JP6461834B2 - Network load balancing apparatus and method - Google Patents

Description

  The present invention relates to an apparatus for controlling a packet transmission destination, and in particular, ensures QoS (Quality of Service) and throughput by achieving both priority control and load distribution for a specific packet in a communication server auxiliary apparatus. The present invention relates to a network load distribution apparatus and method for improving performance.

  Non-patented configuration example of priority control implemented in the front-end hardware of general-purpose network equipment used in a network configured based on the concept of general SDN (Software Defined Networking) / NFV (Network Functions Virtualization) It is disclosed in Document 1.

  FIG. 4 is a diagram for explaining a part of the priority control technique disclosed in Non-Patent Document 1. In the example of FIG. 4, if the Ethertype value of the incoming packet matches the predetermined value (Yes in step S100 in FIG. 4), the incoming packet is classified as the priority control target flow into the queue 200 (step S101 in FIG. 4). . If the FCoE (Fibre Channel over Ethernet) type value of the incoming packet matches the predetermined value (Yes in step S102 in FIG. 4), the incoming packet is classified as a priority control target flow into the queue 201 (FIG. 4). Step S103).

  As described above, in general priority control using a general-purpose NIC (Network Interface Card), a priority control target flow is filtered into a unique queue for each protocol. However, in the technique disclosed in Non-Patent Document 1, since only filtering for fixed field values is performed for each protocol prepared in advance, it is difficult to cope with special conditions (for example, filtering conditions that span multiple fields) There was also a problem in future scalability. In the technique disclosed in Non-Patent Document 1, since the number of queues assigned to each protocol is fixed, it is difficult to use resources dedicated to a specific service. Furthermore, in the technology disclosed in Non-Patent Document 1, since packets that do not meet the predetermined filtering condition are classified into a single queue, there is a concern that transfer performance may deteriorate in use cases where there are many packets that do not meet the filtering condition. It was difficult to achieve high throughput.

  On the other hand, a general example of load distribution that achieves high throughput using multi-queues is round-robin control used in a load balancer or the like. However, in general round robin control, the processing time in each queue varies, and as a result, the order is reversed in the flow. As a solution to this problem, there is a load balancing control proposed on a router as in Patent Document 1.

  FIG. 5 is a diagram for explaining the load distribution control technique disclosed in Patent Document 1. In FIG. In the technique disclosed in Patent Document 1, the destination of a packet is determined, and the packet is transferred to a data buffer corresponding to the route to the destination. The packet is appropriately read from the data buffer and transmitted to the destination. At this time, the load distribution control unit 300 monitors the load status of the data buffers 300-1, 300-2, and 300-3 corresponding to the routes A, B, and C, respectively, and performs dynamic route assignment for selecting a route. And transfer the packet to the data buffer corresponding to the selected route.

  With load distribution control that guarantees the in-flow order proposed on such a router, the problems in round robin control can be solved. However, the technique disclosed in Patent Document 1 has a problem in that the order inversion can occur in the flow at the buffer switching timing because the dynamic path assignment is performed by monitoring the load state of the data buffer. . In addition, the configuration proposed in Patent Document 1 is based on the premise that dedicated hardware is used, and since there is a sufficiently large hardware resource in the apparatus, cooperative control such as priority control is not considered. There is a problem that it is not suitable for mounting with limited hardware on the NIC.

JP 2008-263436 A

“Intel Ethernet (registered trademark) Controller XL710 Datasheet”, 2015, <http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/xl710-10-40-controller-datasheet .pdf>

As described above, with the technology disclosed in Non-Patent Document 1 using a general-purpose NIC, flexible priority control is difficult and high throughput is difficult to achieve.
Further, the technique disclosed in Patent Document 1 has a problem that it is difficult to guarantee packet transmission order and priority control, and it is difficult to implement on limited hardware on the NIC.

  The present invention has been made to solve the above-described problems, and realizes flexible priority control and high-throughput coexistence on small-resource hardware that can be mounted on the NIC, which is the front-end hardware of SDN / NFV. For the purpose.

