KR100618960B1 - Method and apparatus for symmetrical load balancing through load exchange between adjacent nodes - Google Patents

Abstract

The present invention relates to a method and apparatus for symmetrical load balancing through load exchange between adjacent nodes. When the load level is greater than a threshold value, the network is reconfigured so that nodes having small transmission delay times are adjacent to each other in the network. According to the load level of the neighboring node, it sends its load to the node whose load level is lower than the threshold. If its load level is lower than the threshold, the load is received from the node whose load level is higher than the threshold. You can balance the load symmetrically by exchanging, which can greatly improve the performance of the calculation.

Description

Method and apparatus for symmetric load balancing with load exchanging between adjacent nodes

1 illustrates the operation of a conventional PSI technique.

2 is a flowchart of operation according to the present invention.

3A is a flow diagram of a sender operation in accordance with the present invention.

3B is a flowchart of a receiver operation according to the present invention.

4 is a detailed operation flowchart of a node according to the present invention.

5 is a detailed flowchart of a sender step according to the present invention.

6 is a detailed flowchart of the receiver step according to the present invention.

7 shows an embodiment of a load balancing device according to the present invention.

The present invention relates to a method and apparatus for distributing loads of nodes in a network, and more particularly, to a method and apparatus for symmetrically distributing loads through load exchange between adjacent nodes in a distributed processing environment in which loads are processed between adjacent nodes. It is about.

The conventional PSI (Periodic Symmetrically-Initiated) Load Balancing Algorithm proposed by Leeds University in the UK for load distribution is based on IEEE Proc. of 14th International Conference on Distributed Computing Systems, pp.616-623 (August 199). And US patent application US5630129 "Dynamic load balancing of applications" by Stephen R. Wheat on a dynamic load balancing technique.

In the PSI algorithm, the load balancing algorithm does not start when work is sent to the node or when work is done at the node. This method solves the problem of message saturation at high loads, which is a problem of symmetric algorithms. In a PSI-based system, a polling message is sent to a randomly selected node at a period of Pt. At this time, the number of polling is set to Lp.

The operation of the PSI algorithm according to the paper is briefly described as follows.

1 illustrates the operation of the PSI algorithm.

The amount of work imposed on each node is called the load level, and the amount of load the node can handle is called the threshold. The threshold is an integer value set by the network administrator.

The load level of node 1 110 is 5, the load level of node 2 120 is 6, the load level of node 3 130 is 1, and the load level of node 4 140 is 3. Assume the threshold value is four.

The timer 100 randomly selects a node every Pt = 0.2 seconds at regular intervals. This will place a load on the selected node. Assume that node 1 110 is selected 151 by this timer 100. Node 1 110 has a load level of 5, which is greater than threshold 4. Therefore, Node 1 110 is operated by the sender algorithm to reselect any node. It is assumed that node 2 120 has been selected 152 at this time. The load level of the node 2 (120) is 6, and the node 2 (120) rejects the load multiplication (153) than the threshold value 4, so that the load is not multiplied. Since load balancing failed, we poll again to select an arbitrary node. This time node 4 140 is selected 154. Since the load level of node 4 140 is 3, which is less than the threshold, the load balancing is accepted 155 and node 4 140 is operated by the receiver algorithm. This transfers one work (156) from node 1 (110) to node 4 (140) to balance the load.

The patent, filed by Stephen R. Wheat, proposes a dynamic load balancing technique at the application level of a parallel instruction stream-multiple data stream (MIMD) parallel computer. The centralized load balancing technique is achieved by overlapping the work area of the entire processor when the processors of each node perform local load balancing. This method is known to be scalable.

However, the PSI algorithm assumes that the overhead of load balancing is too high and the delay time in the network is constant at all nodes. It is also assumed that the execution time of work at each node is constant. In practice, network latency is not constant at every node, and the execution time at each node is different for each node. In addition, the threshold T and the period Pt become important variables in this algorithm, which requires a lot of experimentation to determine these variables.

The patent filed by Stephen R. Wheat also has the concept of a centralized load balancing technique. However, because this method is designed based on a parallel processing computer, each processor has the same performance and the same network latency. Therefore, this method is not suitable to be used in distributed processing environments where there is a performance difference between the processors of each node and network latency is different.

The technical problem to be achieved by the present invention is to provide a method and apparatus for load balancing between nodes that can be applied in a distributed processing environment without being affected by the threshold value and the selection period of the node to solve the above problems.

According to the present invention for solving the technical problem, a method for distributing the load of the nodes connected to the data transmission path of the network, Reconfiguring each node of the network into a ring structure; And adjusting the load of each node so that the load of each node is equal according to the load level which is the amount of work that each node should do and the load level of the neighboring node, wherein the reconfiguring into the ring structure includes: Obtaining a data transmission delay time between each node using time of transmitting and receiving a message between each node of the node; And rearranging each node of the network such that the delay time between adjacent nodes is minimized.

