Servicing daemon for live debugging of storage systems

• US 8,015,201 B1
• Filed: 02/22/2007
• Issued: 09/06/2011
• Est. Priority Date: 02/22/2007
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Harris, Michael David
• Primary Examiner(s): Sough; H. S.
• Assistant Examiner(s): Anya; Charles E
• Application Number:
  US11/710,351
• Time in Patent Office: 1,657 Days
• Field of Search: 707/669, 711/202, 719/330
• US Class Current: 707/769
• CPC Class Codes: G06F 11/079 Root cause analysis, i.e. error or fault diagnosis in a hardware test environment G06F11/22; in a software test environment G06F11/36
• CPC Class Codes: G06F 11/366 using diagnostics G06F11/0703 takes precedence

Abstract

A servicing daemon is described herein for providing servicing of a running computer system (such as a filer). The servicing daemon resides and executes on the operating system of the filer and communicates across a network with a debugger that resides and executes on a remote administering computer. A debugging session is performed that complies with a protocol relating to the remote accessing of files. The debugging session provides live servicing of an application executing on the filer without requiring an actual corefile (having copied filer memory data) to be created. Rather, the servicing daemon creates a simulated corefile header that is sent to the debugger, receives requests from the debugger, and maps addresses specified in the requests to filer memory addresses. The servicing daemon then reads and retrieves data directly from filer memory at the determined filer memory addresses and sends the data to the debugger for analysis.

Claims

1. A system for servicing an application executing on a local computer using an administering program executing on a remote computer connected with the local computer through a network, the system comprising:

the local computer comprising a local memory storing data;

a memory virtualization component configured to produce a corefile comprising a corefile header representing the local memory of the local computer, wherein the corefile does not comprise data copied from the local memory; and

a remote procedure call (RPC) component and a reverse-address mapping component configured to implement the servicing of the application using the corefile, wherein;

the RPC component is further configured to receive a read request from the administering program, the request comprising a dummy address having a particular value, and to send the corefile header to the administering program in response to the read request; and

the reverse-address mapping component is further configured to determine that the read request is a request for the corefile header by comparing the particular value to a predetermined value associated with the corefile header.

2. The system of claim 1, wherein the corefile header comprises a mapping table that maps between local memory addresses and dummy addresses.

3. The system of claim 1, wherein the RPC component is further configured to send data retrieved in response to the read request to the administering program.

4. The system of claim 3, wherein the reverse-address mapping component is further configured to map the dummy address to a local memory address using the corefile header and to retrieve data from the local memory at the mapped local memory address.

5. The system of claim 1, wherein the predetermined value is determined by a corefile format type for the local computer.

6. The system of claim 1, wherein the administering program uses the corefile header to make read requests having dummy addresses by mapping local memory addresses to dummy addresses.

7. The system of claim 1, wherein:

the local memory comprises one or more segments, each segment having a local memory address range;

the corefile header comprises one or more memory range descriptors, each memory range descriptor corresponding to a particular segment; and

each memory range descriptor comprises a local memory address range of its corresponding segment and a dummy address range based, in part, on the size of its corresponding segment and the size of the corefile header.

8. The system of claim 7, wherein at least one segment of the local memory does not have a corresponding memory range descriptor in the corefile header.

9. The system of claim 1, wherein the local memory comprises a collective physical address space comprising mapped storage locations of one or more memory components of the local computer.

10. The system of claim 1, wherein the application executing on the local computer comprises an operating system of the storage system.

11. The system of claim 1, wherein the corefile comprises a simulated corefile specified by a first predetermined filename and a first predetermined path location, wherein a real corefile comprising copied local memory data is specified by a different predetermined filename and a different predetermined path location.

12. The system of claim 1, wherein the memory virtualization, RPC, and reverse-address mapping components reside and execute on an operating system of the local computer.