The network load distribution apparatus of the present invention includes a hash value calculation means for calculating a first hash value based on a field value included in a received packet, a data buffer provided for each communication path to which the packet is sent, Priority control means for detecting a specific packet subject to priority control based on the first hash value, and determining a communication path to which the packet is to be transmitted, and a second hash based on the first hash value A load distribution control unit that determines a communication path of a transmission destination of the packet that is not subject to priority control according to a value while satisfying load distribution of the data buffer, and a destination determined by the priority control unit or the load distribution control unit And a packet transfer control means for transmitting the packet to a data buffer corresponding to the communication path. It is an feature.
Also, in one configuration example of the network load distribution apparatus of the present invention, the hash value calculation means obtains a field value at a position designated in advance from the outside in the packet, and sets the field value and the outside in advance. The first hash value is calculated based on the key value thus obtained.
In the configuration example of the network load distribution apparatus according to the present invention, the priority control unit associates a possible value of the first hash value calculated by the hash value calculation unit with a communication path of a transmission destination in advance. When the priority route selection table to be stored and the same value as the first hash value are registered in the priority route selection table, information on the destination communication route corresponding to the first hash value is stored in the priority route selection table. And a priority route control means for obtaining from a priority route selection table.

Further, in one configuration example of the network load distribution apparatus according to the present invention, the load distribution control unit includes a first hash value calculated by the hash value calculation unit and information on a predetermined destination usable in the load distribution control. Load distribution hash value calculation means for calculating the second hash value from the above, a possible value of the second hash value calculated by the load distribution hash value calculation means, load distribution setting data set from the outside, and load distribution control The load distribution route selection table preset from the destination communication routes that can be used in the network, and the destination communication route information corresponding to the second hash value calculated by the load distribution hash value calculation means. It is characterized by comprising load distribution path control means acquired from the distribution path selection table.
Further, in one configuration example of the network load distribution apparatus of the present invention, the destination communication path registered in the load distribution path selection table can take the second hash value calculated by the load distribution hash value calculation means. Packets according to the second hash value calculated by the load distribution hash value calculation means from all values, load distribution setting data set from the outside, and information on the destination communication path that can be used in load distribution control Is determined so that the load status of each data buffer when it is distributed to the data buffers that can be used in load balancing control matches the load status specified by the load balancing setting data. .

  The network load distribution method of the present invention includes a hash value calculation step of calculating a first hash value based on a field value included in a received packet, and a priority control target based on the first hash value. A priority control step of detecting a specific packet and determining a communication path of a destination of the packet, and a second hash value based on the first hash value of the destination of the packet not subject to the priority control. In accordance with the load distribution control step for determining the communication path while satisfying the load distribution of the data buffer and the destination communication path determined in the priority control step or the load distribution control step, the data buffer corresponding to this communication path And a packet transfer control step for transmitting the packet.

  According to the present invention, it is possible to efficiently use a limited data buffer by dividing packet distribution processing into priority control and load distribution control, and by coordinating priority control and load distribution control. High-throughput coexistence can be realized by flexible priority control and load distribution on the hardware.

It is a block diagram which shows the structure of the network load distribution apparatus which concerns on embodiment of this invention. It is a flowchart explaining operation | movement of the network load distribution apparatus which concerns on embodiment of this invention. It is a figure explaining the concept of the allocation of the data buffer in embodiment of this invention. It is a figure explaining the conventional priority control technique. It is a figure explaining the conventional load distribution control technique.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a network load distribution apparatus according to an embodiment of the present invention. The network load distribution apparatus includes a hash value calculation unit 1, a priority control unit 2, a load distribution control unit 3, a packet transfer control unit 4, data buffers 5-1 to 5-3, and a hash value calculation control unit 6. And a table allocation control unit 7. In the example of FIG. 1, the number of data buffers provided for each packet transmission destination communication path is three data buffers 5-1 to 5-3, but the number of data buffers is not limited to this. .

  The priority control unit 2 includes a priority route selection table 20 and a priority route control unit 21, and the load distribution control unit 3 includes a load distribution hash value calculation unit 30, a load distribution route selection table 31, and a load distribution route. And a control unit 32.

  The network load distribution apparatus is typically realized by using a device such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) and a program operating on the device or circuit data of the device. When realized by a program, the processor of the device performs the following processing according to the program stored in the memory, and functions as a network load distribution device. Further, the present invention is not limited to this, and the network load distribution apparatus according to the present embodiment may be realized by using a program on a general-purpose device such as a switch or router or a virtual switch on a general-purpose server. it can.

  Hereinafter, the operation of the network load distribution apparatus according to the present embodiment will be described with reference to the flowchart of FIG. This embodiment assumes use at the packet receiving end, and packet format data is input to the network load distribution apparatus. A packet generally has additional data representing the attribute of the packet as header data.

  When the hash value calculation unit 1 of the network load distribution device receives the packet (step S1 in FIG. 2), the hash value calculation unit 1 acquires a field value at a predetermined position in the header data of the packet, and the acquired field value is set in advance. A hash value specific to the attribute of the packet is calculated from the key value (step S2 in FIG. 2). The hash value calculated by the hash value calculation unit 1 is notified to the priority control unit 2.