In accordance with an aspect of the present invention, an apparatus for distributing loads of nodes connected to a data transmission path of a network includes: a node reconfiguring unit configured to reconfigure each node into a ring structure; And a load adjuster configured to adjust the load of each node to be equal according to the load level of each node reconfigured into the ring structure and the load level of the adjacent node. A delay time calculating section for transmitting a confirmation signal and calculating a data transmission delay time between the nodes using a time for which another node retransmits the signal; And a node arrangement unit for arranging each of the nodes and outputting deployment completion information such that the calculated transmission delay time between adjacent nodes is minimized.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A network consists of nodes that perform work and nodes that are connected to the data path between each node. Each node is connected with a server, various terminals, a network access card, a user access device, and the like, and software such as an operating system for operating a communication network, an operating system for a terminal, and a network application program is operated. Each node can either process the work charged to it or send data through another node. And if the amount of work done on one's own node is excessive, then overload this load with other nodes to distribute the load to facilitate network operation.

2 is an operational flowchart of an embodiment according to the present invention.

The schematic operation is as follows.

Reconstructing each node of the network of the present invention into a ring structure includes setting a threshold T of the network (step 200) and obtaining a transmission delay time at each node of the network (step 210). It is preferable to include the step of reconfiguring (step 220) according to the network.

And the step of equally adjusting the load of the node of the present invention, each node receives a job message including the content of the job to be executed by each node to measure the load level (step 230) and according to the measured load level (240) Step) If the load level is greater than the threshold, the sender step is executed (250). If the load level is less than the threshold, the receiver step is performed (step 260), then the node operation step is performed (step 270). And repeating from step 230 again.

The above processes will be described in detail as follows.

When the network system is first started, several variables are set up for network operation. At this time, a threshold value which is an amount of load that can be processed by each node is set (step 200). This threshold is an integer value that can be different for each node depending on the performance and nature of the load. The threshold may be set at any time before each node measures its own load value.

The transmission delay time, which is the time it takes to transmit or receive a message between nodes, depends on the nature of each node, its performance, and how the network is configured. In one method of obtaining a transmission delay time, each node transmits a delay time acknowledgment message including a transmission time to another node, and the node receiving the acknowledgment message confirms the time at which the acknowledgment message was received, and the transmission time. The transmission delay time is obtained by using and the reception time.

In another method of obtaining a transmission delay time, each node transmits a delay time acknowledgment message including a transmission time to another node, and the node receiving the acknowledgment message sends a response message indicating the message reception time. Resend the acknowledgment message to the node that sent the acknowledgment message, and each node retransmitting the response message confirms the time at which the response message was received, and calculates a transmission delay time using the transmission time, the reception time, and the response message reception time. . Using this method, compared to the first method, the traffic to the data transmission path of the network is higher due to the transmission and retransmission of acknowledgment, but it has the advantage of determining whether the other node is in a normal state (step 210).

Based on the transmission delay time, each node of the network is reconfigured into a ring structure such that transmission delay time between adjacent nodes is minimized (step 220). The network is reconfigured into a virtual structure for applying the present invention.

The network may be formed in various forms such as a bus, a tree, a ring, a mesh, or a combination of these structures. In any case, the transmission delay time between nodes can be obtained by measuring the time of sending a message from one node to another node and receiving the message again (step 210). Using the transmission delay time, each node is reconfigured so that two nodes having the smallest transmission delay time obtained from one node are located adjacent to the node (step 220).

In particular, a network having a bus-type structure is a virtual data transmission path between nodes located at both ends of the bus, and it is preferable to reconfigure a ring structure in which nodes at both ends are disposed adjacent to each other.

Each node receives a job message containing the content of a job to be executed by each node, and measures the load level, which is the amount of the current load of the own node (step 230). This work message is a message about load distribution delivered from another node, or includes a message requesting work on the network at a terminal attached to each node.

In this embodiment, the load level is expressed as an integer value. Although the load level values of each load may be different from each other according to the type of load that the node should do, in this embodiment, it is assumed that one load level corresponds to one load. When the network is first started up, the value of the load level will be "0". It is also assumed that if the load is increased by one node, the load level is increased by one and the load level is given by one node. Each node bases its load level on node operation.

In this embodiment, a method of polling adjacent nodes is used to measure load levels of adjacent nodes.

Measuring the load level 230 and the resulting node operation will be described in detail below.

3A is a flowchart of a transmitter operation according to the present invention, and FIG. 3B is a flowchart of a receiver operation according to the present invention.

