HOT ROLLBACK OF UPDATED AGENT

• US 20140059528A1
• Filed: 08/24/2012
• Published: 02/27/2014
• Est. Priority Date: 08/24/2012
• Status: Active Grant

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Inventors: Gagliardi, Marco
• Granted Patent: US 9,817,656 B2
• Time in Patent Office: Days
• US Class Current: 717/170
• CPC Class Codes: G06F 11/3644 by instrumenting at runtime
• CPC Class Codes: G06F 8/656 while running

Abstract

Technology is disclosed herein for managing versions of an Agent associated with an application. Code for the Agent can be updated, and subsequently rolled back without being disruptive to the application.

Claims

1. A method of managing versions of an Agent for an Application, comprising:

running the Agent with the Application in a Java Virtual Machine;

rolling back the Agent to use a previous version of code for the Agent while the Application and the Java Virtual Machine continue to run; and

running the rolled back Agent with the Application in the Java Virtual Machine.

2. The method of claim 1, further comprising:

loading a first shim for the Agent, a second shim for the Agent, classes referenced by the first shim and classes referenced by the second shim; and

dynamically instrumenting the Application to make calls to the first shim, the running the Agent with the Application comprises executing the Agent based on the calls from the instrumented Application to the first shim and the classes referenced by the first shim, the rolling back the Agent comprises dynamically instrumenting the Application to make calls to the second shim, the running the rolled back Agent with the Application comprises executing a new version of the Agent based on the calls from the instrumented Application to the second shim and the classes referenced by the second shim.

3. The method of claim 2, wherein:

the classes referenced by the first shim are stored in a first jar file not in the class path for the Agent; and

the classes referenced by the second shim are stored in a second jar file not in the class path for the Agent.

4. The method of claim 3, wherein:

the classes referenced by the first shim are loaded by a first Class Loader and are in a first namespace; and

the classes referenced by the second shim are loaded by a second Class Loader and are in a second namespace that is different than the first namespace.

5. The method of claim 4, wherein the loading of the classes referenced by the first shim comprises:

the first Class Loader accessing first code for the Agent;

the first Class Loader providing the first code for the Agent to a Class File Transformer;

the Class File Transformer injecting byte code into the first code for the Agent from a source not in the class path for the Agent; and

the first Class Loader providing the first code with the injected byte code to the Java Virtual Machine.

6. The method of claim 1, wherein:

the Agent is implemented using the —

javaagent option of the Java instrumentation API.

7. The method of claim 6, wherein:

the running the Agent comprises executing first code for the Agent from a first jar file; and

the running the rolled back Agent comprises executing second code for the Agent from a second jar file.

8. The method of claim 1, wherein:

the running the Agent comprises executing first code for the Agent from a first source of code not in the class path for the Agent; and

the running the rolled back Agent comprises executing second code for the Agent from a second source of code not in the class path for the Agent.

9. The method of claim 8, wherein:

the running the Agent, the rolling back the Agent and the running the rolled back Agent are performed while the a source of code in the class path for the Agent is locked.

10. A method of managing versions of an Agent for an Application, comprising:

running the Agent with the Application while the Application is running, the Agent is associated with an identified source of code for the Agent;

locking the identified source of code for the Agent;

updating the code for the Agent while the identified source of code for the Agent is locked;

running the updated Agent with the Application;

rolling back the Agent to use a previous version of code for the Agent while the identified source of code for the Agent is locked; and

running the rolled back Agent with the Application.

11. The method of claim 10, wherein:

the Agent is run with the Application in a Java Virtual Machine; and

the rolling back the code is performed while running the Application and the Java virtual machine.

12. The method of claim 10, wherein:

the Agent is implemented using the —

javaAgent option of the Java Instrumentation API.

13. The method of claim 10, wherein:

the updating the code for the Agent comprises loading a first shim for the Agent, loading a second shim for the Agent, loading classes referenced by the first shim, loading classes referenced by the second shim, and dynamically instrumenting the Application to make calls to the first shim;

the running the updated Agent with the Application comprises executing the Agent based on the calls from the instrumented Application to the first shim and the classes referenced by the first shim,

the rolling back the Agent comprises dynamically instrumenting the Application to make calls to the second shim; and

the running the rolled back Agent with the Application comprises executing the Agent based on the calls from the instrumented Application to the second shim and the classes referenced by the second shim.

