JP2013003982A - Load distribution system, load distribution device and server device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load distribution system for normally distributing processing requests from a client even when the layout of virtual machines changes.SOLUTION: The load distribution system includes: a plurality of physical servers on which virtual machines can be operated: and a load distribution device configured to distribute processing requests from a client terminal to the physical servers. Physical servers 12 and 14 are respectively equipped with a function for moving the virtual machine operating on its own server to the other physical server, and configured to, when moving the virtual machine to the other physical server, transmit the information of the physical server of the movement destination to a load distribution device 1, and the load distribution device 1 is configured to hold a distribution table 103 in which information to be used by the distribution destination determination processing of the processing requests is registered, and to, when any change is generated in the physical server on which the virtual machine is operated, update the distribution table 103 on the basis of the information of the physical server of the movement destination acquired from the physical server.

Description

  The present invention relates to a load distribution system in which processing requested from a client is shared by a plurality of virtual machines constructed on a physical server.

  In recent years, virtualization server technology that operates a plurality of virtual servers (virtual machines) with one physical server has become widespread. Also, with the spread of virtualization server technology, a more flexible system configuration can be created. As an example, live migration technology that moves a virtual machine to another physical server in a short time without stopping the running system is used for maintenance and load distribution. For example, if a virtual machine on a physical server to be maintained is moved to another physical server by live migration, hardware maintenance can be performed without stopping the system. Patent Document 1 describes that a high-load virtual machine running on a physical server with no physical resources can be live-migrated to another physical server with sufficient physical resources to obtain the desired performance. Techniques for allocating resources are described. This technology realizes optimization of resource utilization (efficient resource utilization) for the entire system.

JP 2006-244481 A

  On the other hand, an increase in server load may occur when an enormous processing request from a client is input to the system. For this reason, there is also widely known a method of setting (loading) the processing load of each server by installing a load distribution device for distributing input processing requests in the system. However, when this method is simply combined with the method described in Patent Document 1, when a high-load virtual machine is moved to another physical server, the load balancer moves the virtual machine on the distribution-destination physical server. Therefore, after the movement of the virtual machine is completed, the processing request from the client terminal is continuously distributed to the same distribution destination (physical server). That is, when live migration is performed, there is a problem that processing requests are not normally distributed by the load balancer.

  The present invention has been made in view of the above, and processing requests from clients even when the arrangement of virtual machines dynamically changes due to various state changes (high load, maintenance) of a physical server in a virtualization system. An object of the present invention is to obtain a load distribution system, a load distribution device, and a server device that can normally distribute the server.

  In order to solve the above-described problems and achieve the object, the present invention includes a plurality of physical servers capable of operating a virtual machine and a load balancer that distributes processing requests from client terminals to the physical servers. In the load balancing system, the physical server has a function of moving a virtual machine running on the server to another physical server, and when moving the virtual machine to another physical server, the destination The physical server information is sent to the load balancer, and the load balancer stores a table in which information used in the processing request distribution destination determination process is registered, and changes the physical server to operate the virtual machine If this occurs, the table is updated based on the information of the physical server of the movement destination acquired from the physical server.

  According to the present invention, even if the physical server on which the virtual machine operates dynamically changes, the load balancer automatically changes the distribution destination while following this change. There is an effect that it can be distributed flexibly.

FIG. 1 is a diagram showing a configuration example of a load distribution system according to the present invention. FIG. 2 is a diagram illustrating a configuration example of a physical server. FIG. 3 is a diagram illustrating a configuration example of the load distribution apparatus. FIG. 4 is a diagram illustrating an example of a distribution management table. FIG. 5 is a diagram illustrating an example of a service distribution table. FIG. 6 is a diagram illustrating an example of the service distribution table. FIG. 7 is a diagram illustrating an example of a migration control procedure in the load distribution system according to the first embodiment. FIG. 8 is a diagram illustrating an example of a service distribution table after performing migration control. FIG. 9 is a diagram illustrating an example of a migration control procedure in the load distribution system according to the second embodiment. FIG. 10 is a diagram illustrating an example of an operation of moving a virtual machine in the load distribution system according to the third embodiment. FIG. 11 is a diagram illustrating a configuration example of a failover message. FIG. 12 is a flowchart illustrating an example of a service distribution table update procedure.

  Hereinafter, embodiments of a load distribution system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
(Overall configuration of load balancing system)
First, the overall configuration of the load distribution system will be described. FIG. 1 is a diagram showing a configuration example of a load distribution system according to the present invention. As illustrated, the load distribution system includes a load distribution apparatus 1 that distributes requests from the client terminals 301 and physical servers 11 to 15 that process requests distributed by the load distribution apparatus 1. Each physical server is connected via the router 200. The load balancing measure 1 and the client terminal 301 are connected via the network 300.

