KR101884636B1 - Method of distributed service function fail-over for highly available service function chaining and system of the same - Google Patents

Abstract

A fault recovery method is disclosed. Wherein the fault recovery method is performed by a fault recovery system, wherein a transmitter included in the fault recovery system transmits a ping message to a service node providing a next service function on a service function chain at regular intervals, The method includes the steps of: determining whether a determination unit included in the system receives a response to the ping message; and when the failure detection unit included in the failure recovery system determines that a response to the ping message is not returned within a predetermined threshold time And detecting a failure of the next service function.

Description

TECHNICAL FIELD The present invention relates to a method and system for a distributed service disaster recovery for high availability of a service function chain,

The present invention relates to a distributed service dysfunction recovery method for coping with a service dysfunction on a service function chain.

Network function Virtualization technology is a technology implemented on a commercial server by hardwareizing hardware devices that provide network service functions such as Firewall, Network Address Translation (NAT), and Intrusion Detection System (IDS) Advantages have attracted much attention from network operators. Service function Chaining technology is a technology that sequentially arranges and processes the traffic that enters the network after configuring these service functions into a logical service order list (that is, a service function chain) according to the policy. On the other hand, when a service function on a chain fails, the traffic to receive the service may experience a high latency. To prevent this, there is a need to overcome a failure to quickly cope with a service failure.

U.S. Patent Application No. 14 / 572,335 entitled " Methods, systems, and computer readable storage devices for managing faults in a virtual machine network & U.S. Patent Application No. 14 / 572,716 entitled " System, method, and computer program for preserving service continuity in a network function virtualization (NFV)

An object of the present invention is to reduce the overcoming time of a service function through a distributed fail over method for a service function on a service function chain.

In the present invention, a Distributed Fail-over Agent (DFA) is placed in each service function to perform a failure detection and fail-over mechanism for the next service function in the chain, thereby enabling a chain update The objective is to reduce the time to overcome the service dysfunction by overcoming the obstacles in a distributed manner without process.

A failure recovery method according to an embodiment of the present invention is performed by a failure recovery system, and a transmitter included in the failure recovery system transmits a ping message to a service node providing a next service function on a service function chain The method according to claim 1, further comprising the steps of: determining whether a response to the ping message is received by the determination unit included in the failure recovery system; and detecting a failure included in the failure recovery system, And detecting a failure of the next service function if it is not returned within the value time.

The failure recovery system according to an embodiment of the present invention includes a storage unit for holding a backup instance for an (i + 1) th service function, a transmitter for transmitting a ping message at a predetermined cycle to an (i + And a failure detection unit for detecting failure of the (i + 1) th service function when the response to the ping message does not return within a predetermined threshold time.

According to one embodiment, a service failover time can be reduced through a distributed failover method for service functions on a service function chain.

According to one embodiment, a Distributed Fail-over Agent (DFA) may be placed in each service function to perform a failure detection and failover mechanism for the next service function in the chain.

According to an exemplary embodiment, it is possible to overcome a failure in a distributed manner without a chain update process that can be performed only through a centralized service function chaining controller, thereby reducing a service function failure over time.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to more fully understand the drawings recited in the detailed description of the present invention, a detailed description of each drawing is provided.
1 shows a Service Function Chaining (SFC) structure composed of a control plane and a data plane.
FIG. 2 shows a process of overcoming a service failure through a controller of a service function chaining.
FIG. 3 shows a process of overcoming a service failure through a Distributed Fail-over Agent (DFA).
4 is a view for explaining a failure recovery system according to an embodiment.
FIG. 5 is a flowchart of a method for operating a failover processor according to an exemplary embodiment, for a distributed service failure failure of a distributed fail-over agent (DFA).
FIG. 6 is a graph showing a change in average failover time while varying a range of delay time between a controller and a service function.

It is to be understood that the specific structural or functional description of embodiments of the present invention disclosed herein is for illustrative purposes only and is not intended to limit the scope of the inventive concept But may be embodied in many different forms and is not limited to the embodiments set forth herein.

