JP3487430B2 - Server application multiplex communication system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TCP / IP (Tr.
enmission Control Protocol
(Internet / Internet Protocol) The present invention relates to a communication system connected to one or more client computers via a network, and in particular, server application multiplex communication in which a plurality of server computers have the same server application assigned the same port number. Regarding the system.

[0002]

2. Description of the Related Art As is well known, in the TCP / IP protocol, transmission data created in an application layer is used to identify a source port number and a destination application for identifying a source application in a transport layer. Destination port number is added as a protocol header, and the source IP (I
network protocol) and a destination IP address for identifying a destination computer are added as a protocol header, and in addition, a source MAC (Media Acc) for identifying the source communication hardware at the network interface layer.
ess Control) address and the destination MAC address for identifying the destination communication hardware are added as a protocol header and sent to the TCP / IP network.

Therefore, in the TCP / IP protocol,
Since one server application is specified by the combination of IP address and port number, NIC
In a conventional server computer in which only one IP address can be set for one communication hardware such as (Network Interface Card), a server application that waits for an incoming call at a port with a certain port number is also used on one communication hardware. Was limited to one.

However, for example, in order to distribute the load or to prepare for an unexpected failure, it is possible to operate a plurality of the same server applications to which the same port number is assigned.
With one MAC address, the number of server applications to which the same port number was assigned was limited to one, so it was necessary to handle not only the IP address but also a new MAC address.

In view of such a point, an IP address multiplexing system that allows a plurality of IP addresses to be set for one communication hardware is disclosed in Japanese Patent Laid-Open No. 10-1359.
No. 82 publication. In this conventional IP address multiplexing method, a loopback driver is provided separately from the network driver in order to assign two different IP addresses to one MAC address.
One of the two IP addresses is assigned to the network driver, and the other IP address is assigned to the loopback driver.

[0006]

However, this conventional technique has the following problems.

[0007] The first problem is that the processing overhead in mounting is large. The reason is that the IP address multiplexing is implemented by the loopback driver.

The second problem is that it cannot be applied to the same server application operating on a plurality of server computers and assigned the same port number. The reason is that it is premised that the network driver and the loopback driver operate on the same server computer.

An object of the present invention is to allow a plurality of server computers to share one NIC of a communication processing device and to assign an IP address to each server computer so that the same server application to which the same port number is assigned is provided. Another object of the present invention is to provide a server application multiplexing communication system that can be used by a plurality of server computers.

Another object of the present invention is that a plurality of server computers share one NIC of a communication processing device,
Provided is a server application multiplex communication system in which a common IP address is assigned to a plurality of server computers to a communication processing device so that the same server application assigned the same port number can be used in a plurality of server computers. Especially.

As another prior art, Japanese Unexamined Patent Publication No. 20
There is a "network switching method applied to a network system" described in 00-115225.
This method is based on LAN (Local Area Network).
rk) High availability is required by duplicating the segment, which is completely different from the present invention which does not depend on the LAN configuration.

Further, "ATM device supporting multiple IP addresses" described in Japanese Patent Laid-Open No. 2000-307587.
There is an ATM (Asyncronou
s Transfer Mode) —The present invention is specialized for a LAN network, and the present invention, which is based on the TCP / IP protocol, is more versatile.

Further, there is a "method for connecting a wireless terminal device to a data transmission network and a wireless terminal device" described in Japanese Patent Laid-Open No. 11-355322. This method and device wirelessly use a plurality of NICs. The present invention relates to an apparatus and method for performing communication, and is a system for performing communication with a plurality of server computers by setting a plurality of IP addresses for one NIC.
It is completely different from the original configuration.