(Physical server configuration)
Next, the configuration of the physical servers 11 to 15 will be described. Since the basic configuration of each physical server is the same, the configuration of the physical servers 12 and 14 will be described here. FIG. 2 is a diagram illustrating a configuration example of a physical server. The physical server 12 includes a virtual machine 22 that operates inside, a virtual machine control unit 32 that controls the operation of the virtual machine 22, and a management unit 72 that manages the operation of the virtual machine control unit 32. In addition, the virtual machine control unit 32 periodically monitors a resource pool 42 necessary for operating each virtual machine 22, a resource control unit 52 for controlling the resources of the virtual machine 22, and resource state changes. Resource monitoring unit 62. The physical server 14 includes a virtual machine control unit 34 similar to the virtual machine control unit 32 included in the physical server 12 and a management unit 74 similar to the management unit 72. Although it is possible to construct a virtual machine similar to the virtual machine 22 in the physical server 14, FIG. 2 shows the physical server 14 in a state in which no virtual machine is constructed.

  In FIG. 2, the virtual machine 22 running on the physical server 12 can be moved to another physical server without stopping by an instruction from the management unit 72. As an instruction from the management unit 72, for example, the administrator explicitly moves it to another physical server, or moves a high-load virtual machine running on the physical server to a physical server with a low load. Can be given. When moving the virtual machine 22 to the physical server 14 in FIG. 2, the management unit 72 notifies the resource control unit 52 to move the virtual machine 22 to the physical server 14. Upon receiving the notification from the management unit 72, the resource control unit 52 notifies the resource control unit 54 of the physical server 14 that is the migration destination of the migration of the virtual machine 22, and stores the memory of the virtual machine 22 in the resource pool 42 in the physical server. 14, the virtual machine 22 operating on the physical server 12 is stopped when the copy is completed. Further, in the physical server 14, after the copy of the virtual machine 22 is completed, the movement of the virtual machine 22 is completed by starting the virtual machine 22 without delay.

  2 shows an example in which only a single virtual machine 22 is operating on the physical servers 12 and 14 for the sake of simplicity of explanation, but a plurality of virtual machines are operating on each physical server. It is also possible to make it.

(Configuration of load balancer)
Next, the configuration of the load distribution apparatus 1 will be described. FIG. 3 is a diagram illustrating a configuration example of the load distribution apparatus 1. The load distribution apparatus 1 includes a packet distribution unit 101 that distributes processing request messages (requests) received from the client terminal 301 via the network 300, a distribution table 103 that manages rules necessary for distribution of processing request messages, A state management unit 102 that detects a change in the state of each physical server or virtual machine.

  Here, details of the distribution table 103 will be described. The distribution table 103 includes, for example, a plurality of types of tables as shown in FIGS. 4 to 6, that is, a distribution management table (FIG. 4) and a service distribution table (FIGS. 5 and 6). . The distribution management table indicates the correspondence between the type of processing request message received from the client terminal 301 and the service distribution table. Note that processing request messages requesting the same service are treated as the same type. The service distribution table indicates, for each type of processing request message, how the processing request message is distributed to a plurality of processable physical servers. The service distribution table 103-2 illustrated in FIG. 5 is a table used when distributing a process request message requesting service A, and the service distribution table 103-3 illustrated in FIG. 6 is a process request message requesting service B. It is a table used when sorting. The “weight” shown in each service distribution table is information indicating how the processing request message is distributed to each physical server shown in the table.

  For example, when receiving a processing request message requesting service A, the packet distribution unit 101 of the load distribution apparatus 1 first checks the distribution management table 103-1 (FIG. 4) and distributes the received processing request message. It is understood that the service distribution table 103-2 (FIG. 5) is used in the processing. The ratio of the number of processing request messages distributed to the physical servers 11, 12, and 13 based on the distribution result of the service distribution table 103-2 and the same message (processing request message requesting service A) received in the past. The processing request message is distributed so that becomes “1: 1: 2”. In the physical server that has received the processing request message distributed by the packet distribution unit 101, the virtual machine performs processing according to the content of the received processing request message.

