WO2000043882A1 - Appareil de commutation de base de donnees - Google Patents

Appareil de commutation de base de donnees Download PDF

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Publication number
WO2000043882A1
WO2000043882A1 PCT/JP1999/000199 JP9900199W WO0043882A1 WO 2000043882 A1 WO2000043882 A1 WO 2000043882A1 JP 9900199 W JP9900199 W JP 9900199W WO 0043882 A1 WO0043882 A1 WO 0043882A1
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WO
WIPO (PCT)
Prior art keywords
database
unit
signal processing
failure
control unit
Prior art date
Application number
PCT/JP1999/000199
Other languages
English (en)
Japanese (ja)
Inventor
Taro Asao
Original Assignee
Fujitsu Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Limited filed Critical Fujitsu Limited
Priority to PCT/JP1999/000199 priority Critical patent/WO2000043882A1/fr
Publication of WO2000043882A1 publication Critical patent/WO2000043882A1/fr

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Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/16—Error detection or correction of the data by redundancy in hardware
    • G06F11/20—Error detection or correction of the data by redundancy in hardware using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements
    • G06F11/2053—Error detection or correction of the data by redundancy in hardware using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements where persistent mass storage functionality or persistent mass storage control functionality is redundant
    • G06F11/2094—Redundant storage or storage space
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/18—Error detection or correction; Testing, e.g. of drop-outs
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/74—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission for increasing reliability, e.g. using redundant or spare channels or apparatus

