JPH04318655A - Load smoothing control method in multicomputer system - Google Patents

Abstract

PURPOSE:To reduce the overhead of a computer to which the type of an assignment is newly added by transferring unprocessed processing request of relevant type to be eliminated, followed by receiving the request and by smoothing the load. CONSTITUTION:A computer 101 knows a load situation of computers in a multicomputer system from the input and output quantities of computers 102 and 103, and based on the load situation obtained, the computer 101 determines an assigned processing request type that should be changed. Next, the computer from which an assigned type of processing is to be eliminated transfers the assigned processing request type and type information to be eliminated to an external memory unit. After that, computer 101 inputs a relevant type processing request in a computer to which an assigned processing request type is to be added, and after the relevant computer deals with the processing request stored in the external memory unit, the computer deals with the processing request from computer 101. That is, when the main computer reaches a high load, the front computer is made processing requirement of type having a large input quantity to the main computer with a low load, to input followed by dealing with processing requirement of the relevant type.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load smoothing control method in a multi-computer system.

0002

2. Description of the Related Art A conventional method for load smoothing is described in Japanese Patent Application Laid-Open No. 57-120167 "Load Balancing Method in a Multiple Computer System", in which a tightly coupled multiprocessor handles data (processes) from a terminal. It is aimed at systems that receive and process information (directly) in the same position.One predetermined processor performs load patrol, and based on the results, it instructs each processor to change the function to be executed. Dynamically equalizes the load.

0003

The above prior art differs from the present invention in the subject and method of load smoothing in the following points. (1) Tightly coupled multiprocessors are targeted; loosely coupled multiprocessors are not targeted. (2) The system configuration is such that all processors receive data from terminals. Furthermore, there is no description regarding a method for changing the destination of data from a terminal due to switching of processing assignments between processors. (3) The program is loaded onto the main memory when switching the processing allocation between processors,
Large overhead.

An object of the present invention is to provide a method for switching processing allocation between loosely coupled computers with low overhead.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention observes the input amount and output amount of the main computer, and based on the observed input amount and output amount,
Determine the processing request type to be changed between main computers, move the unprocessed processing requests of the type from the computer whose responsible type will be deleted to the main computer where the new responsible type will be added, and then process the relevant type. By inputting a request, the type of processing request in charge is changed.

[0006]

[Operation] In a multi-computer system consisting of a front-end computer that distributes processing requests of multiple types on a per-type basis, and multiple main computers connected in series and parallel to this computer that process the processing requests in parallel, each The main computers monitor their own load status (input and output amounts), and when one main computer becomes highly loaded, the front-end computer sends a type of processing request that requires a large amount of input to the main computer with a low load. Using this as a trigger, the main computer with a low load processes the relevant type of processing request, making it possible to switch processing assignments with little overhead. In addition, since the front-end computer inputs the processing requests of the relevant type after queuing the unprocessed processing requests of the relevant type of the main computer from which the responsible type is deleted to the main computer to which the new responsible type is added, the same It is possible to maintain the processing order of processing requests of different types.

[0007]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 12.

FIG. 2 shows the hardware configuration of the computer system used in this embodiment. This system consists of the following: 104 is a terminal for inputting a processing request. 101 is a computer that accepts processing requests from the terminal 104; 102 and 103 are computers that take in processing requests received by the computer 101 and process the processing requests. Processing request files 106 and 108 record processing requests in chronological order. Reference numerals 107 and 109 are processing result files for recording the results of processing processing requests. 1
05 is an external storage device that can be accessed from the computers 102 and 103.

First, an outline of the processing flow will be described.

Processing requests input from the terminal 104 are sent to the computer 101, and processing requests of the type handled by the computer 102 are recorded in a chronological order in a processing request file 106. Further, processing requests of the type handled by the computer 103 are recorded in a chronological order in a processing request file 108. The computer 102 (computer 103) reads the processing request from the processing request file 106 (processing request file 108), performs data processing, and writes it to the processing result file 107 (processing result file 109). The computer 101 reads data from the processing result file 107 and the processing result file 109 and outputs it to the terminal 105.