[0014]

In a server application multiplexed communication system of the present invention, a plurality of server computers are connected to a communication processing device, and the communication processing device is connected to a TC.
In a communication system connected to one or more client computers via a P / IP network,
Each of the plurality of server computers has a different IP
The communication processing device includes the same server application to which the address is assigned and the same port number is assigned,
A NIC connected to the P network and assigned a MAC address, a server computer / IP address correspondence table that manages the correspondence between the server computer and the IP address, and an IP address / MAC that manages the correspondence between the IP address and the MAC address. Address correspondence table and IP notified from the server computer on which the server application is started when the server application is started
The address is registered in the IP address / MAC address correspondence table in association with the MAC address assigned to the NIC, and based on the destination IP address in the ARP request packet when the ARP request packet is received from the client application. The IP
A MAC address is acquired from the address / MAC address correspondence table, and an ARP response packet including the MAC address is returned to the client application.
The CP / IP control means and the server computer / IP by associating the IP address notified from the server computer on which the server application is started at the time of starting the server application with the server computer.
The server computer is registered in the address correspondence table, and when the connection request packet is received from the client application, the server computer is specified from the server computer / IP address correspondence table based on the destination IP address in the connection request packet And server distribution means for distributing connection requests.

In the server application multiplexed communication system of the present invention, a plurality of server computers are connected to a communication processing device, and the communication processing device is connected to one or more client computers via a TCP / IP network. In the communication system, the plurality of server computers include port switching means for commanding port switching, and are equipped with the same server application to which the same port number is assigned. An IP address commonly assigned to a plurality of server computers and a MAC connected to the TCP / IP network.
An NIC to which an address is assigned, a port number / operation / standby state and a port number state / server computer correspondence table that manages correspondence between server computers, and an IP address / managing correspondence between the IP address and the MAC address / The MAC address correspondence table and the start of the connection request when the server application is started, and when the ARP request packet is received from the client application, the IP address / M is used based on the destination IP address in the ARP request packet.
The MAC address is acquired from the AC address correspondence table and the M
TCP / IP control means for responding to the client application with an ARP response packet including an AC address, and correspondence between port numbers and operating / standby states and server computers according to command instructions from the port switching means. While registering in the computer correspondence table, when the connection request packet is received from the client application, the operating state server computer is specified from the port number status / server computer correspondence table based on the destination port number in the connection request packet. , And port allocation means for allocating connection requests to the server computer.

On the other hand, in the server application multiplexed communication method of the present invention, when the server application is started, the IP address notified from the server computer where the server application is started is made to correspond to the server computer, and the server computer / IP address correspondence is made. The step of registering in the table, and the IP address notified from the server computer on which the server application is started at the time of starting the server application is made to correspond to the MAC address assigned to the NIC, and the IP address / M
The step of registering in the AC address correspondence table, and when the ARP request packet from the client application is received, the MAC address is obtained from the IP address / MAC address correspondence table based on the destination IP address in the ARP request packet AR including address
A step of responding to the client application with a P response packet, and specifying a server computer from the server computer / IP address correspondence table based on the destination IP address in the connection request packet when receiving the connection request packet from the client application And a step of allocating the connection request to the server computer.

Further, the server application multiplex communication method of the present invention uses the port number and the operation / operation according to the command instruction from the port switching means of the server computer.
The step of registering the correspondence between the standby state and the server computer in the port number state / server computer correspondence table, the step of starting the acceptance of the connection request when the server application is activated in the server computer, and the ARP request from the client application. When a packet is received, M is selected from the IP address / MAC address correspondence table based on the destination IP address in the ARP request packet.
ARP including AC address and MAC address
A step of responding a response packet to the client application, and a server in the operating state from the port number status / server computer correspondence table based on the destination port number in the connection request packet when the connection request packet is received from the client application Identifying the computer and allocating the connection request to the server computer.

On the other hand, the program of the present invention causes the computer to associate the IP address notified from the server computer on which the server application is started when the server application is started with the MAC address assigned to the NIC. The address is registered in the address correspondence table, and at the time of receiving the ARP request packet from the client application, the I address is based on the destination IP address in the ARP request packet.
TCP / IP control means for acquiring a MAC address from the P address / MAC address correspondence table and returning an ARP response packet containing the MAC address to the client application; and a server on which the server application is started when the server application is started. The IP address notified by the computer is associated with the server computer, and the server computer / I
The server is registered in the P address correspondence table, and at the time of receiving the connection request packet from the client application, the server computer is specified from the server computer / IP address correspondence table based on the destination IP address in the connection request packet, and the server concerned. It is characterized by causing a computer to function as a server distribution means for distributing connection requests.

