An apparatus collects information stored in a host computer through a
network. A correspondence acquirement unit acquires a correspondence
between an information identifier of requested information and host
identifiers of a plurality of host computers each of which stores the
requested information. A first decision unit decides at least one host
computer to retrieve the requested information by referring to the
correspondence. A second decision unit decides a retrieval method used
for each host computer decided by the first decision unit from a
plurality of retrieval methods. A retrieval unit indicates retrieval of
the requested information based on the retrieval method decided by the
second decision unit and each host computer decided by the first decision
unit.