In contrast to the conventional PSI algorithm, it is assumed that the network consists of four nodes. Each node has a threshold of four. In this case, one node polls the other node to measure the load level of another node. The number of polls is two times. Each node is connected by a data transmission path in a ring structure.

The load level of node 1 300 is 5, the load level of node 2 310 is 6, the load level of node 3 320 is 1 and the load level of node 4 330 is 3.

In FIG. 3A, the load level of node 1 300 is five. Because your load level is greater than the threshold, you need to find nodes whose load level is below the threshold by polling. In other words, the sender operates. At this time, the clockwise node is first polled based on itself (341). (The node in the counterclockwise direction may be polled first.) A sender message is sent to the node 2 310 (341). You are asking if you can send your node's work. Since the load level of the node 2 310 is 6 and greater than the threshold value, the node 1 310 sends a REJECT message to the node 1 300 (342). Node 1 (300) receiving the reject message sends a sender message by polling node 4 (330), which is an adjacent node in the counterclockwise direction. Since the load level of node 4 330 is 3 less than the threshold value, an acknowledgment (ACCEPT) message is sent to node 1 300 (344). (345).

If you set the number of polls to two times above, and the number of polls is 3, if the load distribution is not done after polling clockwise and counterclockwise nodes, it will poll the second neighbor to the third node clockwise. . In this case, the node 3 is polled.

In FIG. 3B, the load level of node 3 320 is one. Because your load level is less than the threshold, you need to find the node whose load level is above the threshold by polling. That is, the receiver operation. First, the neighboring node in the clockwise direction is first polled (351). (Also, the node in the counterclockwise direction may be polled first.) A receiver message is transmitted to the node 4 (330) (351). It means to send work to your node. Since the load level of node 4 330 is 3 less than the threshold, node 4 330 sends a reject message to node 3 320 (352). Node 3 (320) receiving the rejection message sends a recipient message, which is a polling message, to node 2 (310), which is a counterclockwise neighbor (353). Since the load level of node 2 310 is 6, which is greater than the threshold value, work is sent to node 3 320 (354).

In addition, if the number of polling is determined as 2 times, and the number of polling is set to 3, if the load distribution is not performed after polling clockwise and counterclockwise nodes, the clockwise third is applied to the second adjacent node. Will poll.

The method used to implement the invention in the sender mode and the receiver mode is described in detail later.

Receiving a work message containing the content of the work to be executed by each node to measure the load level (step 230), if the content of the work message is an operation mode that the node receiving the work message to perform a predetermined node work Increasing the load level by a predetermined size according to the node's work; and if the content of the work message is a sender mode to send a load from the node that sent the work message to the node that received the message, the load level of the work message. Calculating, if the load level is less than the threshold, sending an accept message to the node that sent the message; if not less than the threshold, sending a reject message to the node that sent the message and the working message The received content of the work message is transmitted from the node that received the work message. In receiver mode to send a load to one node, calculate its load level, if this load level is greater than the threshold, reduce its load level by a certain amount and send the load to the node that sent the message, If it is not greater than the threshold, it is preferable to further include the step of transmitting a reject message to the node that sent the message.

4 is a detailed operation flowchart of a node according to the present invention. The process included in the step of measuring the load level (step 230) is a step from 400 to 440 of FIG. This will be described below.

After the network is started up and the required variables are specified, each node will receive a job message containing the content of the job to be executed (step 400). This work message may be about a node's work, such as work on a node, such as a load due to a user's work or a network operation, or data transmitted from another node. This working message is represented by message.i in FIG.

If the status of the work message is determined (step 402) and the received message is for an operation mode in which the node works with the received node, the received node increases its load level by one. In FIG. 4, the load level is denoted as load.i, and the increase or decrease of the load level is expressed by increasing or decreasing the queue value by one using a queue.

If the work message is a sender mode message to send a load from the node that sent the message to the node that received the message, the node that receives the message calculates the load level of its own node (step 420). If the load level is less than the threshold, an acceptance message is sent to the node that sent the work message (step 424); otherwise, a rejection message is sent to the node that sent the message (step 426). At this time, the node receiving the accept message transmits a load to the node that sent the accept message to lower its load level by one.

If the received message is the receiver mode to send the load from the node that received the message to the node that sent the message, the load level is calculated (step 430). If the load level is greater than the threshold, the load level is reduced by one. The load is transmitted to the node that sent the message (step 434). Otherwise, the rejection message is sent to the node that sent the message (step 436).

After the reference numerals 410 to 436, the load level of the own node is calculated (step 440). The step of measuring the load level (step 230) is completed.

Determine the state of the load level (step 240), if the load level is equal to the threshold, reduce the node's load level by one, perform node operation, and repeat the node operation step (270) from the load level measurement step (230). Step).

