JPH0325582A - Correcting method for time stamp information in distributed processing type information collection system - Google Patents

Abstract

PURPOSE:To freely collect information at a subsystem by providing a means to collect the information at a state where no synchronism of time is guaranteed and to reduce the error of time stamp between the information by correcting the time stamp of collected information. CONSTITUTION:When the real time clock T2 of the subsystem 2 is time- synchronized with the subsystem 1 first after initial start-up, the time stamp of the information already collected in the subsystem 1 is corrected. In a correction system, the difference of the time C2(S) of the clock T2 just before synchronized with the real time clock T1 of the subsystem 1 and synchronizing time C(S) from the clock T1 is used, and correction is applied to the time stamp C2(X) of the information already collected with C(X)=C2(X)+C(S)-C2(S). Thereby, the information can be freely collected at the subsystem.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Commercial Use) The present invention relates to an improvement of an information processing system, and particularly to a distributed processing type management system thereof.

(Prior Art) Conventionally, in this type of system, it is necessary to add a time stamp to collected information as close as possible to the time when the information was generated. For this reason, each subsystem usually has a real-time clock that operates individually. Previously, each subsystem's real-time clock was synchronized with the only real-time clock within the system before information was collected.

(Problems to be Solved by the Invention) In the conventional method described above, even if any subsystem starts up, if the subsystem with the synchronization source real-time clock is not started, the collected information will not be correct. The disadvantage is that a timestamp cannot be added.

An object of the present invention is to be able to collect information even when time synchronization between subsystems is not guaranteed due to initial startup or random stoppage of each subsystem, and to make it possible to collect information that is eventually collected. Correction of timestamp information in a distributed processing information collection system that corrects the timestamps and reduces errors in timestamps between information to eliminate the above-mentioned omissions A'k and add correct timestamps. The goal is to provide a method.

(Means for Solving the Problems) The time stamp information correction method in the distributed processing information collection system b according to the present invention comprises an information collection means and a time stamp error correction means.

The information collecting means is for collecting information in a state where synchronization of time between subsystems is not guaranteed due to initial startup of each subsystem or random stoppage.

The time stamp error correction means corrects the time stamp of the information finally collected by the information collection means to reduce &%M of the time stamp between fW reports.

(Embodiment) FIG. 1 is a block diagram showing an example of a distributed processing information collection system. 1, 2, and 3.4 are subsystems therein, and the subsystems 2, 3.4 collect information, add time stamps to each, and transmit the information to the subsystem 1. All real-time clocks in the system are synchronized by time transmission from subsystem 1.

Next, the system shown in FIG. 1 will be explained with reference to FIG. 2.

This is the true time axis. Assume that subsystem IICD has the same time axis as real-time clock C.

C2 is subsystem 2 before time synchronization processing is performed.
This is the time axis of the real-time clock.

0 2(x). 0 2 (y), 0 2 (zl is the information collected by subsystem 2 @xayaz
This is the time on the time axis 02 added to . O(x)
, 0(y), and O(z) are the times on the time axis C relative to the generation times of the information x6 Y # Z collected by the subsystem 2, respectively. 02(s) is the time on the time axis C2 when time synchronization is performed from the subsystem 1. 0(s) is the synchronized time at that time. The same applies to subsystem 3.4 below. Here, in order to simplify the explanation of Fi, the processing of subsystem 1.2 will be explained.

After subsystem 2 starts up, information x, y, z is generated,
Subsystem 2 collects it.

In this state, the real-time clock of subsystem 2 is not synchronized with subsystem 1, so each piece of information is set at time 0 2 (x) on time axis 02.
, 0 2 (y), 0 2 (z). At this time, subsystem 2 prohibits the transmission of the information collected by function +1) to other subsystems.

When subsystem 1 starts up, subsystem 2 requests time synchronization from subsystem 1.

Subsystem 1 performs time synchronization with subsystem 2. The time on the time axis C2 at this time is 02 (s)
The time after synchronization is C(S). Subsystem 2 corrects the time of the real-time clock and also timestamps the information x, y, z collected by the function (2). Correct according to the first equation. Regarding the subsystem 2, the information x, y, and zit is transmitted to the subsystem 1 in order to cancel the prohibition of transmitting the collected information to other systems. At this time, the time stamp added to the transmitted information has already been corrected and is based on the time axis C.

The information collection system according to the present invention can perform the following actions in each subsystem.

The first action is to request time synchronization.

When it is necessary to send time-stamped information collected by the subsystem 2 that collects information to another subsystem 3 within the entire system,
Between the initial startup of the own system and the current meeting. It is determined whether the real-time clock T2 of the own system is synchronized with the real-time clock Tl of the only subsystem I in the entire system.

If synchronization has not been established based on the above judgment result, subsystem 2 prohibits the transmission of information to other subsystems, and requests subsystem 1 to synchronize the real-time clocks of all systems.

The function of 'ix2 is to correct the time stamp of the collected information. When the real-time clock T2 of subsystem 2 is time-synchronized with subsystem 1 for the first time since initial startup, its time stamp is corrected against the information already collected within subsystem 1. . The correction method is T2 immediately before being synchronized with Tl.
Using the difference between the time 02(s) and the synchronization time 0 (sl) from the TI, the time stamp 02(x) of the already collected information is corrected according to the calculation formula below. That is, 0(x) = 0 2(x) + 0(s) − 0
2(s)''-(1) After this correction process, the prohibition of information transmission from subsystem 2 to other subsystems is lifted.

Among them, these can be realized by using the necessary equipment for performing distributed processing in an information processing system.

According to the lfJl formula, the following second formula is obtained. That is, 0(xl − 0 2(xi − 0(s) − 0
2(s) == (21The second equation shows that the difference in time axis does not change continuously.From this, the first
The validity of the formula is proven.

(Effects of the Invention) As explained above, the present invention can collect information even when time synchronization between subsystems is not guaranteed, such as when each subsystem initially starts up or stops randomly. is completed. In a distributed processing information collection system, even when time synchronization between subsystems is not achieved, by correcting the time stamp of the information finally collected and reducing the error in the time stamp between the pieces of information. This has the effect of allowing information to be freely collected about each subsystem. In addition, regarding the timestamp added to the information, the error between the collection source subsystems is reduced <-r
It has the effect of being able to

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a system that implements a time stamp information correction method in a distributed processing information collection system according to the present invention. FIG. 2 is an explanatory diagram illustrating a process t-adapted to the system of FIG. 1 to 4...Subsystem 21 diagram

Claims (1)

[Claims] Information collection means for collecting information in a state where time synchronization between subsystems is not guaranteed due to initial startup or random stop of each subsystem, and information finally collected by the information collection means 1. A method for correcting time stamp information in a distributed processing information collection system, comprising: time stamp error correction means for correcting time stamps to reduce time stamp errors between pieces of information.