The embodiments according to the concept of the present invention can make various changes and can take various forms, so that the embodiments are illustrated in the drawings and described in detail herein. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms disclosed, but includes all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms may be named for the purpose of distinguishing one element from another, for example, without departing from the scope of the right according to the concept of the present invention, the first element may be referred to as a second element, The component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like are used to specify that there are features, numbers, steps, operations, elements, parts or combinations thereof described herein, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

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

1 shows a Service Function Chaining (SFC) structure 100 composed of a control plane and a data plane.

The controller of the control plane maintains the SFC table. A table entry can consist of a sequence of Service Path Index (SPI), policy, and service functions for the chain. For example, for chain C, the SPI is defined as P. The path on the actual network through which the packet to which the chain is assigned is referred to as a Service Function Path (SFP), and the Service Path Index (SPI) is an identifier for a path on an actual network. The table entry also specifies a policy that applies the chain only to traffic whose destination port number is 80.

Next, paths on the actual network in the order of Service Function (SF) instances (or service functions) are specified in the order SF 1 - SF 2 - SF 3 - SF 4.

The expressions of SF i such as SF 1 and SF 2 used in this specification can be interpreted as a first service function, a second service function, and an i-th service function.

On the other hand, the information in parentheses means a Service Function Forwarder (SFF) to which a corresponding service function is connected. The service function forwarder is responsible for delivering the delivered packets to the service function (or service node) or service function forwarder according to the defined chain.

On the other hand, the controller installs service function instances (or service functions) on each Service Node (SN) on the data plane. SN is a physical or virtual element that provides CPU, memory, and storage space. It can host a service function instance (or service function) in the form of a virtual machine (VM) through Network Function Virtualization (NFV) to provide. When the controller receives a request for a new chain configuration, it enters a new entry into the SFC table. When an entry is input, the controller updates the SFC table of the service classifier (SC) and the service function forwarder so that the specific traffic can be serviced according to the order defined in the path on the actual network according to the policy.

의 시간 동안 핑 메시지에 대한 응답이 없을 시, 해당 서비스 기능에 장애가 발생하였다고 판단할 수 있다.In addition, the controller can perform fault detection for each service function through a periodic ping message. That is, the predefined threshold value

If there is no response to the ping message during the time period of " 0 "

If a failure is detected for a particular service function instance, the controller sends the service function instance for that service function to the service function instance (or service nodes) associated with the service function forwarder, such as a failed service function instance, It can be installed at the same location as a service function instance (or service node) with a minimum delay time and can configure a path on a new physical network so that traffic can pass to a new service function instance (or a service node with a new service function installed) .

The ingress node of the data plane assigns the network service header (NSH) according to the network policy received from the controller for the packets coming into the SFC domain, So that the service can be received according to the order in which they are received. The NSH includes SPI and Service Index (SI) information, which is decremented by 1 for each service function instance to indicate the order in which the packet is currently processed on the path on the actual network. For example, the ingress node can confirm that SPI = P and SI = 255 are assigned to a packet whose destination port number is 80 according to the policy.

After granting the NSH, the ingress node forwards the packet to the service function forwarder connected to the first service function instance specified in the path on the actual network. The service function forwarder forwards the packet through a service function forwarder table consisting of SPI, SI and Next Hop (NH). Since the SPI and SI of the packet received from the SC are P and 255, respectively, the packet is transmitted to the corresponding SF 1.

After processing the packet, SF 1 decrements the SI value by 1 and then transmits it to the service function forwarder 1 again. Repeating this process, the packet is matched in order of 1 - 2 - 3 - 4 - 5 on the service function forwarder table and passes through service function instances in order.

As mentioned earlier, the service function forwarder table is updated by the controller when configuring the path on a new physical network on the controller. The ingress node is responsible for delivering the processed packets to the outside of the SFC domain in the SFC domain.