Definitions

  • the present invention relates to a database switching apparatus, and more particularly to a database switching apparatus for performing a database switching process held by a unit in which a failure has occurred.
  • n 1 is 1.544 Mbit / s
  • SMDS Switchched Multi-megabit Data Service
  • transmission systems are equipped with many failure monitoring mechanisms and automatic recovery mechanisms to achieve high reliability. For example, if a hardware failure occurs in a unit that processes signals, it is necessary to rescue the signal that was being processed by the failed unit (failure unit).
  • a redundant unit is provided with a spare unit, and the protection switch is used to switch between the faulty unit and the spare unit to recover the signal. Switch between the failed unit and the spare unit
  • the data processing unit takes over the data necessary for the operation of the unit.
  • FIG. 11 is a diagram showing an outline of unit switching using a conventional protection switch.
  • the working channel units 300a to 300n are units for actually processing signals from the channels CHa to CHn.
  • the protection switch unit SW is composed of the same number of protection switches SWa to SWn as the current channel units 300a to 300On, and the inside is composed of one spare channel unit 200 and N active switches. Connects a faulty unit in which a fault occurred in channel unit 300a to 300n. That is, a 1: N switch configuration is adopted.
  • the signal that has been rescued by the spare channel unit 200 is switched to the original working channel unit.
  • the fault management unit 400 monitors and controls the faults that occur in the working channel units 300a to 300n and controls the switching of the protection switches SWa to SWn.
  • the database-based switching unit 500 has the databases DBa to DBn held by the current channel units 300a to 300n, respectively. Set the database set in the unit to the spare channel unit 200.
  • the spare channel unit 200 processes the switched signal on the basis of the set database instead of the failed unit.
  • a failure has occurred in the working channel unit 300a.
  • the signal of the channel C Ha is separated.
  • the switch SWa of the protection switch is closed, and the other SWb to SWn are open.
  • the database switching unit 500 transfers the database DBa used in the working channel unit 300a to the spare channel unit 200.
  • the spare channel unit 200 can rescue the signal processed by the working channel unit 300a. Similar switching control is performed when a failure occurs in the other working channel units 300b to 300n.
  • the present invention has been made in view of the above points, and has a high speed and high performance.
  • Another object of the present invention is to provide a transmission system for relieving a failure by efficiently performing data-based switching in a short time without using a high-speed and high-performance CPU or a high-speed bus. That is.
  • a failure of its own unit is performed in a data base switching device 1 for performing a switching process of a database held by a unit in which a failure has occurred.
  • a signal processing spare unit 20 comprising a data selection unit 22 for selecting a corresponding database from the entire database in the event of a failure;
  • a control unit 10 having a database setting means 11 for setting a database in stage 21 and a database switching device 1 comprising:
  • the failure detection means 31 a to 31 ⁇ detect the occurrence of a failure in the own unit.
  • the database holding means 32 a to 32 h hold databases DB to D ⁇ ⁇ required for signal processing.
  • the entire database holding means 21 holds the entire database held by the plurality of signal processing units 30a to 30n.
  • the database selecting means 22 selects a corresponding database from the whole database when a failure occurs.
  • the database setting means 11 sets a database in the database storage means 32 2 a to 32 n and the whole database storage means 21.
  • the failure detection means 31a to 31n that detects the occurrence of failures of the own unit and the data base required for signal processing are held.
  • a plurality of signal processing units 30a, 30b to 30n composed of database holding means 32a to 32n, and a plurality of signal processing units 30a, 30b to 30 0n
  • the entire database holding means 21 that holds the entire database held by n, and the corresponding database is selected from the entire database DBa to DBn when a failure occurs.
  • a database selection means 22 which is composed of: a signal processing auxiliary unit 20 composed of: a database storage means 32 2a to 32n; and a database storage means 21:
  • a control unit 10 having a data base setting means 11 to be set, and a signal processing unit It has the same number of switches SWa, SWb to SWn as 30a, 30b to 30 ⁇ , and controls the opening and closing of switches SWa, SWb to SWn at the time of failure occurrence and recovery, and the signal processing unit in which the failure occurred
  • a protection switch SW for relieving a failure by switching between the power supply unit and the signal processing auxiliary unit 20.
  • the failure detection means 31a to 31n detect the occurrence of a failure in the own unit.
  • the database holding units 32a to 32n hold databases DBa to DBn required for signal processing.
  • the entire database holding means 21 holds the entire database held by the plurality of signal processing units 30a to 30n.
