JP2019161632A - Information processing device, information processing system, and information processing program - Google Patents

Abstract

An information processing apparatus, an information processing system, and an information processing program for improving communication performance are provided.
A switch includes a flow identification unit, a flow discrimination processing unit, and a queue switching processing unit. The flow identification unit 103 identifies a flow of processing for transmitting a plurality of packets. The flow discrimination processing unit 104 acquires a feature amount related to the flow. The queue switching processing unit 105 controls transmission of packets of the flow based on the feature amount related to the flow acquired by the flow determination processing unit 104.
[Selection] Figure 2

Description

  The present invention relates to an information processing apparatus, an information processing system, and an information processing program.

  In recent years, the performance of server computers and client computers has been remarkably improved, and the demand for higher communication performance has been increasing in accordance with these performance improvements. In order to realize high performance of communication, control of a flow level that is a data flow in which a communication source and a transmission destination are determined is required.

  For example, the flow includes traffic for accessing the storage and traffic for inquiring. In the case of access to storage, a large amount of data is often transferred, and data is often transferred using a large packet. On the other hand, when making an inquiry, data is often transferred using small packets. As described above, since the size of the packet is different for each flow, the efficiency of packet transfer can be increased by performing control at the flow level, and the communication performance can be improved.

  When performing such flow level control, it is conceivable to switch the queue for storing packets to be transmitted in accordance with the flow. For example, since a small packet is required to have a low latency, it is preferable that a packet stored in the queue is processed early. On the other hand, since a large packet is required to increase the throughput, it is preferable that the packet always exists without emptying the queue. Therefore, for example, it is conceivable to make the queue for storing small packets different from the queue for large packets.

  As described above, as a method of switching queues by flow level control, there is a conventional technique in which header information is compared using an ACL (Access Control List) and the queues are switched according to the transfer amount. Further, there is a conventional technique in which a flow is specified using a hash value, and a distribution destination of a flow in which no packet remains in the queue is changed to a light-load queue.

JP 2010-161546 A

  However, in the conventional technology for switching queues using ACL, settings for switching queues are manually performed, and it is difficult to automate and to cope with high-speed switching. Also, even when using the conventional technology that switches the queue of a flow that does not have packets remaining in the queue by specifying the flow, the queue is not automatically switched according to the flow type, and the queue can be flexibly set. It is difficult to switch.

  The disclosed technology has been made in view of the above, and an object thereof is to provide an information processing apparatus, an information processing system, and an information processing program that improve communication performance.

  In one aspect of the information processing apparatus, the information processing system, and the information processing program disclosed in the present application, the flow identification unit identifies a flow of processing for transmitting a plurality of packets. The feature amount acquisition unit acquires a feature amount related to the flow. The transmission control unit controls transmission of the packet of the flow based on the feature amount acquired by the feature amount acquisition unit.

  In one aspect, the present invention can improve communication performance.

FIG. 1 is a schematic configuration diagram of an information processing system. FIG. 2 is a block diagram of the switch according to the embodiment. FIG. 3 is a diagram summarizing information transferred at each point between the relay processing unit and the transmission queue set. FIG. 4 is a diagram illustrating an example of a flow identification table. FIG. 5 is a diagram illustrating an example of the transfer amount table. FIG. 6 is a diagram illustrating an example of the queue information management table. FIG. 7 is a block diagram of the transmission queue set. FIG. 8 is a flowchart of the flow identification process by the flow identification unit. FIG. 9 is a flowchart of entry management by the flow identification unit. FIG. 10 is a flowchart of the flow discrimination processing by the flow discrimination processing unit. FIG. 11 is a flowchart of queue switching processing by the queue switching processing unit. FIG. 12 is a flowchart of enqueue processing for a queue. FIG. 13 is a flowchart of dequeue processing for a queue. FIG. 14 is a diagram illustrating an example of a flow identification table according to the second embodiment. FIG. 15 is a flowchart of the flow identification process performed by the flow identification unit according to the second embodiment. FIG. 16 is a diagram illustrating an example of the queue information management table according to the third embodiment. FIG. 17 is a block diagram of a switch according to the fourth embodiment. FIG. 18 is a block diagram of a switch that performs congestion control. FIG. 19 is a diagram summarizing information delivered at each point of the switch in the fifth embodiment. FIG. 20 is a diagram illustrating an example of the queue information management table in the fifth embodiment. FIG. 21 is a block diagram of a transmission queue set according to the fifth embodiment. FIG. 22 is a flowchart of the queue switching process performed by the queue switching processing unit according to the fifth embodiment. FIG. 23 is a block diagram of an information processing system according to the seventh embodiment. FIG. 24 is a diagram illustrating an example of a flow determination table. FIG. 25 is a flowchart of overall processing of flow management by a server according to the seventh embodiment. FIG. 26 is a flowchart of the transmission process performed by the server according to the seventh embodiment. FIG. 27 is a flowchart of the reception process performed by the server according to the seventh embodiment. FIG. 28 is a diagram for explaining the effect when the switch of the fifth embodiment is used.

  Hereinafter, embodiments of an information processing apparatus, an information processing system, and an information processing program disclosed in the present application will be described in detail based on the drawings. The information processing apparatus, the information processing system, and the information processing program disclosed in the present application are not limited by the following embodiments.

  FIG. 1 is a schematic configuration diagram of an information processing system. As illustrated in FIG. 1, the information processing system 1 according to the present embodiment includes a switch 100 and servers 201 to 206.

  Servers 201 to 206 are each connected to the switch 100. The servers 201 to 206 transmit and receive packets to and from each other via the switch 100. Hereinafter, when the servers 201 to 206 are expressed without being distinguished from each other, they are referred to as servers 200. The packet transmission source server 200 is referred to as a “transmission side server 200”, and the packet transmission destination server 200 is referred to as a “reception side server 200”. For example, when the server 201 transmits a packet to the server 204, the server 201 that is the server 200 on the transmission side is an example of “first communication device”, and the server 204 that is the server 200 on the reception side is “second communication device”. This is an example.

  The switch 100 receives a packet addressed to the receiving server 200 transmitted from the transmitting server 200. Then, the switch 100 transmits the packet transmitted from the transmission-side server 200 from the port connected to the server 200 to the reception-side server 200.

  Here, in FIG. 1, the case where the servers 200 are connected to each other by one switch 100 is illustrated, but the connection form is not limited to this, and the switch 100 is connected to the server 200 on the transmission side via another communication device. A server 200 on the receiving side may be connected. In FIG. 1, six servers 201 to 206 are illustrated, but the number of servers is not particularly limited.

  Here, a flow by packet transmission from the server 200 on the transmission side to the server 200 on the reception side will be described. The server 200 on the transmission side and the server 200 on the reception side perform communication for transmitting a series of related packets. Such a process of transmitting a series of packets is called “flow”.

  The packet has a header including information for controlling transmission / reception of the packet and a payload including data to be transmitted. Packet information that is information for identifying a flow is stored in the header of the packet. Here, the same information is stored in each packet transmitted and received as the same flow as information for identifying the flow.

  For example, the header of the packet stores a destination address, transmission source information, destination information, protocol, transmission source port number, destination port number, and the like. For example, the transmission source information is a transmission source IP (Internet Protocol) or the like, and the destination information is a destination IP or the like. In this embodiment, five pieces of information called a source, destination IP, source port number, destination port number, and protocol are used as information for identifying a flow. However, the information for identifying the flow may be any information as long as it can identify a process for transmitting a series of packets represented as a flow.

  Next, the details of the switch 100 will be described with reference to FIG. FIG. 2 is a block diagram of the switch according to the embodiment. This switch 100 is an example of an “information processing apparatus”.

  As illustrated in FIG. 2, the switch 100 includes reception ports 111 to 112, a relay processing unit 102, a flow identification unit 103, a flow determination processing unit 104, a queue switching processing unit 105, a data holding unit 106, and transmission queue sets 171 to 172. And transmission ports 181 to 182. Further, the data holding unit 106 includes a flow identification table 161, a transfer amount table 162, and a queue information management table 163.

  The reception ports 111 to 112 have the same function. Hereinafter, the reception ports 111 to 112 are referred to as “reception ports 110” unless they are distinguished from each other. In addition, the transmission ports 181 to 182 have the same function. Hereinafter, the transmission ports 181 to 182 are referred to as “transmission port 180” unless they are distinguished from each other.

  The reception ports 111 to 112 are connected to one or several servers 200 (not shown). The reception ports 111 to 112 receive packet input from the connection-side transmission server 200. Then, the reception ports 111 to 112 output the input packet to the relay processing unit 102.

  The relay processing unit 102 receives a packet input from the reception port 110. The relay processing unit 102 determines the transmission port 180 that outputs the packet from the information of the receiving server 200 such as the destination information and the destination port stored in the header. Then, the relay processing unit 102 flows the packet information including the source IP, the destination IP, the source port number, the destination port number and the protocol, and the packet together with the transmission port ID (IDentifier) which is the identifier of the determined transmission port 180 The data is output to the identification unit 103. Here, since the packet information is actually included in the header of the packet, the packet information can also be sent by sending the packet. However, in this description, in order to clearly indicate that packet information is exchanged, the packet information is also transmitted together with the packet.