14. The method of claim 13, wherein:

the classes referenced by the first shim are stored in a first jar file not in the class path for the Agent; and

the classes referenced by the second shim are stored in a second jar file not in the class path for the Agent.

15. The method of claim 13, wherein:

the classes referenced by the first shim are loaded by a first Class Loader and are in a first namespace; and

the classes referenced by the second shim are loaded by a second Class Loader and are in a second namespace that is different than the first namespace.

16. The method of claim 15, wherein the loading of the classes referenced by the first shim comprises:

the first Class Loader accessing first code for the Agent;

the first Class Loader providing the first code for the Agent to a Class File Transformer;

the Class File Transformer injecting byte code into the first code for the Agent from a source not in the class path for the Agent; and

the first Class Loader providing the first code with the injected byte code to an execution engine.

17. A computing apparatus, comprising:

a storage device that stores code including a first storage unit of code that at least partially defines an Agent; and

one or more processors in communication with the storage device, the one or more processors implement a Java Virtual Machine and the Agent running in the Java Virtual Machine for an Application using the —

javaagent option of the Java Instrumentation API, the one or more processors perform a hot roll back of the Agent to use a previous versions of code for the Agent while running the Application or the Java Virtual Machine.

18. The computing apparatus of claim 17, wherein:

the one or more processors implement one or more Class Loaders that load a first shim for the Agent, a second shim for the Agent, classes referenced by the first shim and classes referenced by the second shim;

the one or more processors implement one or more Class File Transformers that dynamically instrument the Application to make calls to the first shim;

the Agent is run based on the calls from the instrumented Application to the first shim and the classes referenced by the first shim; and

the hot roll back of the Agent comprises the one or more processors dynamically instrumenting the Application to make calls to the second shim such that the a new version of the Agent is executed based on the calls from the instrumented Application to the second shim and the classes referenced by the second shim.

19. The computing apparatus of claim 18, wherein:

the first storage unit of code is in a class path for the Agent;

the classes referenced by the first shim are stored in a first jar file not in the class path for the Agent;

the classes referenced by the second shim are stored in a second jar file not in the class path for the Agent; and

the hot roll back of the Agent is performed while the a source of code in the class path for the Agent is locked.

20. The computing apparatus of claim 19, wherein:

the classes referenced by the first shim are loaded by a first Class Loader and are in a first namespace; and

the classes referenced by the second shim are loaded by a second Class Loader and are in a second namespace that is different than the first namespace.

21. The computing apparatus of claim 20, wherein:

the one or more processors load the classes referenced by the first shim by executing a Bootstrap Class Loader accessing first code for the Agent and providing the first code for the Agent to a Class File Transformer, the Class File Transformer injecting byte code into the first code for the Agent from a source not in the class path for the Agent.

22. The computing apparatus of claim 17, wherein:

the Agent is implemented using the —

javaagent option of the Java Instrumentation API.

23. A method of managing versions of an Agent for an Application, comprising:

loading a first shim for an Agent, a second shim for the Agent, classes referenced by the first shim and classes referenced by the second shim;

dynamically instrumenting an Application to make calls to the first shim;

executing the Agent based on the calls from the instrumented Application to the first shim and the classes referenced by the first shim;

dynamically instrumenting the Application to make calls to the second shim; and

executing a new version of the Agent based on the calls from the instrumented Application to the second shim and the classes referenced by the second shim.

24. The method of claim 23, wherein:

the Application and Agent are running in a Java Virtual Machine;

the classes referenced by the first shim are stored in a first jar file not in the class path for the Agent; and

the classes referenced by the second shim are stored in a second jar file not in the class path for the Agent.

25. The method of claim 24, wherein:

the classes referenced by the first shim are loaded by a first Class Loader and are in a first namespace; and

the classes referenced by the second shim are loaded by a second Class Loader and are in a second namespace that is different than the first namespace.