Further, the program of the present invention causes the computer to start accepting a connection request when the server application is activated, and at the time of receiving the ARP request packet from the client application, based on the destination IP address in the ARP request packet. TC that acquires a MAC address from the IP address / MAC address correspondence table and sends an ARP response packet including the MAC address to the client application
The P / IP control unit and the port switching unit register the correspondence between the port number and the operating / standby state and the server computer in the port number state / server computer correspondence table according to the command instruction, and the connection request packet from the client application. When receiving, the server computer in the operating state is identified from the port number status / server computer correspondence table based on the destination port number in the connection request packet, and it functions as a port distribution means that distributes the connection request to the server computer. Is characterized by.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(1) First Embodiment Referring to FIG. 1, a server application multiplexing communication system according to a first embodiment of the present invention includes a plurality of server computers 10 and 20 and a plurality of server computers. The communication processing device 30 to which the units 10 and 20 are connected and one or more client computers 50 to which the communication processing device 30 is connected via a TCP / IP network 40 form a main part.

The server computers 10 and 20 have different IP addresses 11 and 21 and the same server application 1 to which the same port number 1 is assigned.
2 and 22 are included. IP addresses 11 and 21 are TCP
/ Server computer 10 on the IP network 40,
ID for identifying 20 (IDentificati
on).

The server applications 12 and 22 use the IP addresses 11 and 21 assigned to the server computers 10 and 20 to send a connection request addressed to the IP addresses 11 and 21 to the server distribution means 34 in the communication processing device 30. Instruct to start reception.

The communication processing device 30 includes a NIC 31 connected to the TCP / IP network 40, a MAC address 32 uniquely assigned to the NIC 31, and a TCP / I.
TCP / IP control means 33 for controlling communication with the P protocol and server distribution means 34 for distributing connection requests to the server computers 10 and 20 using IP addresses.
And server computers 10 and 20 and IP address 1
Server computer / I in which correspondence with 1 and 12 is registered
P address correspondence table 35, IP addresses 11, 21 and M
IP address / correspondence with AC address 32 /
And a MAC address correspondence table 36.

The TCP / IP control means 33 uses the TCP / I
It has a function of interpreting a packet conforming to the P protocol and passing it to an upper application layer. In addition, TCP / I
The P control means 33 requests the MAC address 32 corresponding to the IP address in order to allocate the plurality of IP addresses 11 and 12 to the MAC address 32.
(Address Resolution Proto
col) IP address / M for request packet
MAC address 32 by referring to the AC address correspondence table 36
Has a function of responding to an ARP response packet including

The client computer 50 includes a client application 51.

At the time of connection request, the client application 51 has port numbers (destination port numbers) 1 of the server applications 12 and 22 and IP addresses (destination IP address) 1 of the server computers 10 and 20.
1, 21 and the MAC address of the NIC 31 (destination MA
C address) and.

Referring to FIG. 2, the server computer /
The IP address correspondence table 35 includes the server computer 10,
20 manages the correspondence between IP addresses 11 and 21. Specifically, the IP address 11 is registered for the server computer 10, and the IP address 21 is registered for the server computer 20.

Referring to FIG. 3, IP address / MAC
The address correspondence table 36 includes IP addresses 11 and 21 and MA.
The correspondence with the C address 32 is managed. Specifically, IP
MAC corresponding to address 11 and IP address 21
Register the address 32.

Referring to FIG. 4, the server computer 1
The processing when the server applications 12 and 22 in 0 and 20 are started is performed by the server application starting step S101 and the IP address registration instruction step S10.
2, step S103 of registering the IP address in the server computer / IP address correspondence table, and step S104 of registering the IP address in the IP address / MAC address correspondence table.