In the present invention, a distributed failover agent (which may be termed a distributed failover according to an embodiment) is located in the SNs where all the service function instances included in the path on the actual network are located. It can be assumed that all the SFs included in the path on the actual network are connected to the same service function forwarder. Also, if the path on the real network is SF 1 - SF 2 - SF 3 - ... - SF N, and the distributed failover agent located in the i th service function is called the i th distributed failover agent, then i th distributed failover The agent can perform fault detection and recovery for the (i + 1) th service function when the (i + 1) th service function is connected to the same service function forwarder as the i th service function.

의 시간 동안 응답이 없을 시, i+1번째 서비스 기능(또는 i+1번째 서비스 노드)에 장애가 발생하였다고 판단할 수 있다.First, the i-th distributed failover agent can perform fault detection for the (i + 1) -th service function. That is, the i-th distributed failover agent sends a periodic ping message to the i + 1-th service function (or the (i + 1) th service node)

(I + 1) -th service node (i + 1) -th service node (i + 1) th service node.

On the other hand, the i-th distributed failover agent maintains a backup instance for the i + 1-th service function. The i-th distributed failover agent activates the backup instance for the (i + 1) -th service function when the failure of the (i + 1) -th service function is activated, and after the packets flowing into the i-th service function are processed by the i- , Updates the internal network so that it can be transmitted to the newly activated i + 1 < th > service function and processed.

For example, when a failure occurs in SF 2 in FIG. 1, the distributed failover agent 1 activates the inactivated SF 2 and updates the internal network. Afterwards, the packets arriving at SF 1 are processed at SF 1 and then processed at the same SN 1 at SF 2.

As a result, packets entering SF 1 are processed in SF 1 and SF 2, and the SI value of NSH is decreased by 2, and then forwarded to the service function forwarder 1. Since the SI value is 253, the received packet is not delivered to the failed SF 2 instance but directly to the SF 3 instance. Therefore, it is possible to overcome the obstacle without going through the process of creating the path on the actual network by the controller and updating the service function forwarder table.

On the other hand, when the failure occurs in SF 1 or when the i + 1-th service function is connected to the i-th service function forwarder and is different from the i-th service function, Because there is no distributed failover agent to do, the controller can overcome obstacles by performing path creation and service function forwarder table update procedures on the actual network through the above-mentioned fault detection / recovery mechanism.

FIG. 2 is an embodiment 200 illustrating an SF failover process through an SFC controller.

을 나타낸다. 먼저 컨트롤러는 주기적으로 i번째 서비스 기능의 상태를 확인하며,

의 시간 동안 응답이 없을 시 i번째 서비스 기능에 장애가 발생하였다고 판단한다. 따라서 장애를 탐지하기까지는

의 시간이 소요된다. i번째 서비스 기능은 SN i에 설치되어있다고 하고,

를 SFC 컨트롤러와 i번째 서비스 기능(또는 SN i) 간의 네트워크 지연시간으로 가정할 수 있다. 또한, SN i와 같은 서비스 기능 포워더에 연결된 SN들 중 컨트롤러와의 지연시간이 가장 낮은 SN을 j라 하면, SFC 컨트롤러는 SN j에게 i번째 서비스 기능에 대한 설치 요청을 보내고, 이 때 걸리는 시간은

이다. 그 후, 설치 요청을 받은 SN j가 i번째 서비스 기능을 설치하게 되며, 이 때 걸리는 시간을

라 한다. i번째 서비스 기능의 설치가 완료되면, SN j는 해당 작업에 대한 ACK을 보내고, 컨트롤러는 ACK을 받은 이후 서비스 기능 포워더 테이블을 업데이트한다.

를 컨트롤러와 서비스 기능 포워더 간의 네트워크 지연시간이라 하면, 업데이트 요청 후 서비스 기능 포워더를 받을 때까지 걸리는 시간은

가 된다. 결과적으로

는 [수학식 1]과 같이 계산된다.FIG. 2 is a flowchart illustrating a failure recovery process by the SFC controller and a failure recovery time

. First, the controller periodically checks the status of the i-th service function,

The service function of the i-th service is determined to have failed. Therefore, until the fault is detected

Of time. Assume that the i-th service function is installed in the SN i,

Can be assumed as the network delay time between the SFC controller and the i-th service function (or SN i). Also, if the SN of the SN with the lowest delay time from the controller connected to the service function forwarder such as SN i is j, the SFC controller sends an installation request for the i th service function to the SN j,

to be. Then, the SN j that receives the installation request installs the i-th service function.