FIG. 3 shows programs, tables, etc. in the computers 101, 2, and 3 shown in FIG. The processing operation of a processing request will be explained in detail with reference to FIG. Note that the solid line connecting the program and the table represents the flow of data, and the solid line connecting the program and the terminal represents the flow of data between the program and the terminal.

A processing request input from the terminal 104 is sent to the computer 101. Acceptance of processing requests for computer 101
When the distribution program 201 receives a processing request from the terminal 103, it determines a computer to process the processing request based on the processing request control table 209, and records it in the processing request file shared with the computer in the order of reception. The processing request queuing program 204 of the computer 102 reads out the processing requests in the processing request file 106 in the order in which they were written, and queues them in the processing request queue 205 in order. The business processing program 207 of the computer 102 sequentially takes out the processing requests from the processing request queue 205 from the beginning, processes them, and writes the processing results to the processing result file 109. It also updates the business processing information in the processing request management table 206.

Processing result output program 2 of computer 101
03 reads the processing results of the post-processing result file 108 which is obtained by reading out the processing results of the processing result file 106 in the order in which they were written, and outputs them to the terminal 104. Furthermore, the acceptance serial number (output write pointer) of the final write processing request is written in the processing request management table 206. The write pointer sending program 202 of the computer 101 sends the write pointer on the processing request control table 209 to the computer 102 at 30 second intervals.
, is transmitted to the computer 103. The load control program 208 of the computer 102 receives the write pointer, calculates the input amount, and writes both to the processing request management table 206.

[0014] Also, the load control program 208 is activated by a timer at one minute intervals. When the timer is activated, the processing request management table 206 is referred to, the load is calculated, and if the load is overloaded, a request is made to the computer 101 to change the type in charge. If this is accepted, the movement (responsible computer is changed) type (for example, a type with a long queue) is deleted from the responsible processing request types in the processing request management table 206, and the responsible processing request type to be deleted is The processing request and the person-in-charge type information are moved to the external storage device 105.

When the processing request reception/distribution program 201 of the computer 101 receives a change in the type of person in charge from the computer 102, it requests the computer 103 to report the load (or the computer 101 refers to the processing request file 108 and the processing result file). ). if calculator 1
If the load of 03 is below a certain value, the computer 102 is notified that the change in the type of person in charge is permitted. Thereafter, after waiting for the processing request of the changed type to be moved to the external storage device 105, the computer in charge of processing on the processing request control table 209 is changed, and the processing request is written to the corresponding processing request file.

When the processing request queuing program 204 of the computer 103 finds that the queued processing request is of a type other than the type in charge, it turns on the load shift control flag on the processing request management table 206 and adds the relevant type to the type information in charge. . The business processing program 207 of the computer 103 refers to the load transfer control flag, and if the flag is ON, processes the processing request on the external storage device 105, and then processes the processing request on the processing request queue 205. In addition, calculator 1
02 and computer 103 operate in the same way.

Next, parts related to load smoothing control, which is a feature of this embodiment, will be explained in detail with reference to FIG. FIG. 1 is a flowchart showing load smoothing control. In this method, the computer 101 learns the load status of the computer from the input and output amounts of the computers 102 and 103 (step 1), and determines the processing request type to be changed based on the load status (step 2). . Next, the computer whose type is to be deleted moves the processing request and type information of the type to be deleted to an external storage device (step 3). After that, the computer 101 inputs a processing request of the corresponding processing request type to the computer to which the processing request type is added (step 4), and after the computer processes the processing request on the external storage device using the input as a trigger, the computer 101 10
The processing request from 1 is processed (step 5).

[0018] In the following, the details of the processing request and the structure of the table etc. will be explained first, and then the detailed explanation of Step 1, Step 2, and Step 4 will be explained using the state transition table of FIG. 3. Detailed operation of step 5 is shown in Figure 1
This will be explained using the state transition table of 0 and the flowcharts of FIGS. 11 and 12.

