FAILSAFE MECHANISM FOR DYNAMIC INSTRUMENTATION OF SOFTWARE USING CALLBACKS

• US 20110283265A1
• Filed: 05/11/2010
• Published: 11/17/2011
• Est. Priority Date: 05/11/2010
• Status: Active Grant

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Inventors: Gagliardi, Marco, Sun, Yitao
• Granted Patent: US 8,782,612 B2
• Time in Patent Office: Days
• US Class Current: 717/130
• CPC Class Codes: G06F 11/1438 Restarting or rejuvenating
• CPC Class Codes: G06F 11/3495 for systems
• CPC Class Codes: G06F 11/3644 by instrumenting at runtime
• CPC Class Codes: G06F 2201/875 Monitoring of systems including the internet

Abstract

A failsafe mechanism for installing and removing temporary instrumentation during a runtime of an application. Initially, an application is configured with a baseline set of instrumented components such as methods. Additional instrumentation is then deployed in the application, such as to diagnose a performance problem. The failsafe mechanism ensures that the additional instrumentation is automatically removed, even when there is an interruption in a communication link to the application, a computing device failure, a software failure, or some other type of failure, which renders it impossible to manually roll back the instrumentation from a remote user interface. The failsafe mechanism can be provided using callbacks between the computing devices which detect when a connection is unexpectedly lost or closed. Termination of one callback can cascade to one or more other callbacks. The instrumentation rollback can involve reloading un-instrumented byte code of the application.

Claims

1. A computer-implemented method for providing a failsafe capability for an application, comprising:

receiving a request at an application server to add temporary dynamic instrumentation to the application, the request is received from a computing device (MANAGER) via a respective connection between the computing device and the application server;

in response to the request, adding the temporary dynamic instrumentation to the application during the runtime of the application, and implementing a callback to the computing device via the respective connection, the callback determines if the respective connection is unexpectedly lost; and

in response to the callback determining that the respective connection is unexpectedly lost, restoring the application to a state which does not include the temporary dynamic instrumentation.

2. The computer-implemented method of claim 1, wherein:

the request includes at least one directive to add the temporary dynamic instrumentation to at least one class of the application; and

the temporary dynamic instrumentation is added to the application by redefining the at least one class of the application.

3. The computer-implemented method of claim 1, wherein:

the callback automatically determines that the respective connection is unexpectedly lost so that the application is automatically, without human intervention, restored to the state which does not include the temporary dynamic instrumentation.

4. The computer-implemented method of claim 1, wherein:

the respective connection is made via a socket at the application server; and

the callback determines that the respective connection is unexpectedly lost by determining that the socket generates an event indicating that the respective connection is unexpectedly lost.

5. The computer-implemented method of claim 1, wherein:

the state to which the application is restored includes static instrumentation but not dynamic instrumentation.

6. The computer-implemented method of claim 1, wherein:

maintaining a record of directives, the directives identify classes of the application to which associated instrumentation was added before the temporary dynamic instrumentation was added; and

the restoring comprises loading un-instrumented byte code of the application, and adding the associated instrumentation to the classes identified by the directives in the un-instrumented byte code.

7. The computer-implemented method of claim 6, wherein:

the un-instrumented byte code of the application is accessed from a .JAR file.

8. The computer-implemented method of claim 1, further comprising:

after the temporary dynamic instrumentation is added to the application, thereby becoming previously-added temporary dynamic instrumentation, receiving an additional request to add additional temporary dynamic instrumentation to the application, the additional request is received at the application server from the computing device via another connection between the computing device and the application server;

in response to the additional request, adding the additional temporary dynamic instrumentation to the application during the runtime of the application, and implementing another callback to the computing device, the another callback determines if the another connection is unexpectedly lost; and

in response to determining that the another connection is unexpectedly lost, and that the respective connection is not unexpectedly lost, restoring the application to a state which does not include the additional temporary dynamic instrumentation, but which does include the previously-added temporary dynamic instrumentation.