(Explanation of operation of load balancing system)
Next, a characteristic operation in the load distribution system according to the first embodiment, specifically, an operation in the case of moving a virtual machine running on a physical server to another physical server will be described with reference to FIG. I will explain. FIG. 7 is a diagram illustrating an example of a migration control procedure in the load distribution system according to the first embodiment. In the present embodiment, a procedure for moving the virtual machine 22 running on the physical server 12 to the physical server 14 will be described.

  In the load distribution system according to the present embodiment, the management unit 72 of the physical server 12 has received a movement instruction from the outside to the physical server 14 of the virtual machine 22 or has a high processing load on its own server. When it is detected and decided to move the virtual machine 22 to the physical server 14, the resource control unit 52 is instructed to execute the migration and the physical server that is the migration destination is notified (steps S 11 and S 12). Receiving the instruction, the resource control unit 52 notifies the resource monitoring unit 62 that the migration destination physical server is the physical server 14 and instructs the execution of the migration (step S13). Upon receiving the instruction, the resource monitoring unit 62 notifies the state management unit 102 of the load balancer 1 that the migration destination physical server is the physical server 14 and notifies the execution of the migration (step S14). . In addition, the resource control unit 52 performs the migration operation of the virtual machine 22 to the physical server 14 after executing Step S13 (Step S15).

  When grasping that the virtual machine 22 running on the physical server 12 moves to the physical server 14, the state management unit 102 temporarily stores the movement-source physical server 12 and the movement-destination physical server 14 (step S16). The load distribution apparatus 1 continues to distribute the processing request message to the physical server 12 until the movement of the virtual machine 22 is completed. When the movement of the virtual machine 22 from the physical server 12 to the physical server 14 is completed, the resource control unit 52 of the physical server 12 notifies the resource monitoring unit 62 of the end of the migration (step S17). When the resource monitoring unit 62 receives a notification that the migration has been completed, the resource monitoring unit 62 notifies the state management unit 102 of the load distribution apparatus 1 of the completion of the migration (step S18). When the status management unit 102 receives the migration completion notification, the state management unit 102 updates the service distribution table in which the source physical server 12 is registered as a distribution destination among the service distribution tables included in the distribution table 103 ( Step S19). That is, the part where the distribution destination is “physical server 12” is updated to “physical server 14” indicating the physical server of the movement destination (migration destination). As a result, the service distribution table 103-2 shown in FIG. 5 is changed to the content shown in FIG. 8, and thereafter, a processing request message from the client terminal 301 (a processing request message requesting service A in this example). Are distributed to the physical server 14 instead of the physical server 12.

  In step S16, the state management unit 102 creates a new service distribution table in which the distribution destination is changed to the migration destination physical server. In step S19, the state management unit 102 newly creates the service distribution table in step S16. You may make it replace the table which was used and the table used until then. Thereby, after receiving the notification of the end of migration, the service distribution table can be updated without delay, and the processing request message can be reliably distributed to the physical server of the migration destination.

  In the control procedure shown in FIG. 7, the server information of the migration destination is notified to the state management unit 102 of the load balancer 1 before executing the virtual machine migration operation (step S15). When the amount of information registered in each service distribution table in the table 103 is small and the time required for the table update in step S19 is sufficiently small, the physical server that is the migration destination is also notified when the migration end is notified. You may make it notify simultaneously. In this case, the steps S13 to S16 are not necessary, and the processing load can be reduced.

  As described above, in the load balancing system of this embodiment, when a virtual machine is moved from one physical server to another physical server, the source physical server sends the information of the destination physical server to the load balancer. The load balancer updates the service distribution table according to the notification content from the migration source physical server. After the migration of the virtual machine is completed, the load distribution device uses the updated service distribution table to send a processing request message. It was decided to distribute. As a result, even if the virtual machine placement (physical server on which the virtual machine runs) changes dynamically due to changes in the physical server state (high load, maintenance, etc.), the load balancer automatically follows this change. However, since the distribution destination is changed, the processing request message (processing request) from the client can be distributed normally and flexibly.

Embodiment 2. FIG.
A load distribution system according to the second embodiment will be described. The configuration of the system and each device, and the contents of various sort tables held by the load distribution device 1 are described as being the same as in the first embodiment (see FIGS. 1 to 6). In the present embodiment, description of portions common to the first embodiment is omitted.

  In the load distribution system of this embodiment, migration control is performed according to the procedure shown in FIG. In FIG. 9, the same steps as those in the migration control procedure shown in FIG. Therefore, the description of the processing given the same step number as in FIG. 7 is omitted.