Referring to FIG. 5, the process when a connection request is generated in the client application 51 is the connection request generation step S201 in the client application.
An ARP request packet broadcasting step S202, an ARP response packet response step S203, a connection request packet sending step S204 from the client application, and a distribution destination server computer identification and distribution step S205.

Next, the operation of the server application multiplexing communication system according to the first embodiment configured as described above will be described in detail with reference to FIGS. 1 to 5.

First, the operation when the server applications 12 and 22 in the server computers 10 and 20 are activated will be described (see FIG. 4). Here, a case where the server application 12 is activated in the server computer 10 will be described as an example.

When the server application 12 is activated in the server computer 10 (step S10)
1) Instruct the communication processing device 30 to register the IP address 11 of its own server computer 10 (step S10).
2).

In the communication processing device 30, the server distribution means 34 uses the IP address 11 to cause the TCP / IP control means 33 to start accepting a connection request addressed to the IP address 11, and the IP address 11 is sent to the server. Server computer / I corresponding to computer 10
Register in the P address correspondence table 35 (step S10)
3).

Next, the TCP / IP control means 33 causes the IP
The MAC address 32 is registered in the IP address / MAC address correspondence table 36 corresponding to the address 11 (step S104).

The same operation is performed when the server application 22 is activated in the server computer 20.

Next, the client application 5
The operation when a connection request is generated in No. 1 will be described (see FIG. 5).
However, a case where the destination IP address is the IP address 11 will be described here as an example.

The client computer 50 is triggered by the generation of a connection request from the client application 51 to the server application 12 (step S2).
01), the client application 51 broadcasts an ARP request packet requesting the MAC address corresponding to the destination IP address 11 to the TCP / IP network 40 (step S202).

In the communication processing device 30, the TCP / IP control means 33 controls the destination IP in the ARP request packet.
The MAC address 32 is acquired from the IP address / MAC address correspondence table 36 based on the address 11 and an ARP response packet including the MAC address 32 is returned to the client application 51 (step S20).
3).

In the client computer 50, the AR
When the P response packet is received, the client application 51 sends the destination port number 1, the destination IP
A TCP / IP packet (connection request packet) of a connection request including the address 11 and the destination MAC address 32 is sent to the TCP / IP network 40 (step S).
204).

In the communication processing device 30, the connection request packet on the TCP / IP network 40 is sent to the MAC address 3
The second NIC 31 receives, and the server distribution means 34
Based on the destination IP address 11 in the connection request packet, the server computer / IP address correspondence table 35 is used to identify the destination server computer 10, and the connection request is assigned to the server computer 10 (step S20).
5).

As a result, the client application 51 is connected to the server application 12 and can communicate with the server application 12.

The client application 51
However, when the ARP request packet requesting the MAC address corresponding to the destination IP address 21 is transmitted, the communication processing device 30 specifies the server computer 20 as the distribution destination server computer, and the client application 51 , Will be connected to the server application 22.

According to the first embodiment, a communication processing device 30 to which a plurality of server computers 10 and 20 are connected.
A plurality of IP addresses 11 for one NIC 31 of
Since it has been made possible to assign the same port number 21, the same server application 12, 2 assigned the same port number 1 by a plurality of server computers 10, 20.
2 can be selectively used from the client application 51.

Since different IP addresses 11 and 21 can be assigned to the server computers 10 and 20, the same server application 12 and 22 to which the same port number 1 is assigned can be assigned to a plurality of server computers 10 and 20. By using it, it becomes possible to distribute the loads on the plurality of server computers 10 and 20.

(2) Second Embodiment Referring to FIG. 6, a server application multiplexing communication system according to a second embodiment of the present invention includes a plurality of server computers 10 and 20 and a plurality of server computers. The communication processing device 30 to which the units 10 and 20 are connected and one or more client computers 50 to which the communication processing device 30 is connected via a TCP / IP network 40 form a main part.

The server computers 10 and 20 include the same server applications 12 and 22 assigned the same port number 1, and port switching means 13 and 23.

The server applications 12 and 22 instruct the communication processing device 30 to start accepting a connection request addressed to the IP address 37 at the time of activation.

