CN106502835B - A kind of disaster-tolerant backup method and device - Google Patents

Abstract

The present invention provides a disaster recovery backup method and device. The disaster recovery backup method includes: judging whether the backup node is in the data synchronization interrupted state; when the backup node is in the data synchronization interrupted state, judging the last data update time in the master node Whether the time difference with the system time is less than the first time threshold; if the time difference between the time of the last updated data in the master node and the system time is less than the first time threshold, start the backup node to synchronize data from the master node; poll to detect the backup node, when the backup When the node completes data synchronization, stop the backup node to synchronize data. By using the disaster recovery backup method and device provided by the embodiments of the present invention, each controlled end node can be remotely controlled, and the flow and automation of remote data replication and backup can be realized.

Description

Disaster recovery backup method and device

technical field

The present invention relates to the technical field of communications, in particular to a disaster recovery backup method and device.

Background technique

With the rapid development of information technology, information security has increasingly become an issue of widespread concern in various industries and fields. Although the development of computers has provided people with more real-time and faster information services than ever before, and realized information storage. And the automation of management, but the hidden dangers brought by the wide application of computers are also very large. Once the computer system is irreversibly damaged, it will cause huge losses. In order to quickly restore data after a disaster, data backup methods are generally used in the prior art, including manual backup and automatic backup. NetApp SnapMirror software has proven high efficiency, simplicity and reasonable cost, so this software has been used for many years The preferred technology for replication and disaster recovery in various NetApp storage environments. Although NetApp SnapMirror can achieve efficient off-site replication and backup of data, it requires manual control of data off-site transmission.

Contents of the invention

In order to solve the above technical problems, the present invention provides a disaster recovery backup method and device.

One aspect of the present invention provides a disaster recovery backup method, the disaster recovery backup method comprising:

Determine whether the backup node is in the state of data synchronization interruption;

When the backup node is in the data synchronization interruption state, it is judged whether the time difference between the time of last updating data in the master node and the system time is less than the first time threshold;

If the time difference between the last data update time in the master node and the system time is less than a first time threshold, start the backup node to synchronize data from the master node;

The backup node is polled and detected, and when the backup node completes data synchronization, the backup node is stopped from synchronizing data.

In an embodiment, when the backup node completes data synchronization, if the backup node cannot be stopped, the disaster recovery backup method further includes: polling and detecting the master node for a preset time, if the master node Stop receiving external data within the preset time, then stop the backup node from synchronizing data.

In an embodiment, the disaster recovery backup method further includes: if the state of the master node does not stop receiving external data within the preset time, sending an alarm message for disaster recovery and error reporting.

In an embodiment, when the backup node completes data synchronization, the disaster recovery backup method further includes:

judging whether the time difference between the last data synchronization time in the backup node and the last data update time in the master node is less than a second time threshold;

When the time difference between the last data synchronization time in the backup node and the last data update time in the master node is less than the second time threshold, stop the backup node from synchronizing data.

In one embodiment, the time difference between the time when the data was last updated on the master node and the system time is less than a first time threshold, and after the backup node is started to synchronize data from the master node, the disaster recovery backup method further The method includes: judging whether the backup node is still in the interrupted state of data synchronization, and restarting the backup node to perform data synchronization if the backup node is still in the interrupted state of data synchronization.

In one embodiment, the disaster recovery backup method further includes: starting timing after starting the backup node, and detecting whether the current overall time for data synchronization of the backup node is greater than the third time threshold, and if so, sending Alarm information, for disaster recovery and error reporting.

In one embodiment, the disaster recovery backup method further includes: when the result of judging whether the backup node is in the data synchronization interrupted state is negative, sending out an alarm message for disaster recovery and error reporting.

In an embodiment, the disaster recovery backup method further includes: when the time difference between the last data synchronization time in the backup node and the last data update time in the master node is greater than the second time threshold, making the The above backup node continues to synchronize data.

Another aspect of the embodiment of the present invention also provides a disaster recovery backup device, the disaster recovery backup device includes:

The backup node access unit is used to determine whether the backup node is in a state of data synchronization interruption;

The master node access unit is used to determine whether the time difference between the last data update time in the master node and the system time is less than the first time threshold;

A backup node starting unit, configured to start the backup node to synchronize data from the master node when the time difference between the last data update time in the master node and the system time is less than a first time threshold;

The polling control unit is configured to poll and detect the backup node, and stop the backup node from synchronizing data when the backup node completes data synchronization.

