JP2014085800A - Signal processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately perform request regulation of a system comprising a plurality of signal processing servers and a plurality of data processing servers.SOLUTION: A congestion determination device 50 in a system instructs a signal processing unit 200 to perform request regulation when congestion is detected in a data processing server. The congestion determination device 50 terminates the request regulation when a request number condition sufficiency notification with regard to a regulation target request number in the signal processing server of the signal processing unit 200 is received after the request regulation is started and a resource usage rate in the data processing server becomes lower than a prescribed threshold. A representative server of the signal processing unit 200 estimates a regulation target request number for the whole signal processing unit 200 on the basis of the regulation target request number received in the own server, estimates a data request number for the whole data processing server from the estimated value and transmits the request number condition sufficiency notification to the congestion determination device 50 when the estimated value is less than a prescribed threshold C.

Description

  The present invention relates to a signal processing system including a plurality of signal processing servers that process a request signal from a client device and a plurality of data processing servers that perform processing based on the request signal.

  Conventionally, a system has been proposed in which a plurality of signal processing servers that process request signals from client apparatuses and a plurality of data processing servers that perform processing based on the request signals are arranged. In this system, by increasing or decreasing the number of servers, it is possible to cope with an increase or decrease in the processing load of the entire system. In such a system, the request signal is distributed from the client device to the signal processing server by, for example, a signal distribution device (see Patent Document 1). As a signal distribution method, for example, a method using a consistent hash is used. (See Non-Patent Document 1). In this method, an ID is calculated using the identifier and hash function of the data requested by the received request signal, and the received ID is received depending on which area the ID space of the consistent hash assigned in advance belongs to. This is a method for determining to which server the signal is distributed. In the above example, the signal distribution device to the signal processing server determines to which signal processing server the request signal is distributed using a consistent hash based on the call-ID included in the request signal. . Further, the signal distribution device to the data processing server determines to which data processing server the signal is distributed using the consistent hash based on the user-ID or the like for the signal output from the signal processing server.

JP 2012-160075 A

D. Karger, E. Lehman, T. Leighton, M. Levine, D. Lewin, and R. Panigrahy, “Consistent Hashing and Random Trees: Distributed Caching Protocols for Relieving Hot Spots on the World Wide Web,” in Proceedings of the 29th ACM Symposium on Theory of Computing (STOC'97), May 1997, pp.654-663.

  In a system including the signal processing server group and the data processing server group, congestion may occur in the data processing server due to an increase in request signals. In such a case, how to perform congestion regulation (request regulation) and how to cancel request regulation have not been studied. In particular, if the request restriction is not properly released, there are the following problems. That is, (1) there is a problem that the performance of the system is unnecessarily lowered if the request restriction is continuously performed even though the number of request signals to be regulated is sufficiently small. Further, (2) there is a problem that if the request restriction is canceled even though the number of request signals subject to restriction is large, congestion occurs again in the data processing server. Therefore, an object of the present invention is to solve the above-described problem and appropriately perform request restriction and request restriction release in a system including a plurality of signal processing servers and a plurality of data processing servers.

In order to solve the above-described problem, the invention according to claim 1 is configured to process a request signal from a client device to a data processing server and transmit a data request to the data processing server, and A signal processing system comprising a plurality of the data processing servers that perform processing based on a data request, and a congestion determination unit that determines occurrence of congestion in the data processing server, wherein each of the data processing servers is a target of the data request A data storage unit that stores data to be determined, and when at least one of the resource usage rate and the number of data requests of the own data processing server is equal to or greater than a predetermined threshold, it is determined that congestion has occurred, When a congestion occurrence notification is sent to the congestion judgment means and the resource utilization rate falls below the predetermined threshold, congestion is low. A resource usage condition satisfaction notification is transmitted to the congestion determination unit, and the congestion determination unit includes a storage unit that stores server information indicating identification information of the signal processing server, and the data processing server When the congestion occurrence notification is received, a request restriction instruction indicating the type of the request signal to be restricted is transmitted to each of the signal processing servers, and each of the signal processing servers receives the request restriction instruction. Then, even if the request signal to be regulated is received, request regulation that does not execute processing based on the request signal is performed, and at least one of the signal processing servers that received the request regulation instruction is in the request regulation. , For each predetermined period, count the number of reception of the restriction target signal in its own signal processing server, When the expression (1) is satisfied, a request number condition satisfaction notification is transmitted to the congestion determination unit, the congestion determination unit receives a resource usage condition satisfaction notification from the data processing server, and from the signal processing server. When the request number condition satisfaction notification is received, the request restriction instruction to each of the signal processing servers is canceled.
α × number of reception of request signal to be regulated per time in own signal processing server × reciprocal of ratio of request signal to own signal processing server out of all signal processing servers <C 1)
Where α is the number of data requests transmitted to the data processing server in response to one request signal to the signal processing server, and C is a predetermined threshold value.

  Thus, when congestion occurs in the data processing server of the signal processing system, the signal processing server uses the number of request signals subject to regulation received by its own signal processing server, and the total number of data requests in the data processing server. Is estimated. Then, by using the estimated total number of data requests, it is determined whether or not the number of request signals has decreased to such an extent that the request restriction can be canceled (request number condition satisfaction determination). Thereby, request regulation and request regulation release can be performed appropriately in the signal processing system. Further, since the request restriction and the request restriction release are performed not on the data processing server but on the signal processing server side, it is possible to prevent a load from being applied to the data processing server in which congestion has occurred.

  According to a second aspect of the present invention, the congestion determination means of the signal processing system according to the first aspect uses a request signal to the data processing server in which the congestion occurs as the request signal to be regulated.

  By doing in this way, the congestion determination means can make the request signal subject to the request regulation a data request to the data processing server where the congestion has occurred.

  According to a third aspect of the present invention, in the signal processing system according to the first or second aspect, the signal processing server that performs the request number condition satisfaction determination for determining whether or not the expression (1) is satisfied, Any one signal processing server selected by the congestion determination means.

  In this way, the signal processing server can obtain the estimated value of the total number of data requests in each data processing server relatively easily.

  According to a fourth aspect of the present invention, the signal processing server selected by the congestion determination means of the signal processing system according to the third aspect is a server having the highest predetermined processing capability among the signal processing servers.

  By doing in this way, among the signal processing servers of the signal processing system, a signal processing server having a relatively high processing capacity, that is, a high possibility of having a processing capacity, performs a request number condition satisfaction determination. It is possible to reliably perform the number condition satisfaction determination.

