KR20000054017A - System and method for high availabilty network - Google Patents

Abstract

PURPOSE: A method for implementing a high-usability network system is provided to supply effective measures for server errors and continuous services, by taking a virtual Internet Protocol(IP) address of error servers from other servers using a proxy Address Resolution Protocol(ARP) technology and an IP alias, when generating an error in a specific server, if a server clustering is operated using role-equivalent servers. CONSTITUTION: A method for implementing a high-usability network system comprises the steps of: monitoring states of other network systems in a high-usability demon processor; deciding a network system taking a virtual Internet Protocol(IP) address of an error system, if an error is detected in a specific network system; additionally setting a virtual IP address of the specific error system, to store in a network address information device; notifying a Media Access Control(MAC) address of the reset address information device to modify as a new MAC address, when the IP address requests the MAC address of the specific error system, by operating a network system as a proxy Address Resolution Protocol(ARP) mode; and restoring the virtual IP address of the error system by releasing the proxy ARP mode in an usability demon processor of a network system, when the error system is restored.

Description

High availability network system and its implementation {SYSTEM AND METHOD FOR HIGH AVAILABILTY NETWORK}

The present invention relates to a high availability system and a method for implementing the same. More specifically, in case of clustering servers using a plurality of servers that play the same role, if a specific server fails using proxy ARP technology and IP aliasing technology, The present invention relates to a high-availability network system and a method of implementing the same, which ensures a flexible coping capability and uninterrupted service for failures of servers by obtaining a virtual IP address of a server issued by a failure.

In general, when describing a network, OSI layer 7 is described. The OSI layer 7 includes a physical layer, a data link layer, a network layer, a transport layer, and a session layer. It is divided into (Session Layer), Presentation Layer, and Application Layer. The functions and roles of each layer are as follows.

The first layer, the physical layer, involves the transmission of data from one computer to another via physical media, how the cable is connected to the network adapter card, and what transmission technique is used to transfer the data over the cable. Contains the definition of.

The second layer, the data link layer, is responsible for converting electrical signals from network cards into network frames, and transmits frames from one computer to another.

The data link layer is divided into two sub-layers. The upper layer is a Logical Link Control (LLC) sub-layer, which manages data link communication and defines a service access point (SAP). The Media Access Control (MAC) sublayer performs direct communication with network adapter cards in the physical layer directly below.

The third layer, the network layer, is responsible for reducing the logical address to the physical address and determines a route to the destination computer.

The transport layer, which is the fourth layer, detects and recovers an error. If necessary, the long message is divided into small packets and reassembled.

The fifth layer, the session layer, is involved in everything from different computers to sessions, work, and the end of the session. This layer provides session control between two computers by placing checkpoints between data streams. If the transfer fails, only the data after the last checkpoint is retransmitted.

The sixth layer, the presentation layer, converts the data received from the application layer into an intermediate format. It also relates to encryption / encoding and compression of data. It also converts data received from the application layer into an intermediate format, and handles security matters such as data encryption and data compression to send fewer bits over the network.

The seventh layer, the application layer, is an intermediate layer that translates data. Server Message Blocks (SMBs), which define a set of commands sent from a redirector on a client computer to a service on a server computer, and file transfers. There are application protocols such as File Transfer Protocol (FTP) and Network File System (NFS) for file sharing on a network.

Address Resolution Protocol (ARP) technology requires that protocols that communicate over TCP / IP be translated to hardware addresses on the MAC, which is a sublayer of the datalink layer. Therefore, it is necessary to find out the MAC (Media Access Control) address information of the network interface card where the IP address is set. The protocol used is ARP.

1 is a diagram illustrating a general ARP technique.

As shown here, the first server 100 and the second server 200 may include first to second network address information units 110 and 210 that store their own IP addresses and MAC addresses, and the network itself. The first and second ARP tables 120 and 220 store IP addresses and MAC addresses of connected network systems. Therefore, when a packet is to be sent to a specific IP address, the packet is transmitted by referring to the IP address and the MAC address stored in the first to second ARP tables 120 and 220.

That is, when a packet is to be transmitted from the first server 100 to the second server 200, the first ARP table 120 is the MAC address of 10.10.10.2, which is the IP address corresponding to the second server 200. ) To send the packet.

Since the first ARP table 120 checks the MAC address corresponding to the IP address 10.10.10.2, the MAC address of 00: 00: 00: 00: 00: 12 is stored in the IP address of 10.10.10.2. When transmitting the packet, the packet is transmitted with reference to the first ARP table 120.

Meanwhile, the second server 200 also stores the MAC address corresponding to the IP address 10.10.10.1, 00: 00: 00: 00: 00: 11, in the second ARP table 220, and the second server 200 In order to transmit the packet to the first server 100, the packet is transmitted by referring to the IP address and MAC address corresponding to the first server 100 in the second ARP table 220.

However, when a failure occurs in the first server 100, all services accessing the service IP address of the corresponding server have to be stopped until the failure is repaired.