In an embodiment, when the backup node completes data synchronization, if the backup node cannot be stopped, the polling control unit is further configured to: poll the master node for a preset time, if the master node If the node stops receiving external data within the preset time, the backup node is stopped from synchronizing data.

In an embodiment, the disaster recovery backup device further includes: an error reporting unit, configured to send an alarm message when the status of the master node does not stop receiving external data within the preset time, and perform disaster recovery and error reporting.

In an embodiment, the polling control unit further includes:

A time difference judging module, configured to judge whether the time difference between the last data synchronization time in the backup node and the last data update time in the master node is less than a second time threshold;

A node interruption module, configured to stop the backup node from synchronizing data when the time difference between the last data synchronization time in the backup node and the last data update time in the master node is less than the second time threshold.

In an embodiment, the polling control unit further includes:

A judging module, configured to judge whether the backup node is still in a data synchronization interruption state after the backup node startup unit starts the backup node;

A restart module, configured to restart the backup node to perform data synchronization when the backup node is still in a data synchronization interruption state.

In an embodiment, the disaster recovery backup device further includes a timing unit, configured to start timing after starting the backup node, and detect whether the overall time for the backup node to perform data synchronization is greater than a third time threshold, When the current overall time for the backup node to perform data synchronization is greater than the third time threshold, the error reporting unit sends an alarm message for disaster recovery and error reporting.

In an embodiment, the error reporting unit is further configured to issue an alarm message for disaster recovery and error reporting when the output result of the backup node access unit is negative.

In an embodiment, the polling control unit further includes: an updating module, configured to make the backup node continue to synchronize data when the output result of the time difference judging module is negative.

In an embodiment, the disaster recovery backup device is set in the backup node, and the disaster recovery backup device remotely accesses the master node through SSH, wherein SSH stands for Secure Shell Protocol.

In an embodiment, the disaster recovery backup device is set in the master node, and the disaster recovery backup device remotely accesses the backup node through SSH.

In one embodiment, the disaster recovery backup device is set independently from the backup node and the master node.

By using the disaster recovery backup method and device provided by the embodiments of the present invention, each controlled end node can be remotely controlled, and the flow and automation of remote data replication and backup can be realized.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic flow diagram of a disaster recovery backup method according to an embodiment of the present invention;

FIG. 2 is a schematic flow diagram of another disaster recovery backup method according to an embodiment of the present invention;

3 is a schematic structural diagram of a disaster recovery backup device according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a polling control unit 4 according to an embodiment of the present invention;

FIG. 5 is a structural diagram of a disaster recovery backup device according to an embodiment of the present invention;

FIG. 6 is a control structure diagram of another disaster recovery system according to an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The present invention provides the embodiment of a disaster recovery backup method, as shown in Figure 1, this method mainly comprises the following steps:

Step S1, judging whether the backup node is in a state of data synchronization interruption.

If the backup node is currently in the data synchronization interrupted state, it means that it meets the requirements for continuing to synchronize data. If the output result of step S1 is No, it means that the backup node does not meet the requirements for continuing to synchronize data, and it is necessary to send an alarm message for disaster recovery and error reporting (step S6), no longer perform the following steps.

Step S2. When the backup node is in the data synchronization interruption state, it is further judged whether the time difference between the last data update time in the master node and the system time is smaller than the first time threshold.

Since in the embodiment of the present invention, the master node receives external data at the beginning, and the backup node copies data from the master node, and its data source is the master node, accesses the master node through step S2, and determines the time when the master node last updates data Whether the time difference with the system time is less than a preset time threshold, if yes, it means that the last data update time in the master node is basically synchronized with the external data source, and subsequent steps can be performed. Therefore, it can be seen that the main function of this step is to determine whether the external data acquired in the master node is the latest data.

In one embodiment, the above-mentioned time threshold is usually taken as 15 minutes, that is, the time difference between the last data update time in the master node and the current system time is allowed to be within 15 minutes, and if it exceeds 15 minutes, an alarm message will be sent to perform disaster recovery and error reporting (step S6).

Step S3, if the time difference between the time of last updating data in the primary node and the system time is smaller than the first time threshold, start the backup node to synchronize data from the primary node.

If the time difference between the last data update time on the master node and the current system time does not exceed 15 minutes, you can use the external data last updated by the master node as the latest data, and start the backup node to synchronize data from the master node.

Step S4, polling and detecting the backup node, and judging whether the backup node has completed data synchronization.