According to a fifth aspect of the present invention, in the signal processing system according to the third aspect, when the selected signal processing server performs the request number condition satisfaction determination, the signal processing server counts in its predetermined period. The number of receptions of the restriction target request signal is transmitted to any of the other signal processing servers, and each of the signal processing servers that has received the number of receptions of the restriction target request signal from the other signal processing servers, The number of receptions of the restriction target request signal counted by its own signal processing server in the predetermined period is added to the number of receptions of the restriction target request signal transmitted, and the reception number is still transmitted. The selected signal processing server performs processing to be transmitted to the other signal processing server that is not present, and the selected signal processing server transmits the request signal to be regulated in all other signal processing servers. If the receiving the sum of the received number, in place of the equation (1), when satisfying the following equation (2), transmits the request number condition satisfaction judgment notification.
Α × total value of the number of reception of request signals to be regulated in all the signal processing servers <the C ... expression (2)

  In this way, when the congestion determination means estimates the total number of data requests in each data processing server, the congestion determination means uses the total number of receptions of request signals to be regulated in each signal processing server. A value can be obtained.

  According to a sixth aspect of the present invention, the signal processing server that performs the request number condition satisfaction determination for determining whether or not the expression (1) is satisfied in the signal processing system according to the first or second aspect, All the signal processing servers that have received the request restriction instruction in the system, wherein the congestion determination means receives a resource usage rate satisfaction notification from any of the data processing servers, and the predetermined number a or more When the request number condition satisfaction determination notification is received from the signal processing server, the request restriction instruction to each of the signal processing servers is canceled.

  In this way, when the congestion determination means estimates the total number of data requests in each data processing server, the congestion determination means uses the total number of receptions of request signals to be regulated in each signal processing server. A value can be obtained.

  The invention according to claim 7 is a plurality of signal processing servers for processing a request signal from a client device to a data processing server and transmitting a data request to the data processing server, and a plurality of processing based on the data request. A data processing system comprising: the data processing server; and a congestion determination means for determining occurrence of congestion in the data processing server, wherein each of the data processing servers stores data subject to the data request And determining that congestion has occurred when at least one of the resource usage rate and the number of data requests of the own data processing server is equal to or greater than a predetermined threshold, and notifying the congestion determination means of congestion occurrence And when the resource utilization rate falls below the predetermined threshold, it is determined that congestion is reduced, and the congestion determination A resource usage rate condition satisfaction notification is transmitted to the stage, and the congestion determination means includes a storage unit that stores server information indicating identification information of the signal processing server, and when the congestion occurrence notification is received, the signal processing A request restriction instruction indicating the type of the request signal to be restricted is transmitted to each server, and each of the signal processing servers receives the request signal to be restricted when receiving the request restriction instruction. However, the request restriction that does not execute the processing based on the request signal is performed, and during the request restriction, the number of reception of the request signal to be restricted is counted every predetermined period, and the number of reception of the counted request signal is The congestion determination unit receives a resource usage condition satisfaction notification from the data processing server, and (previous) For one request signal to the signal processing server, the value of the number of data requests to be transmitted to the data processing server α × the total number of received request signals counted by each of the signal processing servers) is a predetermined threshold C When it is determined that the request is less than, the request restriction instruction to each of the signal processing servers is canceled.

  By doing in this way, it is not necessary to determine whether or not the condition of the number of requests to be regulated is satisfied on each signal processing server side of the signal processing system.

  The invention according to claim 8 is a server in which the signal processing server of the signal processing system according to any one of claims 1 to 6 receives the request signal distributed by the consistent hash, When the data processing server is a server that receives the data request distributed by the consistent hash, the request signal is transmitted to its own signal processing server among all the signal processing servers in the equation (1). Is used instead of the reciprocal of the ratio at which all the signal processing servers are assigned in the consistent hash divided by the total of the areas assigned to the own signal processing servers in the consistent hash.

  In this way, it is possible to estimate the number of request signals to be restricted to all signal processing servers when the signal processing server is a server that processes request signals and data requests distributed by the consistent hash. This makes it easier for the signal processing server to accurately estimate the total number of data requests in each data processing server.

  According to the present invention, it is possible to appropriately perform request restriction and request restriction release in a system including a plurality of signal processing servers and a plurality of data processing servers.

It is a figure which shows the whole structure of the system (signal processing system) of each embodiment. It is a figure explaining the outline | summary of the system of each embodiment. It is a figure explaining the outline | summary of the system of each embodiment. It is a figure explaining the outline | summary of the system of each embodiment. It is a figure explaining the outline | summary of the system of 1st Embodiment. It is a figure which shows the structure of the system of 1st Embodiment and 2nd Embodiment. It is a figure which shows the process sequence at the time of the request regulation in the system of 1st Embodiment. It is a figure which shows the process sequence at the time of the request | requirement cancellation | release in the system of 1st Embodiment. It is a figure explaining the outline | summary of the system of 2nd Embodiment. It is a figure which shows the process sequence at the time of the request | requirement cancellation | release in the system of 2nd Embodiment. It is a figure explaining the outline | summary of the system of 3rd Embodiment. It is a figure which shows the structure of the system of 3rd Embodiment. It is a figure which shows the process sequence at the time of the request regulation in the system of 3rd Embodiment. It is a figure which shows the process sequence at the time of the request | requirement cancellation | release in the system of 3rd Embodiment. It is a figure explaining the outline | summary of the system of 4th Embodiment. It is a figure which shows the structure of the system of 4th Embodiment. It is a figure which shows the process sequence at the time of the request | requirement cancellation | release in the system of 4th Embodiment.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described separately from the first embodiment to the fourth embodiment with reference to the drawings.

  First, the overall configuration of the system (signal processing system) of each embodiment will be described. As shown in FIG. 1, the system includes a signal processing unit 200 that is a group of signal processing servers 20 that processes a request signal (request) from a client device (not shown), and a process based on a data request from the signal processing server 20. And a database unit 400 which is a group of a plurality of database servers (data processing servers) 40 for performing The system also distributes a request signal for data acquisition from a client device to each signal processing server 20, and a data request distribution for distributing a data request from each signal processing server 20 to each database server 40. Device 30. Upon receiving a request signal from the client device, the request signal distribution device 10 uses the call-ID included in the request signal to request signals to the signal processing servers 20 using a consistent hash (see Non-Patent Document 1). Sort out. The signal processing server 20 that has received the distributed request signal transmits a data request based on the request signal to the data request distribution device 30. Upon receiving this data request, the data request distribution device 30 distributes the data request to each database server 40 by a consistent hash using the user-ID included in the data request. Upon receiving the distributed data request, the database server 40 performs processing based on the data request and returns the result to the client device via the signal processing server 20. For example, the database server 40 searches the data storage unit 441 (described later) for data that is the target of the data request, and transmits the searched data to the client device via the signal processing server 20.