13. A method for servicing an application executing on a local computer using an administering program executing on a remote computer connected with the local computer through a network, the method comprising:

producing a corefile comprising a corefile header representing a local memory of the local computer, the local memory being configured for storing data, wherein the corefile does not comprise data copied from the local memory;

implementing the servicing of the application using the corefile;

receiving a read request from the administering program, the request comprising a dummy address having a particular value;

determining that the read request is a request for the corefile header by comparing the particular value to a predetermined value associated with the corefile header; and

sending the corefile header to the administering program in response to the read request.

14. The method of claim 13, wherein producing the corefile comprises producing a corefile header comprising a mapping table that maps between local memory addresses and dummy addresses, the method further comprising:

mapping the dummy address to a local memory address using the corefile header;

retrieving data from the local memory at the mapped local memory address; and

sending the retrieved data to the administering program.

15. The method of claim 13, wherein the predetermined value is determined by a corefile format type for the local computer.

16. A non-transitory computer readable medium having instructions stored thereon when executed, service an application executing on a local computer using an administering program executing on a remote computer connected with the local computer through a network, the computer readable medium comprising sets of instructions for:

producing a corefile comprising a corefile header representing a local memory of the local computer, the local memory being configured for storing data, wherein the corefile does not comprise data copied from the local memory;

implementing the servicing of the application using the corefile;

receiving a read request from the administering program, the request comprising a dummy address having a particular value;

determining that the read request is a request for the corefile header by comparing the particular value to a predetermined value associated with the corefile header; and

sending the corefile header to the administering program.

17. The non-transitory computer readable medium of claim 16, wherein the set of instructions for producing the corefile comprises a set of instructions for producing a corefile header comprising a mapping table that maps between local memory addresses and dummy addresses, the computer readable medium further comprising sets of instructions for

mapping the dummy address to a local memory address using the corefile header;

retrieving data from the local memory at the mapped local memory address; and

sending the retrieved data to the administering program.

18. The non-transitory computer readable medium of claim 16, wherein the predetermined value is determined by a corefile format type for the local computer.

a remote procedure call (RPC) component configured to receive a read data request comprising a dummy address, from the administering program, and to send data retrieved in response to the request to the administering program;

and

a reverse-address mapping component configured to map the dummy address to a local memory address using the corefile header and to retrieve data directly from the local memory at the mapped local memory address;

wherein;

the RPC component is further configured to receive a read data request from the administering program, the request comprising a dummy address having a particular value, and to send the corefile header to the administering program in response to the read data request; and

the reverse-address mapping component is further configured to determine that the read request is a request for the corefile header by comparing the particular value to a predetermined value associated with the corefile header.

19. A system for servicing an application executing on a local computer using an administering program executing on a remote computer connected with the local computer through a network, the system comprising:

the local computer comprising a local memory configured for storing data, the local memory being represented by a corefile header comprising a mapping table that maps between local memory addresses and dummy addresses;

a remote procedure call (RPC) component configured to receive a read request comprising a dummy address, from the administering program, and to send data retrieved in response to the request to the administering program; and

a reverse-address mapping component configured to map the dummy address to a local memory address using the corefile header and to retrieve data directly from the local memory at the mapped local memory address;

wherein;

the read request comprising the dummy address includes a particular value, and the sending of data retrieved in response to the read request includes sending the corefile header to the administering program; and

the reverse-address mapping component is further configured to determine that the read request is a request for the corefile header by comparing the particular value to a predetermined value associated with the corefile header.

20. The system of claim 19, wherein the predetermined value is determined by a corefile format type for the local computer.

21. A method for servicing an application executing on a local computer using an administering program executing on a remote computer connected with the local computer through a network, the method comprising:

producing a corefile header representing a local memory of the local computer, the corefile header comprising a mapping table that maps between local memory addresses and dummy addresses;

receiving a read request from the administering program, the request comprising a dummy address having a particular value;

determining that the read request is a request for the corefile header by comparing the particular value to a predetermined value associated with the corefile header;

sending the corefile header to the administering program in response to the read request;

mapping the dummy address to a local memory address using the corefile header;

retrieving data directly from the local memory at the mapped local memory address; and

sending the retrieved data to the administering program.

22. The method of claim 21, wherein the predetermined value is determined by a corefile format type for the local computer.