Step S5, when the backup node completes data synchronization, stop the backup node from synchronizing data.

The embodiment of the present invention uses SSH to remotely control the backup node to obtain external data from the master node to ensure that the data is synchronized to the backup node. When implementing the embodiment of the present invention, only one backup node needs to be managed, and the management object is simple , realizing the process and automation of off-site data replication and backup.

In one embodiment, when the backup node completes the data synchronization, the backup node can usually be stopped in step S5, and its state changes to the data synchronization interruption state. However, if the master node is receiving external data at this time, that is, the master node is in the data transmission state, even if the backup node completes data synchronization, it may not be able to stop it. In order to prevent repeated error reporting, a buffer time is preset for the master node , polling detects the preset buffer time of the master node, if the state of the master node changes to an idle state (that is, stops receiving external data) within the preset buffer time, then it is possible to successfully shut down the backup node. If the state of the master node does not stop receiving external data within the above preset time, an alarm message will be issued for disaster recovery and error reporting.

FIG. 2 is also a schematic flowchart of a disaster recovery backup method provided by an embodiment of the present invention. As shown in Figure 2, a judgment step S7 is also included between the polling detection backup node and the stop backup node synchronous data, for judging whether the backup node is still in the data synchronization interruption state, if the backup node is still in the data synchronization interruption state, It means that the backup node failed to start successfully in step S3, and the backup node needs to be restarted for data synchronization.

As shown in Figure 2, when the backup node completes data synchronization, the disaster recovery backup method also includes a step S8, judging whether the time difference between the time of the last data synchronization in the backup node and the time of the last data update in the master node is less than a time threshold , and when the time difference between the last data synchronization time in the backup node and the last data update time in the master node is less than the time threshold, stop the backup node from synchronizing data. This step is mainly used to verify after the backup node completes data replication, to ensure that the last updated data of the backup node is the latest external data in the master node. When the time difference between the last data synchronization time in the backup node and the last data update time in the master node is greater than the time threshold, the backup node is made to continue to synchronize data. Wherein, the time threshold here may be 5 minutes or 15 minutes, but generally not less than 5 minutes.

The disaster recovery backup method provided by the embodiment of the present invention also includes a timing step (not shown in FIG. 2 ). The embodiment also sets a time threshold, starts timing when the backup node is started, and detects whether the current overall time for data synchronization of the backup node is greater than this time threshold, and if so, performs disaster recovery and error reporting. The time threshold is usually set at 40 minutes, that is, the overall process of data synchronization between the backup node and the master node should be controlled within 40 minutes. Exceeding this time threshold indicates that there is a special situation in the data synchronization process, and some steps may hang In case of death, the check of this threshold is a bottom-up solution to ensure that the entire data synchronization process is controllable.

Based on the same inventive concept as the disaster recovery backup method shown in FIG. 1 and FIG. 2 , the embodiment of the invention also provides a disaster recovery backup device, as described in the following embodiments. Since the problem-solving principle of the disaster recovery and backup device is similar to the disaster recovery and backup method, the implementation of the disaster recovery and backup device can refer to the implementation of the disaster recovery and backup method, and the repetition will not be repeated.

Figure 3 is a schematic structural diagram of a disaster recovery backup device according to an embodiment of the present invention. As shown in Figure 3, the disaster recovery backup device includes: a backup node access unit 1, a master node access unit 2, a backup node startup unit 3 and a polling control unit 4. Wherein, the backup node access unit 1 is used to judge whether the backup node is in the data synchronization interruption state; the master node access unit 2 is used to judge whether the time difference between the time of the last data update in the master node and the system time is less than the first time threshold; the backup node starts Unit 3 is used to start the backup node to synchronize data from the master node when the time difference between the time of the last data update in the master node and the system time is less than the first time threshold; the polling control unit 4 is used to poll and detect the backup node, when the backup node When data synchronization is complete, stop the backup node from synchronizing data.

In an embodiment, when the backup node completes data synchronization, if the backup node cannot be stopped, then the above-mentioned polling control unit 4 can also be used to poll and detect the master node for a preset time, if the master node is within the preset time If you stop receiving external data, you can stop the backup node from synchronizing data.

In an embodiment, the above-mentioned disaster recovery and backup device further includes an error reporting unit 5 for sending an alarm message when the state of the master node does not stop receiving external data within the preset time, for disaster recovery and error reporting.

