JP2000268012A - Method and device for distributing load in client server system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sure high-reliability service to a client by enabling operation with an optimum load. SOLUTION: Concerning a method for distributing a server load, in a client server system, each server 21 weights its own load condition to a CPU load, a job priority, a number of execution jobs and a number of job input queues respectively, allocates a threshold value (server load information weighting setting function part 211) and periodically compares this threshold value with sampled (server load information sampling function part 212) load information so as to perform load judgement for instructing the acceptance or interruption of a local area network(LAN) traffic (LAN traffic acceptance discriminating function part 213). By timely transmitting load control information generated according to the result of the above load judgement to a load distributing device 1 connected to a LAN, the transmission of the LAN traffic to the relevant server is controlled (load distribution control executing function part 12).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for distributing a server load in a client server system.

[0002]

2. Description of the Related Art Network computing is a technique in which computers are networked and the computing power is exerted over the entire network. In network computing, each computer constituting a network divides a task and allows distributed processing to be used mutually. Since a server that provides a service or a client that uses a function of a server is a network computing component, this network computing is sometimes referred to as client-server computing. A client-server system that implements the above-described client-server computing includes a server computer that performs a predetermined process in response to a request, a plurality of client computers that request the server computer to perform a process,
A communication line such as a LAN (Local Area Network) interconnecting the client and server computers.

[0003]

In the client-server system described above, the processing capacity of one server computer is limited, so that the server computer is often composed of a plurality of server computers. Measures are taken to balance the load so that requests are not concentrated on the server. Normally, the load situation is determined only by the CPU load, and the load is distributed. There is also a system in which a load distribution device is connected, a response time between servers is measured, and a load state is determined according to the time. For this reason, the server load is determined only by the CPU usage rate or the response time, and an appropriate server is assigned. Therefore, it is not possible to accurately grasp the load status according to the importance and type of the service. It did not always provide reliable services. The present invention has been made in view of the above circumstances, and decomposes an element of a server load into each priority order, a CPU usage rate, the number of executed jobs, and the number of job input queues defined according to an application in use. It is an object of the present invention to provide a method and apparatus for distributing a server load in a client server system, which can operate at an optimum load by controlling the flow rate of LAN traffic, and can provide a reliable and highly reliable service to a client. .

[0004]

According to a first aspect of the present invention, there is provided a method for distributing a server load, comprising the steps of:
In the client server system under the connection environment, the server load element is decomposed into each priority defined according to the application, the CPU usage rate, the number of executed jobs, and the number of job input queues. Weighting and assigning a threshold value to each of the elements, and periodically comparing the threshold value with the collected load status to accept LAN traffic,
A load determination for rejection is performed, and the result is notified to a load distribution device connected to the LAN, thereby prompting the server concerned or another server to control transmission of LAN traffic according to the weighted load element. It is characterized by.

[0005] The server load distribution device according to claim 2 is
The server load factor is decomposed into each priority, CPU usage, number of executed jobs, and number of job input queues defined according to the application.
In a client-server system that controls transmission of AN traffic, a weight is assigned to each of the decomposed elements, a threshold is assigned, and the threshold is periodically compared with the load information to be collected.
A server that performs load determination for accepting or rejecting AN traffic and notifies the load balancer connected to the LAN, and, depending on the load determination performed by the server, updates a built-in server load management table and loads the weighted load elements To the server or another server according to
A load distribution device that controls transmission of AN traffic. The server load distribution device according to claim 3, wherein the server load management information table includes:
Each of the applications to be managed and assigned with a priority, each of the information setting areas of CPU load status, execution job load status, input job queue load status, is referred to by the load balancing device, It is also characterized in that LAN traffic acceptance determination is performed in an order according to the weight set by the load information weight setting means in the server.

Further, the load distribution device according to the present invention is characterized in that
In a client-server system under an AN connection environment, server load factors are defined by priority, CPU usage rate, number of executed jobs,
A server load information weight setting means in the server which decomposes into the number of job input queues, assigns a weight to each of the decomposed elements, and assigns a threshold value;
A server load information collection unit in the server for periodically collecting a server load status including a PU usage rate, the number of executed jobs, and the number of job input queues; a threshold defined by the server load information weight setting unit; LAN traffic acceptance determination means in the server for periodically comparing server load conditions collected by the load information collection means and accepting or rejecting LAN traffic;
Depending on the result of the comparison, load status communication means in the server for transmitting load control information for interrupting LAN traffic or load control information for resuming acceptance of LAN traffic to a load control device connected to the LAN, A load status communication means in the load control device for receiving load control information and transmitting the load control information to load distribution control execution means;
When load control information for interrupting traffic reception is received, the related status of the relevant server in the server load management information table managed by itself is set to transmission disabled, and other servers can accept jobs from clients. Search for a suitable server and perform routing, LA
When the load control information for resuming the reception of the N traffic is received, the status related to the relevant server in the server load management information table managed by itself is set to be transmittable, and the transmission control of the LAN traffic to the relevant server is performed. And a load distribution control executing means in the load distribution device for prompting