  FIG. 3 is a diagram summarizing information transferred at each point between the relay processing unit and the transmission queue set. As illustrated in FIG. 3, an information set 121 including packet information and a transmission port ID is transmitted as control information for packet transmission transmitted from the relay processing unit 102 to the flow identification unit 103.

  Returning to FIG. 2, the description will be continued. The flow identification table 161 is, for example, the table shown in FIG. FIG. 4 is a diagram illustrating an example of a flow identification table.

  In the flow identification table 161, header information including a source IP, a destination IP, a source port number, a destination port number, and a protocol, an address, and frequency information are registered in association with each other. The frequency information represents the frequency with which a packet included in each flow at a certain time is sent. Furthermore, as will be described later, the address of the flow identification table 161 corresponds to the flow ID.

  The flow identification table 161 according to the present embodiment is a CAM (Content Addressable Memory) that gives the address of the entry in which the information is stored by giving the content of the information.

  The flow identification unit 103 acquires an information set 121 including packet information and a transmission port ID. Furthermore, the flow identification unit 103 receives an input of the packet body. Next, the flow identification unit 103 searches the flow identification table 161 using header information including the source IP, destination IP, source port number, destination port number, and protocol included in the acquired packet information.

  When there is an entry that matches the header information, the flow identification unit 103 acquires an address corresponding to the header information as a flow ID that is identification information of the flow represented by the header information. This flow ID is an identifier of the flow to which the acquired packet belongs. Furthermore, the flow identification unit 103 increments the frequency information corresponding to the flow ID by one. Further, the flow identification unit 103 uses a Found message indicating that a matching entry exists as entry information indicating an entry search result.

  If there is no entry that matches the header information and there is a vacancy in the entry, the flow identification unit 103 registers the header information in the vacant entry and registers 1 in the frequency information. Then, the flow identification unit 103 acquires the address of the registered entry as a flow ID corresponding to the header information. This flow ID becomes the identifier of the flow to which the acquired packet belongs. Further, the flow identification unit 103 uses, as entry information, a New message indicating that a new entry has been generated.

  When there is no entry that matches the header information and there is no empty entry, the flow identification unit 103 uses a Notfound message indicating that there is no entry as entry information. In this case, the flow identification unit 103 may use information indicating that no flow ID exists as the flow ID.

  Thereafter, the flow identification unit 103 outputs the information set 131 including the packet information, the transmission port ID, the flow ID, and the entry information together with the packet body to the flow discrimination processing unit 104 as shown in FIG.

  Further, the flow identification unit 103 manages entries in the flow identification table 161 at regular intervals. Specifically, the flow identification unit 103 stores in advance a cycle for managing entries in the flow identification table 161. Then, when the management timing of entries in the flow identification table 161 comes, the flow identification unit 103 selects one entry from the flow identification table 161 one by one.

  Then, the flow identification unit 103 determines whether or not the frequency information in the selected entry is zero. When the frequency information is not 0, the flow identification unit 103 decrements the frequency information of the selected entry by one. That is, the packet output from the flow identification unit 103 is highly likely to have already been output from the transmission port 180 if a sufficient period has elapsed since it was output. Therefore, the flow identification unit 103 can predict the number of packets remaining in the switch 100 belonging to the flow by reducing the frequency information increased by one at the time of output by one. If the frequency information is 0, it can be predicted that there is a high probability that no packet belonging to the flow exists in the switch 100.

  Therefore, when the frequency information is 0, the flow identification unit 103 acquires the value of the queue counter corresponding to the flow ID of the selected entry from the queue information management table 163. Then, the flow identification unit 103 determines whether or not the queue counter is 0. If the queue counter is 0, the flow identification unit 103 can confirm that no packet belonging to the flow remains in the transmission queue set 170, and therefore no packet belonging to the flow exists in the switch 100. Can be predicted. Therefore, the flow identification unit 103 deletes the selected entry.

  The flow identification unit 103 performs the above processing on all entries of the flow identification table 161 and manages the flow identification table 161. Thereby, unnecessary entries can be deleted, and the flow identification unit 103 can use the flow identification table 161 effectively.

  The transfer amount table 162 is a table representing the transfer amount of each flow. FIG. 5 is a diagram illustrating an example of the transfer amount table. As shown in FIG. 5, the transfer amount is registered in the transfer amount table 162 as the feature amount of each flow in association with the flow ID. In FIG. 5, FID represents a flow ID. In this embodiment, the counters of all transmission ports 180 are managed by one entry for one flow ID. In many cases, communication is unicast communication, and the number of transmission ports 180 serving as an output destination is often limited to one. Therefore, the reason is that even if all the transmission ports 180 are managed by one entry for one flow ID, in most cases, there is no problem.

  The flow discrimination processing unit 104 receives the input of the information set 131 including the packet information, the transmission port ID, the flow ID, and the entry information as shown in FIG. Then, the flow determination processing unit 104 confirms the acquired entry information.

  When the entry information is found, the flow determination processing unit 104 identifies an entry corresponding to the acquired flow ID in the transfer amount table 162. Then, the flow determination processing unit 104 acquires the size of the packet from the packet information, adds the size of the packet to the transfer amount of the entry corresponding to the acquired flow ID in the transfer amount table 162, and writes it.

  When the entry information is New, the flow determination processing unit 104 newly creates an entry corresponding to the flow ID in the transfer amount table 162. Then, the flow determination processing unit 104 initializes the transfer amount. Thereafter, the flow discrimination processing unit 104 acquires the packet size from the packet information, and writes the packet size in the transfer amount of the created entry.

  Next, regardless of whether the entry information is Found or New, the flow determination processing unit 104 checks the packet information and determines whether or not a specific queue is designated as the output queue of the packet. Here, the output queue refers to a queue that inputs and holds a packet, and then outputs the held packet to the transmission port 180. For example, when the priority of a packet is high, a predetermined specific queue that is preferentially processed is designated as the output queue for that packet.

  When a specific queue is specified for the packet, the flow determination processing unit 104 sets the specified specific queue as a candidate queue that is specified as an output queue candidate. Specifically, the flow determination processing unit 104 confirms the priority of the packet stored in the packet information. For example, the priority of a packet is represented by 0-7. In this case, the higher the number, the higher the priority. If the priority of the packet is 7, the flow determination processing unit 104 sets the specific queue to be preferentially processed as the candidate queue for the packet.

  On the other hand, when the specific queue is not specified for the packet, the flow determination processing unit 104 determines whether or not the transfer amount is equal to or greater than a predetermined threshold. When the transfer amount is equal to or greater than a predetermined threshold, the flow determination processing unit 104 sets a long queue among a plurality of queues included in the transmission queue set 170 connected to the transmission port 181 as a candidate queue for the packet. The long queue is a queue assigned to store packets belonging to a flow with a large transfer amount, and is a queue intended to increase the throughput. The transmission queue set 170 will be described in detail later. This long queue is an example of a “first queue”.

  On the other hand, when the transfer amount is less than a predetermined threshold, the flow determination processing unit 104 assigns a short queue of the plurality of transmission queues included in the transmission queue set 170 connected to the transmission port 181 to the packet. A candidate queue. The short queue is a queue assigned to store packets belonging to a flow with a small transfer amount, and is a queue for the purpose of reducing latency. This short queue is an example of a “second queue”.

  On the other hand, when the entry is Notfound, the flow determination processing unit 104 sets the default queue as a candidate queue for the packet.

  Thereafter, the flow discrimination processing unit 104 outputs to the queue switching processing unit 105 an information set 141 including the packet information, the flow ID, the entry information, and the candidate queue ID that is the identification information of the candidate queue, as shown in FIG. . The flow discrimination processing unit 104 is an example of a “feature amount acquisition unit”.

  The queue information management table 163 is a table representing the output queue information of the packets of the flow and the state of the output queue for each flow for each flow. FIG. 6 is a diagram illustrating an example of the queue information management table. The queue information management table 163 stores a flow ID and a Q (Que) ID in association with each other. The QID represents a queue to which a packet of a flow having each flow ID is transmitted, that is, a current queue of a flow having each flow ID. Further, the queue information management table 163 has a queue counter that represents the number of packets of the flow stored in the current queue of the flow having each flow ID for each flow ID.

  The queue switching processing unit 105 receives an input of the information set 141 including packet information, flow ID, entry information, and candidate queue ID from the flow discrimination processing unit 104 together with the packet body. Then, the queue switching processing unit 105 confirms the entry information.

  When the entry information is found, the queue switching processing unit 105 acquires the queue ID of the current queue of the acquired flow ID from the queue information management table 163. Then, the queue switching processing unit 105 determines whether or not queue switching occurs depending on whether or not the candidate queue ID matches the queue ID of the current queue. When queue switching does not occur, the queue switching processing unit 105 sets the output queue as a candidate queue. In this case, the output queue is maintained as the current queue.

  On the other hand, when queue switching occurs, the queue switching processing unit 105 determines whether or not the value of the queue counter corresponding to the acquired flow ID in the queue information management table 163 is zero. If the value of the queue counter is 0, it can be said that no packet of the flow remains in the current queue of the flow. That is, the queue switching processing unit 105 determines whether or not the packet of the flow remains in the current queue of the flow. If the value of the queue counter is 0, no packet remains in the current queue, and the queue switching processing unit 105 changes the output queue of the flow from the current queue to the candidate queue.