  • the database selection means 22 selects a corresponding database from the entire database when a failure occurs.
  • the database setting unit 11 sets the database in the database holding units 32 a to 32 n and the entire database holding unit 21.
  • the protection switch unit SW has the same number of switches SWa and SWb to SWn as the signal processing units 30a and 30b to 30n, and a fault occurs. In addition, at the time of recovery, the switches SWa and SWb to SWn are controlled to open and close, and the failed signal processing unit and the spare signal processing unit 20 are switched to relieve the failure.
  • FIG. 1 is a diagram illustrating the principle of a database switching device according to the present invention.
  • FIG. 2 is a flowchart illustrating an operation procedure of the data base switching device.
  • FIG. 3 is a diagram illustrating a configuration of the first exemplary embodiment.
  • FIG. 4 is a diagram illustrating a configuration of the second embodiment.
  • FIG. 5 is a diagram illustrating a configuration of the third embodiment.
  • FIG. 6 is a diagram illustrating a configuration of the fourth embodiment.
  • FIG. 7 is a diagram illustrating the configuration of the fifth embodiment.
  • FIG. 8 is a diagram illustrating a configuration of the sixth embodiment.
  • FIG. 9 is a diagram illustrating a configuration of a transmission system.
  • FIG. 10 is a flowchart showing the operation procedure of the transmission system.
  • FIG. 11 is a diagram showing an outline of unit switching using a conventional protection switch. BEST MODE FOR CARRYING OUT THE INVENTION
  • FIG. 1 is a principle diagram of the database switching device of the present invention.
  • the data switching device 1 has a control unit 10, a signal processing spare unit 20 and a plurality of signal processing units. It consists of units 30a to 30n, and performs switching processing of the database held by the failed signal processing unit.
  • the signal processing unit 30 a to 30 ⁇ includes failure detection means 31 a to 31 n and data base holding means 32 a to 32 n.
  • the fault detecting means 31a to 31n detect the occurrence of a fault in the own unit.
  • the data storage means 32a to 32n hold data DBa to DBn required for signal processing corresponding to each unit.
  • the signal processing auxiliary unit 20 includes a whole database holding unit 21 and a database selection unit 22.
  • the entire database holding means 21 holds the entire database (all of DBa to DBn) held by the plurality of signal processing units 30a to 30n.
  • the database selecting means 22 selects a corresponding database from the whole database when a failure occurs.
  • the control unit 10 has database setting means 11.
  • the database setting means 11 backs up the database DBa to DBn, and stores the corresponding database in the database base holding means 32a to 32n and the entire database holding means 21. Set.
  • each unit is as follows: the database setting means 11 of the control unit 10; the entire database holding means 21 of the signal processing spare unit 20; the signal processing unit 30 Data base holding means 32 a to 32 n of a to 30 n are connected to line L 1.
  • the database selection means 22 of the signal processing spare unit 20 and the fault detection means 3 la to 31 n of the signal processing unit 30 a to 30 n are connected by a line L 2 different from the line L 1. I do.
  • FIG. 2 is a flowchart showing the operation procedure of the database switching device 1.
  • the signal processing unit 30a It is assumed that a failure has occurred in the signal processing unit 30a during the operation of ⁇ 30n.
  • the database setting means 11 of the control unit 10 sends the signal processing units 30a to 30n and the signal processing spare unit 20 to the database beforehand (at the start of system operation).
  • Set (transfer) the base That is, the databases DBa to DBn are set in the data base holding means 32a to 32n, respectively, and all of the databases DBa to DBn are set in the data base holding means 21.
  • the failure detecting means 31a of the signal processing unit 30a detects the failure and notifies the signal processing spare unit 20.
  • the database selection means 22 of the signal processing spare unit 20 receives the notification of the occurrence of the failure, and then receives the database DB held by the database holding means 32 a of the signal processing spare unit 20. Select a.
  • the spare signal processing unit 20 operates in place of the signal processing unit 30a.
  • the database switching apparatus 1 of the present invention stores all of the data processing units 30a to 30n in the database DBa to DBn in the signal processing spare unit 20 in advance. In this configuration, the database corresponding to the failed signal processing unit is selected by the signal processing spare unit 20.
  • Figure 3 shows the first implementation It is a figure showing composition of a form.
  • the control unit 10 In the data base switching device 11 of the first embodiment, the control unit 10, the signal processing spare unit 20 and the signal processing units 30a to 30n are connected to the bus line L1— Connect with 1.
  • the database selection means 22 includes priority order determination means 22-1. In the following, the same reference numerals are given to the components already described, and the description of the components will be omitted.
  • Control unit 10 includes buffer 15, signal processing spare unit 20 includes buffer 23, signal processing unit 30a to 30n includes buffers 33a to 33n, and each unit Are connected by bus lines L1-1 through these buffers.