The port switching means 13 and 23 are the server applications 12 and 22 in the operating state or the standby state.
Command switching to the communication processing device 30.

The communication processing device 30 includes a NIC 31 connected to the TCP / IP network 40, a MAC address 32 uniquely assigned to the NIC 31, and a TCP / I.
TCP / IP control means 33 for controlling communication by the P protocol, IP address / MAC address correspondence table 36,
It includes an IP address 37 that is assigned to the communication processing device 30 by grouping a plurality of server computers 10 and 20, a port allocation unit 38, and a port number status / server computer correspondence table 39.

The port allocating means 38 uses TCP / IP.
The control means 33 is made to start accepting the connection request addressed to the IP address, and in cooperation with the port switching means 13, 23 in the server computers 10, 20, the port number 1 of the server applications 12, 22 and the operating / standby state are set as ports. The number status / server computer correspondence table 39 is used for management.

Referring to FIG. 7, the port number status / server computer correspondence table 39 manages the correspondence between the port number 1 and the operating / standby status and the server computers 10 and 20. Specifically, the server application 12,
The operating state and the server computer 10 and the standby state and the server computer 20 are registered in correspondence with the port number 1 common to all 22.

Referring to FIG. 8, the server computer 1
When the server applications 12 and 22 in 0 and 20 are started, the server application starting step S301, the connection request reception start instruction step S302 to the communication processing device, and the connection request reception start step S303 to the IP address are executed. Consists of.

Referring to FIG. 9, the process when a connection request is issued from the client application 51 in the client computer 50 is as follows: connection request generation step S401 in client application, ARP request packet broadcast step S402, ARP
It includes a response packet response step S403, a connection request packet transmission step S404 from the client application, and a distribution destination server computer identification and distribution step S405.

It should be noted that parts not specifically mentioned are configured similarly to the server application multiplex communication system according to the first embodiment.

Next, the operation of the server application multiplexing communication system according to the second embodiment configured as described above will be described in detail with reference to FIGS. 6 to 12.

First, the cooperative operation of the port switching means 13 and 23 in the server computers 10 and 20 and the port allocating means 38 in the communication processing device 30 will be described (see FIG. 10).

In the server computer 10, the port switching means 13 gives a command instruction to the communication processing device 30 about the port number 1 and the state (here, the operating state) of the server application 12.

In the communication processing device 30, the port allocating means 38 registers the correspondence between the port number 1 designated by the command and the operating state and the server computer 10 which issued the command in the port number state / server computer correspondence table 39 ( (See FIG. 7).

Further, in the server computer 20, the port switching means 23 causes the port number 1 and the state of the server application 22 (here, the standby state).
Is commanded to the communication processing device 30.

In the communication processing device 30, the port allocating means 38 registers the correspondence between the commanded port number 1 and the standby state and the server computer 20 which issued the command in the port number state / server computer correspondence table 39 ( (See FIG. 7).

Next, the operation when the server applications 12, 22 in the server computers 10, 20 are activated will be described (see FIG. 8). Here, a case where the server application 12 of the server computer 10 is started will be described as an example.

When the server application 12 is started in the server computer 10 (step S30)
1) Instruct the communication processing device 30 to start accepting a connection request (step S302).

In the communication processing device 30, when the reception start instruction of the connection request is received, the TCP / IP control means 33 causes the IP
Reception of the connection request addressed to the address 37 is started (step S303).

The same operation is performed when the server application 22 is activated in the server computer 20.

Next, the client application 5
The operation when a connection request is generated in No. 1 will be described (see FIG. 9).
However, a case where the destination IP address is the IP address 11 will be described here as an example.

In the client computer 50, the client application 51 issues a connection request to the server application 12 (step S4).
01), the client application 51 broadcasts an ARP request packet requesting the MAC address corresponding to the destination IP address 11 to the TCP / IP network 40 (step S402).

In the communication processing device 30, the TCP / IP control means 33 controls the destination IP in the ARP request packet.
The MAC address 32 is acquired from the IP address / MAC address correspondence table 36 based on the address 11 and an ARP response packet including the MAC address 32 is returned to the client application 51 (step S40).
3).