  On the other hand, when the value of the queue counter is not 0 and the packet remains in the current queue, the queue switching processing unit 105 maintains the output queue of the flow as the current queue that has not been set as the candidate queue. To do. Thereby, it is possible to avoid storing the packet in another queue even though the packet remains in the specific queue, and to avoid reversal of the order of the packets.

  When the entry information is New, the queue switching processing unit 105 registers the newly acquired flow ID in the queue information management table 163 and creates a corresponding entry. Further, the queue switching processing unit 105 initializes the queue counter value of the generated entry to zero. Then, the queue switching processing unit 105 sets the output queue of the flow as a candidate queue.

  If the entry information is Notfound, the queue switching processing unit 105 sets the output queue of the flow as a candidate queue.

  Thereafter, the queue switching processing unit 105 outputs the packet, packet information, and the FID of the flow to which the packet belongs to the transmission queue set 170 having the queue determined as the output queue of the flow. Further, along with the output of the packet, the queue switching processing unit 105 outputs the queue ID of the output packet output queue to the transmission queue set 170 that is the output destination of the packet. Further, the queue switching processing unit 105 outputs the flow ID of the flow to which the output packet belongs and a command instructing addition to the queue information management table 163. As a result, the queue switching processing unit 105 increments the queue counter corresponding to the specified flow ID in the queue information management table 163 by one. The queue switching processing unit 105 is an example of a “transmission control unit”.

  FIG. 7 is a block diagram of the transmission queue set. As shown in FIG. 7, the transmission queue set 170 includes a selector 701, a multiplexer 703, a scheduler 704, and a plurality of queues 721 to 723. Hereinafter, when the queues 721 to 723 are not distinguished from each other, they are referred to as “queues 720”.

  The selector 701 receives packet information, flow ID, and packet input from the queue switching processing unit 105. Further, the selector 701 receives an input of a queue ID representing the output queue of the packet from the queue switching processing unit 105. That is, the selector 701 receives from the queue switching processing unit 105 the packet information, the information set 151 including the flow ID and the queue ID shown in FIG.

  Then, the selector 701 outputs the packet information, the flow ID, and the packet to the queue 720 having the designated queue ID.

  The queue 720 specified as the output queue by the queue ID input from the queue switching processing unit 105 receives the packet information, the flow ID, and the packet input from the selector 701. The queue 720 stores the input packet information, flow ID, and packet. Thereafter, the queue 720 sequentially outputs to the multiplexer 703 packet information, flow IDs, and packets held in the order of acquisition timing.

  The scheduler 704 arbitrates packets output from the multiplexer 703. For example, the scheduler 704 selects a queue 720 that outputs a packet by round robin or the like and causes the multiplexer 703 to output it.

  The multiplexer 703 acquires packet information, a flow ID, and a packet from the queue 720 specified from the scheduler 704. Then, the multiplexer 703 outputs the acquired packet information and packet to the transmission port 180. Further, the multiplexer 703 outputs the flow ID of the flow to which the packet belongs to the queue information management table 163 together with a command for instructing subtraction. As a result, the transmission queue set 170 decrements one queue counter corresponding to the specified flow ID in the queue information management table 163.

  Returning to FIG. 2, the description will be continued. The transmission port 180 transmits a packet to the server 200 on the receiving side specified by the destination information included in the packet information.

  Next, the flow of flow identification processing by the flow identification unit 103 will be described with reference to FIG. FIG. 8 is a flowchart of the flow identification process by the flow identification unit.

  The flow identification unit 103 receives the packet information and the transmission port ID from the relay processing unit 102 together with the packet. Then, the flow identification unit 103 searches the flow identification table 161 using the packet information (step S101). In this embodiment, the flow identification unit 103 performs a search by outputting the source IP, destination IP, transmission port number, destination port number, and protocol included in the packet information to the flow identification table 161.

  Then, the flow identification unit 103 detects a flow corresponding to the flow to which the packet belongs (step S102). In this embodiment, since the flow identification table 161 is a CAM, the flow identification unit 103 acquires the flow ID corresponding to the entry from the flow identification table 161 when there is an entry having information corresponding to the transmitted information. To do. If the flow ID can be acquired, the flow identification unit 103 determines that the corresponding flow has been detected.

  When a corresponding flow is detected (step S102: Yes), the flow identification unit 103 sets the packet entry information to Found. Further, the flow identification unit 103 increments the frequency information corresponding to the flow ID in the flow identification table 161 by one (step S103).

  On the other hand, when a corresponding flow is not detected (No at Step S102), the flow identification unit 103 determines whether there is an empty entry in the flow identification table 161 (Step S104).

  When there is an empty entry (step S104: Yes), the flow identification unit 103 sets the packet entry information to New. Further, the flow identification unit 103 registers the flow identification information in the empty entry of the flow identification table 161, and sets the frequency information to 1 (step S105). Then, the flow identification unit 103 acquires the identification information of the registered empty entry as a flow ID.

  On the other hand, if there is no empty entry (No at Step S104), the flow identifying unit 103 sets the entry information of the packet as Notfound (Step S106). In this case, the flow identification unit 103 acquires information indicating that no flow ID exists as a flow ID.

  Next, the flow of entry management by the flow identification unit 103 will be described with reference to FIG. FIG. 9 is a flowchart of entry management by the flow identification unit.

  The flow identification unit 103 determines whether the determination timing has arrived (step S201). When the determination timing has not arrived (No at Step S201), the flow identification unit 103 waits until the determination timing arrives.

  On the other hand, when the determination timing has arrived (step S201: affirmative), the flow identification unit 103 selects one undetermined entry from the flow identification table 161 (step S202).

  Then, the flow identification unit 103 determines whether or not the frequency information in the selected entry is 0 (step S203). When the frequency information is not 0 (No at Step S203), the flow identification unit 103 decrements the frequency information of the selected entry by one (Step S204).

  On the other hand, if the frequency information is 0 (step S203: Yes), the flow identification unit 103 acquires the value of the queue counter corresponding to the flow ID of the selected entry from the queue information management table 163. Then, the flow identification unit 103 determines whether or not the queue counter is 0 (step S205).

  When the queue counter is 0 (step S205: Yes), the flow identification unit 103 deletes the selected entry (step S206). On the other hand, when the queue counter is not 0 (No at Step S205), the flow identifying unit 103 proceeds to Step S207.

  Thereafter, the flow identification unit 103 determines whether or not an undetermined entry remains (step S207). When an undetermined entry remains (Step S207: Yes), the flow identification unit 103 returns to Step S202.

  On the other hand, when there is no undetermined entry remaining (step S207: No), the flow identification unit 103 ends the entry management process.

  Next, with reference to FIG. 10, the flow of flow discrimination processing by the flow discrimination processing unit 104 will be described. FIG. 10 is a flowchart of the flow discrimination processing by the flow discrimination processing unit.

  The flow discrimination processing unit 104 receives input of packet information, transmission port ID, flow ID, and entry information from the flow identification unit 103. Then, the flow determination processing unit 104 determines whether or not the entry information is found (step S301). When the entry information is Found (step S301: Yes), the flow determination processing unit 104 proceeds to step S304.

  On the other hand, when the entry information is not Found (step S301: No), the flow determination processing unit 104 determines whether the entry information is New (step S302).

  When the entry information is New (step S302: Yes), the flow determination processing unit 104 creates an entry corresponding to the newly acquired flow ID in the transfer amount table 162 and initializes the transfer amount (step S303).

  After the entry information is found or after step S303, the flow determination processing unit 104 adds the size of the acquired packet to the transfer amount of the transfer amount table 162 corresponding to the acquired flow ID and registers it (step S304).

  Thereafter, the flow determination processing unit 104 determines whether or not a specific queue is designated as an output queue for the packet (step S305).

  When the specific queue is not specified (No at Step S305), the flow determination processing unit 104 determines whether or not the transfer amount corresponding to the acquired flow ID is equal to or greater than the threshold (Step S306).

  When the transfer amount corresponding to the acquired flow ID is greater than or equal to the threshold (step S306: Yes), the flow determination processing unit 104 sets the long queue as a candidate queue for the packet (step S307).

  On the other hand, when the transfer amount corresponding to the acquired flow ID is less than the threshold (No at Step S306), the flow determination processing unit 104 sets the short queue as a candidate queue for the packet (Step S308).

  On the other hand, when a specific queue is designated (step S305: Yes), the flow determination processing unit 104 sets the specific queue as a candidate queue for the packet (step S309).

  When the entry information is not New (step S302: No), that is, when the entry information is Notfound, the flow determination processing unit 104 sets the default queue as a candidate queue for the packet (step S310).

  Next, a flow of queue switching processing by the queue switching processing unit 105 will be described with reference to FIG. FIG. 11 is a flowchart of queue switching processing by the queue switching processing unit.

  The queue switching processing unit 105 receives input of packet information, flow ID, entry information, and candidate queue ID from the flow determination processing unit 104. The queue switching processing unit 105 determines whether the entry information is found (step S401).

  When the entry information is found (step S401: affirmative), the queue switching processing unit 105 determines whether or not queue switching occurs depending on whether or not the candidate queue and the queue ID of the current queue are the same (step S401). S402).

  When queue switching occurs (Step S402: Yes), the queue switching processing unit 105 determines whether or not the value of the queue counter corresponding to the acquired flow ID in the queue information management table 163 is 0 (Step S403). .