  • the database setting means 11 uses the bus line L111 to set the databases DBa to DBn at the start of the system operation. Therefore, the bus line L1-1 may be a bus with a low transfer rate.
  • the control unit 10 includes a database setting means 11, a CPU 12, a ROM 13, a RAM 14, and a buffer 15.
  • the CPU 12 instructs the data base setting means 11 to distribute the database to the signal processing units 30a to 30n and the signal processing standby unit 20. Also performs other overall control.
  • the ROM 13 holds a program for operating the CPU 12.
  • the RAM I 4 is used as a data storage and a work area necessary for the operation of the CPU 12.
  • the data base selection means 22 in the signal processing spare unit 20 includes priority order determination means 22-1.
  • the priority determining means 22-1 determines the priority of a signal processing unit for relieving a failure when a plurality of failures occur. This priority may be set in advance, or may be determined by a round robin method or the like.
  • the data bases DBa to DBn are held in the signal processing spare unit 20 in advance, and each unit is connected by the bus line L1_1. The configuration was adopted. This eliminates the need to transfer data in the event of a failure, so that the bus line L111 having a low transfer speed can be used.
  • the priority determining means 22-1 is provided in the signal processing spare unit 20. Therefore, even when a plurality of failures occur, the database switching process can be quickly dealt with, and the database switching can be performed efficiently and in a short time.
  • FIG. 4 is a diagram showing the configuration of the second embodiment.
  • the control unit 10 uses the serial communication IZF 16
  • the signal processing spare unit 20 uses the serial communication I / F 24
  • the signal processing unit 30a to 30 ⁇ Includes serial communication IZFs 34a to 34 ⁇ , and each unit is connected by a serial communication line L1_2 via these serial communication IZFs.
  • the second embodiment has a configuration in which the databases DBa to DBn are held in the signal processing spare unit 20 in advance, and each unit is connected by the serial communication line L1-2. did. This eliminates the need to transfer the database when a failure occurs, so that a serial communication line L112 with a low transfer speed can be used.
  • the priority determining means 22-1 is provided in the signal processing reserve unit 20. Therefore, multiple failures occur In this case, the database switching process can be dealt with promptly, and database switching can be performed efficiently and in a short time.
  • FIG. 5 is a diagram showing the configuration of the third embodiment.
  • control unit 10 In the database switching device 1_3 of the third embodiment, the control unit 10, the signal processing spare unit 20 and the signal processing units 30a to 30n are connected by a bus line L1-3. I do.
  • the control unit 10 includes priority order determining means 17-1. Then, the line L2 connecting the database selection means 22 and the failure detection means 32a to 32n in the first and second embodiments is deleted.
  • the failure detection means 31a to 31n controls the failure notification via the nodes 33a to 33n. Send to 10
  • the priority determining means 17-1 in the control unit 10 receives the failure notification via the buffer 15. Then, a database selection instruction is transmitted to the signal processing spare unit 20 via the buffer 15 based on the priority.
  • the database selection means 22 of the signal processing spare unit 20 receives the data selection instruction based on the priority via the buffer 23 and holds the data selection instruction in the data base entire holding means 21. Select the appropriate database from DB a to DB n.
  • the setting of the databases DB a to DB n by the database setting means 11, the failure notification by the failure detecting means 31 a to 31 n, and the database selection instruction based on the priority determining means 17-1 are all performed on the bus line. This is performed using L 1 -3.
  • the priority determining means 17-1 in the figure is independent of the control unit 10.
  • the function program of the priority determining means 17-11 is stored in the ROM 13 and the CPU 12 determines the priority based on the program. , And gives a selection instruction on an overnight basis.
  • the databases DBa to DBn are stored in the signal processing spare unit 20 in advance, and the units are connected by the bus lines L1 to L3.
  • the determination means 17-1 is arranged in the control unit 10.
  • the line L2 can be deleted, and the processing load on the signal processing spare unit 20 can be reduced.
  • FIG. 6 is a diagram showing the configuration of the fourth embodiment.
  • the bus line L1_3 according to the second embodiment is replaced with the serial communication line L1-4. Therefore, the buffers 15, 23, 33a to 33n replace the serial communication I / Fs 16, 24, 34a to 34n.
  • the priority order determining means 17-1 is arranged in the control unit 10.
  • the databases DBa to DBn are held in the signal processing spare unit 20 in advance, and each unit is connected via the serial communication line L14, and the priority is given.
  • the order determining means 17 _ 1 is arranged in the control unit 10.
  • FIG. 7 is a diagram showing the configuration of the fifth embodiment.
