JP2001305256A - Time synchronization method in computer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a time synchronization method wherein stop of program or difficult treatment of time synchronization involved in a time synchronization of each computer on a network by an NTP demon can be improved. SOLUTION: Time synchronization programs 1A-3A for each of the computers 1, 2, 3 set time of a clock in each of its own device having two operating modes, a master mode and a slave mode. Mode management programs 1B-3B set one of the time synchronization programs to the master mode, and other time synchronization programs to the slave mode. A application interface 1D sets the clock of the computer 1 at an optional time if it accepts a setting of the optional time. Normally the time of a clock in own device is set to a time information form an external clock 4 or an internal clock. Other computers are synchronized by the delivery of the time information. The clock of the computer 1 is set at an optional time at an interface. A request for time synchronization is transmitted to other computers to synchronize the clock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a time synchronization method in a computer system, and more particularly to a method for synchronizing a clock of a computer on a network to an arbitrary time.

[0002]

2. Description of the Related Art When synchronizing time between computers on a network, an NTP daemon is often used. This NTP has the following features.

[0005] Time is synchronized by a daemon process that is lightweight and requires little management.

[0004] Dynamic selection of a server whose time is reliable.

[0005] Time is gently synchronized and not changed at once.

[0006] High accuracy.

[0007] Multi-platform (UNIX (registered trademark) .NT) is supported.

[0010] A tool for monitoring the state of time synchronization is provided.

[0009]

NTP assumes a computer whose error from Coordinated Universal Time (UTC) is within a certain range, and all computers on the network correct the time error for that computer. This is a protocol that aims to be within a certain range.

[0010] Therefore, it is not suitable for a case where it is desired to synchronize computers on a network at an arbitrary time. In this case, the NTP daemon is temporarily stopped, then the computer at the highest hierarchical level on the network is synchronized with UTC, a certain computer is set to an arbitrary time by a time setting (date) command, and the ntpdate command is set. Use this to set the time on other computers.

An object of the present invention is to provide a time synchronization method for a computer system that can easily synchronize the clocks of the computers on a network to an arbitrary time without stopping a program.

[0012]

According to the present invention, each computer is provided with a time synchronization program for setting a clock time and a master / slave mode management program thereof, and the time synchronization program of one computer is set as a master mode. The time synchronization program of another computer is set to the slave mode, and the time information of the external clock or the internal clock set by the time synchronization program of the master mode is communicated with the time synchronization program of the slave mode through the inter-device communication program of the computer,
The internal clock of the other computer is time-synchronized, and the application interface that accepts arbitrary time information requests the time information of the external clock or internal clock of the computer that has the time synchronization program of the master mode to the other computer. Is transmitted to enable time synchronization at an arbitrary time, and is characterized by the following method.

A time synchronization method of a computer system for synchronizing time between a plurality of computers connected to a network, wherein each of the computers has two operation modes, a master mode and a slave mode, and has a clock of its own computer. A time synchronization unit capable of setting a time, a mode management unit for setting one of the time synchronization units to a master mode and the other time synchronization unit to a slave mode, and a computer for setting the time synchronization unit to a master mode. Interface means for setting the clock of the computer to an arbitrary time,
At normal time, the time of the own device clock is synchronized with the time information from the external clock or the internal clock by the time synchronization unit set to the master mode, and the time information of the own device is distributed to other time synchronization units. Based on the received time information, the time synchronization means of another computer synchronously sets the clock in its own device, and when the interface means receives an arbitrary time setting, sets the clock of the computer to an arbitrary time, A time synchronization request is transmitted to a computer in a slave mode to synchronize its clock.

Also, at least two of the computers
One computer is provided with time synchronization means that can be in a master mode, performs periodic communication with both computers,
When one of the computers becomes unable to communicate, a duplex mode management means is provided for obtaining time synchronization by setting the time synchronization means of the other computer to the master mode and setting the time synchronization means of the other computers to the slave mode.

[0015]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention. In a system configuration in which the computers 1 to 3 are connected to a network by Ethernet (registered trademark) or the like, the computers 1 to 3 are equipped with time synchronization programs 1A to 3A for synchronizing each other's time.

The time synchronization programs 1A to 3A have two operation modes, a master mode and a slave mode, operate in one of the modes, and one time synchronization program is set to the master mode on the network. This mode setting is set by the mode management programs 1B to 3B, respectively.