  Here, the signal distribution by the consistent hash uses the ID space of the consistent hash as illustrated in FIG. In the consistent hash ID space, the areas in charge of the servers A, B, and C (the signal processing server 20, the database server 40, and the like) are determined, and each distribution device specifies the identification included in the received signal. A hash value is calculated using a key and a hash function. Then, the distribution to the server by each distribution device is performed by determining to which server the calculated hash value belongs to the area in charge in the consistent hash ID space. In this way, by distributing the request signal to each server using the consistent hash, even if the performance of each server is not uniform, the request signal is distributed at a rate corresponding to each performance. be able to. For example, when the performance index values of the servers A to C are the values shown in the graph of FIG. 1, if the assigned area of each server is determined in accordance with the performance index value, the server B having a relatively high performance can be obtained. A large number of signals are distributed, and so many signals are not distributed to the server A having relatively low performance. In this way, by performing signal distribution according to performance, it is possible to include servers with various performances in a system composed of a plurality of servers, and it is easy to ensure system scalability.

  In the present embodiment, the signal processing server 20 group of the signal processing unit 200 and the database server 40 group of the database unit 400 are examples in which signals are distributed according to their performance by consistent hash. However, the present invention is not limited to this. For example, each distribution device may distribute signals according to the performance of each server by a method other than the consistent hash, or distribute signals equally to each server regardless of the server performance. You may make it. In the present embodiment, the signal received by the signal processing server 20 is described as an example of processing by a database server. However, a data processing server other than the database server may be used.

  Next, the outline of the system according to each embodiment will be described with reference to FIGS. In each drawing, each distribution device in FIG. 1 is not shown.

  As shown in FIG. 2, the present system includes a congestion determination device 50 connected to the signal processing unit 200 and the database unit 400. The congestion determination device 50 monitors the congestion state of each database server 40 of the database unit 400, and issues a request restriction instruction to the signal processing server 20 when congestion occurs in the database server 40. When the congestion state in the database server 40 has improved, a request restriction release instruction is issued to each signal processing server 20. Here, the request restriction in the signal processing server 20 means that, for example, even when a request signal from a client device (not shown) is received, an error message is returned to the client device and a data request to the database server 40 is not transmitted. And so on. That is, the present system performs request regulation on the signal processing server 20 side, not on the database server 40 where congestion has occurred. By doing so, it is possible to prevent the congestion in the database server 40 from getting worse.

  Next, the processing outline of the congestion determination apparatus 50 in FIG. 2 will be described with reference to FIG. The congestion determination device 50 in FIG. 2 executes restriction (request restriction) when the resource usage rate exceeds a predetermined condition due to concentration of data requests in each database server 40 (see FIG. 2) of the database unit 400. . As shown in FIG. 3, at the time of request restriction, each signal processing server 20 (see FIG. 2) of the signal processing unit 200 responds to the restriction target request based on an instruction from the congestion determination device 50 (see FIG. 2). Execute restrictions such as error response and discard. Thereafter, the signal processing unit 200 cancels the request restriction based on an instruction from the congestion determination device 50. The request to be regulated here may be a request to a specific server (for example, the database server 40 in which congestion has occurred), for example. All requests or a request for a specific key may be used. When a request to the database server 40 in which congestion occurs is a restriction target request, the congestion determination device 50 uses the above-described consistent hash to identify a key included in the request to the database server 40 in which congestion has occurred, The signal processing server 20 is instructed to restrict the request including the identified key.

Here, the congestion determination device 50 determines to release the request restriction when the following two conditions are satisfied simultaneously.
(1) Resource usage rate of a congested server (database server 40) in the database unit 400 <R (R is a threshold value related to resource usage rate)
(2) Estimated value of the number of data requests to the server (database server 40) in the database unit 400 <C (C is a threshold regarding the number of requests)

  That is, as illustrated in FIG. 4, the database unit 400 (the database server 40 in FIG. 2) monitors its own resource usage rate, and when the condition that the resource usage rate is less than a predetermined threshold R is satisfied, To the congestion determination device 50. That is, the database server 40 notifies the congestion determination device 50 to the effect that the congestion in the server itself is being resolved. Further, the signal processing unit 200 (the signal processing server 20 in FIG. 2) counts the number of requests subject to restriction (hereinafter abbreviated as the number of requests as appropriate) received at its own server every predetermined period after the start of request restriction. Do. Then, the signal processing server 20 estimates the number of data requests that are normally transmitted to the database unit 400 (database server 40) from the received number of requests to be regulated (details will be described later). When the condition that the estimated value of the number of data requests is less than the predetermined threshold C is satisfied, that is, when it is determined that the request number condition is satisfied, the signal processing unit 200 notifies the congestion determination device 50 to that effect. To do. That is, the signal processing server 20 estimates that the number of data requests to the database unit 400 will decrease when the number of requests subject to restriction received by its own server decreases, and notifies the congestion determination device 50 to that effect. Then, the congestion determination device 50 determines that the request restriction is to be released when the request processing condition satisfaction notification in the signal processing unit 200 and the resource utilization condition satisfaction notification in the database unit 400 are received. Perform release.

<First Embodiment>
(Overview)
The outline of the system according to the first embodiment will be described with reference to FIG. As shown in FIG. 5, the system according to the first embodiment is configured so that the representative server of the signal processing unit 200 makes a request based on the number of requests to be controlled received by its own server, as shown in FIG. The number condition satisfaction determination is performed, and the congestion determination apparatus 50 is notified when the request number condition is satisfied. That is, the total number of requests subject to restriction (the number of requests subject to restriction received by the entire signal processor 200) is estimated from the number of requests subject to restriction received by a representative server (for example, a server with high performance) of the signal processing unit 200, Using the estimated value, the number of original data requests is further calculated, and the request number condition satisfaction determination is performed.

Here, the number of restriction target requests received by the entire signal processing unit 200 is:
(Number of requests subject to restriction per time in own server (representative server)) × (reciprocal of ratio of request signal distributed to own server (representative server) among all signal processing servers 20 of signal processing unit 200 Therefore, the request number condition satisfaction determination when requests are distributed by the consistent hash as in this system is performed based on the following equation (3).

  α x (number of requests subject to restriction per time to own server) x (total of assigned areas in consistent hash of all servers (all signal processing servers 20)) / total of assigned areas in consistent hash of own server <C ... Formula (3)

  However, it is assumed that the consistent hash assigned area is determined in proportion to the performance index value of each signal processing server 20. Further, α is the number of data requests to be transmitted to the database server 40 for one request signal to the signal processing server 20, and C is a threshold value used for request number condition satisfaction determination.

  That is, the signal processing server 20 estimates the number of requests subject to restriction of the entire signal processing unit 200 from the number of requests subject to restriction for the server itself, and the total number of requests to the database unit 400 (number of data requests) from the estimated value. Calculate And the signal processing server 20 performs request number condition satisfaction determination using the calculated total number of requests.