If the load level is greater than the threshold, a sender step of polling a node adjacent to itself and transmitting its load to the neighbor node when the load level of the neighbor node is smaller than the threshold value is performed (step 250). . The process proceeds to a node task step (step 270).

If the load level is less than the threshold, polling the node adjacent to itself and performing the receiver step of receiving the load of the neighbor node when the load level of the neighbor node is greater than the threshold (step 260). The process proceeds to a node task step (step 270).

Steps from reference numeral 240 of FIG. 2 to reference numeral 270 will be described in detail with reference to reference numerals 442 to 480 of FIG. 4.

If the load level calculated in reference numeral 440 is determined (step 442), and if the load level is equal to the threshold value, reduce the load level of the node by one and perform node operation (step 450), and measure the load level (step 230 or From step 400).

Determine the status of the load level (step 442), if the load level is greater than the threshold, polling the node adjacent to itself and transmitting its load to that neighbor when the load level of that neighbor is less than the threshold. (Sender) is performed (step 460). Thereafter, the process returns to step 465 to return to the node operation step 270 or 450.

In the transmitter step (step 250 or step 460), when measuring the load of the adjacent node, it is preferable to measure only two nodes adjacent to each other located in the clockwise and counterclockwise directions among the nodes configured in the ring structure. This is because the simulation results show that the most efficient polling is to double the number of polls and measure the load of only two adjacent nodes. In other words, when reconfiguring the network, since the nodes having the smallest transmission delay are reconfigured to be adjacent to each other, it is most efficient to poll two nodes having the smallest transmission delay and measure the load of the nodes.

5 is a detailed flowchart of a sender step according to the present invention.

Reference numeral 500 of FIG. 5 is the beginning of the sender step of reference numeral 250 of FIG. 2 or reference numeral 460 of FIG.

The sender step (step 250 or step 460) selects a node F having a small transmission delay time among clockwise or counterclockwise nodes of each node and transmits a message (Sender Probe) to transmit the load to the node. Sender mode transmission step (step 510), receiving an acknowledgment message (Acknowledge, Af) in response to the sender mode message at the selected node (step 520), if the acknowledgment message Af is an acceptance message (ACCEPT) ( Step 530) reduce the load level of one's own node, transfer the load to the selected node (step 540), and proceed to node operation step (step 270 or 450) (580) and the recognition message Af is rejected. If the message is a REJECT (step 530), the sender mode transmission to the other node (S) of the node in the clockwise or counterclockwise direction (step 550), the other in response to the sender mode transmission If the acknowledgment message (Acknowledge, As) received from the node (step 560) is the acknowledgment message (ACCEPT) (step 570), reduce the load level of one's own node and transmit the load to the other node (step 540) and then the node operation step ( If the message As received from the other node is a reject message (REJECT) (step 570), the process proceeds to the node operation step (step 270 or 450) (step 580). It is preferable to further comprise the step of.

In this case, the node operation step (step 270 or step 450) may further include repeating the step of measuring the load level (step 230) if the load level value of the node is not '0'.

If the load level of the node is less than the threshold, polling the node adjacent to itself and performing the receiver step of receiving the load of the neighbor node when the load level of the neighbor node is greater than the threshold (step 470). Return (465) to return to the node operation step (step 270 or 450).

In the receiver step (step 260 or step 470), when measuring loads of adjacent nodes, it is preferable to measure only two adjacent nodes located in clockwise and counterclockwise directions at each node configured in a ring structure. This is because the simulation results show that the most efficient polling is to double the number of polls and measure the load of only two adjacent nodes.

6 is a detailed flowchart of the receiver step according to the present invention.

The reference numeral 600 of FIG. 6 is the start stage of the receiver step of the reference numeral 260 of FIG. 2 or the reference numeral 470 of FIG.

The receiver step (step 260 or step 460) selects a node (F) having a small transmission delay time among clockwise or counterclockwise nodes of each node and transmits a message (Receiver Probe) to receive the load from the node. A receiver mode transmission step (step 610), a step of receiving an acknowledgment message (Acknowledge, Af) in response to the receiver mode message at the selected node (step 620), and if the acknowledgment message Af is WORK, Increasing the load level of the node by one (step 640) and proceeding to the node operation step (step 270 or 450) (step 680) and if the recognition message Af is a rejection message REJECT, the clockwise or counterclockwise direction. The receiver mode transmission (Receiver Probe) to the other node (S) of the node (step 650), the acknowledgment message (Acknowledge, As) received from the other node in response to the receiver mode transmission (step 660) If it is WORK (step 670), increase the load level of one's own node (step 640), proceed to node work step (step 270 or 450) (step 680), and the recognition message As received from the other node is If it is a reject message (REJECT) (step 670) it is preferable to further include the step of proceeding to the node operation step (step 270 or 450) (step 680).