  When the queue counter is 0 (step S403: Yes), the queue switching processing unit 105 switches the packet output queue to the candidate queue (step S404).

  On the other hand, if the queue switching does not occur (step S402: negative) and the queue counter is not 0 (step S403: negative), the queue switching processing unit 105 maintains the output queue in the current queue (step S403). S406).

  On the other hand, when the entry information is not Found (No at Step S401), the queue switching processing unit 105 determines whether the entry information is New (Step S405). If the entry information is not New (step S405: No), that is, if the entry information is Notfound, the queue switching processing unit 105 proceeds to step S408.

  In contrast, when the entry information is New (step S405: Yes), the queue switching processing unit 105 initializes the created entry by creating an entry corresponding to the acquired flow ID in the queue information management table 163 ( Step S407) and the process proceeds to Step S408.

  The queue switching processing unit 105 sets the output queue as a candidate queue (step S408).

  Next, the flow of enqueue processing for the queue 720 will be described with reference to FIG. FIG. 12 is a flowchart of enqueue processing for a queue.

  The queue switching processing unit 15 increments the queue counter of the entry of the queue information management table 163 corresponding to the flow ID to which the output packet belongs by one (step S501).

  Next, the queue switching processing unit 15 enqueues the packet information, the flow ID, and the packet in the queue 720 corresponding to the queue ID (Step S502).

  Next, the flow of dequeue processing for the queue 720 will be described with reference to FIG. FIG. 13 is a flowchart of dequeue processing for a queue.

  The queue 720 dequeues the packet information, flow ID, and packet, and outputs them to the transmission port 180 (step S601).

  Thereafter, the queue 720 decrements the queue counter of the entry of the queue information management table 163 corresponding to the flow ID by one (step S602).

  Here, in this embodiment, the case where the transfer amount is used as the feature amount for determining the candidate queue has been described. However, other information may be used as the feature amount as long as it is information that can identify the type of flow. For example, an increase rate of the transfer amount representing an increase in the transfer amount per unit time may be used as the feature amount. In this case, the flow discrimination processing unit 104 measures the increment of the transfer amount at regular intervals, and when the measurement result is equal to or greater than a predetermined increment threshold, the long queue is set as a candidate queue, and the measurement result is less than the increment threshold. Uses the short queue as a candidate queue.

  In this embodiment, the packet transmission destination is divided into two types of queues 720, that is, the long queue and the show queue, in addition to the specific queue. However, the number and types of the queues 720 are not limited to this, and the flow As long as classification according to type is possible, other numbers and types of queues 720 may be used.

  For example, consider a case where the flow identification unit 103 classifies storage traffic, streaming, and other flows as the types of flows using packet information. In this case, as the queue 720, three types of queues 720 corresponding to storage traffic, streaming, and other flows are prepared. The queue switching processing unit 105 determines a packet output queue according to the type of flow determined by the flow determination processing unit 104.

  It is also possible to combine these queue configurations. For example, six queues 720 may be prepared: a specific queue that is a priority queue, a long queue and a short queue for storage traffic, a queue for streaming, and a long queue and a short queue for other traffic.

  As described above, when receiving the packet, the switch according to the present embodiment identifies the flow to which the packet belongs, and determines an output queue candidate according to the feature amount related to the flow. Further, when there are no packets belonging to the flow in the candidate queue, the switch switches the output queue to the candidate queue and stores the packet in the output queue after switching. As a result, the switch according to the present embodiment can automatically and at high speed discriminate the flow according to the feature amount of the flow while keeping the order of the packets, and dynamically and rapidly switch the queue for storing the packets. Can do. Therefore, the queue can be switched by the control at the flow level, and the communication performance can be improved.

  In particular, the switch according to the present embodiment can switch the output queue of packets according to the transfer amount for each flow, and can separate short packets and long packets and store them in the queue. As a result, queues that require low latency and queues that require high throughput can be separated, and communication performance can be improved by selecting queues according to the characteristics of each flow.

  Next, Example 2 will be described. The switch according to the present embodiment is different from the first embodiment in that a table that performs a search using a hash value is used as a flow identification table. The switch according to this embodiment is also represented by the block diagram of FIG. In the following description, the description of the operation of each part similar to that of the first embodiment is omitted.

  FIG. 14 is a diagram illustrating an example of a flow identification table according to the second embodiment. As shown in FIG. 14, in the flow identification table 161 according to the present embodiment, header information is registered at an address corresponding to a hash value based on packet information. For example, in this embodiment, a hash value obtained from the source IP, destination IP, source port, destination port, and protocol is used.

  The flow identification unit 103 acquires the source IP, destination IP, source port, destination port, and protocol from the packet information acquired from the relay processing unit 102. Then, the flow identification unit 103 obtains a hash value from the acquired transmission source IP, destination IP, transmission source port, destination port, and protocol.

  Next, the flow identification unit 103 reads the flow identification table 161 using the calculated hash value as an address. When the entry is in use and the header information of the read entry matches the header information of the packet, the flow identification unit 103 sets the entry information of the packet as Found. Further, the flow identification unit 103 acquires the address of the read entry, that is, the hash value as a flow ID. Further, the flow identification unit 103 increments the frequency information of the entry having the hash value as an address by one.

  On the other hand, when the entry having the hash value as an address is unused, the flow identification unit 103 registers the packet header information in the empty entry and sets the frequency information to 1. Then, the flow identification unit 103 sets the packet entry information to New.

  If an entry whose address is a hash value is in use and the header information of the entry does not match the header information of the packet, the flow identification unit 103 determines whether the frequency information of the entry is zero. . If the frequency information is 0, the flow identification unit 103 acquires the value of the queue counter of the flow ID corresponding to the entry from the queue information management table 163. If the queue counter is 0, the flow identification unit 103 registers the header information of the entry and sets the frequency information to 1. Furthermore, the flow identification unit 103 sets the packet entry information to New. When the frequency information is not 0, or when the frequency information is 0 but the queue counter is not 0, the flow identification unit 103 sets the packet entry information as Notfound.

  In parallel with these, the flow identification unit 103 periodically scans the flow identification table 161 and decrements the frequency information of each entry by one with 0 as the minimum value, as in the first embodiment.

  Next, the flow of flow identification processing by the flow identification unit 103 according to the present embodiment will be described with reference to FIG. FIG. 15 is a flowchart of the flow identification process performed by the flow identification unit according to the second embodiment.

  The flow identification unit 103 acquires the source IP, destination IP, source port, destination port, and protocol from the packet information acquired from the relay processing unit 102. Then, the flow identification unit 103 calculates a hash value from the acquired transmission source IP, destination IP, transmission source port, destination port, and protocol (step S701).

  Next, the flow identification unit 103 searches for a flow from the flow identification table 161 using the calculated hash value (step S702).

  Then, the flow identification unit 103 determines whether or not a flow corresponding to the flow to which the packet belongs is registered in the flow identification table 161 (step S703).

  When the corresponding flow has been registered (step S703: affirmative), the flow identification unit 103 increments the frequency information by one with the entry information as Found (step S704).

  When the corresponding flow is not registered (step S703: No), the flow identification unit 103 reads the flow identification table 161 using the calculated hash value as an address, and determines whether the read entry is an unused entry. (Step S705). When the entry is an unused entry (step S705: Yes), the flow identification unit 103 sets the entry information of the packet as New. Furthermore, the flow identification unit 103 registers a hash value in the empty entry and sets the frequency information of the entry to 1 (step S706).

  On the other hand, if the entry is in use (No at Step S705), the flow identification unit 103 determines whether the frequency information is 0 and the queue counter is also 0 (Step S707).

  If the frequency information is 0 and the queue counter is also 0 (step S707: Yes), the flow identification unit 103 sets the packet entry information to New. Furthermore, the flow identification unit 103 registers a hash value in the empty entry and sets the frequency information of the entry to 1 (step S706).

  On the other hand, when the frequency information is not 0 or the queue counter is not 0 (No at Step S707), the flow identifying unit 103 sets the packet entry information as Notfound (Step S708).

  In parallel with these, the flow identification unit 103 scans the flow identification table 161 and decrements the frequency information of each entry by 1 as 0 and the minimum value.

  Here, in this embodiment, the flow identification unit 103 has been described as managing the flow identification table 161 each time there is no empty entry when receiving a packet. The timing is not limited to this. For example, the flow identification unit 103 may repeat the management of the flow identification table 161 at a constant cycle as in the first embodiment. Conversely, in the first embodiment, the flow identification table 161 may be managed at the timing described in the present embodiment.

  As described above, the switch according to this embodiment determines whether or not the flow to which the packet belongs is registered using the hash value. As described above, even when the flow is searched using the hash table without using the CAM, the switch can switch the queue by the control at the flow level, and the communication performance can be improved. . In this case, the flow identification table can be held by a normal large-capacity memory, the circuit scale can be reduced, and the power consumption can be suppressed as compared with the CAM.

  Next, Example 3 will be described. The switch according to the present embodiment is different from the first embodiment in that a queue information management table having a different entry for each transmission port is used for each flow. The switch according to this embodiment is also represented by the block diagram of FIG. In the following description, the description of the operation of each part similar to that of the first embodiment is omitted.