(Constitution)
Next, the configuration of the signal processing server 20, the database server 40, and the congestion determination device 50 in the system according to the first embodiment will be described with reference to FIG. In the following description, the client device, the request signal distribution device 10 and the data request distribution device 30 in FIG. 1 are not shown.

(Signal processing server)
The signal processing server 20 is a server that processes a request signal from a client device (not shown). When the signal processing server 20 receives a request signal from the client device, the signal processing server 20 transmits a data request based on the request signal to the database server 40 and returns a response result of the data request to the client device. The signal processing server 20 includes a control unit 21, an input / output unit 22, a memory unit 23, and a storage unit 24.

  The control unit 21 controls the entire signal processing server 20, and includes a request processing unit 211, a request regulation unit 212, and a request number condition satisfaction determination unit 213. The request number addition transfer unit 214 indicated by a broken line may or may not be equipped, and the case where it is equipped will be described later.

  Upon receiving a request signal from the client device via the request signal distribution device 10 (see FIG. 1), the request processing unit 211 transmits a data request based on the request signal to the database server 40, and a response result of the data request To the client device.

  The request restriction unit 212 performs request restriction based on a request restriction instruction from the congestion determination device 50. In other words, the request restriction unit 212 instructs the request processing unit 211 to perform an error response, discard, or the like to the request processing unit 211 for the restriction target request indicated in the request restriction instruction transmitted from the congestion determination device 50.

  The request number condition satisfaction determination unit 213 counts the number of requests to be regulated in its own server for each predetermined period during the request regulation period, and sums the number of data requests to all database servers 40 based on the counted number of requests to be regulated. Estimate the value. Then, the request number condition satisfaction determination unit 213 performs request number condition satisfaction determination (that is, determines whether the estimated total number of data requests is less than a predetermined threshold C), and the estimated number of data requests is a predetermined number. When the value is less than the threshold value C, a request number condition satisfaction notification is transmitted to the congestion determination device 50. That is, the request number condition satisfaction determination unit 213 performs request number condition satisfaction determination according to the above-described equation (3), and transmits a request number condition satisfaction notification to the congestion determination device 50 if the condition is satisfied.

  The input / output unit 22 inputs and outputs information with other devices and servers. For example, the input / output unit 22 receives a request from the client device and transmits a data request based on the request to the database server 40 or receives a request restriction instruction from the congestion determination device 50. The input / output unit 22 includes a communication interface that transmits and receives information via a communication line, and an input / output interface that performs input / output between an input device such as a keyboard (not shown) and an output device such as a monitor. The

  The memory unit 23 includes a storage device such as a RAM (Random Access Memory), and temporarily stores information necessary for data processing in the control unit 21.

  The storage unit 24 includes a storage device such as a hard disk device or a flash memory, and stores restriction target request information 241 included in the restriction target request instruction notified from the congestion determination device 50. The restriction target request information 241 is information indicating the type of request to be restricted (for example, a specific key included in the restriction target request). The restriction target request information 241 is referred to when the request restriction unit 212 performs request restriction.

(Database server)
Based on the data request from the signal processing server 20, the database server 40 searches the data storage unit 441 (described later) for the data to be requested, and transmits the searched data to the signal processing server 20. The database server 40 includes a control unit 41, an input / output unit 42, a memory unit 43, and a storage unit 44.

  The control unit 41 controls the entire database server 40 and includes a data request reception unit 411, a data transmission unit 412, a congestion determination unit 413, and a resource monitoring unit 414.

  The data request receiving unit 411 receives a data request from the signal processing server 20.

  Based on the data request from the signal processing server 20, the data transmission unit 412 searches the data storage unit 441 (to be described later) for the data to be requested, and transmits the retrieved data to the signal processing server 20.

  The congestion determination unit 413 determines whether or not the resource monitoring rate of the own server by the resource monitoring unit 414 (described later) is less than a predetermined threshold R indicated in the congestion determination information 442 (described later). Then, when the congestion determination unit 413 determines that the resource usage rate of the own server is equal to or greater than the predetermined threshold R, the congestion determination unit 413 transmits the fact to the congestion determination device 50 as a congestion occurrence notification. When the congestion determination unit 413 determines that the resource monitoring rate of the local server by the resource monitoring unit 414 (described later) is less than the predetermined value R after transmitting the congestion occurrence notification, the resource usage rate It transmits to the congestion determination apparatus 50 as a condition satisfaction notification.

  The resource monitoring unit 414 monitors the resource usage rate (for example, CPU (Central Processing Unit) usage rate, memory usage rate, etc.) of the server itself.

  The input / output unit 42 inputs / outputs information to / from other devices and servers. For example, the input / output unit 42 receives a data request from the signal processing server 20, and transmits the requested data to the signal processing server 20 based on the data request, or notifies the congestion determination device 50 of the occurrence of congestion. Or send. The input / output unit 42 includes a communication interface that transmits and receives information via a communication line, and an input / output interface that performs input / output between an input device such as a keyboard (not shown) and an output device such as a monitor. The

  The memory unit 43 includes a storage device such as a RAM, and temporarily stores information necessary for data processing in the control unit 41.

  The storage unit 44 includes a storage device such as a hard disk device or a flash memory, and stores a data storage unit 441 that accumulates data to be transmitted to the signal processing server 20, and congestion determination information 442 that indicates a predetermined threshold R used for congestion determination. Remember. The congestion determination information 442 is transmitted from the congestion determination device 50, for example.

(Congestion determination device)
The congestion determination device 50 is a device that transmits a request restriction instruction to the signal processing server 20 or issues a request cancellation instruction. The congestion determination device 50 includes a control unit 51, an input / output unit 52, a memory unit 53, and a storage unit 54.

  The control unit 51 controls the entire congestion determination apparatus 50 and includes a request restriction instruction unit 511, a request restriction determination unit 512, a server selection unit 513, and a request number condition determination instruction unit 514.

  The request restriction instruction unit 511 transmits a request restriction instruction to each of the signal processing servers 20 when the request restriction determination unit 512 determines that the request restriction is performed. This request restriction instruction includes restriction target request information 241 indicating the type of restriction target request (such as a specific key). Further, the request restriction instruction unit 511 transmits a request restriction release instruction to each of the signal processing servers 20 when the request restriction determination unit 512 determines that the request restriction is to be released.

  The request restriction determination unit 512 determines whether to perform request restriction on each signal processing server 20 of the signal processing unit 200 and whether to release the request restriction. Specifically, when the request restriction determination unit 512 receives a congestion occurrence notification from the database server 40, it determines that the request restriction is to be performed. Further, the request restriction determination unit 512 receives the resource usage rate satisfaction notification from the database server 40 and receives the request number condition satisfaction determination notification from the signal processing server 20 during the request restriction period. It is determined that the request restriction to each of the 20 is released.