In the case shown in the figure, the time synchronization program 1A of the computer 1 operates in the master mode, obtains time information from the external clock 4, synchronizes the time of the internal clock with this time information, and then publishes it in the device list. It distributes its own time information to the slave mode time synchronization programs 2A and 3A. The information distribution is performed by the inter-device communication program 1C.
3C.

Time synchronization program 2 in slave mode
When the time information is received, A and 3A set the time of the internal clock of the own device as the reception time information.

The computer 1 having the time synchronization program 1A in the master mode is provided with an application interface 1D for receiving a request for setting the internal clock to an arbitrary time.
have. When receiving the time setting request, the interface 1D sets the external clock 4 or the internal clock to the specified time, and thereafter obtains the time information of the external clock or the internal clock to obtain the time synchronization program 2 in the slave mode.
A time synchronization request is transmitted to computers 2 and 3 having A and 3A. In the computers 2 and 3, the mode management programs 2B and 3B
The internal clock is synchronized with the time of the reception time information by the mode setting and the processing of the programs 2A and 3A.

With the above configuration, the computers 1 to 3 can normally synchronize the time of the internal clock with the time of the external clock or the internal clock of the time synchronization program in the master mode. Then, when the application interface 1D receives an arbitrary time synchronization, each computer can synchronize with the time. In this time synchronization, it is possible to easily perform synchronization with an arbitrary time as compared with the conventional processing of synchronizing with UTC by fog, time setting by a date command, and time synchronization of another computer by an ntpdate command.

Next, a method for improving the reliability of the time synchronization program will be described. For this reason, in the present embodiment,
A time synchronization program that can be in the master mode is provided in at least two computers in a duplex configuration. For example,
The time synchronization programs 1A and 2A of the computers 1 and 2 are duplicated so that they can be switched between a master mode (hot state) and a slave mode (standby state).

A duplication mode management program for managing this duplication device is prepared. This program periodically communicates with the computers 1 and 2 having the duplicated time synchronization programs 1A and 1B. When one of the computers becomes unable to communicate, it determines that the computer has gone down, and If the time synchronization program is hot, the mode is switched to standby and the time synchronization program of another computer is switched to hot.

This mode management transmits a mode switching notice to the time synchronization program when the mode is changed.
The time synchronization program operates in the master mode if hot and in the slave mode if standby according to the received mode.

According to the above-described mode management, when one computer becomes unable to communicate, time synchronization by another computer can be ensured.

[0025]

As described above, according to the present invention, a time synchronization program and its master / slave mode management program are provided, one of which is set to the master mode, the other is set to the slave mode, and the time synchronization program in the master mode is provided. The time information of the clock to be set is synchronized with the communication between the computer devices, and the interface that accepts any time information has the time synchronization program of the computer with the master mode time synchronization program. By transmitting the request, the time can be synchronized at an arbitrary time, so that there is an effect that the clocks of the computers on the network can be synchronized at an arbitrary time without stopping the program.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a computer system showing an embodiment of the present invention.

[Explanation of symbols]

 1, 2, 3 ... computer 1A, 2A, 3A ... time synchronization program 1B, 2B, 3B ... mode management program 1C, 2C, 3C ... device communication program 1D ... application interface 4 ... external clock

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 15/177 678 G06F 15/177 680F 680 1/04 351A

Claims (2)

[Claims] 1. A time synchronization method of a computer system for performing time synchronization between a plurality of computers connected to a network, wherein each of the computers has two operation modes of a master mode and a slave mode. A time synchronization unit capable of setting a time of a clock; a mode management unit configured to set one of the time synchronization units to a master mode; and the other time synchronization unit to a slave mode; and the time synchronization unit is set to a master mode. Interface means for setting the clock of the computer to an arbitrary time provided in the computer. In normal times, the time synchronizing means set to the master mode converts the time information from the external clock or the internal clock to the time of the own device. The time of the clock is synchronized, the time information of the own device is delivered to other time synchronization means, and the time synchronization of the other computer is performed based on the received time information. Sets the clock in its own device, and when the interface means receives an arbitrary time setting, sets the clock of the computer to an arbitrary time and transmits a time synchronization request to the computer in the slave mode. A time synchronization method for a computer system, wherein the clocks are synchronized. 2. At least two of the computers are provided with time synchronization means capable of being in a master mode, perform periodic communication with both of the computers, and one of the computers becomes incapable of communication. 2. The computer system according to claim 1, further comprising a duplex mode management means for obtaining time synchronization by setting the time synchronization means of the other computer to the master mode and setting the time synchronization means of the other computers to the slave mode. Time synchronization method.