  • the buffer 15 in the control unit 10 the buffer 23 in the signal processing standby unit 20, and the signal processing units 30a-3 Buffers 33a to 33n in On are connected by bus lines L1-5.
  • a data base selecting means 17 including priority order determining means 17-1 is arranged in the control unit 10.
  • the database selecting means 17 in the control unit 10 and the entire database holding means 21 in the signal processing spare unit 20 are connected by a line L2-5.
  • the setting of the database DBa to DBn by the database setting means 11 and the fault notification by the fault detecting means 31a to 31n are performed on the bus line L1-5.
  • the selection of the database based on the priority order at the time of failure occurrence is performed via the line L2-5 by the database selection means 17 arranged in the control unit 17.
  • the databases DBa to DBn are held in the signal processing spare unit 20 in advance, the units are connected by the bus lines L15, and the control unit is connected.
  • the database selecting means 17 in the network 10 and the entire database holding means 21 in the signal processing auxiliary unit 20 are connected by a line L2-5 different from the bus line L1-5.
  • FIG. 8 shows the sixth embodiment.
  • FIG. 14 is a diagram showing a configuration.
  • the bus line L1-5 of the fifth embodiment is replaced with the serial communication line L16. Therefore, the buffers 15, 23, 33a to 33n replace the serial communication IZFs 16, 24, 34a to 34n.
  • Other configurations are the same as those of the fifth embodiment.
  • the databases DBa to DBn are held in the signal processing spare unit 20 in advance, and the units are connected by the bus lines L1-6.
  • the data base selection means 17 in the control unit 10 and the entire database holding means 21 in the signal processing auxiliary unit 20 are connected by a line L2-6 different from the bus line L1-6. Configuration.
  • FIG. 9 is a diagram showing the configuration of the transmission system.
  • the signal processing units 30a to 30 ⁇ of the transmission system 2 process signals from the channels CHa to CHn.
  • the protection switch unit SW is internally configured with the same number of protection switches S Wa to SWn as the signal processing units 30a to 3On, and one signal processing spare unit 20 and N signals It connects to the faulty unit in which a fault occurred in the processing units 30a to 30n. That is, a 1: N switch configuration is adopted.
  • FIG. 10 is a flowchart showing the operation procedure of the transmission system 2.
  • the database setting means 11 of the control unit 10 sets the data base in advance in the signal processing units 30a to 30n and the signal processing auxiliary unit 20. That is, the database DBa to DBn is set for each of the database holding means 32a to 32n, and the databases DBa to DBn are set for the database whole holding means 21.
  • the failure detection means 31a of the signal processing unit 30a detects the failure and notifies the signal processing spare unit 20.
  • the database selection means 22 of the signal processing spare unit 20 sets the data base holding means 3 2a of the signal processing spare unit 20. Select the database DB a that was held.
  • the protection switch SWa is closed, and the other SWb to SWn are open.
  • the switch opening / closing control may be performed based on a failure notification signal from the failure detection means 31a to 31n, or may be performed based on a control signal from the control unit 10.
  • the signal processing spare unit 20 operates in place of the signal processing unit 30a to relieve a failure that has occurred in the signal processing unit 30a.
  • the first to sixth embodiments relating to the above-described database switching device 1 can be applied to the transmission system 2.
  • the database switching apparatus 1 and the transmission system 2 include the signal processing units 30a to 3a in the signal processing spare unit 20.
  • the entire database DBa to DBn held by 0n is held, and the corresponding database is selected when a failure occurs.
  • the signal processing unit 30 a to 30 ⁇ that performs DS1 (frame relay) transmission processing is switched to the signal processing standby unit 20.
  • the signal processing spare unit 20 When writing to the signal processing spare unit 20, it took several hundred ms or more.
  • switching can be performed in several ms because only switching processing time is required.
  • the shortening of switching has been described for a database.
  • the present invention is not limited to a database but can be applied to other general data aggregates (for example, files).
  • the database switching apparatus of the present invention has a configuration in which the entire database held by the signal processing unit is held in the signal processing standby unit, and the corresponding database is selected when a failure occurs. As a result, short-time switching of the database can be performed efficiently without using a high-speed and high-performance CPU or a high-speed bus.
  • the transmission system of the present invention allows the signal processing spare unit to hold the entire data base held by the signal processing unit, selects a corresponding database when a failure occurs, and sets the protection switching unit. Switch between the signal processing unit and the signal processing standby unit by means of a ⁇
  • the short-term switching of the service can be performed efficiently, and the fault can be remedied quickly.