In this case, the node operation step (step 270 or step 450) may further include repeating the step of measuring the load level (step 230) if the node load level value is not '0'.

Steps 400 to 480 of FIG. 4 are represented by the following pseudo code.

program NeighborSymmetric

begin

Find the delay time of the adjacent node.

f = node with lowest latency

s = node with second lowest latency

while (while performing node operations) do

begin

Receive a message (message.i).

if (message.i == work) then increments the queue by one end;

else if (message.i == SENDER) then

Calculate your load level (load.i).

send if (load.i <T) ACCEPT Send else REJECT.

end;

else if (message.i == RECEIVER) then

Calculate your load level (load.i).

if (load.i> T) then dequeue and send work end;

Send else REJECT.

end;

Calculate your load level (load.i).

if (load.i> T) then call Sender (f, s) end;

else if (load.i <T) then call Receiver (f, s) end;

Reduce the queue by one and perform node operations.

end;

end.

The Sender (f, s) procedure is represented by the following pseudo code.

Procedure Sender (f, s)

begin

Send a Sender Probe to f

Receive Acknowledge (A.f) at f.

if (A.f == ACCEPT) then Decrease the queue and send the job. end;

else if (A.f == REJECT) then

Send Sender Probe to s

Receive Acknowledge (A.s) in s

if (A.s == ACCEPT) then Decrease the queue and send the job. end;

end;

end.

The Receiver (f, s) procedure is represented by the following pseudo code.

Procedure Receiver (f, s)

begin

Send Receiver Porbe to f.

Receive Acknowledge (A.f) at f.

if (A.f == WORK) then Increments the queue. end;

if (A.f == REJECT) then

Send Receiver Probe to s

Receive Acknowledge (A.s) in s

if (A.s == WORK) then Increments the queue. end;

end;

end.

7 shows an embodiment of a load balancing device according to the present invention.

The apparatus includes a node reconstruction unit 700 and a load control unit 720.

The node reconstruction unit 700 functions to reconfigure nodes connected to the data transmission path of the network into a ring structure, and the load control unit 720 is adjacent to the load level, which is an amount of work to be performed by each node reconfigured into the ring structure. It controls the load of each node according to the load level of the nodes.

The node reconstruction unit 700 includes a delay time calculation unit 705 and a node arrangement unit 710. The delay calculation unit 705 calculates a data transmission delay time between the nodes using the time at which each node transmits a delay acknowledgment signal to another node and the other node retransmits the signal. The node arrangement unit 710 arranges the nodes and outputs deployment completion information such that the calculated transmission delay time between adjacent nodes is minimized. This batch completion information is transmitted to the load adjustment part 720.

The node arranging unit 710 further includes a function of arranging nodes at both ends adjacent to each other, when a virtual data transmission path is connected between nodes located at both ends of the bus structure when the network is a bus structure. It is preferable.

The load adjusting unit 720 preferably includes a load calculating unit 730, a transmission setting unit 740, a reception setting unit 750, and a node task execution unit 760.

Hereinafter, the operation of each component will be described in detail.

The load calculation unit 730 receives the batch completion information, receives a job message including the content of a job to be executed by the node, receives node job completion information of its own node, calculates a load level of the node, and If the load level is greater than the predetermined threshold, the transmit signal is output; if the load level is small, the receive signal is output;

Upon receiving the transmission signal, the transmission setting unit 740 transmits its load to a node having a load level smaller than the predetermined threshold value among the two nodes adjacent to each other in the ring structure in the clockwise and counterclockwise directions. Outputs a transmission completion signal.

It is preferable that the detailed operation of the apparatus which performed the function of the transmission setting part 740 is as follows.

The transmission setting unit 740 transmits a sender mode message to transmit a load to a node having a smaller transmission delay time among clockwise or counterclockwise nodes. And if the message responding to the sender mode message at the node is an acknowledgment message (ACCEPT), reduce the load level of the own node by a predetermined amount, transmit a predetermined load (WORK) to the selected node, and output a transmission completion signal. do. If the response message is a reject message (REJECT), the sender mode message is transmitted to another node that is not selected among the clockwise or counterclockwise nodes, and the message received from the other node responding to the sender mode message is accepted. If it is a message, the load level of the own node is reduced by a predetermined amount, and a transmission completion signal is output after transmitting a predetermined load to the other node. If the message received from the other node is a rejection message, the transmission completion signal is output.

When receiving the reception signal, the reception setting unit 750 receives a load from a node having a load level greater than the threshold value among the two nodes adjacent in the clockwise and counterclockwise directions at each node having the ring structure, and receives a reception completion signal. Output

The detailed operation of the apparatus that performed the function of the reception setting unit 750 is as follows.