In the above-described configuration, the present invention provides a method for distributing LAN traffic load to a server group in a LAN environment, wherein the server group and the load distribution device cooperate to distribute the LAN traffic load of the server group. Features. Each server weights its own load status for each of CPU load, job priority, number of executed jobs, and number of job input queues, assigns a threshold value, and periodically compares the threshold value with the collected load information. By doing
A load judgment for accepting or suspending LAN traffic is performed. Then, by transmitting timely the load control information generated according to the result of the load determination to the load balancer connected to the LAN, the transmission control of the LAN traffic to the corresponding server is performed. This makes it possible to optimally and efficiently distribute the LAN traffic load of the server group. According to the present invention, a server group can be operated with an optimal load, and a highly reliable service can be reliably provided to a client.

[0008]

FIG. 1 is a block diagram showing a configuration of a client server system to which the present invention is applied.
In FIG. 1, a client server system is connected to a load distribution device 1 and a server group 2 and a client computer (not shown) via a LAN line 3. The server group 2 in which the load distribution method of the present invention is embodied includes servers 21 and
2,25. The load balancer 1 transmits the LAN traffic to each of the servers 21, 22, 23 constituting the server group 2.
Control while monitoring the load status of

FIG. 2 is a block diagram showing an embodiment of a load distribution device in the client server system of the present invention. In the figure, blocks that are the same as the numbers shown in FIG. 1 are the same as those in FIG. In the figure, server group 2
The server 21 is a server load information weighting setting function unit 211, a server load information collection function unit 212,
Traffic reception judgment function unit 213 and load status communication function unit 2
Consists of 14 The servers 22 and 23 have the same configuration as the server 21. A feature of the present invention is to decompose a server load element into each priority order defined according to an application, a CPU usage rate, the number of executed jobs, and the number of job input queues, and to control the flow rate of LAN traffic for each. It is in. Server load information weight setting function section
The 211 performs weighting described later on each of the decomposed elements, assigns a threshold described later, and supplies the threshold to the LAN traffic acceptance determination function unit 213. Further, the server load information collection function unit 212 periodically collects a server load condition including the CPU usage rate, the number of executed jobs, and the number of job input queues, and performs the LAN traffic reception determination function unit 213.
To supply. LAN traffic acceptance determination function unit 213
Periodically compares the threshold value defined by the server load information weight setting function unit 211 with the server load status collected by the server load information collection function unit 212, accepts or rejects LAN traffic, and performs load control to that effect. The information is supplied to the load status communication function unit 214 as information. The load status communication function unit 214 includes a LAN traffic reception determination function unit 2
Depending on the result of the comparison operation by 13, load control information for interrupting LAN traffic or load control information for resuming reception of LAN traffic is transmitted to the load balancer 1 connected to the LAN.

The load distribution device 1 includes a load status communication function unit 11
And a load distribution control execution function unit 12 and a server load management table 13. The load status communication function unit 11 is a server
The load control information transmitted from the load status communication function unit 214 is received and transmitted to the load distribution control execution function unit 12. When receiving the load control information for interrupting the reception of the LAN traffic, the load distribution control execution function unit 12 sets the related status of the corresponding server in the server load management information table managed by itself to a transmission disabled state, The server searches for a server capable of accepting a job from the client, performs routing, and receives load control information for resuming reception of LAN traffic. Set the relevant status so that it can be sent,
The user is prompted to control the transmission of LAN traffic to the server. As shown in an example in FIG. 5, the server load information management table 13 stores, for each application to be managed, a priority assigned application, a CPU load status, an execution job load status, and an input job queue load. Each information setting area of the status is referred to by the load distribution control execution function unit 12 of the load distribution device 1, and is determined to accept LAN traffic in the order according to the weight set by the load information weight setting function unit 211 in the server 21. Is performed.

