Method and system for providing high availability to computer applications

• US 20060090097A1
• Filed: 08/26/2005
• Published: 04/27/2006
• Est. Priority Date: 08/26/2004
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Inventors: Havemose, Allan, Ngan, Ching-Yuk Paul, Hortikar, Sanjay D., Tewksbury, Lauren, Raman, Vishwas
• Granted Patent: US 8,122,280 B2
• Time in Patent Office: Days
• US Class Current: 714/6.12
• CPC Class Codes: G06F 11/0709 in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems
• CPC Class Codes: G06F 11/1402 Saving, restoring, recovering or retrying
• CPC Class Codes: G06F 11/141 for bus or memory accesses
• CPC Class Codes: G06F 11/1438 Restarting or rejuvenating
• CPC Class Codes: G06F 11/1482 by means of middleware or OS functionality
• CPC Class Codes: G06F 11/20 using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements
• CPC Class Codes: G06F 11/2002 where interconnections or communication control functionality are redundant flexible arrangements for bus networks involving redundancy H04L12/40176
• CPC Class Codes: G06F 11/2023 Failover techniques
• CPC Class Codes: G06F 11/2028 eliminating a faulty processor or activating a spare
• CPC Class Codes: G06F 11/203 using migration
• CPC Class Codes: G06F 11/2046 where the redundant components share persistent storage G06F11/2043 takes precedence
• CPC Class Codes: G06F 11/30 Monitoring
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses

Abstract

A set of system-level high availability services for computer systems, including a service that functions in general terms like an extension of the operating system. By providing High Availability (HA) at the system-level, modifications to the applications or the operating system kernel are not required.

Claims

1. A method for achieving transparent integration of an application program with a high availability protection program, comprising:

injecting registration code, transparently and automatically, into an application program during launch;

wherein said application program automatically registers with said high availability protection program;

wherein modification of the application program or application program recompilation is not required; and

wherein a custom loader is not required.

2. A method as recited in claim 1, further comprising:

monitoring unregistration of said application program from said high availability program; and

designating said unregistration as a normal exit.

3. A method as recited in claim 1, wherein said registration code comprises et_init( ).

4. In a high availability protection computer program, the improvement comprising:

injecting registration code, transparently and automatically, into an application program during launch;

wherein said application program automatically registers with said high availability protection program;

wherein modification of the application program or application program recompilation is not required; and

wherein a custom loader is not required.

5. An improvement as recited in claim 4, further comprising:

monitoring unregistration of said application program from said high availability program; and

designating said unregistration as a normal exit.

6. An improvement as recited in claim 4, wherein said registration code comprises et_init( ).

7. A computer program for transparently registering an application program with a high availability computer program, comprising a set of instructions stored on a media accessible by a computer and executable on said computer, wherein said computer program performs the steps comprising:

injecting registration code, transparently and automatically, into an application program during launch;

wherein said application program automatically registers with said high availability protection program;

wherein modification of the application program or application program recompilation is not required; and

wherein a custom loader is not required.

8. A computer program as recited in claim 7, wherein said program performs the steps further comprising:

monitoring unregistration of said application program from said high availability program; and

designating said unregistration as a normal exit.

9. A computer program method as recited in claim 7, wherein said registration code comprises et_init( ).

10-17. -17. (canceled)

18. A method for system management in a high availability computer program, comprising:

providing a mechanism to ensure that processes that comprise an application program are launched in a proper order, and with the proper timing constraints during recovery.

19. A method as recited in claim 18, further comprising:

providing a mechanism to ensure that application programs are recovered in the proper order.

20. A method as recited in claim 18, further comprising:

providing a mechanism to configure the high availability characteristics of an application program through a user interface without requiring any modification or recompilation of the application program.

21. In a high availability computer program, the improvement comprising:

a mechanism to ensure that processes that comprise an application program are launched in the proper order, and with the proper timing constraints during recovery.

22. An improvement as recited in claim 21, further comprising:

a mechanism to ensure that application programs are recovered in the proper order.

23. An improvement as recited in claim 21, further comprising:

a mechanism to configure the high availability characteristics of an application program through a user interface without requiring any modification or recompilation of the application program.

24. A method for lossless migration of an application program from a primary node to a backup node without replication which is transparent to a client connected to the primary node over a TCP/IP connection, comprising:

providing a loadable kernel module comprising a dummy device driver;

providing an application checkpointing procedure which invokes said kernel module;

providing an application restoration procedure which invokes said kernel module;

wherein, during checkpointing, the checkpointing procedure notifies the kernel module, and the kernel module captures the state of all the TCP connections that are open for that process in a byte buffer and sends the state to the checkpointing procedure; and

sending the connection state to a backup node along with the application state;

wherein, during restoration on the backup node, the restoration procedure invokes the kernel module with the saved byte buffer, and the kernel module uses the data in the byte buffer to restore all the TCP connections in the exact same state as they were in the primary node.