The reception setting unit 750 transmits a receiver mode message to the node that has a smaller transmission delay time among clockwise or counterclockwise nodes to receive the load from the node. If the node responds to the receiver mode message, the node increases its load level by a predetermined amount and outputs a reception completion signal. If the message is a rejection message, the receiver mode message is transmitted to another node that has not been selected among the clockwise or counterclockwise nodes. If the acknowledgment message received from the other node in response to the receiver mode transmission is a load, increase the load level of the own node by a predetermined amount and output a reception completion signal; if the acknowledgment message received from the other node is a rejection message, the reception completion signal is received. Output

When the node task execution unit 760 receives one of the task completion signal, the transmission completion signal, or the reception completion signal, the node task execution unit 760 executes a predetermined node task, decreases the load level by a predetermined size according to the node task, Outputs a job completion signal.

The load calculator 730 preferably further includes a job message analyzer 732, a load transmission processor 734, a load reception processor 736, and a load state controller 738.

Hereinafter, the operation of each component will be described in detail.

When the job message interpreter 732 receives the completion information of the node arrangement unit 710, and receives a node work completion signal of the node job execution unit 760, the job message analyzer 732 analyzes the received job message to perform the operation. If the content of the message is an operation mode, a load increase signal indicating a load level and an increase state of a predetermined size according to the node operation is output. The message of the operation mode may be a network operation transmitted from another node, or may be a case where a network connection requested by a terminal connected to the node needs to perform a network operation. If the work message is a sender mode, a load transmission signal is output. The work message in the sender mode is transmitted by the transmission setting unit of another node, according to the method of the present invention. In addition, if the work message is in the receiver mode, a load reception signal is output. This receiver mode message is transmitted from the reception setting part of another node.

When the load transmission signal is input, the load transmission processing unit 734 determines the load level of the own node and transmits an acceptance signal to the node that has transmitted the work message when the load transmission signal is less than a predetermined threshold. The load is then transferred from that node. The job message sent is the sender setting of the adjacent node and receives the load sent by that sender. Then, a completion signal indicating that the load transmission processing is finished is output. If the load level is not smaller than the threshold value, a rejection message is output to the node that has transmitted the work message, that is, the transmission setting unit of the node, and then a completion signal indicating that the load transmission process is completed.

When the load receiving signal is input, the load receiving processing unit 736 receives a load corresponding to a predetermined magnitude according to a load to send its load level to send its load to an adjacent node when the load level of the node is greater than the predetermined threshold. Reduce And a predetermined load is transmitted to the node which sent the said work message. Since the load level is reduced because the load is removed, a load reduction signal indicating a load level and a reduction state of a predetermined size according to the transmitted load is output. In addition, if the load level of the node is not greater than the predetermined threshold value, and outputs a rejection message to the node that has sent the work message, and outputs a completion signal indicating the end of the load reception process.

After the load increase signal, the load decrease signal, or the completion signal is input, the load state controller 738 outputs a transmission signal if the load level is greater than the predetermined threshold value, a reception signal if the load level is smaller, and a work signal if the load level is the same. These signals are transmitted to the transmission setting unit 740, the reception setting unit 750, and the node task execution unit 760, respectively.

As a result of comparing the performance with the existing load balancing techniques by producing a simulator using the present invention and testing it in various environments, it can be seen that the present invention is not significantly affected by the threshold value. The response time between nodes is also shorter than the conventional method.

If the present invention is applied to a wireless network, a distributed system network can be easily configured. In the case of a computer network connected by a wireless LAN, the delay time varies greatly depending on the distance between the connected computers. However, if the existing load balancing technique is used, the performance of the network may be degraded. The load exchange between the nodes with the least heads reduces the data transfer time, and the network performance can be greatly improved by efficiently exchanging loads with the closest computer with the smallest transmission delay even when the node is heavily loaded.

According to the present invention, if the load level is greater than the threshold, the network is reconfigured so that the nodes having the smallest transmission delay time are adjacent to the nodes in the network. If the load level is less than the threshold, the load is transmitted from the nodes with the load level higher than the threshold, and the load can be exchanged symmetrically to balance the load. Can be.