Therefore, in order for a server operator to quickly recognize a failure situation, there was an inconvenience of purchasing an expensive NMS (Network Management System) and always waiting for failure recovery.

The present invention was created to solve the above problems, and an object of the present invention is to use a proxy ARP technology and IP aliasing technology when a server clustering using a plurality of servers that play the same role. It provides a high-availability network system and its implementation method that can ensure a flexible response to the failure situation of the servers and to ensure uninterrupted service by taking the virtual IP address of the server that failed in another server.

Proxy ARP technology used in the present invention is a technology defined in RFC1027 (Request For Comments 1027) as shown in Figure 2, the server connected to the network and the IP address for a specific network or server sent from another server and When the ARP request is received to find out the MAC address information, it is a technology that receives a packet to go to a specific network or server by telling its IP address and MAC address.

That is, when the second server 200 is set to proxy ARP for the IP address 10.10.10.1, when the third server 300 asks the MAC address of the IP address 10.10.10.1 by ARP, the second server 200 Intercepts an ARP request and does not announce 00: 00: 00: 00: 00: 11, which is the MAC address for IP address 10.10.10.1 of the first server 100, and is 00: MAC address of the second server 200; In the present invention, when a failure occurs in a specific server, a normal server may receive a packet to be delivered to the failed server to provide a service.

In addition, as shown in FIG. 3, the IP aliasing technology has one IP address as 10.10.10.1 before performing the IP aliasing, but after performing the IP aliasing, two IP addresses, 10.10.10.1 and 10.10.10.2, are used. As a technique for specifying an arbitrary virtual IP address in addition to a static IP address specified in a network interface card used to connect a server to a network, the present invention uses a virtual IP address used by a failed server as a normal server. In addition, it can be set to provide new MAC address.

1 is a diagram illustrating a general ARP technique.

2 is a diagram for explaining a proxy ARP technique.

3 is a diagram for explaining an IP aliasing technique.

4 to 7 are diagrams for explaining a method of implementing a high availability network system according to the present invention.

-Explanation of symbols for the main parts of the drawings

100,200,300: first to third server

110, 210, 310: first to third network address information unit

120,220,320: first to third ARP table

130,230,330: first to third IP information table

140,240,340: first to third high availability daemon processor

A high availability network system for realizing the above object is a network system for performing TCP / IP communication, comprising: a network address information unit storing static IP address information, virtual IP address information, and MAC address information of a network system itself; An ARP table that stores IP addresses and MAC addresses of all other network systems connected to the ARP table, an IP information table that stores virtual IP address information and static IP address information of all network systems connected to the network, and management of the virtual IP address. It includes a high availability daemon processor that monitors the status of network systems, provides a modified MAC address of a failed network system to a normal network system in the event of a failure, and recovers the MAC address when the failure is recovered.

In addition, the method for implementing a high availability network system according to the present invention includes the steps of monitoring the status of other network systems in a high availability daemon processor of a network system, and if a normal network system fails as a result of the monitoring, all normal network systems fail. Determining which network system to take the virtual IP address of the failed network system after detecting the occurrence, and further adding the virtual IP address of the specific network system that failed in one network system using IP aliasing technology. Setting and storing the MAC address in the network address information unit; and when the MAC address is requested by the virtual IP address of a specific network system that has failed by operating in a proxy ARP mode in one network system, Informs the server to correct the new MAC address, disables proxy ARP mode on the availability daemon processor of one network system and recovers the virtual IP address from the failed network system. It is characterized by consisting of steps to recover.

According to the present invention made as described above, in the case of clustering using a plurality of network systems having the same role, when a failure occurs in a specific network system, the MAC address is taken from one network system by taking a virtual IP address of the failed network system. When you try to access a network system that has failed in the network, it will be connected to one network system according to the newly provided MAC address so that service can be provided continuously without interruption while recovering the network system. High availability can be guaranteed by enabling recovery of a failed network system.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the present embodiment is not intended to limit the scope of the present invention, but is presented by way of example only and the same parts as the conventional configuration using the same reference numerals and names.

4 to 7 are diagrams for explaining a method for implementing a high availability network system using the proxy ARP technology and IP aliasing technology according to the present invention.

As shown in FIG. 4, the network system according to the present invention is a network system that performs TCP / IP communication. In the case of the first server 100, a fixed IP address of 10.10.10.1 and a virtual IP address of 1.1.1.1 and The first network address information unit 110, which stores the MAC address 00: 00: 00: 00: 00: 11, is installed, and in the case of the second server 200, 10.10.10.2, which is a fixed IP address, and a virtual IP address, 1.1.1.2 and a second network address information unit 210 which stores MAC addresses 00: 00: 00: 00: 00: 12 are provided.

The first to second ARP tables 120 and 220 in which virtual IP addresses and MAC addresses of all other network systems connected to the network are stored are installed in the first server 100 and the second server 200, respectively.