  The position of the field value to be acquired in the header data of the packet is designated in advance by the hash value calculation unit 1 from the outside via the hash value calculation control unit 6. Similarly, the key value is also set in advance from the outside via the hash value calculation control unit 6.

  Next, in the priority route selection table 20 of the priority control unit 2, values that can be taken by the hash value calculated by the hash value calculation unit 1 and the communication path of the transmission destination are stored in advance in association with each other. The priority route selection table 20 is set in advance via the table assignment control unit 7 from the outside.

  The priority route control unit 21 of the priority control unit 2 collates the hash value calculated by the hash value calculation unit 1 with the priority route selection table 20, and the same value as the hash value calculated by the hash value calculation unit 1 is the priority route. If registered in the selection table 20 (YES in step S3 in FIG. 2), information on the destination communication path corresponding to this hash value is obtained from the priority path selection table 20, and information on the destination communication path is obtained. The packet transfer control unit 4 is notified (step S4 in FIG. 2).

  If the same value as the hash value calculated by the hash value calculation unit 1 is not registered in the priority route selection table 20 (NO in step S3), the priority route control unit 21 calculates the hash value calculated by the hash value calculation unit 1 Is notified to the load distribution control unit 3 (step S5 in FIG. 2).

  In the load distribution route selection table 31 of the load distribution control unit 3, values that can be taken by the hash value calculated by the load distribution hash value calculation unit 30 described later and the communication path of the transmission destination are stored in advance. A method of creating the load distribution route selection table 31 will be described later.

  The load distribution hash value calculation unit 30 of the load distribution control unit 3 calculates a hash value to be used for load distribution processing from the hash value calculated by the hash value calculation unit 1 and information on a predetermined destination that can be used for load distribution control. Calculation is performed (step S6 in FIG. 2). Specifically, the load distribution hash value calculation unit 30 uses the hash value calculated by the hash value calculation unit 1 as the number of destination communication paths that can be used in load distribution control (the data buffer 5 that can be used in load distribution control). (Number of -1 to 5-3).

  The destination communication paths (data buffers 5-1 to 5-3) are shared only by priority control, those used only by load distribution control, and shared by priority control and load distribution control. There is a thing. Therefore, the destination communication paths that can be used in the load distribution control include those that are used only in the load distribution control and those that are shared in the priority control and the load distribution control. Information on destination communication paths (data buffers 5-1 to 5-3 that can be used in load distribution control) that can be used in load distribution control is notified in advance via the table allocation control unit 7 from the outside.

  As described above, the hash value calculated by the hash value calculation unit 1 is a value unique to the attribute of the packet. On the other hand, the hash value calculated by the load balancing hash value calculation unit 30 is not necessarily a value specific to the attribute of the packet, and the same value may be calculated for different attributes.

  The load distribution path control unit 32 of the load distribution control unit 3 collates the hash value calculated by the load distribution hash value calculation unit 30 with the load distribution path selection table 31, and the hash value calculated by the load distribution hash value calculation unit 30 Is acquired from the load distribution route selection table 31 and the destination communication route information is notified to the packet transfer control unit 4 (step S7 in FIG. 2).

  Next, the packet transfer control unit 4 sends the received packet to one of the data buffers 5-1 to 5-3 according to the information on the destination communication path notified from the priority control unit 2 or the load distribution control unit 3. (Step S8 in FIG. 2). Specifically, when the packet transfer control unit 4 receives information on the destination communication path from the priority path control unit 21 of the priority control unit 2, the packet transfer control unit 4 selects the priority among the data buffers 5-1 to 5-1. When a packet is transmitted to the data buffer corresponding to the destination communication path notified from the path control unit 21 and information on the destination communication path is received from the load distribution path control unit 32 of the load distribution control unit 3 The packet is transmitted to the data buffer corresponding to the destination communication path notified from the load distribution path control unit 32. The packet is appropriately output from the data buffers 5-1 to 5-3 to the corresponding communication path and transmitted to the destination.

  Next, a method for creating the load distribution route selection table 31 of the load distribution control unit 3 will be described. In order to create the load distribution route selection table 31, all values that can be taken by the hash value calculated by the load distribution hash value calculation unit 30, load distribution setting data set from the outside, and load distribution control can be used. The packet is subjected to load distribution control according to the hash value calculated by the load distribution hash value calculation unit 30 based on the information of the communication path of the appropriate transmission destination (data buffers 5-1 to 5-3 that can be used for load distribution control). The destination communication path may be determined so that the load status of each data buffer when it is allocated to the available data buffer matches the load status specified by the load distribution setting data. In this manner, the hash value calculated by the load distribution hash value calculation unit 30 is associated with the destination communication path, and the load distribution path selection table 31 can be set.