In the client computer 50, the AR
When the P response packet is received, the client application 51 sends the destination port number 1, the destination IP
A connection request packet including the address 11 and the destination MAC address 32 is sent to the TCP / IP network 40 (step S404).

In the communication processing device 30, the MAC address 3
The second NIC 31 receives the connection request packet on the TCP / IP network 40, and the port distribution unit 38
Identifies the active server computer 10 from the port number status / server computer correspondence table 39 based on the destination port number 1 in the connection request packet, and distributes the connection request to the server computer 10 (step S40).
5).

As a result, the client application 51 is connected to the server application 12 and can communicate with the server application 12.

The client application 51
However, when the ARP request packet requesting the MAC address corresponding to the destination IP address 21 is broadcast, the communication processing device 30 identifies the server computer 20 as the distribution destination server computer, and the client application 51 ,
It will be connected to the server application 22.

Finally, the server computer 10 in operation
The server computer switching operation in the case where the server application 21 having the port number 1 has a failure will be described (see FIG. 11).

When the server application 21 with the port number 1 fails in the operating server computer 10, the port switching means 2 is operated by a command from the console of the server computer 20 in the standby state.
3, a command instruction is given to the communication processing device 30 that the server application in the operating state of the port number 1 is switched from the server computer 12 to the server application 22.

In the communication processing device 30, the port allocating means 38 updates the port number status / server computer correspondence table 39 based on the command instruction from the server computer 20. Specifically, the state of port number 1 corresponding to the server computer 10 is changed from active to standby, and the state of port number 1 corresponding to the server computer 20 is changed from standby to active (see FIG. 12).

Subsequent client application 51
The connection request from is referred to the port number status / server computer correspondence table 39, and is connected to the server application 22 in the server computer 20.

According to the second embodiment, the IP address 37 common to the plurality of server applications 12 and 22 is assigned to the communication processing device 30 and the port allocating means 38 is provided so that one IP address can be obtained from the client application 51. At 37, the same server application 12, 22 assigned the same port number 1 on a plurality of server computers 10, 20 can be distributed to the active system and the standby system for use.

(3) Third Embodiment FIG. 13 is a block diagram showing the configuration of a server application multiplexing communication system according to the third embodiment of the present invention. In the server application multiplexed communication system according to the present embodiment, the communication processing device 30 uses TCP / I.
The communication processing program 100 that realizes the functions of the P control unit 33 and the server distribution unit 34 is provided.

In the server application multiplex communication system according to the third embodiment, the communication processing program 100 is a computer.
Read as the TCP / IP control means 33 and the server distribution means 34. The detailed operation of each of these means is exactly the same as in the case of the server application multiplexing communication system according to the first exemplary embodiment shown in FIGS. 1 to 5, so a detailed description thereof will be omitted.

(4) Fourth Embodiment FIG. 14 is a block diagram showing the configuration of a server application multiplexing communication system according to the fourth embodiment of the present invention. In the server application multiplexed communication system according to the present embodiment, the communication processing device 30 uses TCP / I.
A communication processing program 200 for realizing the functions of the P control means 33 and the port allocating means 38 is provided.

In the server application multiplex communication system according to the fourth embodiment as described above, the communication processing device 30 is a computer in which the communication processing program 200 is a computer.
Read as the TCP / IP control means 33 and the port distribution means 38. The detailed operation of each of these means is exactly the same as in the case of the server application multiplexing communication system according to the second exemplary embodiment shown in FIGS. 6 to 12, and therefore its detailed description is omitted.

In each of the above embodiments, the server computers connected to the communication processing device 30 are two server computers 10 and 20, but when there are three or more server computers connected to the communication processing device 30. But
It goes without saying that the invention is likewise applicable.

[0084]

The first effect is that the same server application assigned the same port number can be used by a plurality of server computers. The reason is,
This is because a plurality of IP addresses can be assigned to one NIC.