FIG. 4 is a diagram showing detailed contents of processing requests written to the processing request file 106 and the processing request file 108. Processing requests written to the processing request file 106 and processing request file 108 include the processing request reception serial number 70 assigned by the processing request reception/distribution program 201 to the processing request input from the terminal 104 and the processing request input from the terminal 103. processing request data 7. Further, the processing request data 7 includes a type number 71 and business processing information 72. The processing request reception serial number 70 is a serial number indicating the order in which processing requests are received by the processing request reception/distribution program 201. Type number 71 is
This is a number representing the type of processing request, and corresponds to each type in order starting from 1. The business processing information 72 is information that is not particularly related to load smoothing control.

FIG. 5 is a diagram showing details of the processing request control table 209. The processing request control table 209 is
Write pointer 1 area 3500, write pointer 2 area 3501, and n control information areas 502x (x=a
- n). In the light pointer 1 area 500,
The processing request acceptance serial number of the most recently written processing request is stored in the processing request file 106. The write pointer 2 area 501 stores the processing request reception serial number of the processing request most recently written to the processing request file 108. The control information area 502x is an area that stores control information for processing requests of type x by type.

FIG. 6 is a diagram showing details of an arbitrary control information area 502x of the processing request control table 209 shown in FIG. The control information area 502x consists of a type x type number area 601 and a type x processing computer number area 602. The type x type number area 601 stores the type number of type x. Type x processing computer number area 60
2 stores the serial number of the computer that processes the processing request of type x.

FIG. 7 is a diagram showing details of the processing request management table 206. The processing request management table 206 includes a load transfer control flag area 701, an external storage address area 702, an input amount area 703, an input write pointer area 704, an input read pointer area 705,
It consists of an output amount area 706, an output write pointer 707, and m person-in-charge type information areas 708x (x=am). The load transfer control flag area 701 stores a flag indicating whether or not the type in charge has been added (ON when added, OFF otherwise). The external storage device address area 702 stores the start address of the processing request storage area on the external storage device. Input amount area 70
3 stores the input amount of the computer. The input write pointer area 704 stores the value of the write pointer 1 area 500 sent from the computer 101. The input read pointer area 705 stores the processing request reception serial number of the processing request most recently read from the processing request file accessed by the computer having this table. The output amount area 706 stores the output amount of the computer. The output write pointer area 707 contains the processing result serial number most recently written to the processing result file accessed by the computer that has this table (the processing result has a processing result serial number and type number added to the processing result). ) are stored. Person in charge type information area 708x
Management information of type x is stored in .

FIG. 8 is a diagram showing details of the arbitrary person-in-charge type information area 708x in FIG. The person in charge type information area 708x includes a type x type number area 801, a type x queue length area 802, and a type x business processing information area 803.
Consists of. The type x type number area 801 stores the type number of type x. Type x queue length area 8
02 stores the queue length of processing requests of type x in the processing request queue. Type x business processing information area 803
Management information for business processing of type x is stored in .

The operation of load smoothing control, which is a feature of this embodiment, will be explained in detail below. Steps 1, 2, and 4 in FIG. 1 are executed by the processing request reception/distribution program 201. The operation of this processing request reception/distribution program 201 will be explained in detail using the state transition table shown in FIG. Here, the position of the action being explained is indicated by (event number, state number). Further, the transition destination state is shown in a small box at the bottom right of the action in the table. Terminal 1 when waiting for processing request input (state 1)
When a processing request is received from 04 (event 1), the processing request is written to the processing request file based on the type (event 1).
,1). However, when a load transfer request is received from the computer 102 (event 2), a load status notification request is sent to the computer 102.
At step 3, the timer for transmission and response monitoring is set, and the state of waiting for a load status notification response (state 2) is established (2, 1). In this state, a load status notification response is received (event 3), and if the load of the computer 103 is