. When the installation of the i-th service function is completed, the SN j sends an ACK for the job, and the controller updates the service function forwarder table after receiving the ACK.

Is the network delay time between the controller and the service function forwarder, the time taken to receive the service function forwarder after the update request is

. As a result

Is calculated as shown in Equation (1).

[Equation 1]

는 장애 탐지 타임아웃 값으로 해석될 수 있고,

는 SF 설치에 걸리는 시간으로 해석될 수 있으며,

는 i번째 서비스 기능과 SFC controller 사이의 네트워크 지연시간으로 해석될 수 있고,

는 서비스 기능 포워더와 SFC controller 사이의 네트워크 지연시간으로 해석될 수 있으며,

는 centralized fail-over의 경우, i번째 서비스 기능에 대한 장애 복구시간으로 해석될 수 있고,

는 centralized fail-over의 경우, 평균 장애 복구시간으로 해석될 수 있으며,

는 distributed fail-over의 경우, i번째 서비스 기능에 대한 장애 복구시간으로 해석될 수 있으며,

는 distributed fail-over의 경우, 평균 장애 복구시간으로 해석될 수 있다.At this time,

May be interpreted as a failure detection timeout value,

Can be interpreted as the time taken to install the SF,

Can be interpreted as the network delay time between the i-th service function and the SFC controller,

Can be interpreted as the network delay time between the service function forwarder and the SFC controller,

Can be interpreted as the failure recovery time for the i-th service function in the case of centralized fail-over,

In the case of centralized fail-over, it can be interpreted as average failure recovery time,

Can be interpreted as the failure recovery time for the i-th service function in case of distributed fail-over,

Can be interpreted as average failure recovery time in case of distributed fail-over.

이다. SFC 컨트롤러를 통한 평균 장애 극복 시간

는 [수학식 2]과 같이 계산된다.At this time,

to be. Average failover time with SFC controller

Is calculated as shown in Equation (2).

&Quot; (2) "

는 centralized fail-over의 경우, i번째 서비스 기능에 대한 장애 복구시간으로 해석될 수 있다.At this time,

Can be interpreted as the failure recovery time for the i-th service function in the case of centralized fail-over.

3 illustrates a service failover process through a distributed failover agent.

를 타나낸다. That is, FIG. 3 shows a process for failing over the i-th service function when i is 2 or more (i.e., when i is not the first SF of the path on the real network) Recovery time

.

의 시간 동안 응답이 없을 시 i번째 서비스 기능에 장애가 발생하였다고 판단한다. 따라서 장애를 탐지하기까지는

의 시간이 소요된다. i-1번째 분산 페일오버 에이전트는 장애를 탐지하면 SN i-1에 위치한 back-up i번째 서비스 기능을 활성화시키고, 내부 네트워크를 업데이트 시켜 i번째 서비스 기능이 SN i-1에에 제공될 수 있도록 한다.The i-th distributed failover agent-1 periodically checks the status of the i-th service function,

The service function of the i-th service is determined to have failed. Therefore, until the fault is detected

Of time. When the i-1th distributed failover agent detects a failure, it activates the back-up i-th service function located at SN i-1 and updates the internal network so that the i-th service function can be provided to SN i-1 .

와 동일하다고 가정한다. i번째 서비스 기능에 대한 복구 시간은 [수학식 3]과 같다.The time it takes is the time it takes to install the i-th service function

. The recovery time for the i-th service function is expressed by Equation (3).

&Quot; (3) "

는 장애 탐지 타임아웃 값으로 해석될 수 있고,

는 서비스 기능 설치에 걸리는 시간으로 해석될 수 있으며,

는 centralized fail-over의 경우, i번째 서비스 기능에 대한 장애 복구시간으로 해석될 수 있다.

May be interpreted as a failure detection timeout value,

Can be interpreted as the time taken to install the service function,

Can be interpreted as the failure recovery time for the i-th service function in the case of centralized fail-over.