The second effect is that the load of a plurality of server computers can be distributed by using the same server application assigned the same port number in a plurality of server computers.
The reason is that the number of client computers to be connected can be dispersed by assigning an IP address to each server computer and providing the communication processing device with a server distribution unit.

The third effect is that the same server application to which the same port number is assigned on a plurality of server computers by one IP address can be distributed and used for the active system and the standby system. Is. The reason is that one IP address is commonly assigned to a plurality of server computers, the operating server computer is specified based on the destination port number in the connection request packet, and the connection request is distributed to the server computer. This is because a means is provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a server application multiplexing communication system according to a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing an example of contents of a server computer / IP address correspondence table in FIG.

FIG. 3 is a diagram showing an example of contents of an IP address / MAC address correspondence table in FIG.

4 is a flowchart showing a process when a server application in the server computer in FIG. 1 is activated.

5 is a flowchart showing a process when a connection request is generated in the client application shown in FIG.

FIG. 6 is a block diagram showing a configuration of a server application multiplexing communication system according to a second exemplary embodiment of the present invention.

FIG. 7 is a diagram showing an example of the contents of a port number status / server computer correspondence table in FIG.

8 is a flowchart showing a process when a server application in the server computer shown in FIG. 6 is activated.

9 is a flowchart showing a process when a connection request is generated from a client application in the client computer shown in FIG.

10 is a diagram for explaining the operation of the port switching means in the server computer and the port allocating means in the communication processing device in FIG.

FIG. 11 is a diagram illustrating a server computer switching operation when a server application fails in the operating server computer in FIG. 6;

FIG. 12 is a diagram for explaining the transition of the contents of the port number status / server computer correspondence table of FIG. 7.

FIG. 13 is a block diagram showing a configuration of a server application multiplexing communication system according to a third exemplary embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a server application multiplexing communication system according to a fourth embodiment of the present invention.

[Explanation of symbols]

10, 20 Server computer 11, 21 IP address 12, 22 Server application 13, 23 Port switching means 30 Communication processing device 31 NIC 32 MAC address 33 TCP / IP control means 34 Server distribution means 35 Server computer / IP address correspondence table 36 IP Address / MAC address correspondence table 40 TCP / IP network 50 Client computer 51 Client application 100, 200 Communication processing program S101 Server application start step S102 IP address registration instruction step S103 IP address registration to server computer / IP address correspondence table S104 Step S201 Registration of IP Address in IP Address / MAC Address Correspondence Table Client Application Connection request generation step S202 ARP request packet broadcast step S203 ARP response packet response step S204 Connection request packet transmission step from client application step S205 Distribution destination server computer identification and distribution step S301 Server application startup step S302 Connection to communication processing device Request reception start instruction step S303 Connection request reception start step for the IP address S401 Connection request from client application step S402 ARP request packet broadcast step S403 ARP response packet response step S404 Connection request packet transmission from client application step S405 Distribution destination server Computer identification and sorting step

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Claims (6)

