VReplication: Do not delete sharded target vschema table entries on C…

…ancel (#13146) * Don't delete vschema table entries that VReplication does not create Signed-off-by: Matt Lord <[email protected]> * Update unit test accordingly Signed-off-by: Matt Lord <[email protected]> * Improve comment Signed-off-by: Matt Lord <[email protected]> * Adjust workflow complete unit test as well Signed-off-by: Matt Lord <[email protected]> * Limit this behavior change to Cancel Signed-off-by: Matt Lord <[email protected]> * Improve comment Signed-off-by: Matt Lord <[email protected]> --------- Signed-off-by: Matt Lord <[email protected]>
vitessio · May 25, 2023 · f5a460c · f5a460c
1 parent 6ab9a67
commit f5a460c
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Showing 2 changed files with 22 additions and 3 deletions.
diff --git a/go/vt/wrangler/traffic_switcher.go b/go/vt/wrangler/traffic_switcher.go
@@ -1687,6 +1687,14 @@ func (ts *trafficSwitcher) dropParticipatingTablesFromKeyspace(ctx context.Conte
 	if err != nil {
 		return err
 	}
+	// VReplication does NOT create the vschema entries in SHARDED
+	// TARGET keyspaces -- as we cannot know the proper vindex
+	// definitions to use -- and we should not delete them either
+	// (on workflow Cancel) as the user must create them separately
+	// and they contain information about the vindex definitions, etc.
+	if vschema.Sharded && keyspace == ts.TargetKeyspaceName() {
+		return nil
+	}
 	for _, tableName := range ts.Tables() {
 		delete(vschema.Tables, tableName)
 	}
@@ -1774,7 +1782,6 @@ func (ts *trafficSwitcher) removeTargetTables(ctx context.Context) error {
 	}
 
 	return ts.dropParticipatingTablesFromKeyspace(ctx, ts.TargetKeyspaceName())
-
 }
 
 func (ts *trafficSwitcher) dropTargetShards(ctx context.Context) error {

diff --git a/go/vt/wrangler/workflow_test.go b/go/vt/wrangler/workflow_test.go
@@ -455,8 +455,20 @@ func TestMoveTablesV2Cancel(t *testing.T) {
 
 	require.True(t, checkIfTableExistInVSchema(ctx, t, wf.wr.ts, "ks1", "t1"))
 	require.True(t, checkIfTableExistInVSchema(ctx, t, wf.wr.ts, "ks1", "t2"))
-	require.False(t, checkIfTableExistInVSchema(ctx, t, wf.wr.ts, "ks2", "t1"))
-	require.False(t, checkIfTableExistInVSchema(ctx, t, wf.wr.ts, "ks2", "t2"))
+
+	// Should target vschema table entries be deleted upon Cancel. For unsharded
+	// keyspaces they should be as they are empty table entries that we also
+	// create when the workflow is Created.
+	targetVSchemaEntriesRemain := false
+	if len(tme.targetShards) > 1 {
+		// If the target keyspace is sharded -- which it is today in the test -- the
+		// vschema must be created by the user before the workflow is started. Thus
+		// we should also not delete the vschema table entries upon Cancel as the
+		// management of the sharded vschema is up to the user.
+		targetVSchemaEntriesRemain = true
+	}
+	require.Equal(t, targetVSchemaEntriesRemain, checkIfTableExistInVSchema(ctx, t, wf.wr.ts, "ks2", "t1"))
+	require.Equal(t, targetVSchemaEntriesRemain, checkIfTableExistInVSchema(ctx, t, wf.wr.ts, "ks2", "t2"))
 }
 
 func TestReshardV2(t *testing.T) {