  FIG. 16 is a diagram illustrating an example of the queue information management table according to the third embodiment. In the queue information management table 163 according to the present embodiment, an entry corresponding to one flow ID is registered for each transmission port 180. FIG. 16 shows a state in which entries corresponding to the transmission ports 181 to 182 are registered corresponding to each flow ID. However, in the queue information management table 163, all the transmission ports 181 to 182 are registered if the transmission port 180 to which the queue 720 in use is connected as the current queue of the packet belonging to the flow ID is registered. It does not have to be.

  The queue switching processing unit 105 uses the queue information management table 163 to manage the packet storage state for each transmission queue set 170 connected to each transmission port 180. Also in this case, if the current queue and the candidate queue are different for each transmission port 180, the queue switching processing unit 105 sets the candidate queue as the output queue if the queue counter corresponding to the flow to which the packet belongs is 0. And

  As described above, the switch according to this embodiment can perform output queue switching control for each transmission port by using a queue information management table having an entry for each transmission port for each flow. Therefore, the switch according to the present embodiment can switch the queue at a more appropriate timing than in the case of the first embodiment, and can further improve the communication performance.

  FIG. 17 is a block diagram of a switch according to the fourth embodiment. The switch 100 according to the present embodiment is different from the first embodiment in that the packet body is not sent to the queue 720 but a pointer indicating the position of the packet is sent. In the following description, the description of the operation of each part similar to that of the first embodiment is omitted. The switch 100 according to the present embodiment includes a packet buffer 191 and a control unit 192 in addition to the components of the first embodiment.

  When receiving the packet, the reception port 110 stores the received packet in the packet buffer 191 and obtains a pointer indicating the packet storage location in the packet buffer 191. Then, the reception port 110 outputs packet information to the relay processing unit 102 together with a pointer indicating the storage location of the packet.

  Each of the relay processing unit 102, the flow identification unit 103, the flow discrimination processing unit 104, and the queue switching processing unit 105 transmits a pointer indicating a packet storage location instead of the packet body.

  The queue 720, which is an output queue in the transmission queue set 170, stores packet information, a flow ID, and a pointer indicating the storage location of the packet.

  The control unit 192 receives from the transmission queue set 170 the packet information of the packet to be output and the pointer indicating the packet storage location. Then, the control unit 192 acquires the packet main body stored in the packet buffer 191 using a pointer indicating the packet storage location. Then, the control unit 192 combines the packet information and the packet body, and outputs the packet information to the transmission port 180 corresponding to the transmission queue set 170 that has output the packet.

  As described above, the switch according to the present embodiment flows the pointer indicating the position of the packet without flowing the packet body into the queue, and acquires and outputs the packet body according to the pointer output from the queue. . Thus, even if the processing is performed in a state where the packet is stored in another place, the same effect as in the first embodiment can be obtained.

(Hardware configuration)
Here, the switch 100 described in each of the above embodiments can be realized by, for example, an LSI (Large Scale Integration). For example, the data holding unit 160 and the transmission queue set 170 illustrated in FIGS. 2 and 17 and the packet buffer 191 illustrated in FIG. 17 are realized by a storage device using an LSI. Further, the storage device using the LSI includes the relay processing unit 102, the flow identification unit 103, the flow discrimination processing unit 104, the queue switching processing unit 105 exemplified in FIGS. 2 and 17, and the control unit exemplified in FIG. Various programs including programs for realizing the functions of 192 are stored.

  The control circuit using the LSI reads out and executes various programs from the storage device, so that the relay processing unit 102, the flow identification unit 103, the flow discrimination processing unit 104, the queue switching processing unit 105, and the control unit 192 Realize the function. In particular, the LSI switch 100 often has the mode shown in the fourth embodiment.

  As technologies for realizing storage traffic by Ethernet (registered trademark), technologies such as NVMeoF (Non Volatile Memory express (registered trademark) over Fabric) and RoCE (RDMA (Remote Direct Memory Access) over Converged Ethernet) have been proposed. In RoCE, a congestion control algorithm called DCQCN (Data Center Quantized Congestion Notification) is often used. On the other hand, since there is a possibility that a phenomenon in which communication performance deteriorates due to a microburst in which communication concentrates in a short time, a response to such a phenomenon is also required.

  In the past, a technique called tail drop has been used as a congestion control technique in networks, where packets are discarded when the queue is full, and the transmission rate is lowered when the discard of the packet is detected. It was. Thereafter, a congestion control technique in a network called ECN (Explicit Congestion Notification) has been used. ECN is realized by the following operation. The switch sets a queue threshold in advance, and marks the packet according to the queue length. The receiving side device detects congestion by detecting a mark attached to the packet, and notifies the transmitting side device of the occurrence of the congestion. The transmission-side apparatus performs control to lower the transmission rate upon receiving notification of occurrence of congestion.

  Thereafter, a technique called MA (Microburst Aware) -ECN has been proposed as a congestion control technique for suppressing microburst. In MA-ECN, packets are transmitted to a queue with a small ECN threshold at the initial point of the flow, and the throughput upon entry when a microburst occurs is suppressed, thereby reducing the influence on other flows. In TCP (Transmission Control Protocol) communication, MA-ECN suppresses a decrease in communication throughput even when a microburst occurs.

  However, in RoCE, even if MA-ECN is used, a decrease in communication throughput may occur. There are the following reasons for this. In DCQCN of the congestion control method used in RoCE, control is performed so that packets are transmitted at a high rate from the initial stage of the flow and the queue length is close to the threshold value. This is because a relatively high communication rate is required and a flow control technique called PFC is used to prevent packet loss. In this case, when a microburst occurs at the start of the flow, the output from the short queue is not suppressed, and as a result, many marks for ECN are added to the output packet from the long queue, and the long queue is used. There is a risk that the transfer rate of the flow will decrease. Therefore, it is required that the transfer rate is not lowered even when a microburst occurs in the configuration using DCQCN.

  FIG. 18 is a block diagram of a switch that performs congestion control. The switch 100 according to the embodiment performs bandwidth control of the short queue, performs congestion control, determines the congestion state of the long queue based on the queue length of the long queue, and selects the short queue as a candidate if the congestion state is not present Even in the case of a packet, it is different from the first embodiment in that the packet is routed to a long queue. In the following description, the description of the functions of the same parts as those in the first embodiment will be omitted.

  Here, in the present embodiment, the relay processing unit 102 is disposed between the flow determination processing unit 104 and the queue switching processing unit 105 as shown in FIG. Thereby, although the determination process of the transmission port 180 that outputs the packet moves after the first embodiment, there is almost no change other than the change of the position of the process. That is, the relay processing unit 102 may be disposed in front of the flow identification unit 103 as in the first embodiment.

  Data exchanged between the units is shown in FIG. FIG. 19 is a diagram summarizing information delivered at each point of the switch in the fifth embodiment. That is, an information set 211 including packet information is transmitted as information transmitted from the reception port 110 to the flow identification unit 103. Further, as information transmitted from the flow identification unit 103 to the flow discrimination processing unit 104, an information set 212 including packet information, a flow ID, and entry information is transmitted. Further, as information transmitted from the flow discrimination processing unit 104 to the relay processing unit 102, an information set 213 including packet information, flow ID, entry information, and candidate queue ID is transmitted. Also, as information transmitted from the relay processing unit 102 to the queue switching processing unit 105, an information set 214 including packet information, flow ID, entry information, candidate queue ID, and transmission port ID is transmitted. Further, as information transmitted from the queue switching processing unit 105 to the transmission queue set 170, an information set 215 including packet information, a flow ID, and a queue ID is transmitted.

  In the queue information management table 163 according to the present embodiment, congestion information is registered in addition to the FID, QID, and queue counter as shown in FIG. FIG. 20 is a diagram illustrating an example of the queue information management table in the fifth embodiment. The congestion information is information indicating whether congestion has occurred in the queue 720 having the corresponding QID. Here, in this embodiment, all ports are managed by one entry, but it is also possible to register an entry for each port in the queue information management table 163.

  The queue switching processing unit 105 receives, from the relay processing unit 102, an information set 214 including packet information, flow ID, entry information, candidate queue ID, and transmission port ID together with the packet body. Then, the queue switching processing unit 105 confirms the entry information.

  When the entry information is found, the queue switching processing unit 105 checks the candidate queue ID and determines whether the candidate queue is a short queue. If the candidate queue is a long queue, the queue switching processing unit 105 maintains the candidate queue.

  On the other hand, when the candidate queue is a short queue, the queue switching processing unit 105 checks the congestion information of each long queue in the queue information management table 163 and determines whether or not congestion occurs in each long queue. To do. If congestion does not occur, the queue switching processing unit 105 sets the candidate queue as a long queue. On the other hand, when congestion has occurred, the queue switching processing unit 105 maintains the candidate queue as a short queue.

  That is, even if the candidate queue is a short queue, the queue switching processing unit 105 outputs a packet to the long queue because the transfer rate of the long queue is still sufficient if there is no congestion in the long queue. On the other hand, when congestion occurs, the queue switching processing unit 105 distributes packets to the short queue in order to maintain the long queue transfer rate.

  Thereafter, the queue switching processing unit 105 determines whether or not queue switching occurs. When queue switching does not occur, the queue switching processing unit 105 sets the output queue as a candidate queue. In this case, the output queue is maintained as the current queue.

  On the other hand, when queue switching occurs, if the value of the queue counter corresponding to the acquired flow ID in the queue information management table 163 is 0, the queue switching processing unit 105 sets the output queue of the flow from the current queue. Change to a candidate queue.