(57) [Claims] 1. A communication system in which a plurality of server computers are connected to a communication processing device, and the communication processing devices are connected to one or more client computers via a TCP / IP network, wherein the plurality of server computers are , Each has a different IP address, and has the same server application with the same port number.
A NIC to which the communication processing device is connected to the TCP / IP network and to which a MAC address is assigned;
A server computer / IP address correspondence table managing the correspondence between the server computer and the IP address, an IP address / MAC address correspondence table managing the correspondence between the IP address and the MAC address, and the server application when the server application is started. The IP address notified by the started server computer is set to the N
The IP address is registered in the IP address / MAC address correspondence table in association with the MAC address assigned to the IC, and the IP address is based on the destination IP address in the ARP request packet when the ARP request packet is received from the client application. / MAC
The MAC address is acquired from the address correspondence table and the MAC
The TCP / IP control means for responding to the client application with an ARP response packet including an address, and the IP address notified by the server computer on which the server application is activated when the server application is activated are associated with the server computer. While registering in the server computer / IP address correspondence table, at the time of receiving the connection request packet from the client application, the server computer is specified from the server computer / IP address correspondence table based on the destination IP address in the connection request packet. And a server distribution unit that distributes a connection request to the server computer. 2. A communication system in which a plurality of server computers are connected to a communication processing device, and the communication processing devices are connected to one or more client computers via a TCP / IP network, wherein the plurality of server computers are , An IP which includes port switching means for commanding port switching, and which is equipped with the same server application to which the same port number is allocated, and the communication processing device is commonly allocated to the plurality of server computers. Address, NIC connected to the TCP / IP network and assigned a MAC address, port number and operation /
Port number status / server computer correspondence table for managing correspondence between standby state and server computer, IP address / MAC address correspondence table for managing correspondence between IP address and MAC address, and connection at the time of starting the server application When the reception of an ARP request packet from a client application is started while receiving a request, the IP address / MAC is based on the destination IP address in the ARP request packet.
The MAC address is acquired from the address correspondence table and the MAC
TCP / IP control means for responding to the client application with an ARP response packet containing an address, and correspondence between port numbers and operating / standby states and server computers according to command instructions from the port switching means. While registering in the correspondence table, at the time of receiving the connection request packet from the client application, based on the destination port number in the connection request packet, identify the server computer in the operating state from the port number status / server computer correspondence table, A server application multiplexing communication system, comprising: a port distribution unit that distributes a connection request to the server computer. 3. A step of registering, in a server computer / IP address correspondence table, an IP address notified from a server computer on which the server application is started when the server application is started, and a step of registering the IP address with the server computer. The IP address / MAC that corresponds to the MAC address assigned to the NIC is associated with the IP address notified by the server computer on which the server application is started at the time of startup.
From the IP address / MAC address correspondence table based on the destination IP address in the ARP request packet when the ARP request packet is received from the client application
Obtaining a C address and responding to the client application with an ARP response packet including the MAC address; and upon receiving a connection request packet from the client application, the server based on the destination IP address in the connection request packet. A server application multiplex communication method comprising the step of identifying a server computer from a computer / IP address correspondence table and allocating a connection request to the server computer. 4. A step of registering a correspondence between a port number and an operating / standby state and the server computer in a port number state / server computer correspondence table according to a command instruction from a port switching means of the server computer; A step of starting acceptance of a connection request when the server application is activated, and a MAC from the IP address / MAC address correspondence table based on the destination IP address in the ARP request packet when the ARP request packet is received from the client application.
Obtaining the address and responding to the client application with an ARP response packet including the MAC address; and, upon receiving a connection request packet from the client application, the port number based on the destination port number in the connection request packet. A server application multiplex communication method, comprising the step of identifying a server computer in an operating state from a status / server computer correspondence table and allocating a connection request to the server computer. 5. A computer is provided with an NIC which is an IP address notified from a server computer on which the server application is activated when the server application is activated.
Is registered in the IP address / MAC address correspondence table in association with the MAC address assigned to the IP address / MAC, and when the ARP request packet is received from the client application, the IP address / MAC is based on the destination IP address in the ARP request packet. TCP / IP control means for acquiring a MAC address from the address correspondence table and sending an ARP response packet including the MAC address to the client application, and a server computer on which the server application is started when the server application is started. Registered IP address in the server computer / IP address correspondence table in association with the server computer, and a connection request packet from the client application is registered. Program for functioning as a server distributing means for distributing a connection request from said server computer / IP address table of the destination IP address in the connection request packet based on the time signal to identify the server computer to the server computer. 6. The computer starts accepting a connection request when the server application is activated, and at the time of receiving an ARP request packet from the client application, an IP address / MAC address based on a destination IP address in the ARP request packet. TCP / IP control means for obtaining a MAC address from the correspondence table and sending an ARP response packet containing the MAC address to the client application, and a port number and an operating / standby state and a server computer according to a command instruction from the port switching means. Is registered in the port number status / server computer correspondence table, and at the time of receiving the connection request packet from the client application, based on the destination port number in the connection request packet, Identify the operating server computer from the port number status / server computer correspondence table,
A program for causing the server computer to function as a port distribution unit that distributes a connection request.