As shown in FIG. 4 , the above-mentioned polling control unit 4 includes a time difference judgment module 41 and a node interruption module 42 . Time difference judging module 41 is used for judging whether the time difference between the time of the last synchronous data in the backup node and the time of last update data in the master node is less than the second time threshold; When the time difference between the time of last updating data in the nodes is smaller than the second time threshold, the backup node is stopped from synchronizing data. The above-mentioned second time threshold may be not less than 5 minutes.

In one embodiment, the polling control unit 4 also includes a judging module 43 and a restart module 44, the judging module 43 is used to judge whether the backup node is still in data synchronization after the backup node startup unit 3 starts the backup node Interrupted state; the restart module 44 is used to restart the backup node to perform data synchronization when the backup node is still in the interrupted state of data synchronization. After the backup node starting unit 3 starts the backup node, if the judging result of the judgment module 43 is that the backup node is still in the data synchronization interruption state, it means that the backup node has failed to start successfully, and the restart module 44 is needed to restart the backup node for data synchronization.

In one embodiment, the above-mentioned disaster backup device further includes a timing unit 6, which is used to start timing after the backup node is started, and detect whether the overall time for the backup node to perform data synchronization is greater than the third time threshold, when When the current overall time for data synchronization of the backup node is greater than the second time threshold, the error reporting unit 5 sends out an alarm message for disaster recovery and error reporting.

In one embodiment, when the output result of the backup node access unit 1 is negative (that is, the initial state of the backup node is not the data synchronization interruption state), the error reporting unit 6 will send out an alarm message for disaster recovery and error reporting.

In one embodiment, the polling control unit 4 also includes an updating module 45, which is used to jump to the backup node starting unit 3 when the output result of the time difference judging module 41 is no, and start the backup node to continue from the master node. sync data.

By using the disaster recovery backup method and device provided by the embodiments of the present invention, each controlled end node can be remotely controlled, and the flow and automation of remote data replication and backup can be realized.

The above-mentioned disaster recovery backup device can be set in the backup node, can also be set in the master node, or can be set independently outside the master node and the backup node. When the disaster recovery backup device is set in the backup node, the disaster recovery backup device can remotely access the master node through SSH (Secure Shell, secure shell protocol). When the disaster recovery backup device is set in the master node, the backup node can be remotely accessed through SSH. When the disaster recovery backup device is set independently from the backup node and the master node, the master node and the backup node can be remotely accessed through SSH.

FIG. 5 is a configuration diagram of a disaster recovery backup device provided by an embodiment of the present invention. The present invention is only illustrated by taking the setting of the disaster recovery backup device independent of the master node and the backup node as an example, and does not limit the present invention. As shown in Figure 5, the master node is used to obtain external source data, and the backup node is used to copy data from the master node for data synchronization. The nodes are respectively connected through the network, and the main and backup nodes can be accessed through SSH, which is used to control the backup node to copy data from the main node.

In order to better understand the disaster recovery backup method, server, and system provided in the embodiments of the present invention, the following description will be made in conjunction with specific examples.

NetApp SnapMirror software's proven efficiency, simplicity, and cost-effectiveness have made it the technology of choice for replication and disaster recovery in a variety of NetApp storage environments for many years. The NetApp SnapMirror software based on the Data ONTAPP operating system of Network Appliance can be used to build the backup node and master node in the disaster recovery backup system, and the disaster recovery backup device can be used to monitor and remotely control the backup node and master node in the NetApp SnapMirror software. The control structure diagram shown in Figure 6 realizes remote data synchronization. In the embodiment of the present invention, the NetApp SnapMirror software is deployed on two nodes in Beijing: node A and node B serve as the master node and the backup node respectively.

Firstly, check the relevant parameters of the disaster recovery and backup device, and if the parameter check is normal, then further check whether the status of the node B is in the data synchronization interruption (ie broken_off) status. If the B node is not in the broken_off state, it will report an error and exit, and the following operations will not be performed.

If node B is in the broken_off state, it meets the requirements for continuing to synchronize data, and further checks whether the time difference between the time when node A last updated data and the system time is less than 15 minutes. If the last data update time of node A is slower than the system time by more than 15 minutes, then continue to poll A node 20 times with an interval of 30 seconds each time. If the last data update time of node A is still not synchronized to the current time after 10 minutes If it is within, an error will be reported and exited.

If the time difference between the last data update time of node A and the system time is less than 15 minutes, or the time difference between the last data update time of node A and the system time is found to be less than 15 minutes after polling node A for many times, it means that node A has Get the latest external data, proceed to the next steps, start the B node, and start data synchronization from the A node (that is, start the snapmirrior replication).