Further, the first to second IP information tables 130 and 230 in which the virtual IP addresses and the static IP addresses of the first server 100 and the second server 200 connected to the network are stored are respectively the first server 100. ) And the second server 200. In addition, the first to the second to monitor the management of the virtual IP address and the status of other network systems, to provide a modified MAC address of the failed network system to a normal network system when the failure occurs, and to recover the MAC address when the failure is recovered. The high availability daemon processors 140 and 240 are installed in the first server 100 and the second server 200, respectively.

In this state, the first high availability daemon processor 140 of the first server 100 uses the Internet Control Message Protocol (ICMP) as the second high availability daemon processor 240 of the second server 200. Monitor the status of servers connected to the server. That is, when ICMP is requested from the first server 100 having the virtual IP address 1.1.1.1 to the second server 200 having the virtual IP address 1.1.1.2, the second server 200 sends the first server 100. It monitors the status of servers as it sends echo.

While monitoring the status of the servers as described above, the MAC address of 1.1.1.1, which is the virtual IP address of the first server 100 with reference to the third ARP table 320 in the third server 300 as shown in FIG. If you try to connect to 00: 00: 00: 00: 11, communication is impossible because the first server 100 has a failure.

After all of the normal servers detect the failure condition as described above, the second server 200 is determined as the server to take the virtual IP address of the failed first server 100, and the second server 200 is determined. 1.1.1.1, which is a virtual IP address of the first server 100 that has failed, is additionally stored in the second network address information unit 230 using an IP aliasing technique.

At this time, the servers or devices participating in the network know the MAC address of the virtual IP address of the failed first server 100 as the MAC address of the failed first server 100. Therefore, communication with the failed virtual IP address is lost until the changed MAC address information of the failed virtual IP address is known to all servers participating in the network.

Since the second server 100 operates in the proxy ARP mode, as shown in FIG. 6, when the third server 300 requests the MAC address as 1.1.1.1 which is the virtual IP address of the first server 100, the second server ( In step 200, the MAC address of the third server 300 changes the MAC address of the virtual IP address of the failed first server 100 to the MAC address of the virtual IP address in the third ARP table 330. The address will be modified to 00: 00: 00: 00: 00: 12.

Therefore, since the second server 200 also services the virtual IP address 1.1.1.1 of the failed first server 100, the third server 300 has the IP address of the first server 100 and has a second address. In communication with the server 200.

As such, when it is confirmed that the failure of the first server 100 is recovered by the second high availability daemon processor 240 while providing the service of the failed first server 100 through the second server 200, FIG. As shown in FIG. 7, the proxy ARP mode of the second server 200 is released and the high availability daemon processor 140 of the first server 100 is initially configured with the virtual IP address 1.1 of the first server 100. Find .1.1. Thereafter, the ARP information for the first server 100 is automatically modified in the second server 200 and the third server 300 by ICMP communication between the high availability daemon processors.

As described above, when the server clustering using a plurality of servers that play the same role, if a specific server fails using proxy ARP technology and IP aliasing technology, a virtual IP address of the failed server is obtained from another server. As a result, it is possible to guarantee a flexible response to the failure situation of the server and to ensure uninterrupted service.

In addition, the present invention has the advantage that the server can use the virtual IP address to provide a service to ensure a flexible coping capacity of the server and to minimize the time it takes to detect a failure situation by monitoring the virtual IP address of the server.

On the other hand, there is no need to separately install a load balancing firewall or load balancer that provides server clustering and high availability to ensure high availability of the server has the advantage of reducing the system construction cost.

Claims (4)

In a network system that performs TCP / IP communication, A network address information unit storing static IP address information, virtual IP address information, and MAC address information of the network system itself; An ARP table storing IP addresses and MAC addresses of all other network systems connected to the network; An IP information table that stores virtual IP address information and static IP address information of all network systems connected to the network; A high availability daemon processor that monitors the management of virtual IP addresses and the status of other network systems and, in the event of a failure, provides the MAC address of the failed network system as that of a normal network system and recovers the MAC address when the failure is recovered. A high availability network system, characterized in that consisting of. The high availability network system of claim 1, wherein the network address information unit is configured to additionally set a virtual IP address of a specific network system that fails. Monitoring the status of other network systems in a high availability daemon processor of the network system; If the monitoring results in a failure of a specific network system, after all normal network systems detect a failure, determining which network system to take the virtual IP address of the failed network system; Additionally setting a virtual IP address of a specific network system in which any one of the network systems has failed, and storing the virtual IP address in a network address information unit; Operating one of the network systems in a proxy ARP mode to notify the MAC address of the network address information set additionally when requesting the MAC address by the virtual IP address of the specific network system that has failed to modify the new MAC address; Wow, Disabling proxy ARP mode on the availability daemon processor of one network system and recovering the virtual IP address on the specific failed network system when the failed network system is recovered. Implementation method of a high availability network system, characterized in that made. 4. The method of claim 3, wherein additional setting is performed through an IP aliasing technology when additionally setting a virtual IP address of a specific network system that has a failure.