  In the migration control of this embodiment, the resource monitoring unit 62 of the physical server 12 acquires all the service distribution tables held by the state management unit 102 when the migration destination physical server is notified in step S13. (Steps S21 and S22). Then, the acquired service distribution table is updated based on the information of the migration destination physical server. Specifically, in the service distribution table in which the own physical server (migration source physical server 12) is registered as the distribution destination in the acquired service distribution table, the distribution destination is “physical server 12” Is updated to “physical server 14” indicating the physical server of the migration destination.

  Thereafter, upon receiving a migration end notification in step S17, the updated service distribution table is transmitted to the state management unit 102 as a post-migration distribution table (step S23).

  The state management unit 102 that has received the table transmitted in step S23 overwrites the received table on the distribution table 103 and updates the distribution table 103 (more specifically, the service distribution table 103-2) (step S24).

  As described above, in the load balancing system of this embodiment, when a virtual machine is moved from one physical server to another physical server, the source physical server acquires the service distribution table held by the load balancer. The updated table is updated based on the information of the physical server that is the migration destination, and after the migration of the virtual machine is completed, the updated table is sent to the distributed load device and processed using this updated table. Request messages are distributed. Thus, as in the first embodiment, even if the placement of the virtual machine dynamically changes due to a change in the state of the physical server, the load balancer automatically changes the distribution destination while following this change. Processing request messages from clients can be distributed normally and flexibly.

Embodiment 3 FIG.
A load distribution system according to the third embodiment will be described. The configuration of the system and each device, and the contents of various sort tables held by the load distribution device 1 are described as being the same as in the first and second embodiments (see FIGS. 1 to 6). In the present embodiment, description of portions common to the first and second embodiments is omitted.

  In the present embodiment, a virtual machine migration operation when the migration source physical server cannot directly notify the load balancing apparatus 1 of virtual machine migration will be described.

  FIG. 10 is a diagram illustrating an example of an operation of moving a virtual machine between physical servers in the load distribution system according to the third embodiment. FIG. 10 shows a control procedure for moving a virtual machine by failover.

  When a failure or an explicit service stop occurs in the physical server 12 (migration source physical server) in which the virtual machine 22 is operating, the resource monitoring unit 62 detects this change in state and detects the migration destination physical server 14. In response to this, a failover occurrence message 81 (a message for moving the operating virtual machine to another physical server) is notified (steps S31 and S32).

  FIG. 11 is a diagram showing a configuration example of the failover message. As shown in the figure, the failover occurrence message 81 includes “source”, “source”, “service to be stopped”, and “virtual machine to be stopped”. Contains information. “Sender” indicates the physical server of the message sender. “Occurrence source” indicates a physical server in which a phenomenon that causes a failover occurrence message 81 such as a failure has occurred. The “service to be stopped” indicates a service to be stopped on the “source” physical server. The “virtual machine to be stopped” indicates a virtual machine whose operation is to be stopped among the virtual machines that have been operating on the “source” physical server.

  In the failover message transmitted by the resource monitoring unit 62 in step S32, information on the physical server 12 is set in the transmission source and the generation source, and information on the service name or port number stopped in the physical server 12 is set in the service to be stopped. Is set. Further, information of the virtual machine 12 is set for the virtual machine to be stopped. When a failure occurs in the virtual machine, the resource monitoring unit 62 sets all service names (or port numbers) processed by the virtual machine to “stopped service”. If you want to stop some services that have been processed by the virtual machine, set the name of the service to be stopped (or port number) to “stop service”.

  When the resource monitoring unit 64 of the physical server 14 receives the failover occurrence message 81 transmitted in step S <b> 32, the resource monitoring unit 64 confirms the “virtual machine to be stopped” and recognizes that the virtual machine to be stopped is the virtual machine 22. Then, the resource control unit 54 is notified to start the virtual machine 22. Thereafter, when the virtual machine 22 is activated by the resource control unit 54 (step S33), the resource monitoring unit 64 sets the “source” of the failover occurrence message 81 received in step S32 to the own physical server (physical server 14). The information is rewritten and transmitted to the state management unit 102 of the load balancer 1 (step S34).

  When the state management unit 102 receives the failover occurrence message 81 from the resource monitoring unit 64, the state management unit 102 updates the service distribution table (see FIG. 5, FIG. 6, etc.) in the distribution table 103 in the procedure shown in FIG. 12 (step S35).

  The service distribution table update operation in step S35 will be described with reference to FIG.