이 된다. 분산 페일오버 에이전트를 통한 평균 장애 극복시간

는 [수학식 4]와 같이 계산된다.On the other hand, if i is 1, failover is performed by the controller,

. Average Failover Time with Distributed Failover Agent

Is calculated as shown in Equation (4).

&Quot; (4) "

4 is a view for explaining a failure recovery system according to an embodiment.

FIG. 4 shows a structure / technique for performing distributed fault detection / recovery when a service function (SF) fails.

Specifically, according to the present invention, a distributed fail-over agent and a back-up SF can be located in the SN. Also, the distributed failover agent can perform distributed failover through distributed fault detection and back-up SF. According to the present invention, service failures can be recovered without having to go through the SFC controller with a short failover time compared to the conventional SFC controller-based failover method. In addition, according to an embodiment, the failover system 400 shown in FIG. 4 may also mean a service node.

The failure recovery system 400 may include a storage unit 410, a transmission unit 420, a determination unit 430, and a failure detection unit 440. In addition, the failover system 400 may be referred to as a failover device.

The storage unit 410 according to the embodiment may maintain a back-up instance for the (i + 1) th service function (SF i + 1). Meanwhile, the transmitter 420 may transmit a ping message to the (i + 1) th service function (or the (i + 1) th service node) at regular intervals. The determination unit 430 may determine whether the transmitted ping message is received (or whether a response to the ping message is received).

If the response to the transmitted ping message does not return within a predefined threshold time, the failure detection unit 440 according to an embodiment determines whether the i + 1th service function (SF) Can be detected.

At this time, the failure recovery system 400 according to another embodiment may further include a failure recovery processing unit 450 for activating a backup instance (or a backup service function) to recover the failure. In particular, if a failure is detected, the failure recovery processor 45 may activate a back-up instance for the (i + 1) -th service function (SF). That is, after the packets received in the i-th service function (SF) are processed by the i-th service function (SF), the i + 1-th service Function (SF), and update the internal network so that it can be processed.

In addition, the failure recovery processing unit 450 extracts a service index (Service) of a post-processing network service header (NSH) from an i-th service function (SF) and an i + Index, SI) is reduced by a constant value.

The failure recovery processing unit 450 according to an embodiment generates a path (Service Function Path, SFP) on the actual network through the controller when a failure is detected in the (i + 1) th service function (SF) It updates the Service Function Forwarder (SFF) table corresponding to the path (Service Function Path (SFP) on the actual network) and can handle the failure using the updated Service Function Forwarder (SFF) table have.

5 is a flowchart of a method for operating a failover processor, according to an embodiment, for distributed SF failover of a distributed failover agent.

At least one Distributed Fail-over Agent (DFA) located in a Service Function (SF) can be maintained.

First, according to an exemplary operation method of the failure recovery processor, an i-th distributed failover agent transmits a ping message to an (i + 1) -th service function (step 510). That is, among the at least one Distributed Fail-over Agent (DFA), the (i + 1) th Service Function (SF) in the i-th Distributed Fail- The ping message can be sent periodically.

The method of operation of the failover processor according to one embodiment may determine whether to receive a transmitted ping message (step 520).

Next, the method of operating the failover processor according to an exemplary embodiment of the present invention transmits a ping message again when a response is received within the To time (step 510). If there is no response within the To time, the back-up SF of the (i + 1) -th service function is activated (step 530). Also, the internal network is updated so that the packets processed in the i-th service function are transmitted to the i + 1-th service function (step 540).

That is, the operation method of the failure recovery processor can detect a failure of the (i + 1) -th service function (SF) when the response to the transmitted ping message does not return within a predefined threshold time. If a failure is detected, a back-up instance for the i + 1th service function (SF) is activated in the i-th Distributed Fail-over Agent (DFA) . In addition, after the packets received in the i-th service function (SF) are processed by the i-th service function (SF), the i + 1 th The internal network can be updated so that it can be transferred to and processed in a service function (SF).

