Virtual machine monitoring

• US 20060143359A1
• Filed: 12/28/2004
• Published: 06/29/2006
• Est. Priority Date: 12/28/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Dostert, Jan, Kilian, Frank
• Granted Patent: US 7,886,294 B2
• Time in Patent Office: Days
• US Class Current: 711/6
• CPC Class Codes: G06F 11/301 where the computing system is a virtual computing platform, e.g. logically partitioned systems virtual machines G06F9/45533; logical partitioning of resources G06F9/5077
• CPC Class Codes: G06F 11/3055 Monitoring arrangements for monitoring the status of the computing system or of the computing system component, e.g. monitoring if the computing system is on, off, available, not available error or fault processing without redundancy G06F11/0703; error detection or correction by redundancy in data representation G06F11/08; error detection or correction by redundancy in operation G06F11/14; error detection or correction by redundancy in hardware G06F11/16
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 9/544 Buffers; Shared memory; Pipes

Abstract

A system and method for monitoring internal operation of a virtual machine (“VM”). The VM is operated to interpret and execute a program. During operation of the VM, status information regarding internal operation of the VM is stored to an internal memory buffer. The status information is subsequently extracted from the internal memory buffer during operation of the VM to monitor internal operation of the VM from a vantage point external to the VM.

Claims

1. A method, comprising:

operating a virtual machine (“

VM”

) to interpret and to execute a program;

storing status information of internal operation of the VM to an internal memory buffer of the VM during the operating of the VM; and

extracting the status information from the internal memory buffer during the operating of the VM to monitor internal operation of the VM from external to the VM.

2. The method of claim 1, wherein the VM comprises a Java virtual machine (“

JVM”

) and the program comprises Java bytecode.

3. The method of claim 2, wherein storing the status information to the internal memory buffer comprises accessing the internal memory buffer via a Java application programming interface (“

API”

).

4. The method of claim 2, wherein the JVM is included within an application server instance and the program comprises an enterprise application to service client requests.

5. The method of claim 1, further comprising:

storing objects created during execution of the program to a heap; and

garbage collecting the objects no longer referenced by the program with an automatic garbage collector,

wherein storing the status information of the VM to the internal memory buffer comprises storing garbage collecting activity information to the internal memory buffer.

6. The method of claim 5, wherein the garbage collecting activity information includes at least one of a runtime of the garbage collecting, a count of a number of garbage collecting events, a number of the objects collected from the heap, and an amount of memory available within the heap.

7. The method of claim 1, wherein extracting the status information from the internal memory buffer of the VM comprises:

executing a VM monitor external to the VM to retrieve the status information;

accessing the VM via a native application programming interface (“

API”

); and

retrieving the status information to the VM monitor through the native API.

8. The method of claim 7, further comprising:

invoking the VM monitor to retrieve the status information, wherein the VM monitor comprises native machine code, not interpreted by the VM; and

communicating the status information to a monitoring console for display on the monitoring console.

9. The method of claim 7, further comprising accessing the internal memory buffer after failure of the VM to investigate the failure.

10. The method of claim 1, further comprising interpreting and executing a VM monitoring program on the VM, the VM monitoring program dedicated to gathering at least a portion of the status information from components of the VM and storing the portion to the internal memory buffer.

11. A machine-accessible medium that provides instructions that, if executed by a machine, will cause the machine to perform operations comprising:

interpreting a program on a virtual machine (“

VM”

);

generating status information of the VM from within the VM;

storing the status information of the VM to an internal memory buffer of the VM during the interpreting of the program; and

accessing the status information, stored within the internal memory buffer, from external to the VM to monitor internal operation of the VM.

12. The machine-accessible medium of claim 11, wherein the VM comprises a Java virtual machine (“

JVM”

) and the program comprises Java bytecode.

13. The machine-accessible medium of claim 12, wherein storing the status information to the internal memory buffer comprises accessing the internal memory buffer via a Java application programming interface (“

API”

).

14. The machine-accessible medium of claim 13, wherein the Java API insulates the internal memory buffer from corruption in the event the VM fails.

15. The machine-accessible medium of claim 11, wherein generating the status information of the VM comprises executing monitoring code embedded within a sub-entity of the VM to obtain the status information, and wherein storing the status information to the internal memory buffer comprises executing the monitoring code to store the status information to the internal memory buffer.

16. The machine-accessible medium of claim 15, further providing instructions that, if executed by the machine, will cause the machine to perform further operations, comprising:

interleaving execution of the monitoring code with execution of program code of the sub-entity, wherein the sub-entity includes one of a heap manager and an input/output system.

17. The machine-accessible medium of claim 11, further providing instructions that, if executed by the machine, will cause the machine to perform further operations, comprising:

storing objects created by the program to a heap; and

garbage collecting those objects no longer referenced by the program with an automatic garbage collector,

wherein storing the status information of the VM to the internal memory buffer comprises storing garbage collecting activity information to the internal memory buffer.

18. The machine-accessible medium of claim 17, wherein the garbage collecting activity information includes at least one of a runtime of the garbage collecting, a count of a number of garbage collecting events, a number of the objects collected from the heap, an amount of memory available within the heap.

19. The machine-accessible medium of claim 11, wherein accessing the status information from external to the VM comprises:

executing a VM monitor external to the VM; and

retrieving the status information from the internal memory buffer through function calls to a native application programming interface.

20. A system, comprising:

a server node to execute an application server (“

AS”

) instance, the AS instance including logic executable by a processor of the server node to;

interpret a program on a virtual machine (“

VM”

);

generate status information of the VM from within the VM;

store the status information of the VM to an internal memory buffer of the VM during the interpreting of the program; and

access the status information, stored within the internal memory buffer, from external to the VM to monitor internal operation of the VM.

21. The system of claim 20, wherein the VM comprises a Java virtual machine complaint with the Java 2 Enterprise Edition standard and the program comprises a Java program.

22. The system of claim 21, wherein the logic executable by the processor of the server node to generate the status information of the VM comprises monitoring code embedded within an automatic garbage collector executed to reclaim memory of a heap consumed by objects no longer referenced by the Java program.

23. The system of claim 21, further comprising:

a client node to execute a monitoring console, the monitoring console including logic executable by a processor of the client node to;

send a status query to the server node;

receive the status information from the server node in response to the status query; and

display the status information.