Claims (21)

delete In the method of distributing the load of the nodes connected to the data transmission path of the network, Reconfiguring each node of the network into a ring structure; And And adjusting the load of each node so that the load of each node is equal according to the load level that is the amount of work that each node has to do and the load level of the adjacent node. Reconstructing the ring structure, Obtaining a data transmission delay time between each node using time of transmitting and receiving a message between each node of the network; And Rearranging each node of the network such that the delay time between adjacent nodes is minimized. The method of claim 2, wherein the obtaining of the data transmission delay time comprises: Each node transmitting a delay time acknowledgment message including a transmission time to another node; And The node receiving the acknowledgment message confirms the time at which the acknowledgment message was received and obtains a transmission delay time using the transmission time and the reception time. Load balancing method. The method of claim 2, wherein the obtaining of the data transmission delay time comprises: Each node transmitting a delay time acknowledgment message including a transmission time to another node; Retransmitting, at the node receiving the confirmation message, a response message describing the time of receipt of the message; And The node having retransmitted checks the time at which the response message is received, and obtains a transmission delay time using the transmission time, the reception time, and the response message reception time. Red load balance method. The method of claim 2, wherein the obtaining of the data transmission delay time comprises: And setting a threshold value, which is a maximum amount of load that each node of the network can handle. The method of claim 2, wherein rearranging the nodes comprises: If the network is a bus structure, the virtual data transmission path is continued between the nodes at both ends of the bus structure, and placing the nodes at both ends adjacent to each other, the load exchange between adjacent nodes. Symmetrical load balancing method through The method of claim 6, wherein adjusting the load comprises: Receiving a task message including a content of a task to be executed by the node, and measuring a load level which is an amount of a current load; A transmitter step of measuring a load level of an adjacent node if the load level is greater than a threshold value and transmitting its load to the neighbor node when the load level of the neighbor node is less than the threshold value; A receiver step of measuring a load level of an adjacent node if the load level is less than the threshold, and receiving a load of the neighbor node when the load level of the neighbor node is greater than the threshold value; And And reducing the load level by a predetermined size, performing a node operation, and repeating the operation from the load level measurement step. The method of claim 7, wherein measuring the load level, If the content of the work message is an operation mode in which a node receiving the work message performs a predetermined node work, increasing its load level by a predetermined size according to the node work; If the content of the work message is a sender mode for transmitting a load from the node that has sent the work message to the node that has received the work message, and if the load level of the own node is less than the threshold, an acceptance message is sent to the work message. Transmitting a rejection message to a node that has transmitted the work message, if it is less than the threshold; And If the content of the work message is a receiver mode for transmitting the load from the node that received the work message to the node that sent the work message, the own node if the load level of the own node is greater than the threshold. Reducing the load level by a predetermined amount to transmit the load to the node that has sent the work message, and transmitting a reject message to the node that has sent the message if it is not greater than the threshold. Symmetric load balancing method through load exchange between nodes. The method of claim 7, wherein the sender step, When measuring the load level of adjacent nodes, the load level between two adjacent nodes is measured in the clockwise and counterclockwise directions in each ring-structured node. Load balancing method. The method of claim 8 or 9, wherein the sender step, A sender mode transmitting step of selecting a node having a smaller transmission delay time among clockwise or counterclockwise nodes and transmitting a message to transmit the load to the node; Receiving a recognition message responsive to the sender mode message at the selected node; If the acknowledgment message is an acceptance message, reducing the load level of the own node by a predetermined amount and transmitting a predetermined load to the selected node and then proceeding to the node work step; And If the acknowledgment message is a rejection message, sender mode transmission is performed to another node that is not selected among the clockwise or counterclockwise nodes. If the acknowledgment message received from the other node responding to the sender mode transmission is an acceptance message, Reducing the load level by a predetermined amount and transmitting the predetermined load to the other node, and then proceeding to the node work step, and if the message received from the other node is a rejection message, further comprising proceeding to the node work step. Symmetrical load balancing method through load exchange between adjacent nodes. The method of claim 10, wherein working with the node, If the load level value of the node is not '0' symmetric load balancing method through the load exchange between adjacent nodes comprising the step of repeating from the step of measuring the load level. The method of claim 7, wherein the recipient step, When measuring the load level of adjacent nodes, the load level between two adjacent nodes is measured in the clockwise and counterclockwise directions in each ring-structured node. Load balancing method. The method of claim 8 or 12, wherein the recipient step, A receiver mode transmitting step of selecting one node having a smaller transmission delay time from a clockwise or counterclockwise node and transmitting a message that the node is to receive a load; Receiving a recognition message responsive to the receiver mode message at the selected node; If the recognition message is a load, increasing the load level of the own node by a predetermined size and proceeding to the node work step; And If the acknowledgment message is a rejection message, the receiver mode transmission is performed to another node that is not selected among the clockwise or counterclockwise nodes. If the recognition message received from the other node responding to the receiver mode transmission is a predetermined load, Increasing the load level by a predetermined size and proceeding to the node operation step, and if the recognition message received from the other node is a rejection message, further comprising the step of proceeding to the node operation step through load exchange between adjacent nodes Symmetric Load Balancing Method. 