Development Task

There are some similar code with etcd watch loop:

1. pd/pkg/tso/keyspace_group_manager.go

   Line 463 in 400e3bd

   func (kgm *KeyspaceGroupManager) watchKeyspaceGroupsMetaChange(revision int64) (int64, error) {

2. pd/pkg/keyspace/tso_keyspace_group.go

   Line 299 in 400e3bd

   func (m *GroupManager) watchServiceAddrs(ctx context.Context, revision int64) (int64, error) {

3. pd/server/server.go

   Line 1772 in 400e3bd

   func (s *Server) watchServicePrimaryAddr(ctx context.Context, serviceName string, revision int64) (nextRevision int64, err error) {

4. pd/server/keyspace_service.go

   Line 72 in 400e3bd

   func (s *KeyspaceServer) WatchKeyspaces(request *keyspacepb.WatchKeyspacesRequest, stream keyspacepb.Keyspace_WatchKeyspacesServer) error {