Start timing while starting node B, and check whether the overall time for data synchronization of node B is less than 40 minutes. If it exceeds 40 minutes, it means that some modules of the system may hang during the data synchronization process, and then report an error and exit.

If the overall time for data synchronization by node B does not exceed 40 minutes, proceed to the next step, polling to check the status of node B and node A. Determine whether node B and node A are in the "snapmirrored&transferring" state (that is, node B is in the state of data synchronization completion (snapmirrored) and node A is in the state of data transmission (transferring)), if so, wait for 1 minute before checking A node and B The state of the node. Here, before checking the status of node B and node A, it is necessary to judge again whether the overall data synchronization time of node B is less than 40 minutes. Only when the overall data synchronization time of node B is still less than 40 minutes Then check the status of Node B and Node A again. Node A is in the transferring state, which means that node A is currently receiving external data. If node B is stopped at this time, it may not succeed. In order to ensure that node B is successfully stopped, this embodiment adds a step of checking node A. The manner is a further supplement to the relevant embodiments of the method and device of the present invention, and is not intended as a limitation of the present invention.

If B node and A node are not in "snapmirrored&transferring" state, then further judge whether B node and A node are in "snapmirrored&idle" state (that is, B node is in snapmirrored state and A node is in idle (idle) state). Node A is in the idle state, which means that node A neither receives external data nor transmits data to node B. If node B is stopped at this time, it will not fail to stop.

If the states of Node B and Node A are not in the "snapmirrored&idle" state, further determine whether Node B and Node A are in the "broken_off&idle" state (that is, Node B is in the state of data synchronization interruption and Node A is in the idle state), if Node B and Node A The node is in the "broken_off&idle" state, indicating that the B node has not started successfully, and the B node needs to be restarted for data synchronization. In specific implementation, further judgment may be made only on the node B. When the node B is in the state of data synchronization interruption, it means that the node B has failed to start successfully, and the node B needs to be restarted to synchronize data.

If the statuses of node B and node A are "snapmirrored&idle", it means that the data synchronization is complete. Further check whether the time difference between the last data synchronization time on node B and the last data update time on node A is less than 5 minutes. If it is less than 5 minutes, It means that the data synchronization is successful. If it is longer than 5 minutes, execute the update (update) command to make the B node continue to synchronize data from the A node. When the difference between the last data synchronization time in node B and the last data update time in node A is less than 5 minutes, it is usually considered that node B has successfully synchronized the latest data in node A.

In the embodiment of the present invention, by combining the disaster recovery application server and the NetApp SnapMirror software, the remote control of each controlled end node by the management center is realized, and the process and automation are realized, and the data synchronization status of the NetApp SnapMirror software is automatically monitored. It realizes efficient and automatic remote data synchronization, makes remote SSH data interaction controllable, and realizes the automatic execution of remote commands.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

In the present invention, specific examples have been applied to explain the principles and implementation methods of the present invention, and the descriptions of the above examples are only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to this The idea of the invention will have changes in the specific implementation and scope of application. To sum up, the contents of this specification should not be construed as limiting the present invention.

Claims (19)

1. a kind of disaster-tolerant backup method, which is characterized in that the disaster-tolerant backup method includes：

Judge whether backup node is in data sync break state；

When the backup node is in data sync break state, the time of final updating data and system in host node are judged Whether the time difference of time is less than first time threshold；

If the time of final updating data and the time difference of system time are less than first time threshold in the host node, start The backup node is from synchrodata from the host node；

Poll detects the backup node, when the backup node, which completes data, to be synchronized, stops the same step number of the backup node According to.

2. disaster-tolerant backup method according to claim 1, which is characterized in that complete data when the backup node and synchronize When, if can not stop the backup node, the disaster-tolerant backup method further includes：Poll detects the host node one when presetting Between, if the host node stops receiving external data in the preset time, stop the backup node synchrodata.

3. disaster-tolerant backup method according to claim 2, which is characterized in that the disaster-tolerant backup method further includes：If The state of the host node does not stop receiving external data in the preset time, then sends out warning information, carries out disaster tolerance report It is wrong.

4. disaster-tolerant backup method according to claim 1 or 2, which is characterized in that when backup node completion data are same When step, the disaster-tolerant backup method further includes：

Judge in the backup node time of final updating data in the time of last synchrodata and the host node when Between difference whether be less than second time threshold；

When the time of the time of last synchrodata and the time of final updating data in the host node in the backup node When difference is less than the second time threshold, stop the backup node synchrodata.