  The server selection unit 513 refers to the information of the signal processing server 20 shown in the server information 541 (described later), and performs a request number condition satisfaction determination from the signal processing servers 20 constituting the signal processing unit 200 (representative). Server). For example, the server selection unit 513 refers to the performance information of each server indicated in the server information 541 and selects the signal processing server 20 having the highest performance (high processing capability) among the signal processing servers 20. By selecting the signal processing server 20 with high performance in this way, the request number condition satisfaction determination by the signal processing server 20 can be surely performed.

  The request number condition determination instruction unit 514 instructs the representative server selected by the server selection unit 513 to perform the request number condition satisfaction determination. When the request restriction determination unit 512 determines that the request restriction is to be released, the request restriction determination unit 512 instructs the representative server to end the request number condition satisfaction determination. It should be noted that the instruction for performing the request number condition satisfaction determination may include various parameters used for the request number condition satisfaction determination (α in the above-described equation (3), threshold C, etc.).

  The input / output unit 52 inputs / outputs information to / from other devices and servers. For example, the input / output unit 52 receives a congestion occurrence notification and a resource usage rate satisfaction notification from the database server 40, and transmits a request restriction instruction and a request restriction release instruction to the signal processing server 20. The input / output unit 52 includes a communication interface that transmits and receives information via a communication line, and an input / output interface that performs input / output between an input device such as a keyboard (not shown) and an output device such as a monitor. The

  The memory unit 53 includes a storage device such as a RAM, and temporarily stores information necessary for data processing in the control unit 51.

  The storage unit 54 includes a storage device such as a hard disk device or a flash memory, and stores server information 541 indicating identification information and performance of the signal processing server 20 and the database server 40 of the system.

(Processing procedure)
Next, the processing procedure of the system will be described using FIG. 7 and FIG. 8 with reference to FIG. Here, a case where the representative server is the signal processing server 20C and the congestion server is the database server 40A will be described as an example. In the following description, although not shown, requests from the client device 1 are distributed to one of the signal processing servers 20 by the request signal distribution device 10 of FIG. It is assumed that the request is distributed to one of the database servers 40 by the data request distribution device 30 in FIG. All sorts use a consistent hash.

  When each of the signal processing servers 20 (20A, 20B, 20C) of the signal processing unit 200 receives a request from the client device 1 (S1 in FIG. 7), to the database server 40 (40A, 40B, 40C) of the database unit 400. A data request is transmitted (S2), and each database server 40 that has received the data request transmits data retrieved from its own data storage unit 441 to the signal processing server 20 (S3). Each of the signal processing servers 20 that have received the data returns a response to the client device 1 (S4).

  Further, the congestion determination unit 413 (see FIG. 6) of the database server 40 performs the resource usage rate condition satisfaction determination (S5), and when the resource usage rate is equal to or greater than a predetermined threshold R, notifies the congestion determination device 50 of the occurrence of congestion. Is transmitted (S6). For example, the database server 40A whose resource usage rate is equal to or greater than a predetermined threshold R as a result of the resource usage rate condition satisfaction determination transmits a congestion occurrence notification to the congestion determination device 50.

  Upon receiving the congestion occurrence notification, the congestion determination device 50 determines the restriction target request by the request restriction determination unit 512 (see FIG. 6), and selects the representative server of the signal processing unit 200 by the server selection unit 513 (see FIG. 6). (S7). And the congestion determination apparatus 50 transmits the request regulation instruction | indication with respect to a request | requirement object request | requirement with respect to each signal processing server 20 of the signal processing part 200 by the request regulation instruction | indication part 511 (S8). Each of the signal processing servers 20 that has received the request restriction instruction regulates the restriction target request by the request restriction unit 212. That is, for example, even if the signal processing server 20 receives a request from the client device 1 (S10), it returns an error response (S11). In addition, the congestion determination device 50 instructs the signal processing server 20C, which is a representative server, to perform the request number condition satisfaction determination by the request number condition determination instruction unit 514 (see FIG. 6) (S9).

  Next, with reference to FIG. 6, a request restriction release processing procedure will be described with reference to FIG. 8. When receiving the request (S21), the signal processing server 20C that has received the request restriction instruction counts the number of restriction target requests by the request number condition satisfaction determination unit 213 (see FIG. 6) (S22), and the request restriction unit 212 ( An error response is returned to the client device 1 (see FIG. 6) (S23). Then, the signal processing server 20C performs the request number condition satisfaction determination at a predetermined interval by the request number condition satisfaction determination unit 213 using the count value of the number of requests to be regulated and the above-described formula (3) (S24). Here, when it is determined that the condition is not satisfied as a result of the request condition satisfaction determination, the request number condition satisfaction determination unit 213 performs a counter reset of the number of requests to be regulated (S25). On the other hand, when it is determined that the request number condition is satisfied (S26), the request number condition satisfaction determination unit 213 transmits a request number condition satisfaction notification to the congestion determination device 50 (S27). And the counter reset of the number of requests subject to restriction is performed (S28).

  Further, the database server 40 performs the resource usage rate condition satisfaction determination at predetermined intervals by the congestion determination unit 413 (see FIG. 6) (S31), and determines that the resource usage rate condition is satisfied as a result of the resource usage rate condition satisfaction determination. When it is determined (S32), that is, when it is determined that the resource usage rate is less than the predetermined threshold R, a resource usage rate condition satisfaction notification is transmitted to the congestion determination device 50 (S33). For example, when the database server 40A determines that the resource usage rate condition is satisfied, the database server 40A transmits a resource usage rate condition satisfaction notification to the congestion determination device 50. That is, when it is determined that the resource usage rate in the database server 40 of the own database has decreased and congestion is being resolved, the database server 40 notifies the congestion determination device 50 to that effect.

  When the request restriction determination unit 512 (see FIG. 6) of the congestion determination device 50 receives the resource usage rate satisfaction notification from the database server 40 and receives the request number condition satisfaction notification from the signal processing server 20, the signal processing is performed. It is determined to cancel the request restriction instruction to each of the servers 20 (S34: request restriction release determination). Then, the congestion determination device 50 transmits a request restriction release instruction to each of the signal processing servers 20 by the request restriction instruction unit 511 (see FIG. 6) (S35). In addition, the congestion determination device 50 transmits a request number condition satisfaction determination end instruction to the signal processing server 20C, which is a representative server, by the request number condition determination instruction unit 514 (see FIG. 6) (S36).

  Thus, in the congestion determination device 50, the resource usage rate in the database server 40 is less than the predetermined threshold R, and the number of data requests based on the number of restriction target requests received by the signal processing server 20 is less than the predetermined value C. The request restriction is removed. Thereby, the congestion determination apparatus 50 can release the request restriction at an appropriate timing.