The operation method of the failure recovery processor may be configured such that the i-th service function (SF) and the (i + 1) -th service function (SF) The service index (SI) of the network service header (NSH) after the processing can be reduced by a predetermined value.

(I + 2) th service function (SF) is skipped if the service index (SI) of the incoming packet is greater than a specific value, Th service function (SF).

In addition, when the failure is detected in the (i + 1) -th service function (SF), the operation method of the failure recovery processor generates a path (Service Function Path, SFP) on the actual network through the controller, Updating a Service Function Forwarder (SFF) table corresponding to a path on the network (Service Function Path, SFP), and processing the failure using the updated Service Function Forwarder (SFF) table can do.

FIG. 6 is a graph 600 illustrating a change in the average failover time while varying the range of the delay time between the controller and the SF.

That is, in the graph 600 of FIG. 6, the simulation is performed for performance evaluation of the present invention and compared with the existing methods. The result of Distributed Fail-over corresponding to reference numeral 620 in the drawing showing the result of the simulation is the result of the Centralized Fail-over corresponding to the present invention and reference numeral 610, the SFC controller performs the fault detection / .

The graph 600 shows the change in average failover time while varying the range of delay times between the controller and the SFs. As can be seen in graph 600, it can be seen that the delay time of the present invention achieves a lower average failover time. This is because the present invention minimizes the overcoming of the service function failure through the controller through the distributed service failover method through the distributed failover agent.

As a result, when using the present invention, it is possible to reduce the time taken to overcome a service failure by a distributed failover method for a service function on a service function chain. In addition, it is possible to place a distributed fail-over agent in each service function to perform a failure detection and fail-over mechanism for the next service function in the chain, and to perform a chain that can only be achieved through a centralized SFC controller It is possible to overcome the failure of the service failure by overcoming the failure in a distributed manner without an update process.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a PLU a programmable logic unit, a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (8)

(I is a natural number smaller than N) fault recovery systems among N (N is a natural number of 3 or more) fault recovery systems each providing a service function of any one of a plurality of service functions included in the service function chain A method for recovering from a distributed service failure,
The transmitter included in the i-th fail-over system transmits a ping message to the (i + 1) -th fail-over system providing the next service function on the service function chain at regular intervals;
Determining whether a response to the ping message is received by the determination unit included in the i < th >
Detecting a failure of the next service function when a failure detection unit included in the i-th failure recovery system does not return a response to the ping message within a predefined threshold time; And
Wherein the failure recovery processing unit included in the i < th > failback system includes a step of activating a backup instance for the next service function when the failure is detected.
How to recover from a failure.
The method according to claim 1,
The failure recovery processing unit may process the packets received in the i-th failure recovery system by the service function provided by the i-th failure recovery system, The method further comprising:
How to recover from a failure.
3. The method of claim 2,
Packets received in the service function provided by the i-th fail-over system are processed in the service function and the next service function after the Service Index (SI) of the Network Service Header (NSH) ≪ / RTI >
How to recover from a failure.
The method of claim 3,
Wherein the service index is reduced by two.
(I is a natural number smaller than N) fault recovery systems among N (N is a natural number of 3 or more) fault recovery systems each providing a service function of any one of a plurality of service functions included in the service function chain As a result,
a storage unit for holding a backup instance for the i + 1 < th > service function;
a transmitter for transmitting the ping message to the (i + 1) th service node at regular intervals;
A determination unit for determining whether a response to the ping message is received;
A failure detection unit for detecting failure of the (i + 1) -th service function when the response to the ping message does not return within a predefined threshold time; And
and a failure recovery processor for recovering a failure by activating the backup instance for the (i + 1) -th service function if a failure of the (i + 1) th service function is detected.
Failover system.
delete 6. The method of claim 5,
The failure recovery processing unit,
Th service function provided by the i < th > failure recovery system is processed by the i < th > service function, and after the backup instance is transferred to the activated i + A failover system that updates the network.
8. The method of claim 7,
The failure recovery processing unit,
And processes the packets flowing into the i-th service function so that the service index of the network service header after processing in the i-th service function and the (i + 1) -th service function is decreased by a predetermined value.

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