  The load distribution setting data includes desired usage rate data of each data buffer and shared setting data of each data buffer (for example, a desired ratio of data buffer usage by priority control and data buffer usage by load distribution control). is there.

  The load distribution route selection table 31 is basically created in advance so as to realize uniform distribution of packets in which the utilization rate of all data buffers is constant for the data buffers that can be used in load distribution control. Depending on the load distribution setting data set from the outside, the utilization rates of all the data buffers are not necessarily the same. FIG. 3 shows the concept of such data buffer allocation.

  In the example of FIG. 3, the data buffers 5-1 and 5-2 are buffers used only for priority control, the data buffer 5-3 is a buffer shared by priority control and load distribution control, and the data buffer 5 -4 to 5-6 are buffers used only for load distribution control. A flow (packet) # 1 having an attribute is transmitted to the data buffer 5-1 by priority control, and a flow # 2 having another attribute is transmitted to the data buffer 5-2 or 5-3 by priority control. The flow is transmitted to one of the data buffers 5-3 to 5-6 by load distribution control.

  Note that the load distribution route selection table 31 may be created and set by the load distribution route control unit 32 by the above method, or the load distribution route selection table 31 created externally is loaded via the table allocation control unit 7. You may make it set to the dispersion | distribution control part 3. FIG.

  In addition, the load distribution control unit 3 calculates new hash values so as to match the load distribution route selection table 31 for all hash values notified from the priority route control unit 21 of the priority control unit 2. . The calculation method at this time may divide the notified hash value by the number of destination communication paths that can be used in load distribution control (the number of data buffers that can be used in load distribution control).

  However, the hash value notified from the priority route control unit 21 of the priority control unit 2 may be used as it is without calculating the hash value by the load distribution hash value calculation unit 30. In this case, in order to create the load distribution route selection table 31, all values that the hash value calculated by the hash value calculation unit 1 can take, load distribution setting data set from the outside, and use in load distribution control The load distribution of each data buffer when the packet is distributed to the data buffer that can be used in load distribution control according to the hash value calculated by the hash value calculation unit 1 from the information on the possible communication path of the destination What is necessary is just to determine the communication path of a transmission destination so that it may correspond with the load condition prescribed | regulated by setting data.

  In the present embodiment, since the position of the field value to be acquired in the header data of the packet can be designated from the outside, it is not a fixed field value as disclosed in Non-Patent Document 1, but an arbitrary length. Packet identification processing can be realized for any field value having. In this embodiment, it is possible to cope with special conditions (for example, acquisition of field values from a plurality of fields), and future expandability can be secured.

  Also, in the present embodiment, unlike the techniques disclosed in Patent Document 1 and Non-Patent Document 1, it is possible to realize free allocation of a data buffer used for priority control and a data buffer used for load distribution, As a result, an efficient service on resource-saving on-chip such as NIC can be realized.

  In addition, in this embodiment, in addition to the hash calculation for data buffer allocation in the priority control, the hash calculation suitable for the data buffer that can be used in the load distribution control is performed again. Packets that are not targeted can be eliminated, and a decrease in throughput due to distribution of packets to a single data buffer can be avoided. Further, in this embodiment, it is possible to ensure that packet order reversal does not occur due to packet identification by hash operation and data buffer allocation.

  The embodiment of the present invention has been shown and described above. The network load distribution apparatus according to the present embodiment may be a circuit or a device. Although the configuration in which the network load distribution apparatus shown in the present embodiment includes a priority control processing function for realizing a QoS function and a load distribution processing function for realizing high throughput is regarded as the best mode, the present embodiment The network load distribution apparatus may be implemented by firmware such as firmware stored in a ROM and hardware such as a reconfigurable device, element, board, and wiring. Alternatively, the network load distribution device may be configured by a combination of software and hardware, and further by a combination of firmware. Firmware and software are stored as programs in a recording medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD. The program is read and executed by the CPU. In other words, the program causes the computer to function as the network load distribution apparatus according to the present embodiment. Alternatively, the computer executes each step of the network load distribution apparatus.

  The present invention can be applied to packet destination control implemented on small resource hardware.