<Second Embodiment>
(Overview)
Next, an outline of a system according to the second embodiment will be described with reference to FIG. Constituent elements similar to those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. In the system according to the second embodiment, after the start of request restriction by the signal processing unit 200, each signal processing server 20a sequentially adds the number of restriction target requests counted by its own server in order from the representative server of the signal processing unit 200. However, the data is transferred to another signal processing server 20a. Then, when the total number of requests subject to regulation that have been added returns to the representative server, the representative server performs a request number condition satisfaction determination. For example, when the number of restriction target requests counted in the representative server (server A) in FIG. 9 is 95 call, the value 95 Call is transferred to the server B. Server B then transfers to server C a value of 195 call obtained by adding 100 call counted by its own server and 95 Call received from server A. When such processing is repeated and the value obtained by adding the value of the number of requests subject to restriction is returned to the representative server in all the signal processing servers 20a of the signal processing unit 200, the request number condition satisfaction determination is performed using this value. When the request number condition is satisfied, this is notified to the congestion determination device 50. In addition, the condition satisfaction determination of the number of requests to be regulated here is performed based on the following formula (4). Α and C in the formula (4) are the same as α and C in the formula (3).
α × total number of requests subject to restriction of all servers (all signal processing servers 20a) per time <C (4)

  That is, each signal processing server 20a of the signal processing unit 200 counts the number of requests for restriction, and the total value is transmitted to the representative server. Therefore, the representative server determines the number of requests based on the exact number of requests for restriction. Condition satisfaction determination can be performed.

(Constitution)
Next, the configuration of the system according to the second embodiment will be described with reference to FIG. As illustrated in FIG. 6, the signal processing server 20 a according to the second embodiment further includes a request number addition transfer unit 214. Moreover, it replaces with the request number condition satisfaction determination part 213, and is provided with the request number condition satisfaction determination part 213a.

  When the request count addition transfer unit 214 receives the number of restriction target requests from the other signal processing server 20a, the request number addition transfer unit 214 adds the number of restriction target requests counted by the request number addition transfer unit 214 of the own server to the number of restriction target requests. . Then, the request number addition transfer unit 214 uses the added value as a signal that is clockwise adjacent to its own server in another signal processing server 20a that has not yet received the number of requests to be regulated (for example, in the consistent hash ID space). To the processing server 20a). When the own server is a representative server, the number of restriction target requests counted in the own server is sent to the other signal processing server 20a without waiting for reception of the count value of the restriction request number from the other signal processing server 20a. Just forward.

  When the total value of the number of requests subject to restriction in all the other signal processing servers 20a of the signal processing unit 200 is returned, the request number condition satisfaction determination unit 213a uses this value to make a request according to the above equation (4). Number condition satisfaction judgment is performed. Then, the request number condition satisfaction determination unit 213a transmits a condition satisfaction notification (request number condition satisfaction notification) to the congestion determination device 50 at the time of request number condition satisfaction determination.

(Processing procedure)
Next, the processing procedure of the system according to the second embodiment will be described with reference to FIG. Since the procedure for request regulation is the same as that in the first embodiment, a description thereof will be omitted, and a procedure for canceling request regulation after request regulation will be described. Here, the case where the representative server is the signal processing server 20C and the congestion server is the database server 40A will be described as an example. Note that the same processing contents as those in FIG. 8 are denoted by the same step numbers and description thereof is omitted.

  Since S21 to S23 in FIG. 10 have the same processing contents as S21 to S23 in FIG. In S41, the signal processing unit 200 counts the number of requests subject to restriction (number of requests) counted by the request number addition transfer unit 214 at predetermined intervals sequentially from the signal processing server 20a (the signal processing server 20C in FIG. 10) that is the representative server. The addition of the number of restriction target requests received from the other signal processing server 20a, the transmission of the added number of restriction target requests, and the reset of the counter (counter of the number of restriction target requests) are performed (S41). When the request number condition satisfaction determination unit 213a (see FIG. 6) in the representative server receives the total value of the number of requests to be regulated for all the signal processing servers 20a, the total value and Expression (4) are used. The request number condition satisfaction determination is performed (S42). As a result of the condition satisfaction determination, when it is determined that the condition is not satisfied, the number of requests subject to regulation counted by the own server between the signal processing servers 20a and the other signal processing servers 20a are received again sequentially from the representative server. Addition with the number of restriction target requests, transmission of the added number of restriction target requests, and reset of the counter (counter of restriction target requests) are performed (S43). On the other hand, when it is determined that the request number condition is satisfied as a result of the request number condition satisfaction determination by the request number condition satisfaction determination unit 213a (S44), the request number condition satisfaction determination unit 213a makes a request to the congestion determination device 50. A number condition satisfaction notification is transmitted (S45). The subsequent processing is the same as the processing of S34 to S36 in FIG. It is assumed that the count of the number of requests subject to restriction in each signal processing server 20a is stopped when, for example, a request restriction release instruction is received from the congestion determination device 50. Even in this way, the congestion determination device 50 can determine whether to cancel the request restriction.

<Third Embodiment>
(Overview)
Next, an outline of a system according to the third embodiment will be described with reference to FIG. Constituent elements similar to those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 11, in the system of the third embodiment, after starting request regulation, each signal processing server 20 of the signal processing unit 200 performs request number condition satisfaction determination according to the above-described equation (3), It notifies to the congestion determination apparatus 50a at the time of satisfaction. Then, when the congestion determination device 50a receives a condition satisfaction notification from a predetermined number a or more of servers (signal processing server 20) and the resource usage rate of the database server 40 becomes less than a predetermined threshold R, the request regulation is performed. Determine to cancel.

(Constitution)
The signal processing server 20 and the database server 40 in the system of the third embodiment have the same configuration as that of the first embodiment, but the configuration of the congestion determination device 50a is different. That is, as shown in FIG. 12, the congestion determination device 50a includes a request restriction determination unit 512a instead of the request restriction determination unit 512 of FIG. When the request restriction determination unit 512a receives a resource usage rate satisfaction notification from the database server 40 and receives a request number condition satisfaction notification from the signal processing server 20 of a predetermined number a or more, each signal processing server 20 It is determined that the request restriction instruction is canceled. In addition, the request number condition determination instruction unit 514 of the congestion determination device 50 a instructs each signal processing server 20 of the signal processing unit 200 to perform the request number condition satisfaction determination of the signal processing unit 200. When the request restriction determination unit 512a determines that the request restriction is to be released, the request number condition determination instruction unit 514 instructs each signal processing server 20 to end the request number condition satisfaction determination. Note that the congestion determination device 50a does not select the representative server, and therefore does not include the server selection unit 513 in FIG.

