METHOD AND APPARATUS FOR REALIZING APPLICATION HIGH AVAILABILITY

• US 20100241895A1
• Filed: 03/22/2010
• Published: 09/23/2010
• Est. Priority Date: 03/23/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Yang, Jie, Qiu, Jie, Zhong, Xiao, Li, Ying
• Granted Patent: US 8,195,979 B2
• Time in Patent Office: Days
• US Class Current: 714/4
• CPC Class Codes: G06F 11/2025 using centralised failover control functionality
• CPC Class Codes: G06F 11/2038 with a single idle spare processing component
• CPC Class Codes: G06F 11/2046 where the redundant components share persistent storage G06F11/2043 takes precedence
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/1734 Details of monitoring file system events, e.g. by the use of hooks, filter drivers, logs
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: H04L 61/2503 Translation of Internet protocol [IP] addresses
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes

Abstract

A method and apparatus for realizing application high availability. The application is installed on both a first node and a second node, the first node being used as an active node, and the second node being used as a passive node. The method includes: monitoring access operations to files by an application during its execution on the active node; replicating the monitored updates to the file by the application from the active node to a storage device accessible to the passive node if the application performs updates to a file during the access operations; sniffing the execution of the application on the active node; and switching the active node to the second node and initiating the application on the second node in response to sniffing a failure in the execution of the application on the active node.

Claims

1. A computer implemented method for realizing application high availability, wherein the application is installed respectively on a first node and a second node, the first node being used as an active node and the second node being used as a passive node, the method comprising:

monitoring access operations to files by the application during execution of the application on the active node;

replicating a monitored update to a file by the application if the application performed an update to the file during the access operations, such replication being from the active node to a storage device accessible by the passive node;

sniffing execution of the application on the active node; and

switching the application to and initiating the application on the second node in response to sniffing a failure in the execution of the application on the active node.

2. The method according to claim 1, wherein, a first sub file system is created on the first node and a first dedicated block device is mounted on the first sub file system, and a second sub file system is created on the second node and a second dedicated block device is mounted on the second sub file system:

wherein the replicating step includes replicating the updates in the first dedicated block device to the second dedicated block device; and

wherein the method further comprises redirecting monitored updates to the file by the application to the first sub file system.

3. The method according to claim 2, wherein the step of replicating the updates in the first dedicated block device to the second dedicated block device is implemented by a disk operation hook that is hooked into the operating system, and wherein the hook is initiated whenever an update to a file is written into the first dedicated block device.

4. The method according to claim 1, wherein a first sub file system is created on the first node and a storage device shared between the first node and the second node is mounted on the first sub file system, a second sub file system is created on the second node and the storage device is mounted on the second sub file system, and

the step of replicating the monitored updates to the file by the application from the active node to a storage device accessible to the passive node includes redirecting monitored updates to the file by the application to the first sub file system.

5. The method according to claim 2, wherein the step of redirecting monitored updates to the file by the application to the first sub file system comprises:

copying the file from outside the first sub file system into the first sub file system in response to the first monitored update to a file outside the first sub file system;

creating in the memory a file data structure of the file descriptor associated with the copy file in the first sub file system; and

writing monitored updates to the file outside the first sub file system by the application to the copy file within the first sub file system by using the file data structure.

6. The method according to claim 2, further comprising:

determining whether the application is a high availability application;

redirecting the updates to the file by the application to the first sub file system; and

replicating the updates in the first dedicated block device to the second dedicated block device in response to a determination that the application is a high availability application.

7. The method according to claim 6, the step of determining whether the application is a high availability application includes:

registering the ID of the application in a registry in response to any application being initiated by a dedicated initiator;

determining whether the ID of the application is in the registry in response to receiving a file access request from an application; and

determining the application to be a high availability application in response to determining the ID of the application is in the registry.

8. The method according to claim 2, wherein the steps of monitoring access operations to files by the application and redirecting updates to the file by the application to the sub file system are implemented by a file operation hook that is hooked onto file access system calls of the operating system.

9. The method according to claim 2, wherein:

when the application is installed on the first sub file system and on the second sub file system, the step of redirecting monitored updates to the file by the application to the first sub file system includes the step of redirecting the monitored access operations to the file outside the first sub file system by the application to the first sub file system.

10. An apparatus for realizing application high availability, wherein the application is installed on a first node and on a second node, the first node being used as an active node, and the second node being used as a passive node, the apparatus comprising:

a monitoring module for monitoring access operations to files by the application during its execution on the active node;

a replicating module for replicating the monitored updates to the file by the application from the active node to a storage device accessible to the passive node, if the application performs updates to a file during the access operations;

a sniffing module for sniffing the execution of the application on the active node; and

a switching and initiating module for switching the active node to the second node and initiating the application on the second node in response to sniffing a failure in the execution of the application on the active node.

11. An apparatus according to claim 10, wherein, a first sub file system is created on the first node and a first dedicated block device is mounted on the first sub file system, and a second sub file system is created on the second node and a second dedicated block device is mounted on the second sub file system, the apparatus further comprising:

a redirecting module for redirecting monitored updates to the file by the application to the first sub file system, wherein the replicating module replicates the updates in the first dedicated block device to the second dedicated block device.

12. The apparatus according to claim 11, wherein the replicating module is implemented by a disk operation hook that is hooked into the operating system, and the hook is initiated whenever an update to a file is written into the first dedicated block device.

13. The apparatus according to claim 10, wherein a first sub file system is created on the first node and a storage device shared between the first node and the second node is mounted on the first sub file system, a second sub file system is created on the second node and the storage device is mounted on the second sub file system, and the replicating module comprises:

a redirecting module for redirecting monitored updates to the file by the application to the first sub file system.

14. The apparatus according to claim 11, wherein, the redirecting module:

is responsive to the first monitored update to a file outside the first sub file system, to copy the file from outside the first sub file system into the first sub file system, and create in the memory a file data structure of the file descriptor associated with the copy file in the first sub file system; and

is configured to write monitored updates to the file outside the first sub file system by the application to the copy file within the first sub file system by using the file data structure.

15. The apparatus according to claim 11, wherein the redirecting module further comprises:

means for determining whether the application is a high availability application;

means for redirecting the updates to the file by the application to the first sub file system; and

means for replicating the updates in the first dedicated block device to the second dedicated block device in response to determining the application is a high availability application.

16. The apparatus according to claim 15, wherein the means for determining whether the application is a high availability application comprises:

means for registering the ID of the application in a registry in response to initiation of any application by a dedicated initiator;

means for determining whether the ID of the application is in the registry, in response to receiving a file access request from an application; and

means for determining the application is a high availability application, in response to determining the ID of the application is in the registry.

17. The apparatus according to claim 10, wherein, the monitoring module and the redirecting module are implemented by a file operation hook that is hooked onto file access system calls of the operating system.

18. The apparatus according to claim 11, wherein the application is installed respectively on the first sub file system and the second sub file system, and the redirecting module is configured to redirect monitored access operations to a file outside the first sub file system by the application to the first sub file system.

19. The apparatus according to claim 10, wherein the switching and initiating module comprises:

a switching module and an initiating module.