  DESCRIPTION OF SYMBOLS 1 ... Hash value calculation part, 2 ... Priority control part, 3 ... Load distribution control part, 4 ... Packet transfer control part, 5-1-5-6 ... Data buffer, 6 ... Hash value calculation control part, 7 ... Table allocation Control unit, 20 ... priority route selection table, 21 ... priority route control unit, 30 ... load distribution hash value calculation unit, 31 ... load distribution route selection table, 32 ... load distribution route control unit.

Claims (8)

Hash value calculation means for calculating a first hash value based on a field value included in the received packet;
A data buffer provided for each communication path of the packet destination;
Priority control means for detecting a specific packet subject to priority control based on the first hash value and determining a communication path of a destination of the packet;
Load distribution control means for determining a communication path of a transmission destination of a packet not subject to priority control by a second hash value based on the first hash value while satisfying load distribution of the data buffer;
A network load distribution apparatus comprising: packet transfer control means for transmitting the packet to a data buffer corresponding to the communication path in accordance with a destination communication path determined by the priority control means or the load distribution control means. . The network load distribution apparatus according to claim 1,
The hash value calculation means acquires a field value at a position designated in advance from the outside in the packet, and calculates the first hash value based on the field value and a key value set in advance from the outside. A network load balancer characterized by computing. The network load distribution apparatus according to claim 1 or 2,
The priority control means includes
A priority route selection table that stores in advance a correspondence between a value that can be taken by the first hash value calculated by the hash value calculation means and a communication path of a transmission destination;
Priority for acquiring information on the destination communication path corresponding to the first hash value from the priority path selection table when the same value as the first hash value is registered in the priority path selection table A network load distribution apparatus comprising: a path control unit. The network load distribution apparatus according to any one of claims 1 to 3,
The load distribution control means includes
Load balancing hash value computing means for computing a second hash value from the first hash value computed by the hash value computing means and information on a predetermined destination usable in load balancing control;
Load distribution set in advance from a possible value of the second hash value calculated by the load distribution hash value calculation means, load distribution setting data set from the outside, and a destination communication path that can be used in load distribution control A route selection table;
A network load comprising: a load distribution path control unit that acquires information about a destination communication path corresponding to the second hash value calculated by the load distribution hash value calculation unit from the load distribution path selection table. Distributed device. The network load distribution apparatus according to claim 4, wherein
The destination communication path registered in the load distribution path selection table includes all possible values of the second hash value calculated by the load distribution hash value calculation means, load distribution setting data and load set from the outside When a packet is distributed to a data buffer that can be used for load distribution control according to a second hash value calculated by the load distribution hash value calculation means, based on information on a destination communication path that can be used for distribution control A network load distribution apparatus, wherein a load condition of each data buffer is determined so as to match a load condition defined by the load distribution setting data. A hash value calculation step of calculating a first hash value based on a field value included in the received packet;
A priority control step of detecting a specific packet subject to priority control based on the first hash value and determining a communication path of a destination of the packet;
A load distribution control step of determining a communication path of a transmission destination of a packet not subject to priority control based on a second hash value based on the first hash value while satisfying load distribution of the data buffer;
And a packet transfer control step of transmitting the packet to a data buffer corresponding to the communication path according to the destination communication path determined in the priority control step or the load distribution control step. . The network load balancing method according to claim 6, wherein
The hash value calculation step acquires a field value at a position designated in advance from the outside in the packet, and calculates the first hash value based on the field value and a key value set in advance from the outside. Including a step of calculating,
The priority control step includes:
Reference is made to a priority route selection table in which values that can be taken by the first hash value and destination communication routes are stored in advance, and the same value as the first hash value is registered in the priority route selection table. A priority route control step of obtaining information of a communication route of a transmission destination corresponding to the first hash value from the priority route selection table,
The load balancing control step includes
A load distribution hash value calculation step of calculating a second hash value from the first hash value and information of a predetermined destination available in load distribution control;
Refer to a load distribution route selection table set in advance from values that can be taken by the second hash value, load distribution setting data set from the outside, and communication routes of destinations that can be used in load distribution control, and the load A load distribution path control step of acquiring from the load distribution path selection table information on a destination communication path corresponding to the second hash value calculated in the distributed hash value calculation step. . The network load balancing method according to claim 7,
The destination communication path registered in the load distribution path selection table includes all possible values of the second hash value calculated in the load distribution hash value calculation step, load distribution setting data and load set from the outside. When a packet is distributed to a data buffer that can be used in load distribution control according to the second hash value calculated in the load distribution hash value calculation step, based on information on the destination communication path that can be used in distribution control A network load balancing method, wherein the load situation of each data buffer is determined so as to match the load situation defined by the load balancing setting data.

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