[0025]

[Math 1]

If the following is satisfied, the load is large, so a load transfer rejection response is returned to the computer 102, and the computer 102 enters a state (state 1) in which it waits for a processing request input. Also, the load on the computer 103 is several 1
If the above is not satisfied, a load transfer permission response is returned to the computer 102, and the load sharing completion notification waiting state (state 3), that is, the processing request of the type whose assigned type is changed and the value of the assigned type information area 708x are stored in the external storage device. 105 (3, 2). In this state, when a load sharing completion notification is received from the computer 102 (event 4), the control information area 5 of the processing request control table 209
Computer 1 in type x processing computer number area 602 of 02x
After setting the number corresponding to 03, it processes the processing requests connected to the queue and returns to the state of waiting for processing request input (state 1
) becomes (4, 3).

Step 3 in FIG. 1 is executed by the load control program 208. The operation of the load control program 208 will be explained according to the state transition table shown in FIG. In any state, the write pointer 1 is sent from the computer 101.
When the value of area 500 is received (event 5), the value obtained by subtracting the value of input light pointer area 704 from the value of light pointer 1 area 500 is input to the input amount area 703, and the value of the above write pointer 1 area is input to the input light pointer area 704. and keep the original state (5, 1), (5
,2),(5,3). Note that the value of the write pointer 1 area is sent at 1 minute intervals. In addition, when the timer is activated at 1-minute intervals in the state of waiting for the activation of the timer at 1-minute intervals (state 1), the processing result sequence number of the most recently written processing result in the processing request file 106 is read, and output is based on this value. The result of subtracting the value in the write pointer area 707 is set in the output amount area 706, and the processing result serial number is set in the output write pointer area 707. After this, the load situation is determined using the following formula.

[0028]

[Math 2]

In other words, if Equation 2 is satisfied, the computer 101 is deemed to be overloaded, a load shift request is sent to the computer 101, and the computer 101 enters a state of waiting for a load shift response (state 2). Also, if it is not satisfied,
It does not take any action and remains in the state of waiting for the 1-minute timer to start (1, 1).

When a load shift permission response is received (event 2) while waiting for a load shift response (state 2), the following processing is performed. (1) The value of the input write pointer area 704 and the value of the input read pointer area 705 are compared until the value of the input write pointer area 705 and the value of the input read pointer area 705 become the same. (2) Based on the value of the address area 702 on the external storage device, the processing request of the type handled by the computer 103 and the handled type information area 70
The value of 8x is moved to the external storage device 105. (3) Send a load sharing completion notification to the computer 101. The state changes to a state (state 3) of waiting for a load sharing completion notification response. If a load transfer rejection response is received from the computer 101 (
Event 2), no action is taken and the state waits for the timer to start at 1 minute intervals (state 1) (2, 2). When a load sharing completion notification response is received (event 6) in the state of waiting for a load sharing completion notification response (state 3), the state enters a state of waiting for activation of a one-minute timer (state 1).

Step 5 in FIG. 1 is executed by the processing request queuing program 204 and the business processing program 208. The operation of the processing request queuing program will be explained according to the flowchart of FIG. First, it is determined whether there is a processing request that has not yet been read in the processing request file by determining whether the value in the input read pointer area 705 is smaller than the value in the input pointer area 704 (step 1101). If the value in the input read pointer area 705 and the value in the input write pointer area 704 are the same, the system waits for activation from the system control program after a certain period of time (step 1102). Input read pointer area 7
If the value of 05 is smaller than the value of the input write pointer area 704, the processing request is queued in the processing required queue 205. (Step 1103). Next, it is checked whether there is a processing request of a type other than the type in charge among the queued processing requests (step 1104), and if there is, the load shift control flag area 701 is set to 1 (step 1105).
, the relevant type is added to the person-in-charge type information area 708x, and the value of the queue length area 802 is increased by the number of queued processing requests (step 1107). If there is no processing request of a type other than the type in charge, the process returns to step 1101.