FIG. 3 to FIG. 5 are diagrams cited for explaining the operation of the embodiment of the present invention. Each of the weights set by the server load information weight setting function unit 211 is shown in a table format. Table 1 shows an example of a load collection status collected by the server load information collection function unit 212 in a rating format, and Table 3 shows a data structure of the server load information management table 13 in a table format. In Table 1 shown in FIG. 3, the weighting information is
It consists of priority, CPU usage, number of executed jobs, and number of job input queues. For each of these elements, load information is weighted for accepting LAN traffic in the order of the CPU usage rate, the number of executed jobs, and the number of job input queues, and upper and lower thresholds are set for each of the elements. Further, a job reception limit threshold and a job reception restart threshold are also set. Note that for each application used, for example, mission-critical tasks have priority 1, WWW (World
Wide Web.) Access shall be set to priority 10. Table 2 shown in FIG. 4 is a table in which the server load information collection function unit 212 collects the CPU usage rate, the number of executed jobs, and the number of input job queues at certain intervals for each job priority. <Table 3> shown in FIG. 5 is a server load information management table 13 managed by the load distribution control execution function unit 12 of the load distribution device 1, and includes a CPU for each server to be managed.
It shows the status of accepting or not accepting LAN traffic for each of the load, the execution job load, and the input job queue load. The determination of acceptance of LAN traffic is made in the order of CPU load, execution job load, and input job queue load according to the weight information set by the load information weight setting function unit 211. 6 and 7 are flowcharts cited for describing the operation of the present invention, and are flowcharts showing the operation procedure of the server 21 and the operation procedure of the load distribution control execution function unit 12 of the load distribution apparatus 1 respectively. is there.

Referring now to FIGS. 1 to 3 with reference to FIGS.
The operation of the embodiment of the present invention shown in FIG. 2 will be described in detail. A feature of the present invention is to decompose a server load element into each priority order defined according to an application, a CPU usage rate, the number of executed jobs, and the number of job input queues, and to control the flow rate of LAN traffic for each. Is as described above. Therefore, the server load information weighting function setting unit 211 weights the server load status for each element (step S61), and sets and defines it as a threshold (step S62). Here, as shown as <Table 3> in FIG. 3, the weighting for each element is weighted in the order of the CPU usage rate, the number of executed jobs, and the number of input job queues. The upper threshold of the CPU usage rate is 30%, the lower threshold is 15%, the upper threshold of the number of executed jobs is 60, the lower threshold is 40, the upper threshold of the input job queue is 20, the lower threshold is 10, and the priority is higher. For applications to which degree 2 has been assigned, the upper threshold of the CPU usage rate is 20%, the lower threshold is 7%, the upper threshold of the number of executed jobs is 40, the lower threshold is 20, the upper threshold of the input job queue is 15, and the lower threshold is set. The threshold value is set to 7, the upper limit threshold value of the CPU usage rate is set to 5%, the lower limit threshold value is set to 4%, the upper limit threshold value of the number of executed jobs is set to 50, and the lower limit threshold value is set. 40, 80 the upper threshold of the input job queue, the lower threshold is 50, and the accepted limit threshold or resume threshold, for each element for acceptance determination processing in LAN traffic admission determination function unit 213 to be described later.

On the other hand, the server load information collection function unit 212
The server load status is periodically collected from the CPU load, the number of executed jobs for each job priority, and the number of job input queues (step S63), and is supplied to the LAN traffic reception determination function unit 213. Here, the collected server load status is shown as <Table 2> in FIG. Here, regarding the job of priority 1, the CPU usage rate is 24% and the number of executed jobs is 4
3, the number of input job queues is 9, and for jobs of priority 2, the CPU usage rate is 21%, the number of executed jobs is 36,
It is assumed that the number of input job queues is 5, and the CPU usage rate is 24%, the number of executed jobs is 43, and the number of input job queues is 9 for jobs of priority 10. The LAN traffic reception determination function unit 213 periodically compares the reception limit threshold and the reception restart threshold for each element defined by the server load information weighting function unit 211 with the load status collected by the server load collection function 212. Then, it is determined whether to accept / resume or reject LAN traffic (step S64). LA
When the N traffic reception determination function unit 213 confirms that the reception limit threshold value defined in the server load information weight setting function unit 211 is exceeded, the load status communication function unit 21
4 transmits load control information for interrupting LAN traffic reception to the load distribution device 1 (step S6).
5) Also, when the load decreases to the threshold for resuming reception, LA
The load control information for resuming reception of N traffic is transmitted (step S66). If it falls within the defined threshold, the server is permitted to accept LAN traffic (step S67).

The load distribution device 1 includes a load status communication function unit 11
When the load control information is received from the load status communication function unit 214 of the server 21, the information is transmitted to the load distribution control execution function unit 12
Transfer to Also, the server instructed by the load balancing control information described later generated by the load balancing control execution function unit 12
21 to the load status communication function unit 214. The load distribution control execution function unit 12 checks the load control information transmitted from the server 21 (step S71). If the load control information for suspending the reception of the LAN traffic is received here, it is managed in the load distribution device 1. The related status of the corresponding server 3 is changed to the transmission disabled state (step S7).
2), reply a reception confirmation message to the server 21 (step S73). Further, a server capable of accepting a job from a client in another server of the server group 2 is round-robin searched from the server load information management table 13 and is routed (step S74). On the other hand, from server 21 to L
Upon receiving the load control information for resuming reception of the AN traffic, the corresponding server 214 managed in the load distribution device 1
Is changed to a transmittable state (step S75), and a reception confirmation message is returned to the server 3 (step S76). <Table 3> shown in FIG. 5 is a server load information management table 13 managed by the load distribution control execution function unit 12 of the load distribution device 1, and includes a CPU load, an execution job load, and an input for each server to be managed. For each of the job queue loads, the state of accepting or not accepting LAN traffic is shown. For example, for a job to which the priority of the server 01 is assigned, the CPU load status is acceptable, the execution job load status is not acceptable, the input job queue load status is acceptable, and the priority of the server 02 is The job to which 8 is assigned is in a state in which the CPU load status, the execution job load status, and the input job queue load status are all acceptable.

