tablet *topodatapb.Tablet, config *tabletenv.Tabl
 		existingTablet, err := tm.TopoServer.GetTablet(ctx, tablet.Alias)
 		if err != nil && !topo.IsErrType(err, topo.NoNode) {
 			// Error other than "node doesn't exist" - return it
-			return vterrors.Wrap(err, "failed to check for existing tablet record")
+			return vterrors.Wrap(err, "--init-tablet-type-lookup is enabled but failed to get existing tablet record from topology, unable to determine tablet type during startup")
 		}
 
-		// If we found an existing tablet record, use its tablet type instead of the initial one
+		// If we found an existing tablet record, check its type
 		if err == nil {
-			// Skip transient operational types (BACKUP, RESTORE)
-			// These are temporary states that should not be preserved across restarts
-			if existingTablet.Type == topodatapb.TabletType_BACKUP || existingTablet.Type == topodatapb.TabletType_RESTORE {
+			if existingTablet.Type == topodatapb.TabletType_PRIMARY {
+				// Don't set to PRIMARY yet - let checkPrimaryShip() validate and decide
+				// checkPrimaryShip() has the logic to verify shard records and determine if this tablet should really be PRIMARY
+				log.Infof("Found existing tablet record with PRIMARY type, setting to REPLICA and allowing checkPrimaryShip() to validate")
+				tablet.Type = topodatapb.TabletType_REPLICA
+			} else if existingTablet.Type == topodatapb.TabletType_BACKUP || existingTablet.Type == topodatapb.TabletType_RESTORE {
+				// Skip transient operational types (BACKUP, RESTORE)
+				// These are temporary states that should not be preserved across restarts
 				log.Infof("Found existing tablet record with transient type %v, using init-tablet-type %v instead",
 					existingTablet.Type, tablet.Type)
 			} else {
+				// Safe to restore the type for non-PRIMARY, non-transient types
 				log.Infof("Found existing tablet record with --init-tablet-type-lookup enabled, using tablet type %v from topology instead of init-tablet-type %v",
 					existingTablet.Type, tablet.Type)
 				tablet.Type = existingTablet.Type
-				// If it was a PRIMARY, preserve the start time
-				if existingTablet.Type == topodatapb.TabletType_PRIMARY {
-					tablet.PrimaryTermStartTime = existingTablet.PrimaryTermStartTime
-				}
 			}
 		} else {
 			log.Infof("No existing tablet record found, using init-tablet-type: %v", tablet.Type)

go/vt/vttablet/tabletmanager/tm_init_test.go

@@ -1036,12 +1036,21 @@ func TestInitTabletTypeLookup_PreservesPrimaryWithTermTime(t *testing.T) {
 	})
 	require.NoError(t, err)
 
-	// 3. Restart with flag enabled - should preserve PRIMARY and term start time
+	// 3. Update shard's PrimaryAlias to point to this tablet so checkPrimaryShip will promote it
+	_, err = ts.UpdateShardFields(ctx, "ks", "0", func(si *topo.ShardInfo) error {
+		si.PrimaryAlias = alias
+		si.PrimaryTermStartTime = protoutil.TimeToProto(now)
+		return nil
+	})
+	require.NoError(t, err)
+
+	// 4. Restart with flag enabled - should set to REPLICA initially, then checkPrimaryShip promotes to PRIMARY
 	initTabletTypeLookup = true
 	err = tm.Start(tablet, nil)
 	require.NoError(t, err)
 	ti, err = ts.GetTablet(ctx, alias)
 	require.NoError(t, err)
+	// Should be promoted to PRIMARY by checkPrimaryShip and preserve the term start time
 	assert.Equal(t, topodatapb.TabletType_PRIMARY, ti.Type)
 	assert.Equal(t, now.Unix(), ti.GetPrimaryTermStartTime().Unix())
 	tm.Stop()