Next, the operation of the business processing program 207 will be explained according to the flowchart shown in FIG. First, refer to the value in the load transfer control flag area 701 (step 1
201), if 1 is set, the external storage device 10
After moving the above processing request and the person in charge type information to the main memory and adding the person in charge type information to the person in charge type information area 708x, the above processing request is processed (step 1202).
. Further, 0 is set in the load transfer control flag area 701 (step 1203). After this, the processing request input from the computer 101 is processed (step 1204),
The value in the queue length area 802 is decremented (step 1205). 0 in load transfer control flag area 701
If set (step 1201), the process of step 1204 is performed.

In the above embodiment, the computer 1 may observe the input and output amounts of the computers 1 and 2 at one-minute intervals, and determine the type of processing request to be changed based on this.

Note that the computer 1 may inquire of the computers 2 and 3 about their respective input and output amounts or load conditions, and based on this, determine the type of processing request to be changed.

[0035] When the computer 2 is overloaded, the computer inquires about the input amount and output amount or the load status of the computer 3, and when the type of processing request in charge can be changed, this is notified to the computer 1, and the computer 1 The responsible processing request type may be changed by inputting a processing request of the relevant type into the computer 3.

Note that the load on the computer may be evaluated from the system time or CPU utilization rate of computer 2 or computer 3.

Note that when the computer 2 is overloaded, the computer 2
Among the types that are in charge of, Calculator 3 selects types that have a large amount of input, or conversely have short queues or have a small amount of input.
You may take on new responsibility.

Note that the operator may specify the type of processing request for changing responsibility between computer 2 and computer 3 during system operation. This is done by providing an area on the table in which the type of change is written by the operator command, and having the processing request reception/distribution program 201 refer to the flag on the table that is updated by the operator command to select the specified type, rather than the type with a long queue. This can be achieved by adding logic to select the selected type.

Note that the operator may forcefully change the processing request type in charge by inputting a command regardless of the load on the computers 2 and 3. This is done by providing an area on the table in which the change type is written by the operator command, and the processing reception/distribution program 201 and the load judgment program 208 refer to the flags on the table that are updated by the operator command, and judge the load according to Equations 1 and 2. This can be achieved by adding logic to bypass and select the specified type.

Note that the load judgment criteria for the computer 2 or the computer 3 such as (1) and (2) may be changed by the operator while the system is in operation.

Note that the number of computers that share the processing of processing requests is not limited to two, ie, computer 2 and computer 3, but may be three or more.

Note that two or more computers may be used to distribute processing requests by type.

According to the above embodiment, the computer 10
2. The computer 103 observes each input amount and output amount, and when one of the computers, for example, the computer 102, becomes overloaded, the computer 101 causes the computer 103 to input a type of processing request that requires a large amount of input.

Using this as a trigger, the computer 103
also processes the above-mentioned types of processing requests, making it possible to switch with small overhead.

[0045]

Effect of the Invention: In a multi-computer system consisting of a front-end computer that distributes processing requests of a plurality of types on a per-type basis, and a plurality of main computers that are connected to this in series and in parallel and process the processing requests in parallel, Each main computer observes its own load status (input amount and output amount),
When a main computer has a high load, the front computer inputs a type of processing request that requires a large amount of input to a main computer with a low load. Using this as a trigger, the main computer with a low load subsequently processes the processing request of the relevant type, which has the effect of making it possible to switch processing assignments with small overhead. In addition, since the front-end computer inputs the processing requests of the relevant type after queuing the unprocessed processing requests of the relevant type of the main computer from which the responsible type is deleted to the main computer to which the new responsible type is added, the same This has the effect that the processing order of processing requests of different types can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the basic operation according to an embodiment of the present invention.

FIG. 2 is a hardware configuration of a computer system to which an embodiment of the present invention is applied.

FIG. 3 is a configuration diagram of each program and each table applied within the computer system of FIG. 2;

FIG. 4 is a diagram showing details of the contents of a processing request file.