  On the other hand, when the value of the queue counter is not 0, the queue switching processing unit 105 maintains the output queue of the flow as the current queue that has not been set as the candidate queue.

  When the entry information is New, the queue switching processing unit 105 registers the newly acquired flow ID in the queue information management table 163 and creates a corresponding entry. Then, the queue switching processing unit 105 sets the output queue of the flow as a candidate queue.

  If the entry information is Notfound, the queue switching processing unit 105 sets the output queue of the flow as a candidate queue.

  Thereafter, the queue switching processing unit 105 outputs the packet, packet information, and the FID of the flow to which the packet belongs to the transmission queue set 170 having the queue determined as the output queue of the flow. Further, along with the output of the packet, the queue switching processing unit 105 outputs the queue ID of the output packet output queue to the transmission queue set 170 that is the output destination of the packet. Further, the queue switching processing unit 105 outputs the flow ID of the flow to which the output packet belongs and a command instructing addition to the queue information management table 163.

  FIG. 21 is a block diagram of a transmission queue set according to the fifth embodiment. Similar to the first embodiment, the transmission queue set 170 includes a selector 701, a multiplexer 703, a scheduler 704, and a plurality of queues 721 to 723.

  The selector 701 receives packet information, flow ID, and packet input from the queue switching processing unit 105. Further, the selector 701 receives an input of a queue ID representing the output queue of the packet from the queue switching processing unit 105. Then, the selector 701 outputs the packet information, the flow ID, and the packet to the queue 720 having the designated queue ID.

  The queue 720 specified as the output queue by the queue ID input from the queue switching processing unit 105 receives the packet information, the flow ID, and the packet input from the selector 701. The queue 720 stores the input packet information, flow ID, and packet. Thereafter, the queue 720 sequentially outputs to the multiplexer 703 packet information, flow IDs, and packets held in the order of acquisition timing. Further, the queue 720 compares its own queue length with a predetermined congestion threshold, and if the queue length is equal to or greater than the threshold, the occurrence of congestion is registered in the queue information management table 163 as congestion information. On the other hand, when the queue length is less than the threshold, the queue 720 registers that no congestion has occurred in the queue information management table 163 as the congestion information.

  The congestion control unit 109 has a congestion determination threshold that is a queue length for determining congestion in each transmission queue set 171. The congestion control unit 109 acquires the queue length of each transmission queue set 171. In FIG. 18, for convenience of illustration, the communication path between the congestion control unit 109 and the transmission queue set 171 is shown. However, actually, the congestion control unit 109 communicates with other transmission queue sets 170. Have a route. When the queue length of a certain queue 700 exceeds the congestion determination threshold, the congestion control unit 109 adds a mark indicating the occurrence of congestion to a packet output from the queue 700. When the congestion control unit 109 adds a mark, the server 200 that transmits and receives a packet via the switch 100 can control the amount of packet transmission according to the mark to eliminate the congestion.

  The scheduler 704 has a band designation value for each output band of each queue 720 in advance. This band designation location is an example of “predetermined value”. Then, for each queue 720, the scheduler 704 calculates an output bandwidth that is the amount of output data per unit time if it is not empty. The scheduler 704 determines the output of a packet from a queue 720 when the calculated output bandwidth is less than the specified bandwidth value. Thereafter, the scheduler 704 arbitrates packets output from the multiplexer 703 for the plurality of queues 720 whose output has been determined. The scheduler 704 is an example of a “bandwidth control unit”.

  The multiplexer 703 outputs the packet information and the packet to the transmission port 180 according to the designation from the scheduler 704. Further, the multiplexer 703 outputs the flow ID of the flow to which the packet belongs to the queue information management table 163 together with a command for instructing subtraction.

  Next, a flow of queue switching processing by the queue switching processing unit 105 according to the present embodiment will be described with reference to FIG. FIG. 22 is a flowchart of the queue switching process performed by the queue switching processing unit according to the fifth embodiment.

  The queue switching processing unit 105 receives input of packet information, flow ID, entry information, candidate queue ID, and transmission port ID from the relay processing unit 102. Then, the queue switching processing unit 105 determines whether or not the entry information is found (step S801).

  When the entry information is Found (step S801: Yes), the queue switching processing unit 105 determines whether the candidate queue is a short queue and there is a long queue in which congestion has not occurred. Here, the long queue in which no congestion occurs is a long queue whose queue length is less than the congestion threshold (step S802). If the candidate queue is a long queue or there is no long queue in which congestion has not occurred (No at Step S802), the queue switching processing unit 105 proceeds to Step S804.

  If the candidate queue is a short queue and there is a long queue in which congestion has not occurred (step S802: Yes), the queue switching processing unit 105 sets the long queue as a candidate queue (step S803).

  Next, the queue switching processor 105 determines whether or not queue switching occurs depending on whether or not the candidate queue and the current queue have the same queue ID (step S804).

  When queue switching occurs (step S804: Yes), the queue switching processing unit 105 determines whether or not the value of the queue counter corresponding to the acquired flow ID in the queue information management table 163 is 0 (step S805). .

  When the queue counter is 0 (step S805: Yes), the queue switching processing unit 105 switches the packet output queue to the candidate queue (step S806).

  On the other hand, when the queue switching does not occur (step S804: negative) and when the queue counter is not 0 (step S805: negative), the queue switching processing unit 105 maintains the output queue in the current queue (step S805). S807).

  On the other hand, when the entry information is not Found (No at Step S801), the queue switching processing unit 105 determines whether the entry information is New (Step S808). If the entry information is not New (step S808: No), that is, if the entry information is Notfound, the queue switching processing unit 105 proceeds to step S810.

  In contrast, if the entry information is New (step S808: Yes), the queue switching processing unit 105 initializes the created entry by creating an entry corresponding to the acquired flow ID in the queue information management table 163 ( Step S809) and the process proceeds to Step S810.

  The queue switching processing unit 105 sets the output queue as a candidate queue (step S810).

  As described above, the switch according to the present embodiment determines whether a packet for which the short queue is determined as a candidate queue from the congestion state of the long queue is routed to the long queue or the short queue. Thereafter, the switch determines a queue for outputting data so as to be suppressed to a predetermined bandwidth. As a result, the output rate of the long queue can be kept high, and abrupt congestion control due to microburst or the like can be avoided.

  Next, a switch according to embodiment 6 will be described. A block diagram of the switch according to the present embodiment is also shown in FIG. The switch 100 according to the present embodiment is different from the fifth embodiment in that it performs congestion control and performs scheduling of a queue 720 for outputting packets using DRR (Deficit Round Robin). In the following description, description of functions of the same parts as those in the fifth embodiment is omitted.

  The queue information management table 163 according to the present embodiment has, for example, the same format as that shown in FIG. That is, the queue information management table 163 according to the present embodiment may not have congestion information. Also in this case, the queue information management table 163 may have an entry for each port.

  Then, the queue switching processing unit 105 according to the present embodiment performs the same processing as in the first embodiment, and determines an output queue of packets included in each flow. That is, the queue switching processing unit 105 does not need to consider the congestion state of each queue 720 in determining the output queue.

  Furthermore, the transmission queue set 170 according to the present embodiment has, for example, the configuration shown in FIG. That is, in the transmission queue set 170 according to the present embodiment, the queue 721 does not need to determine the congestion state and register it in the queue information management table 163.

  Then, the scheduler 704 uses the DRR algorithm to select a queue 720 that outputs a packet so that the output bandwidth of each queue 720 has a predetermined ratio. This process corresponds to an example of a process of “controlling the packet transmission rate to be a predetermined ratio”. In this embodiment, the DDR algorithm is used. However, the scheduler 704 may use another algorithm as long as it maintains the output bandwidth of each queue. For example, WRR (Weighted Round Robin) or WFQ ( Weighted Fair Queuing) may be used.

  As described above, according to the bandwidth control using the DRR, the switch according to this embodiment outputs the short queue bandwidth without being limited when there is no packet in the long queue. This makes it possible to maintain the data transfer performance in both the long queue and the short queue.

  FIG. 23 is a block diagram of an information processing system according to the seventh embodiment. The information processing system 1 according to the present embodiment is different from the sixth embodiment in that the server 200 performs flow identification processing and flow determination processing, and the switch 100 performs queue switching processing. Each part having the same reference numeral as in the first embodiment has the same function unless otherwise specified.

  The server 200 includes a communication unit 221, a flow determination unit 222, a flow determination table 223, and a reception buffer 224.

  The communication unit 221 establishes a connection with the communication partner. Then, the communication unit 221 transmits and receives data and processes the flow. At the time of data transmission, the communication unit 221 outputs the data to the flow determination unit 222.

  Further, the communication unit 221 is connected to the transmission port 181 of the switch 100 although not shown. Then, the communication unit 221 receives the packet output from the transmission port 181. When the received packet includes an ACK (Acknowledgement), the communication unit 221 executes a protocol process for the ACK. Then, the communication unit 221 notifies the flow determination unit 222 that ACK has been received. If the received packet includes data, the communication unit 221 stores the data in the reception buffer 224. After the data transmission / reception is completed, the communication unit 221 disconnects the connection.

