A GC cluster is a computer system in which a cluster of nodes on which a containerized application runs is constructed. The GC cluster communicates with a first CDC cluster that is another computer system in which the cluster is constructed and to which data on the containerized application is transmitted. The GC cluster communicates with a second CDC cluster that is still another computer system in which the cluster is constructed and to which the data is transmitted instead of the first CDC cluster. The GC cluster receives a bfd packet repeatedly transmitted from the first CDC cluster. The GC cluster transmits the data to the second CDC cluster instead of the first CDC cluster when the bfd packet transmitted from the first CDC cluster has not been received.