(Processing procedure)
Next, with reference to FIG. 12 and FIG. 7, the processing procedure at the time of request restriction in the system of the third embodiment will be described using FIG. Here, the case where the congestion server is the database server 40A will be described as an example. Note that the same processing contents as those in FIG. 7 are denoted by the same step numbers and description thereof is omitted. The processing procedure at the time of request regulation in the system of the third embodiment is almost the same as the processing procedure shown in FIG. 7, but as shown in S13 in FIG. The difference is that the representative server is not selected. In S14, the congestion determination device 50a is different in that the request number condition determination instruction unit 514 (see FIG. 12) instructs each signal processing server 20 to perform condition satisfaction determination of the number of requests to be regulated. .

  Next, with reference to FIG. 12, a processing procedure for canceling the request restriction will be described with reference to FIG. Note that the same processing numbers as those in FIGS. 8 and 10 are denoted by the same step numbers and description thereof is omitted. When each of the signal processing servers 20 (20A, 20B, 20C) of the signal processing unit 200 receives a request from the client device 1 (S21), the request number condition satisfaction determination unit 213 (see FIG. 12) sets the number of requests to be regulated. Counting is performed (S22), and an error response is returned to the client device 1 by the request restricting unit 212 (see FIG. 12) (S23).

  Then, each of the signal processing servers 20 performs a request number condition satisfaction determination based on the above-described formula (3) at a predetermined interval using the count value of the number of requests to be regulated by the request number condition satisfaction determination unit 213 (S51). ) When it is determined that the condition is not satisfied as a result of the condition satisfaction determination, the request number condition satisfaction determination unit 213 performs counter reset of the number of requests to be regulated (S52). On the other hand, when it is determined that the request number condition is satisfied as a result of the request number condition satisfaction determination unit 213 by the request number condition satisfaction determination unit 213 (S53), the signal processing server 20 is congested by the request number condition satisfaction determination unit 213. A request number condition satisfaction notification is transmitted to the determination device 50 (S45), and the counter number of restriction target requests is reset (S54).

  In S <b> 46, the congestion determination device 50 a that has received the resource usage rate satisfaction notification from the database server 40 determines the request number condition satisfaction notification condition by the request restriction determination unit 512 a (see FIG. 12). That is, when the request restriction determination unit 512a receives a request number condition satisfaction notification from the signal processing server 20 of a predetermined number a or more and receives a resource usage rate satisfaction notification from the database server 40, the signal processing server 20 It is determined that the request restriction instruction to each is released (S47: request restriction release determination). Then, the congestion determination apparatus 50a transmits a request restriction release instruction to each of the signal processing servers 20 by the request restriction instruction unit 511, and transmits a request number condition determination end instruction by the request number condition determination instruction unit 514 ( S48). Even in this way, the congestion determination device 50a can cancel the request restriction.

<Fourth embodiment>
(Overview)
Next, an outline of a system according to the fourth embodiment will be described with reference to FIG. Constituent elements similar to those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 15, the system according to the fourth embodiment counts the number of requests to be regulated by each signal processing server 20 b of the signal processing unit 200 and transmits it to the congestion determination device 50 b every predetermined period. Then, the congestion determination device 50b performs the request number condition satisfaction determination by adding the received number of restriction target requests. That is, it is characterized in that the request number condition satisfaction determination of the signal processing unit 200 performed by the representative server according to the expression (4) in the second embodiment is performed on the congestion determination device 50b side.

(Constitution)
The database server 40 in the system of the fourth embodiment has the same configuration as that of the first to third embodiments, but the configurations of the signal processing server 20b and the congestion determination device 50b are different. That is, as illustrated in FIG. 16, the control unit 21 of the signal processing server 20 b includes a request processing unit 211 and a request restriction unit 212, but does not have the request number condition satisfaction determination unit 213 in FIG. A transmission unit 215 is provided. Furthermore, the congestion determination device 50b includes a request restriction determination unit 512b instead of the request restriction determination unit 512a in FIG. 12, and does not have the request number condition determination instruction unit 514 in the congestion determination device 50a in FIG.

  The request count transmission unit 215 counts the number of restriction target requests and transmits the number of restriction target requests to the congestion determination device 50b every predetermined period. Further, the request restriction determination unit 512b of the congestion determination device 50b performs the request number condition satisfaction determination according to the above-described equation (4).

(Processing procedure)
Next, the processing procedure of the system according to the fourth embodiment will be described with reference to FIG. Since the procedure for request regulation is the same as that in the first embodiment, a description thereof will be omitted, and a procedure for canceling request regulation after request regulation will be described. Note that the same processing numbers as those in FIGS. 8 and 10 are denoted by the same step numbers and description thereof is omitted.

  Similarly to the system of the third embodiment, when the signal processing server 20b (20A, 20B, 20C) of the signal processing unit 200 receives a request from the client device 1 (S21), the request number transmission unit 215 ( 16), the number of requests subject to restriction is counted (S22), and an error response is returned to the client device 1 by the request restriction unit 212 (see FIG. 16) (S23). Then, each of the signal processing servers 20b transmits the number of restriction target requests counted in S22 to the congestion determination device 50b by the request number transmission unit 215 at a predetermined interval (S61, S63), and resets the number of restriction target requests counter. Perform (S52, S54). When the congestion determination device 50b receives the number of requests subject to restriction from each of the signal processing servers 20b, the request restriction determination unit 512b performs the request number condition satisfaction determination according to the above-described equation (4) (S62). Here, as a result of performing the request number condition satisfaction determination, the request restriction determination unit 512b satisfies the request number condition and receives a resource usage rate satisfaction notification from the database server 40 (S64). It is determined to cancel the request restriction instruction to each of 20b (S65: request restriction release determination). Then, the congestion determination device 50b transmits a request restriction release instruction to each of the signal processing servers 20b by the request restriction instruction unit 511, and instructs the request restriction determination unit 512b to end transmission of the number of requests to be restricted. (S66). Even in this way, the congestion determination device 50b can determine whether to cancel the request restriction. In the system of the fourth embodiment, since the request number condition satisfaction determination is performed on the congestion determination device 50b side, the processing load on each of the signal processing servers 20b can be reduced.

  In each of the embodiments described above, the occurrence of congestion in the database server 40 (see FIG. 6) is determined based on whether or not the resource usage rate of the own server is less than a predetermined threshold. The number of data requests) may be used, or a combination of the resource usage rate and the number of requests may be used.