25. A method as recited in claim 24:

wherein the kernel module hooks into the networking stack during checkpointing and restoration and freezes the entire connection; and

wherein the client experiences a connection delay during the time the process is checkpointed and restored on the backup node.

26. A computer executable program for lossless migration of an application program from a primary node to a backup node without replication which is transparent to a client connected to the primary node over a TCP/IP connection, comprising:

a loadable kernel module comprising a dummy device driver;

an application checkpointing procedure which invokes said kernel module;

an application restoration procedure which invokes said kernel module;

wherein, during checkpointing, the checkpointing procedure notifies the kernel module, and the kernel module captures the state of all the TCP connections that are open for that process in a byte buffer and sends the state to the checkpointing procedure;

wherein the checkpointing procedure sends the connection state to a backup node along with the application state; and

wherein, during restoration on the backup node, the restoration procedure invokes the kernel module with the saved byte buffer, and the kernel module uses the data in the byte buffer to restore all the TCP connections in the exact same state as they were in the primary node.

27. A computer executable program as recited in claim 26:

wherein the kernel module hooks into the networking stack during checkpointing and restoration and freezes the entire connection; and

wherein the client experiences a connection delay during the time the process is checkpointed and restored on the backup node.

28. A method for achieving transparent integration of an application program with a high availability protection program, comprising:

injecting registration code, transparently and automatically, into an application program during launch, without the need of modifying or recompiling the application program and without the need of a custom loader;

registering said application program automatically with said high availability protection program;

detecting a failure in the execution of said application program running on a primary server; and

executing said application program from one or more designated backup servers automatically in response to said failure.

29. A method as recited in claim 28, further comprising:

monitoring unregistration of said application program from said high availability program; and

designating said unregistration as a normal exit.

30. A method as recited in claim 28, further comprising managing high availability policy using an automatic profiler monitoring application execution, or in response to policy adjustments from an administrator.

31. A method as recited in claim 30, wherein said profiler monitors application execution, builds a statistical description of the execution and uses the statistical description for generating and/or recommending optimal settings.

32. A method as recited in claim 30, wherein said policy comprises characterstics for controlling a heart-beat frequency, a checkpointing interval, configuration of health-checks, or start/stop/restart scripts.

33. A method as recited in claim 28, further comprising performing healthchecks during the execution of said application program for said detecting of a failure in the execution of said application program.

38. A method as recited in claim 28, further comprising:

process checkpointing single-threaded and multi-threaded application processes;

wherein said process checkpointing is selected from the group of checkpointing mechanisms consisting essentially of;

(a) checkpointing daemonized multi-process applications;

(b) checkpointing general multiprocess applications;

(c) full and incremental checkpointing; and

(d) checkpointing to either local or shared disk.

39. A method as recited in claim 28, further comprising storage checkpointing and synchronizing storage checkpointing with process checkpointing.

40. A method as recited in claim 28, wherein during said storage checkpointing, the checkpointing procedure notifies the kernel module which captures the state of the open TCP connections for the checkpointing procedure.

41. A method as recited in claim 28, wherein said method is configured as a mechanism for ensuring that processes within an application program are launched and recovered in a proper order, and that proper timing constraints are maintained during recovery.

43. A method as recited in claim 28, wherein said method is implemented as a computer program for transparently registering an application program with a high availability computer program and comprises a set of instructions stored on a media accessible by a computer and executable on said computer for performing said method steps.

34-37. -37. (canceled)

42. (canceled)

44. A method for performing lossless migration of an application program from a primary node to a backup node and while being transparent to a client connected to the primary node over a TCP/IP connection, comprising:

loading a kernel module comprising a dummy device driver;

executing a checkpointing procedure for said application to invoke said kernel module for capturing the state of TCP connections that are open for that process and sending the connection state to said checkpointing procedure and to a backup server node in conjunction with application state; and

executing application restoration procedures to invoke said kernel module for restoring the backup server node to restore TCP connections in the exact state as they were in the primary server.

45. A method as recited in claim 44:

wherein the kernel module hooks into the networking stack during checkpointing and restoration and freezes the entire connection; and

wherein the client experiences a connection delay during the time the process is checkpointed and restored on the backup node.

46. A computer executable program for lossless migration of an application program from a primary node to a backup node which is transparent to a client connected to the primary node over a TCP/IP connection, comprising:

a loadable kernel module comprising a dummy device driver;

an application checkpointing procedure configured for invoking said kernel module for capturing the state of all the open TCP connections for that process and communicating the connection states back to the checkpointing procedure and to a backup node along with the application state; and

an application restoration procedure configured for invoking said kernel module to restore all the TCP connections in the exact same state as they were in the primary node.

47. A computer executable program as recited in claim 46:

wherein the kernel module hooks into the networking stack during checkpointing and restoration and freezes the entire connection; and

wherein the client experiences a connection delay during the time the process is checkpointed and restored on the backup node.