As described above, according to the present invention, the elements of the server load are decomposed into each priority defined according to the application to be used, the CPU usage rate, the number of executed jobs, and the number of job input queues. The flow can be controlled with an optimum load.

[0016]

As described above, according to the present invention, the server and the load distribution device cooperate with each other to control the load distribution of each server in detail according to the importance and type of the service. Can operate with optimal load and can reliably provide clients with highly reliable services.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a client server system to which the present invention is applied.

FIG. 2 is a block diagram showing an embodiment of the present invention.

3 is a diagram illustrating an example of a weighting and threshold setting definition defined by a weighting setting function unit illustrated in FIG. 2 as <Table 1>.

FIG. 4 is a diagram showing an example of load information collected by a load information collecting function unit shown in FIG. 2 as <Table 2>.

FIG. 5 shows an example of a data structure of a server load information management table managed by the load distribution device shown in FIG.
FIG.

FIG. 6 is a flowchart cited for explaining the operation of the server in FIG. 2;

FIG. 7 is a flowchart cited for explaining the operation of the load distribution control execution function unit in FIG. 2;

[Explanation of symbols]

1 ... load balancer, 2 (21, 22, 23) ... server, 11 (214)
... Load status communication function unit, 12 ... Load distribution control execution function unit,
13: server load information management table, 211: server load information weight setting function unit, 212: server load information collection function unit, 213: LAN traffic reception determination function unit

Claims (4)

[Claims] In a client-server system under a LAN connection environment, a server load element is decomposed into priority, CPU utilization, number of executed jobs, and number of job input queues defined according to an application. The server assigns a threshold and assigns a threshold to each of the decomposed elements, and periodically compares the threshold with a sampled load situation to determine a load for accepting or rejecting LAN traffic,
A server load distribution method for notifying a server or another server of transmission of LAN traffic in accordance with the weighted load element by notifying the result to a load distribution apparatus connected to the LAN. . 2. The server load factor is decomposed into each priority defined according to an application, a CPU usage rate, the number of executed jobs, and the number of job input queues, and transmission control of LAN traffic is performed based on the respective factors. In the client-server system performing weighting, a weight is assigned to each of the decomposed elements, a threshold is assigned, and the threshold is periodically compared with the collected load information, so that LAN traffic can be accepted or rejected. A server that performs a load determination and notifies the load balancer connected to the LAN, and updates the built-in server load management table depending on the load determination by the server and updates the built-in server load management table to the corresponding server or another server according to the weighted load element. , A load distribution device for controlling transmission of LAN traffic A server load distribution apparatus characterized in that: 3. The server load management information table includes information settings for each of the applications used and assigned a priority by each server to be managed, CPU load status, execution job load status, and input job queue load status. 3. The server load distribution according to claim 2, wherein the determination of the acceptance of the LAN traffic is performed in an order according to a weight which is configured by a load information weighting setting means in the server and which is referred to by the load distribution device. apparatus. 4. In a client server system under a LAN connection environment, a server load element is decomposed into each priority defined according to an application, a CPU usage rate, the number of executed jobs, and the number of job input queues. Server load information weight setting means in the server that assigns a weight and assigns a threshold value to each of the elements, and periodically collects a server load status including the CPU usage rate, the number of executed jobs, and the number of job input queues. The server load information collecting means in the server, and the threshold defined by the server load information weight setting means and the server load status collected by the server load information collecting means are periodically compared to accept LAN traffic or Rejecting the LAN traffic acceptance determining means in the server; Depending on the result of the comparison, load status communication means in the server for transmitting load control information for interrupting LAN traffic or load control information for resuming reception of LAN traffic to a load control device connected to the LAN; Load status communication means in the load control device for receiving control information and transmitting the control information to load distribution control execution means; and server load management information managed by itself when load control information for interrupting LAN traffic reception is received. When the related status of the corresponding server in the table is set to the transmission disabled state, routing is performed by searching for a server that can accept a job from the client by another server, and load control information for resuming LAN traffic reception is received. The corresponding server in the server load management information table managed by itself Associated the status is set to transmittable state, dispersion of the server load, characterized in that it comprises a load balancing control execution means in the load balancer to prompt the transmission control LAN traffic for the corresponding server device.