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Signal Processing (AREA)
  • Quality & Reliability (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

La présente invention concerne un appareil performant de commutation de base de données comprenant des moyens détecteurs de défaillances (31a - 31n) destinés à détecter des défaillances de leur unité respective, des moyens (32a - 32n) destinés à contenir des bases de données (DBa - DBn) nécessaires au traitement du signal, des moyens totaux (21) destinés à contenir toutes les bases de données contenues dans une pluralité d'unités de traitement du signal (30a - 30n), des moyens de sélection (22) de base de données destinés, lors d'une panne, à sélectionner une base correspondante parmi les bases de données, et des moyens de désignation (11) afin de désigner des bases aux moyens contenant les bases de données (32a - 32n) ainsi qu'aux moyens totaux (21) contenant ces bases.
PCT/JP1999/000199 1999-01-20 1999-01-20 Appareil de commutation de base de donnees WO2000043882A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP1999/000199 WO2000043882A1 (fr) 1999-01-20 1999-01-20 Appareil de commutation de base de donnees

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Application Number Priority Date Filing Date Title
PCT/JP1999/000199 WO2000043882A1 (fr) 1999-01-20 1999-01-20 Appareil de commutation de base de donnees

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WO2000043882A1 true WO2000043882A1 (fr) 2000-07-27

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009245076A (ja) * 2008-03-31 2009-10-22 Fujitsu Ltd コンピュータシステム
CN110763997A (zh) * 2019-11-04 2020-02-07 华北电力大学（保定） 一种同步电机定子早期故障预警方法

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Publication number Priority date Publication date Assignee Title
JPH03201738A (ja) * 1989-12-28 1991-09-03 Nec Corp 変復調装置切替方式
JPH0447403A (ja) * 1990-06-13 1992-02-17 Mitsubishi Electric Corp オペレーターズステーションの冗長化装置
JPH05145579A (ja) * 1991-11-22 1993-06-11 Mitsubishi Electric Corp パケツト交換機のプロセツサ切り替え方式
JPH0635739A (ja) * 1992-07-16 1994-02-10 Nec Eng Ltd 切替制御方式
JPH07121395A (ja) * 1993-10-27 1995-05-12 Nippon Telegr & Teleph Corp <Ntt> 予備装置優先選択方法
JPH10285251A (ja) * 1997-04-10 1998-10-23 Nec Corp データ処理装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03201738A (ja) * 1989-12-28 1991-09-03 Nec Corp 変復調装置切替方式
JPH0447403A (ja) * 1990-06-13 1992-02-17 Mitsubishi Electric Corp オペレーターズステーションの冗長化装置
JPH05145579A (ja) * 1991-11-22 1993-06-11 Mitsubishi Electric Corp パケツト交換機のプロセツサ切り替え方式
JPH0635739A (ja) * 1992-07-16 1994-02-10 Nec Eng Ltd 切替制御方式
JPH07121395A (ja) * 1993-10-27 1995-05-12 Nippon Telegr & Teleph Corp <Ntt> 予備装置優先選択方法
JPH10285251A (ja) * 1997-04-10 1998-10-23 Nec Corp データ処理装置

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009245076A (ja) * 2008-03-31 2009-10-22 Fujitsu Ltd コンピュータシステム
JP4547440B2 (ja) * 2008-03-31 2010-09-22 富士通株式会社 仮想テープシステム
US8370682B2 (en) 2008-03-31 2013-02-05 Fujitsu Limited Virtual tape system take-over-controlled by standby server computer
CN110763997A (zh) * 2019-11-04 2020-02-07 华北电力大学（保定） 一种同步电机定子早期故障预警方法

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