  The flow determination table 223 has information indicating the correspondence between priority and flow type as shown in FIG. 24, for example. The priority is a value registered in a priority field existing in a VLAN (Virtual Local Area Network) tag of the packet header. FIG. 24 is a diagram illustrating an example of a flow determination table. In this embodiment, the priority has values of 0 to 7. The flow type corresponding to the priority with a value of 3 is a flow type of “long” representing a flow with a large transfer amount. The flow type corresponding to the priority with a value of 4 is a flow type of “short” representing a flow with a small transfer amount. The other flow types corresponding to the priorities of values 0 to 2 and 5 to 7 represent “other” flow types.

  When the establishment of the connection with the communication partner by the communication unit 221 is completed, the flow determination unit 222 initializes the information on the transmission amount of the flow held by itself to zero. Next, the flow determination unit 222 acquires a packet to be transmitted from the communication unit 221. Next, the flow determination unit 222 determines whether the flow transmission amount is equal to or greater than a predetermined determination threshold. If the transmission amount is less than the determination threshold, the flow determination unit 222 acquires “3” that is a value representing the priority corresponding to the short flow from the flow determination table 223. Then, the flow determination unit 222 registers “3” in the priority field of the VLAN tag in the packet header.

  On the other hand, when the transmission amount is equal to or greater than the determination threshold, the flow determination unit 222 determines whether the queue used at the previous transmission of the packet belonging to the flow is a short queue. When the long queue is used at the previous transmission, the flow determination unit 222 acquires “4”, which is a value representing the priority corresponding to the long flow, from the flow determination table 223. Then, the flow determination unit 222 registers “4” in the priority field of the VLAN tag in the packet header.

  In contrast, when the short queue is used at the previous transmission, the flow determination unit 222 determines whether or not the communication unit 221 has received an ACK reception notification for the previous packet transmission. If the notification of ACK reception for the previous packet transmission is not received from the communication unit 221, the packet may be accumulated in the queue 720. The transmission process ends.

  On the other hand, when a notification of ACK reception for the previous packet transmission is received from the communication unit 221, the flow determination unit 222 determines that there is no possibility that the packet is accumulated in the queue 720. Next, the flow determination unit 222 acquires “4” that is a value representing the priority corresponding to the long flow from the flow determination table 223. Then, the flow determination unit 222 registers “4” in the priority field of the VLAN tag in the packet header.

  Then, the flow determination unit 222 transmits a packet having a value set in the priority field to the switch 100. Furthermore, the flow determination unit 222 adds the packet length to the flow transmission amount. Thereafter, the flow determination unit 222 proceeds to a process for transmitting the next packet belonging to the flow. The flow determination unit 222 corresponds to an example of “a transmission control unit in the first communication device”.

  The switch 100 includes a reception port 110, a relay processing unit 102, a queue switching processing unit 105, a congestion control unit 109, a transmission queue set 170, a transmission port 180, and a relay table 121. In the relay table 121, information of the transmission port 180 corresponding to the address is registered. The information of the transmission port 180 includes the queue ID of the queue 700 that outputs a packet to the transmission port 180, the identification information of the transmission port 180, and the like.

  The reception port 110 receives a packet whose value is set in the priority field from the server 220. Then, the reception port 110 outputs the received packet to the flow discrimination processing unit 104.

  The flow discrimination processing unit 104 receives a packet input from the reception port 110. Then, the flow discrimination processing unit 104 acquires the value set in the priority field of the packet header. When the value set in the priority field is 3, the flow discrimination processing unit 104 sets the packet output queue as a long queue. When the value set in the priority field is 4, the flow determination processing unit 104 sets the packet output queue as a short queue. Then, the queue switching processing unit 105 outputs the packet together with the output queue designation information to the relay processing unit 102.

  The relay processing unit 102 receives a packet input from the flow discrimination processing unit 104 together with output queue designation information. Then, the relay processing unit 102 acquires a destination address from the packet header. Next, the relay processing unit 102 acquires information on the transmission port 180 corresponding to the acquired address from the relay table 121. Thereafter, the relay processing unit 102 outputs the packet to the queue switching processing unit 105 together with the information of the transmission port 180 that transmits the packet and the designation information of the output queue.

  The queue switching processing unit 105 receives the packet input from the relay processing unit 102 together with the transmission port 180 information and the output queue designation information. Then, the queue switching processing unit 105 stores the packet in the queue 720 corresponding to the output queue designation information among the queues 720 in the transmission queue set 170 designated by the information of the transmission port 180.

  Using the DRR algorithm, the scheduler 704 selects a queue 720 that outputs a packet so that the output bandwidth of each queue 720 has a predetermined ratio. In this embodiment, the DDR algorithm is used. However, the scheduler 704 may use another algorithm as long as it maintains the output bandwidth of each queue. For example, WRR or WFQ may be used. . The multiplexer 703 acquires a packet from the queue 720 selected by the scheduler 704 and outputs the packet to the transmission port 180.

  Next, a flow of flow management processing by the server 200 according to the present embodiment will be described with reference to FIGS. FIG. 25 is a flowchart of overall processing of flow management by a server according to the seventh embodiment. FIG. 26 is a flowchart of the transmission process performed by the server according to the seventh embodiment. FIG. 27 is a flowchart of the reception process performed by the server according to the seventh embodiment.

  With reference to FIG. 25, the overall flow of the flow management processing by the server 200 according to the present embodiment will be described.

  The communication unit 221 establishes a connection with the communication partner (step S901).

  The flow discriminating unit 222 initializes the information of the flow transmission amount to 0 (step S902).

  Next, the flow determination unit 222 executes transmission processing for transmitting a packet to the communication partner (step S903).

  Thereafter, the communication unit 221 executes reception processing for receiving a packet from the communication partner (step S904).

  The communication unit 221 determines whether or not to disconnect the communication partner (step S905). When the connection is not disconnected (No at Step S905), the flow management process returns to Step S903.

  On the other hand, when the connection is disconnected (step S905: Yes), the communication unit 221 disconnects the connection with the communication partner and ends the communication (step S906). Thereby, the flow management process is also terminated.

  Next, a flow of packet transmission processing in the server 200 will be described with reference to FIG. Each process included in the flow described in FIG. 26 corresponds to an example of a process executed in step S903 in FIG.

  The flow determination unit 222 determines whether there is a transmission packet based on whether a packet is input from the communication unit 221 (step S911). If there is no packet to be transmitted (No at Step S911), the flow determination unit 222 ends the packet transmission process.

  On the other hand, when there is a packet to be transmitted (step S911: affirmative), the flow determination unit 222 determines whether or not the transmission amount is equal to or greater than a determination threshold (step S912). When the transmission amount is less than the determination threshold (No at Step S912), the flow determination unit 222 adds short information to the packet as information indicating the flow type (Step S913).

  On the other hand, when the transmission amount is equal to or greater than the determination threshold (step S912: affirmative), the flow determination unit 222 determines whether the queue used at the previous transmission of the packet belonging to the flow is a short queue (step S912). S914). When the long queue is used at the previous transmission (step S914: No), the flow determination unit 222 proceeds to step S916.

  On the other hand, when the short queue is used at the previous transmission (step S914: Yes), the flow determination unit 222 determines whether an ACK for the previous packet transmission is received (step S915). When the ACK for the previous packet transmission has not been received (No at Step S915), the flow determination unit 222 ends the packet transmission process.

  On the other hand, when a notification of ACK reception for the previous packet transmission is received from the communication unit 221 (step S915: affirmative), long information is added to the packet as information indicating the flow type (step S916).

  Next, the flow determination unit 222 transmits a packet in which a value is set in the priority field to the switch 100 (step S917).

  Next, the flow determination unit 222 adds the packet length to the flow transmission amount (step S918). Thereafter, the flow determination unit 222 returns to step S911.

  Next, referring to FIG. 27, the flow of packet reception processing in the server 200 will be described. Each process in the flow described in FIG. 27 corresponds to an example of a process executed in step S904 in FIG.

  The communication unit 221 determines whether there is a received packet (step S921). When there is no received packet (No at Step S921), the communication unit 221 ends the packet reception process.

  On the other hand, when there is a received packet (step S921: Yes), the communication unit 221 receives the packet (step S922).

  Next, if the received packet is a packet including ACK, the communication unit 221 performs protocol processing including ACK (step S923). Then, the communication unit 221 notifies the flow determination unit 222 that ACK has been received.

  Next, when the received packet includes data, the communication unit 221 acquires the data from the packet and stores it in the reception buffer 224 (step S924). Thereafter, the communication unit 221 returns to Step S921.

  As described above, the information processing system according to the present exemplary embodiment executes flow scheduling management and packet overtaking prevention processing on the server side, and queue scheduling that suppresses congestion on the switch side. As described above, even if the flow management process and the congestion control process are separated by the server and the switch, the data transfer performance can be maintained in both the long queue and the short queue. In the case of the configuration according to the present embodiment, since the switch performs normal congestion control, it is not necessary to prepare a special switch. Therefore, the information processing system according to the present embodiment can be easily introduced.

  FIG. 28 is a diagram for explaining the effect when the switch of the fifth embodiment is used. A graph 91 represents a change in throughput when a microburst occurs when the switch 100 of the fifth embodiment is not used. A graph 95 represents a change in throughput when a microburst occurs when the switch 100 according to the fifth embodiment is used. In both graphs 91 and 95, the vertical axis represents throughput and the horizontal axis represents time.