  In each of the above-described embodiments, the congestion determination devices 50, 50a, and 50b have been described by way of example as separate devices from the signal processing servers 20, 20a, and 20b, but the signal processing servers 20, 20a, and You may make it incorporate in a part of 20b. Furthermore, when the congestion determination devices 50, 50a, 50b receive the congestion occurrence notification from any one of the database servers 40, the congestion determination device 50, 50a, 50b performs the request restriction. The request restriction may be performed when the message is received. Also, regarding request restriction release, when a resource usage rate condition satisfaction notification is received from a predetermined number of database servers 40 and it is determined that the request number condition is satisfied, it may be determined that the request restriction is released.

1 Client device 20, 20a, 20b Signal processing server 21, 41, 51 Control unit 22, 42, 52 Input / output unit 23, 43, 53 Memory unit 24, 44, 54 Storage unit 40 Database server (data processing server)
50, 50a, 50b Congestion judgment device (congestion judgment means)
200 Signal Processing Unit 211 Request Processing Unit 212 Request Restriction Unit 213, 213a Request Number Condition Satisfaction Determination Unit 214 Request Number Addition Transfer Unit 215 Request Number Transmission Unit 241 Restriction Target Request Information 400 Database Unit 411 Data Request Reception Unit 412 Data Transmission Unit 413 Congestion determination unit 414 Resource monitoring unit 441 Data storage unit 442 Congestion determination information 511 Request restriction instruction unit 512, 512a, 512b Request restriction determination unit 513 Server selection unit 514 Request number condition determination instruction unit 541 Server information

Claims (8)

A plurality of signal processing servers for processing a request signal from a client device to a data processing server and transmitting a data request to the data processing server, a plurality of the data processing servers performing processing based on the data request, and the data A signal processing system comprising congestion determination means for determining occurrence of congestion in a processing server,
Each of the data processing servers is
A data storage unit for storing data to be subjected to the data request;
When at least one of the resource usage rate of the data processing server and the number of data requests is equal to or greater than a predetermined threshold, it is determined that congestion has occurred, and a congestion occurrence notification is transmitted to the congestion determination unit, When the resource usage rate becomes less than the predetermined threshold, it is determined that congestion is reduced, and a resource usage rate condition satisfaction notification is transmitted to the congestion determination unit,
The congestion determination means includes
A storage unit for storing server information indicating identification information of the signal processing server;
When the congestion occurrence notification is received from the data processing server, a request restriction instruction indicating the type of the request signal to be restricted is transmitted to each of the signal processing servers,
Each of the signal processing servers is
When the request restriction instruction is received, even if the restriction target request signal is received, request restriction that does not execute processing based on the request signal is performed.
At least one of the signal processing servers that has received the request restriction instruction,
During the request restriction, the number of reception of the restriction target signal in its own signal processing server is counted every predetermined period, and when the following expression (1) is satisfied, a request number condition satisfaction notification is sent to the congestion determination means. Send
The congestion determination means includes
When a resource usage rate condition satisfaction notification is received from the data processing server and a request number condition satisfaction notification is received from the signal processing server, a request restriction instruction to each of the signal processing servers is canceled. Signal processing system.
α × number of reception of request signal to be regulated per time in own signal processing server × reciprocal of ratio of request signal to own signal processing server out of all signal processing servers <C 1)
Where α is the number of data requests transmitted to the data processing server in response to one request signal to the signal processing server, and C is a predetermined threshold value. The congestion determination means includes
The signal processing system according to claim 1, wherein a request signal to the data processing server in which the congestion has occurred is the request signal to be regulated.   The signal processing server that performs the request number condition satisfaction determination for determining whether or not the expression (1) is satisfied is any one signal processing server selected by the congestion determination unit. The signal processing system according to claim 1 or 2.   4. The signal processing system according to claim 3, wherein the signal processing server selected by the congestion determination unit is a server having the highest predetermined processing capability among the signal processing servers. The selected signal processing server is
When performing the request number condition satisfaction determination, the number of receptions of the restriction target request signal counted by its own signal processing server in the predetermined period is transmitted to any other signal processing server,
Each of the signal processing servers that has received the number of received request signals to be regulated from the other signal processing servers,
The number of receptions of the restriction target request signal counted by its own signal processing server in the predetermined period is added to the number of receptions of the restriction target request signal transmitted, and the reception number is still transmitted. Do not send to other signal processing server,
When the selected signal processing server receives the total number of receptions of the restriction target request signals in all other signal processing servers, the following equation (2) is substituted for the equation (1). The signal processing system according to claim 3, wherein when the condition is satisfied, the request number condition satisfaction determination notification is transmitted.
Α × total value of the number of reception of request signals to be regulated in all the signal processing servers <the C ... expression (2) The signal processing servers that perform the request number condition satisfaction determination for determining whether or not the expression (1) is satisfied are all the signal processing servers that have received the request restriction instruction in the system,
The congestion determination means includes
When a resource usage rate satisfaction notification is received from any one of the data processing servers and a request number condition satisfaction determination notification is received from the signal processing server of a predetermined number a or more, a request to each of the signal processing servers The signal processing system according to claim 1, wherein the restriction instruction is canceled. A plurality of signal processing servers for processing a request signal from a client device to a data processing server and transmitting a data request to the data processing server, a plurality of the data processing servers performing processing based on the data request, and the data A signal processing system comprising congestion determination means for determining occurrence of congestion in a processing server,
Each of the data processing servers is
A data storage unit for storing data to be subjected to the data request;
When at least one of the resource usage rate of the data processing server and the number of data requests is equal to or greater than a predetermined threshold, it is determined that congestion has occurred, and a congestion occurrence notification is transmitted to the congestion determination unit, When the resource usage rate becomes less than the predetermined threshold, it is determined that congestion is reduced, and a resource usage rate condition satisfaction notification is transmitted to the congestion determination unit,
The congestion determination means includes
A storage unit for storing server information indicating identification information of the signal processing server;
When the congestion occurrence notification is received, a request restriction instruction indicating the type of the request signal to be restricted is transmitted to each of the signal processing servers,
Each of the signal processing servers is
When receiving the request restriction instruction, even if the request signal to be restricted is received, request restriction is performed so that processing based on the request signal is not performed. Count the number of received request signals, and send the counted number of received request signals to the congestion determination means,
The congestion determination means includes
The resource usage condition satisfaction notification is received from the data processing server, and (in response to one request signal to the signal processing server, the number of data requests to be transmitted to the data processing server α × each of the signal processing servers When it is determined that the value of the total number of received request signals is less than a predetermined threshold C, the request restriction instruction to each of the signal processing servers is canceled. When the signal processing server is a server that receives the request signal distributed by the consistent hash, and the data processing server is a server that receives the data request distributed by the consistent hash,
In the equation (1), out of all the signal processing servers, instead of the reciprocal of the ratio of the request signal being distributed to its own signal processing server,
The area in charge of all the signal processing servers in the consistent hash / the total of the areas in charge of distribution to the signal processing server in the consistent hash is used. The signal processing system according to item.

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