Abstract: An overall management device decides network information on an internet GW router and a router. A cloud environment management device performs a first setting on the internet GW router based on the network information decided by the overall management device and cancels, if the first setting has failed, the first setting performed on the internet GW router. A local connection environment management device performs a second setting on the router based on the network information decided by the overall management device and cancels, if the cloud environment management device fails the first setting, the second setting performed on the router.

Abstract: A virtual resource information storing unit stores therein information on physical network device in which each virtual resource is arranged and a physical device information storing unit stores therein the number of remaining definitions of each of the physical network devices. When the device management unit is not able to add to a virtual resource arranged in a physical network device, the device management unit rearranges the virtual resource to another physical network device by using the virtual resource information storing unit and the physical device information storing unit.

Abstract: An objective of the present invention is to secure the continuity of the communication between a client device and a standby server device, when a failure occurs and switch to the standby device is performed. A communication processing unit of the client device establishes connection with a plurality of server devices simultaneously by transmitting a UDP packet to the plurality of server devices by multicast. After establishing the connection, data of the application is transmitted by multicast to the plurality of the server devices. In the even of a failure, a standby server device receives the data packet multicast from the client device to continue the inter-application communication.

Abstract: An objective of the present invention is to secure the continuity of the communication between a client device and a standby server device, when a failure occurs and switch to the standby device is performed. A communication processing unit of the client device establishes connection with a plurality of server devices simultaneously by transmitting a UDP packet to the plurality of server devices by multicast. After establishing the connection, data of the application is transmitted by multicast to the plurality of the server devices. In the even of a failure, a standby server device receives the data packet multicast from the client device to continue the inter-application communication.

Abstract: The backup server in the backup site receives messages multicast from business servers in the primary site, extracts the business data, and stores it in backup databases for each business server. Upon this storing of business data, the sequence numbers in the messages are added to the business data to be stored in the backup databases. Detection of loss in sequence numbers allows the detection of which piece of the business data is lost. The backup server does not request a business server in the primary site to retransmit data even when business data is partially lost, but instead directly requests the database server in the primary site to transmit the lost business data.

Abstract: A relay apparatus that transfers packets each including identification information specifying connection between a first apparatus and a second apparatus, a destination address, and a source address performs: receiving, from the first apparatus, a first packet in which the identification information includes encryption information obtained by encrypting an address of the first apparatus; transmitting, to the second apparatus, a second packet in which the source address of the first packet is converted into an address of the relay apparatus; receiving, from the second apparatus, a third packet in which the destination address and source address of the second packet are switched; and transmitting, to the first apparatus, a fourth packet in which the destination address is converted on the basis of the address of the first apparatus, which is obtained by decrypting encryption information included in the identification information of the third packet.

Abstract: A server-load-balancing program for establishing a permanent connection to a server in advance, and requesting the server to execute a processing request received from a client, by using the permanent connection. First, history information indicating conditions of use of at least one permanent connection in each of first time intervals into which each of at least one preceding period is divided is stored. Next, an optimum value of the number of at least one permanent connection to be established in each of second time intervals into which a coming period is divided is determined based on the history information. Then, the at least one permanent connection to the server in each of the second time intervals in the coming period is established so that the number of the at least one permanent connection in each of the second time intervals is equal to the optimum value.

Abstract: A multi-stage load distributing apparatus is constituted of a preceding stage load distributing apparatus connected to a network, a plurality of latter stage load distributing apparatuses connected to the preceding load distributing apparatus, and one or plural servers connected to each latter stage load distributing apparatus, where, after a request from a client is distributed from the preceding stage load distributing apparatus to either of the latter stage load distributing apparatuses, the request is distributed to either of the servers.

Abstract: A server-load-balancing program for establishing a permanent connection to a server in advance, and requesting the server to execute a processing request received from a client, by using the permanent connection. First, history information indicating conditions of use of at least one permanent connection in each of first time intervals into which each of at least one preceding period is divided is stored. Next, an optimum value of the number of at least one permanent connection to be established in each of second time intervals into which a coming period is divided is determined based on the history information. Then, the at least one permanent connection to the server in each of the second time intervals in the coming period is established so that the number of the at least one permanent connection in each of the second time intervals is equal to the optimum value.