  A line segment 92 in the graph 91 represents the throughput in the long queue. A line segment 93 represents the throughput in the short queue. A line segment 94 represents the combined throughput of the long queue and the short queue.

  As indicated by a line segment 93, the throughput sometimes rapidly increases in the short queue due to the occurrence of the microburst. Then, as indicated by a line segment 92, the throughput of the long queue drops when a microburst occurs, affected by the rapid increase in throughput of the short queue. As a result, the overall throughput also decreases when a microburst occurs, as indicated by line segment 94.

  On the other hand, a line segment 96 in the graph 95 represents the throughput in the long queue. A line segment 97 represents the throughput in the short queue. A line segment 98 represents the combined throughput of the long queue and the short queue.

  As indicated by the line segment 97, as in the graph 91, the throughput sometimes increases rapidly in the short queue due to the occurrence of the microburst. However, even if a rapid increase in throughput occurs in the short queue, as shown by the line 96, the throughput of the long queue is almost unaffected and the speed is maintained. In this case, the overall throughput can be maintained even if a microburst occurs as indicated by the line segment 98. Here, the switch 100 of the fifth embodiment is taken as an example, but the switch 100 of the sixth and seventh embodiments can obtain substantially the same effect. Therefore, it can be seen that by using the switch 100 described in the fifth to seventh embodiments, a large performance degradation when a microburst occurs can be avoided even if congestion control is performed by DCQCN.

  The function of the switch 100 described in the fifth to seventh embodiments can also be realized by an LSI, for example. For example, the storage device using the LSI includes various programs including programs for realizing the functions of the relay processing unit 102, the flow identification unit 103, the flow discrimination processing unit 104, and the queue switching processing unit 105 illustrated in FIGS. Is stored. The control circuit using the LSI reads out and executes various programs from the storage device, thereby realizing the functions of the relay processing unit 102, the flow identification unit 103, the flow discrimination processing unit 104, and the queue switching processing unit 105.

  The server 200 described in the seventh embodiment includes a CPU (Central Processing Unit) and a memory. In the memory, for example, various programs including programs that realize the functions of the communication unit 221 and the flow determination unit 222 illustrated in FIG. 23 are stored. Further, the memory implements the function of the reception buffer 224. The memory also stores a flow discrimination table 223. The CPU implements the functions of the communication unit 221 and the flow determination unit 222 by reading out various programs from the memory, developing them, and executing them.

  The following supplementary notes are further disclosed with respect to the embodiments including the above examples.

(Supplementary Note 1) A feature amount acquisition unit that acquires a feature amount related to the flow;
An information processing apparatus comprising: a transmission control unit that controls transmission of the packet of the flow based on the feature amount acquired by the feature amount acquisition unit.

(Supplementary note 2) Further comprising a plurality of queues for storing the packets and sequentially outputting the stored packets,
The transmission control unit determines a queue for transmitting the packet of the flow based on the feature amount acquired by the feature amount acquisition unit, and transmits the packet of the flow to the determined queue. The information processing apparatus according to appendix 1.

(Supplementary note 3) In the supplementary note 2, the transmission control unit transmits the packet of the flow to the determined queue when the packet of the flow is not accumulated in any of the queues. The information processing apparatus described.

(Supplementary Note 4) The transmission control unit previously has a threshold value related to the feature value, and determines the first queue as a queue for transmitting the packet of the flow when the feature value of the flow is equal to or greater than the threshold value. The information processing apparatus according to appendix 2 or 3, wherein when the feature amount of the flow is less than the threshold, the second queue is determined as a queue for transmitting the packet of the flow.

(Additional remark 5) The said feature-value acquisition part acquires the transfer amount of the said packet as said feature-value,
The transmission control unit has a transfer amount threshold in advance, and when the transfer amount is equal to or greater than the transfer amount threshold, determines the first queue as a transmission queue for transmitting the packet of the flow, and the transfer amount is the transfer amount The information processing apparatus according to any one of appendices 2 to 4, wherein the second queue is determined as a queue for transmitting the packet of the flow when the amount is less than a threshold value.

(Supplementary Note 6) A bandwidth control unit that controls the transmission rate of the packet to be a predetermined value or less;
A congestion control unit that suppresses congestion of the packet;
The information processing according to any one of appendices 1 to 5, wherein the transmission control unit) determines a queue for transmitting the packet based on a retention amount of the packet in addition to the feature amount. apparatus.

(Supplementary Note 7) A bandwidth control unit that controls the transmission rate of the packet to be a predetermined ratio;
The information processing apparatus according to any one of appendices 1 to 5, further comprising: a congestion control unit that suppresses congestion of the packet.

(Supplementary note 8) An information processing system for communicating with a first communication device and a second communication device via a packet processing unit,
The first communication device transmits a packet destined for the second communication device via the packet processing unit,
The second communication device receives a packet originating from the first communication device via the packet processing unit,
The packet processing unit
A flow identification unit for identifying a flow of transmission processing of a plurality of packets addressed to the second communication device transmitted from the first communication device;
A feature amount acquisition unit for acquiring a feature amount related to the flow;
An information processing system comprising: a transmission control unit that controls transmission of the packet of the flow to the second communication device based on the feature amount acquired by the feature amount acquisition unit.

(Supplementary Note 9) A switch is provided between the first communication device and the second communication device.
The information processing system according to appendix 8, wherein the switch includes the packet processing unit.

(Supplementary Note 10) A switch provided between the first communication device and the second communication device,
The first communication device includes the packet processing unit,
The switch is
A bandwidth controller for controlling the transmission rate of the packet to be a predetermined ratio;
A congestion control unit for suppressing congestion of the packet,
The information processing system according to appendix 8, wherein the second communication device receives a packet originating from the first communication device from the switch.

(Appendix 11) Identify the flow of processing to send multiple packets,
Obtaining a feature value for the flow;
An information processing program for causing a computer to execute processing for controlling transmission of the packet of the flow based on the acquired feature amount.

DESCRIPTION OF SYMBOLS 1 Information processing system 100 Switch 102 Relay processing part 103 Flow identification part 104 Flow discrimination | determination part 105 Queue switching process part 106 Data holding part 109 Congestion control part 110-112 Reception port 121 Relay table 161 Flow identification table 162 Transfer amount table 163 Queue Information management table 170 to 172 Transmission queue set 180 to 182 Transmission port 191 Packet buffer 192 Control unit 200 to 206 Server 221 Communication unit 222 Flow determination unit 223 Flow determination table 224 Reception buffer 701 Selector 703 Multiplexer 704 Scheduler 720 to 723 Queue

Claims (9)

A flow identification unit for identifying a flow of processing for transmitting a plurality of packets;
A feature amount acquisition unit for acquiring a feature amount related to the flow;
An information processing apparatus comprising: a transmission control unit that controls transmission of the packet of the flow based on the feature amount acquired by the feature amount acquisition unit. A plurality of queues for storing the packets and sequentially outputting the stored packets;
The transmission control unit determines a queue for transmitting the packet of the flow based on the feature amount acquired by the feature amount acquisition unit, and transmits the packet of the flow to the determined queue. The information processing apparatus according to claim 1.   The information according to claim 2, wherein the transmission control unit transmits the packet of the flow to the determined queue when the packet of the flow is not accumulated in any of the queues. Processing equipment.   The transmission control unit has a threshold related to the feature amount in advance, and determines the first queue as a queue for transmitting the packet of the flow when the feature amount of the flow is equal to or greater than the threshold, and the flow of the flow The information processing apparatus according to claim 2 or 3, wherein when the feature amount is less than the threshold value, the second queue is determined as a queue for transmitting the packet of the flow. The feature amount acquisition unit acquires a transfer amount of the packet as the feature amount,
The transmission control unit has a transfer amount threshold in advance, and when the transfer amount is equal to or greater than the transfer amount threshold, determines the first queue as a transmission queue for transmitting the packet of the flow, and the transfer amount is the transfer amount 5. The information processing apparatus according to claim 2, wherein the second queue is determined as a queue that transmits the packet of the flow when the amount is less than a threshold value. A bandwidth control unit for controlling the transmission rate of the packet to be a predetermined value or less;
A congestion control unit that suppresses congestion of the packet;
The information processing according to claim 1, wherein the transmission control unit determines a queue for transmitting the packet based on a retention amount of the packet in addition to the feature amount. apparatus. A bandwidth controller for controlling the transmission rate of the packet to be a predetermined ratio;
The information processing apparatus according to claim 1, further comprising: a congestion control unit that suppresses congestion of the packet. An information processing system that communicates with a first communication device and a second communication device via a packet processing unit,
The first communication device transmits a packet destined for the second communication device via the packet processing unit,
The second communication device receives a packet originating from the first communication device via the packet processing unit,
The packet processing unit
A flow identification unit for identifying a flow of transmission processing of a plurality of packets addressed to the second communication device transmitted from the first communication device;
A feature amount acquisition unit for acquiring a feature amount related to the flow;
An information processing system comprising: a transmission control unit that controls transmission of the packet of the flow to the second communication device based on the feature amount acquired by the feature amount acquisition unit. Identify the flow of processing to send multiple packets,
Obtaining a feature value for the flow;
An information processing program for causing a computer to execute processing for controlling transmission of the packet of the flow based on the acquired feature amount.

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