14. The method of claim 13, wherein said node working step is If the load level value of the node is not '0' symmetric load balancing method through the load exchange between adjacent nodes comprising the step of repeating from the step of measuring the load level. delete An apparatus for distributing load on nodes connected to a data transmission path of a network, A node reconfiguration unit for reconfiguring each node into a ring structure; And It includes a load control unit for adjusting the load of each node evenly according to the load level of the load level of the adjacent node and the load level which is the amount of work to be reconstructed in each ring structure, The node reconstruction unit, A delay time calculating unit for transmitting a delay acknowledgment signal to another node and calculating a data transmission delay time between the nodes using the time when the other node retransmits the signal; And And a node arranging unit for arranging the nodes and outputting deployment completion information such that the calculated transmission delay time between neighboring nodes is minimized. The method of claim 16, wherein the node arrangement unit, When the network is a bus structure, the virtual data transmission path is connected between nodes located at both ends of the bus structure, and the load exchange between adjacent nodes further comprises arranging the nodes at both ends adjacently. Symmetrical load balancing device The method of claim 17, wherein the load control unit, Receiving the batch completion information, receiving a job message including the contents of the job to be executed by the node, receiving a node job completion signal of its own node, calculating the load level of the node, and the load level being a predetermined threshold A load calculation unit that outputs a transmission signal if greater, a reception signal if smaller, and a work signal if equal; When receiving the transmission signal, each node configured in the ring structure transmits its load to a node whose load level is smaller than the predetermined threshold value among the two clockwise and counterclockwise adjacent transmissions and outputs a transmission completion signal. Setting unit; A reception setting unit configured to receive a load from a node having a load level greater than the threshold value among two nodes adjacent in clockwise and counterclockwise directions at each node having the ring structure, and output a reception completion signal; And A node which executes a predetermined node task, reduces a load level by a predetermined size according to the node task, and outputs the node task completion signal when one of the task completion signal, the transmission completion signal, or the reception completion signal is received; Symmetric load balancing device through the load exchange between adjacent nodes, characterized in that it comprises a task execution unit. The method of claim 18, wherein the transmission setting unit, The sender mode message is transmitted to a node having a lower transmission delay time among clockwise or counterclockwise nodes, and if the node responds to the sender mode message in response to the sender mode message, the load level of the node is determined. Reduce the size of the signal and transmit a predetermined load to the selected node, and output a transmission completion signal. If the response message is a reject message, the sender mode message is transmitted to another node that was not selected among the clockwise or counterclockwise nodes. If the message received from the other node in response to the sender mode message is an acceptance message, reduce the load level of the own node by a predetermined amount, transmit a predetermined load to the other node, and output a transmission completion signal. Send complete signal if received message is rejected by Symmetrical ramp load apparatus through the load exchanged between adjacent nodes, it characterized in that the output. The method of claim 18, wherein the reception setting unit, The load level of the node if the sender mode message is transmitted to the node of the clockwise or counterclockwise direction with a smaller transmission delay time and the node responds to the receiver mode message. Increase the received signal by a predetermined size and output a reception completion signal, and if the message is a rejection message, transmit a receiver mode message to another node that has not been selected among the clockwise or counterclockwise nodes, and respond to the receiver mode transmission. An adjacent node, if the recognition message received from the other node is a load, increases the load level of the node by a predetermined size and outputs a reception completion signal; and if the recognition message received from the other node is a rejection message, the neighbor node outputs a reception completion signal. Symmetric load balancing device through load exchange between. The load calculation unit according to claim 19 or 20, After receiving the batch completion information and receiving the node work completion signal, the received work message is analyzed, and if the content of the work message is an operation mode, the load level and increase state of a predetermined size according to the node work are analyzed. A job message analyzer for outputting a load increase signal to be displayed, outputting a load transmission signal in a transmitter mode, and outputting a load reception signal in a receiver mode; When the load transmission signal is input, when the load level is less than the predetermined threshold value, an accept signal is output to the node that has transmitted the work message and a completion signal is output; when the load level is not less than the threshold value, the work message is output. A load transmission processor for outputting a completion signal after outputting a rejection message to the node which has transmitted the data; When the load reception signal is input, if the load level is greater than the predetermined threshold value, reduce its own load level by a predetermined size and transmit a predetermined load to the node that has transmitted the work message, and have a predetermined size according to the transmitted load. A load receiving processor for outputting a load reduction signal indicative of a load level and a reduced state, outputting a rejection message to the node that sent the work message if the load level of the node is not greater than the predetermined threshold value, and outputting a completion signal; ; And And a load state controller for outputting a transmission signal if the load level is greater than the predetermined threshold value, a reception signal if the load signal is smaller, and a work signal if the load level signal is greater than the predetermined threshold value after inputting the load increase signal, the load reduction signal, or the completion signal. Symmetric load balancing device through load exchange between adjacent nodes.

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