5. disaster-tolerant backup method according to claim 1, which is characterized in that the final updating data in the host node Time and the time difference of system time are less than first time threshold, start the backup node from synchrodata from the host node Afterwards, the disaster-tolerant backup method further includes：The backup node is judged whether still in data sync break state, if described Backup node restarts the backup node and carries out data synchronization still in data sync break state.

6. disaster-tolerant backup method according to claim 1 or 5, which is characterized in that the disaster-tolerant backup method further includes： Start timing after starting the backup node, and detect the backup node currently carry out data synchronization overall time it is whether big In third time threshold, if it is, sending out warning information, carries out disaster tolerance and report an error.

7. disaster-tolerant backup method according to claim 1, which is characterized in that the disaster-tolerant backup method further includes：Judge When the result whether backup node is in data sync break state is no, warning information is sent out, disaster tolerance is carried out and reports an error.

8. disaster-tolerant backup method according to claim 4, which is characterized in that the disaster-tolerant backup method further includes：Work as institute The time difference for stating the time of final updating data in the time of last synchrodata and the host node in backup node is more than institute When stating second time threshold, the backup node is made to continue synchrodata.

9. a kind of disaster-tolerant backup device, which is characterized in that the disaster-tolerant backup device includes：

Backup node access unit, for judging whether backup node is in data sync break state；

Host node access unit, for judging whether the time of final updating data and the time difference of system time are small in host node In first time threshold；

Backup node start unit, for small when the time of final updating data in the host node and the time difference of system time When first time threshold, start the backup node from synchrodata from the host node；

Polling system unit detects the backup node for poll, when the backup node, which completes data, to be synchronized, stops institute State backup node synchrodata.

10. disaster-tolerant backup device according to claim 9, which is characterized in that complete data when the backup node and synchronize When, if can not stop the backup node, the polling system unit is additionally operable to：Poll detects the host node one when presetting Between, if the host node stops receiving external data in the preset time, stop the backup node synchrodata.

11. disaster-tolerant backup device according to claim 10, which is characterized in that the disaster-tolerant backup device further includes：Report Wrong unit, for sending out alarm letter when the state of the host node does not stop the when of receiving external data in the preset time Breath carries out disaster tolerance and reports an error.

12. disaster-tolerant backup device according to claim 9 or 10, which is characterized in that the polling system unit further includes：

Time difference judgment module, it is last in the time of last synchrodata and the host node for judging in the backup node Whether the time difference of the time updated the data is less than second time threshold；

Node interrupts module, for when the time of last synchrodata in the backup node and final updating in the host node When the time difference of the time of data is less than the second time threshold, stop the backup node synchrodata.

13. disaster-tolerant backup device according to claim 9, which is characterized in that the polling system unit further includes：

Judgment module, after the backup node start unit starts backup node, for judging the backup node whether still In data sync break state；

Module is restarted, for when the backup node is still in data sync break state, restarting the backup Node carries out data synchronization.

14. the disaster-tolerant backup device according to claim 9 or 13, which is characterized in that the disaster-tolerant backup device further includes One timing unit for starting timing after starting the backup node, and detects the backup node currently to carry out data same Whether the overall time of step is more than third time threshold, when the overall time that the backup node currently carries out data synchronization is more than When the third time threshold, the unit that reports an error sends out warning information, carries out disaster tolerance and reports an error.

15. disaster-tolerant backup device according to claim 11, which is characterized in that the unit that reports an error is additionally operable to when backup section When the output result of point access unit is no, warning information is sent out, disaster tolerance is carried out and reports an error.

16. disaster-tolerant backup device according to claim 12, which is characterized in that the polling system unit further includes：More New module, for when the output result of the time difference judgment module is no, the backup node being made to continue synchrodata.

17. disaster-tolerant backup device according to claim 9, which is characterized in that the disaster-tolerant backup device is set to described In backup node, the disaster-tolerant backup device remotely accesses the host node by SSH, wherein SSH indicates Secure Shell association View.

18. disaster-tolerant backup device according to claim 9, which is characterized in that the disaster-tolerant backup device is set to described In host node, the disaster-tolerant backup device remotely accesses the backup node by SSH.

19. disaster-tolerant backup device according to claim 9, which is characterized in that the disaster-tolerant backup is installed on the backup It is independently arranged except node and host node.