FIG. 5 is a detailed diagram of a processing request control table.

FIG. 6 is a detailed diagram of a control information area of a processing request control table.

FIG. 7 is a detailed diagram of a processing request management table.

FIG. 8 is a detailed diagram of the assigned type information area of the processing request management table.

FIG. 9 is a state transition table showing detailed operations of a processing request reception/distribution program.

FIG. 10 is a state transition table showing detailed operations of the load control program.

FIG. 11 is a flowchart showing detailed operations of a processing request queuing program.

FIG. 12 is a flowchart showing detailed operations of a business processing program.

[Explanation of symbols]

101...Calculator, 102...Calculator, 103...Calculator, 1
04...Terminal, 105...External storage device, 106...Processing request file, 107...Processing result file, 108...Processing request file, 109...Processing result file, 201...Processing request reception/distribution program, 204...Processing request queuing program , 206...Processing request management table, 2
07...Business program, 208...Load control program,
209...Processing request control program.

Claims (11)

[Claims] 1. A multi-computer system comprising at least one front-end computer that distributes processing requests of a plurality of types by type, and a plurality of main computers that are connected in series and in parallel to this computer and process the processing requests in parallel. , the main computer observes the respective input and output quantities and notifies the front-end computer in case of overload, and the front-end computer makes changes between the main computers based on the input and output quantities of the other main computers. Determine the processing request type to be handled, transfer the unprocessed processing requests of the relevant type of the computer whose responsible type will be deleted to the main computer where the responsible type is newly added, and then input the processing request of the relevant type. A load smoothing control method in a multi-computer system characterized by changing the type of processing request in charge. 2. In the load smoothing control method in a multi-computer system according to claim 1, the front-end computer periodically observes the input amount and output amount of the main computer, and based on this, changes should be made between the main computers. A load smoothing control method in a multi-computer system, characterized by determining the type of processing request to be handled. 3. In the load smoothing control method in a multi-computer system according to claim 1, the front end computer periodically inquires of the main computer about its input amount and output amount or load status, and based on this, the front end computer 1. A load smoothing control method in a multi-computer system, characterized by determining the type of processing request to be handled by changing. 4. In the load smoothing control method in a multi-computer system according to claim 1, an overloaded main computer can inquire about the input amount and output amount or load status of other main computers and change the processing request type in charge. , the front-end computer notifies the front-end computer of this fact, and the front-end computer changes the processing request type in charge by inputting the processing request of the type to the main computer to which the new processing request type is added. Load smoothing control method in computer systems. 5. A load smoothing control method in a multi-computer system according to claims 1, 2, 3, and 4, comprising:
1. A load smoothing control method in a multi-computer system, characterized in that a processing request type to be changed between main computers is determined based on the internal time or CPU utilization rate of each main computer. 6. The load smoothing control method in a multi-computer system according to claim 1, wherein another main computer is assigned to handle processing requests of a type that has a long queue or a large amount of input. Load smoothing control method in the system. 7. A load smoothing control method in a multi-computer system according to claim 1, wherein another main computer is assigned to handle processing requests of a type that has a short queue or a small amount of input. Load smoothing control method in the system. 8. In the load smoothing control method in a multi-computer system according to claim 1, a load judgment criterion for determining whether or not to change the processing request type in charge between main computers is changed during system operation. A load smoothing control method in a multi-computer system characterized by: 9. The load smoothing control method in a multi-computer system according to claim 1, wherein the load smoothing control method in a multi-computer system is characterized in that the processing request type in charge of which should be changed between main computers is specified during system operation. Method. 10. A load smoothing control method in a multi-computer system according to claim 1, wherein the load smoothing control method in a multi-computer system is characterized in that the type of processing request in charge is forcibly changed regardless of the load on the main computer. . 11. A load smoothing control method in a multi-computer system, wherein processing of a processing request of a type that is not currently input is started upon input of a processing request of a type that is not currently input.