9. The computer-implemented method of claim 1, further comprising:

receiving a request from the computing device, upon expiration of a timer at the computing device, to restore the application to a state which existed before the temporary dynamic instrumentation was added; and

in response to the request to restore the application, restoring the application to the state which existed before the temporary dynamic instrumentation was added, where the state which existed before the temporary dynamic instrumentation was added includes instrumentation other than the temporary dynamic instrumentation.

10. The computer-implemented method of claim 1, further comprising:

receiving a request from the computing device, upon expiration of a timer at the computing device, to terminate the callback to the computing device, and in response to the request to terminate the callback to the computing device, terminating the callback to the computing device, and restoring the application to a state which existed before the temporary dynamic instrumentation was added, where the state which existed before the temporary dynamic instrumentation was added includes instrumentation other than the temporary dynamic instrumentation.

11. A computer-implemented method for providing a failsafe capability for applications, comprising:

receiving a request at a first computing device (MANAGER) from a second computing device (MOM), the request identifies an application server and includes at least one directive for adding associated temporary dynamic instrumentation to an application at the application server; and

in response to the request, implementing a timer, and providing, from the first computing device to the application server via a first connection, the at least one directive to add the associated temporary dynamic instrumentation to the application, and a request to implement a callback to the first computing device, the callback determines if the first connection is unexpectedly lost; and

upon expiration of the timer, if the first connection is not unexpectedly lost, providing a request to the application server via the first connection to restore the application to a state which existed before the associated temporary dynamic instrumentation was added.

12. The computer-implemented method of claim 11, further comprising:

upon expiration of the timer, if the first connection is not unexpectedly lost, providing a request to the application server via the first connection to terminate the callback to the first computing device via the first connection.

13. The computer-implemented method of claim 11, further comprising:

in response to the request from the second computing device, implementing a callback to the second computing device via a second connection, which is between the first and second computing devices; and

upon expiration of the timer, terminating the callback to the second computing.

14. The computer-implemented method of claim 13, wherein:

in response to the request from the second computing device, implementing a callback to the second computing device via a second connection, which is between the first and second computing devices;

at the first computing device, listening to the first connection to the determine if the first connection is unexpectedly lost, and in response to determining that the first connection is unexpectedly lost, terminating the call back to the second computing device.

15. In an application server, tangible computer readable storage having computer readable software embodied thereon for programming at least one processor to perform a method for providing a failsafe capability for an application, the method comprising:

establishing a connection with a computing device (MANAGER);

receiving a request, from the computing device, via the connection, to add temporary dynamic instrumentation to the application, and to invoke a callback object;

in response to the request, adding the temporary dynamic instrumentation to the application during the runtime of the application, and invoking the callback object, the callback object implements a callback to the computing device by monitoring the connection; and

if the callback object determines that the connection has been terminated, restoring the application to a state which does not include the temporary dynamic instrumentation.

16. The tangible computer readable storage of claim 15, wherein:

the state to which the application is restored includes instrumentation other than the temporary dynamic instrumentation.

17. The tangible computer readable storage of claim 15, wherein the method performed further comprises:

maintaining a record of directives, the directives identify classes of the application to which instrumentation was added before the temporary dynamic instrumentation was added; and

the restoring comprises loading un-instrumented byte code of the application, and adding the associated instrumentation to the classes identified by the directives in the un-instrumented byte code.

18. The tangible computer readable storage of claim 15, wherein:

the request includes a directive to add the temporary dynamic instrumentation to at least one class of the application; and

the temporary dynamic instrumentation is added to the application by redefining the at least one class of the application.

19. The tangible computer readable storage of claim 15, wherein:

the callback automatically determines that the connection is unexpectedly lost so that the application is automatically, without human intervention, restored to the state which does not include the temporary dynamic instrumentation.

20. The tangible computer readable storage of claim 15, wherein:

the connection is made via a socket at the application server; and

the callback determines that the respective connection is unexpectedly lost by determining that the socket generates an event indicating that the respective connection is unexpectedly lost.