  When the failover occurrence message 81 is received, the state management unit 102 first identifies a service distribution table that needs to be updated in the distribution table 103 based on the content of the received failover occurrence message 81 (step S41). Specifically, the service distribution table corresponding to the service indicated by the “stop service” is grasped as requiring updating. Next, whether there is a failed physical server in the “distribution destination” of the specified service distribution table, that is, whether the physical server indicated by “source” is registered in the “distribution destination” of the service distribution table Is confirmed (step S42). If the physical server indicated by “source” is registered in the “distribution destination” of the service distribution table (step S43: Yes), the “distribution destination” is the failover destination physical server, that is, the failover occurrence message 81 The physical server indicated by “transmission source” is changed (step S44). In the present embodiment, the part where the “distribution destination” of the distribution table identified in step S41 is “physical server 12” is changed to “physical server 14”.

  As a result, the service distribution table 103-2 shown in FIG. 5 is changed to the content shown in FIG. 8, and the processing request message (processing request message requesting the service A) from the client terminal 301 is subsequently changed to the physical distribution table 103-2. It is distributed to the physical server 14 instead of the server 12.

  As described above, in the load balancing system according to the present embodiment, when a failure occurs in a physical server or when service provision is stopped, the resource monitoring unit that detects the failure sends a failover occurrence message to another physical server (resource The other server that has transmitted the failover occurrence message to the monitoring unit and started the virtual machine that was running on the physical server that sent the message, and forwarded the failover occurrence message to the load balancer. Further, the load balancer that has received the transferred failover occurrence message updates the service distribution table that is held based on the content of the message. As a result, as in the first and second embodiments, even if the placement of the virtual machine changes dynamically due to a change in the state of the physical server, the load balancer automatically changes the distribution destination while following this change. Therefore, processing request messages from clients can be distributed normally and flexibly.

  As described above, the load distribution system according to the present invention is useful when a plurality of virtual machines constructed on a physical server are used and processing according to requests from clients is distributed.

1 Load balancing device 11, 12, 13, 14, 15 Physical server 22 Virtual machine 32, 34 Virtual machine control unit 42, 44 Resource pool 52, 54 Resource control unit 62, 64 Resource monitoring unit 72, 74 Management unit 81 Failover occurs Message 101 Packet distribution unit 102 State management unit 103 Distribution table 103-1 Distribution management table 103-2, 103-3 Service distribution table 200 Router 300 Network 301 Client terminal

Claims (5)

A load distribution system including a plurality of physical servers capable of operating a virtual machine and a load distribution device that distributes processing requests from client terminals to physical servers,
The physical server has a function of moving a virtual machine running on its own server to another physical server. When moving a virtual machine to another physical server, information on the destination physical server is stored in the physical server. Sent to the load balancer,
The load balancer holds a table in which information used in the processing request distribution destination determination process is registered, and when a change occurs in a physical server that operates a virtual machine, A load balancing system, wherein the table is updated based on server information. A load distribution system including a plurality of physical servers capable of operating a virtual machine and a load distribution device that distributes processing requests from client terminals to physical servers,
The load balancer holds a table in which information used in the processing request distribution destination determination process is registered,
The physical server has a function of moving a virtual machine running on its own server to another physical server. When moving a virtual machine to another physical server, the physical server acquires the table from the load balancer. Further, the table is updated based on the information of the other physical server, the updated table is transmitted to the load balancer, and the distribution destination of the processing request is determined using the updated table. A load balancing system characterized by instructing to make a decision. If the physical server migrates a virtual machine that was running on another physical server to its own server due to a failover, the information about services provided by the virtual machine, information about the local server, and migration of the virtual machine Send a message containing the information of the original physical server to the load balancer,
The load distribution system according to claim 1, wherein, when the message is received, the load distribution device updates the table based on information included in the message. A load balancer that can operate a virtual machine and can move a virtual machine on its own device to another device, and distributes processing requests from client terminals to the physical server The load distribution apparatus of a load distribution system comprising:
If there is a change in the physical server that operates the virtual machine, the table that contains the information used in the processing request distribution destination determination process is retained, and the virtual machine is operated before the change. A load balancer that is obtained from a physical server and further updates the table based on the obtained information. A plurality of server devices capable of operating a virtual machine and a load distribution device that distributes a processing request from a client terminal to the server device, the server device being a virtual machine running on its own device A server device having a function of moving to a server device, wherein the load distribution device is a server device of a load distribution system holding a table in which information used in the processing request distribution destination determination process is registered,
When moving a virtual machine to another server device, the table is acquired from the load balancer, and the table is updated based on the information of the other server device, and the updated table is the load balancer. A server apparatus characterized by transmitting to the apparatus and instructing to determine a distribution destination of the processing request using the updated table.

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