Determination of working sets by logging and simulating filesystem operations

• US 5,713,008 A
• Filed: 06/08/1995
• Issued: 01/27/1998
• Est. Priority Date: 06/08/1995
• Status: Expired due to Term

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems (Oracle Corporation)
• Inventors: Falkner, Sam L.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US08/486,006
• Time in Patent Office: 964 Days
• Field of Search: 395/500, 395/600, 395/425, 395/400, 395/375, 395/463, 395/460, 395/440, 395/497.01, 395/445, 364/200 MS File
• US Class Current: 711/118
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/1734 Details of monitoring file system events, e.g. by the use of hooks, filter drivers, logs
• CPC Class Codes: G06F 2201/87 Monitoring of transactions
• CPC Class Codes: G06F 2201/885 Monitoring specific for caches
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]

Abstract

A method and apparatus for determining the size of a file cache for storing data is described. The method includes activating a filesystem logging mechanism to monitor filesystem transactions performed on the computer by the user. Next, a file cache is provided under computer control for storing at least a portion of at least one computer file. Also, a filesystem log file is provided for storing records of filesystem transactions invoked by the computer. A user work cycle is then performed during which the filesystem logging mechanism monitors filesystem transactions invoked by the computer and stores records of certain filesystem transactions to the filesystem log file. Finally, the size of the file cache required to store the information cached during the work cycle is determined by processing the log file. Also provided is a computer program product having computer readable code for determining the size of a file cache.

Claims

1. A computer-implemented method for determining the size of a file cache on a computer, the computer-implemented method comprising the computer-implemented steps of:

activating a filesystem logging mechanism under computer control to monitor filesystem transactions performed on the computer;

providing under computer control a file cache for storing at least a portion of at least one computer file and a filesystem log file for storing records of filesystem transactions invoked by the computer;

performing under computer control a user work cycle during which user work cycle the filesystem logging mechanism monitors under computer control filesystem transactions invoked by the computer and stores records of certain filesystem transactions to the filesystem log file; and

determining under computer control an appropriate size of the file cache based at least in part on the records stored in the filesystem log file.

2. The computer-implemented method as recited in claim 1, wherein the step of activating a filesystem logging mechanism includes the computer-implemented steps of:

a) determining under computer control whether a prior file cache exists in memory associated with the computer; and

b) mounting under computer control a filesystem, wherein the step of mounting includes identifying the file cache as the location for storing data transferred from the filesystem to the computer.

3. The computer-implemented method as recited in claim 2, further including the step of creating a file cache under computer control in response to a determination that a file cache does not exist in memory associated with the computer.

4. The computer-implemented method as recited in claim 1, wherein the step of storing records of certain filesystem transactions comprises the step of writing under computer control logging records corresponding to certain filesystem transactions to the filesystem log file.

5. The computer-implemented method as recited in claim 1, wherein the step of determining the size of the file cache comprises the computer-implemented steps of:

a) determining a record type for each record stored in the filesystem log file;

b) processing each record stored in the filesystem log file; and

c) updating a cache size indicator to reflect the size of the file cache required to store data associated with the record that is transferred from the filesystem to the file cache.

6. The computer-implemented method as recited in claim 5, wherein the step of processing each record stored in the filesystem log file comprises the computer-implemented steps of:

a) determining that the record type is a file record;

b) determining that the file record is listed in an ad-hoc filesystem table;

c) subtracting the amount of memory space occupied by the data associated with the file record from the file cache size; and

d) determining the present amount of memory space occupied by data associated with the file record and adding that amount of memory space to the file cache size.

7. The computer-implemented method as recited in claim 6, wherein the step of determining the present amount of space occupied by the data associated with the file record comprises the computer-implemented steps of:

a) determining whether the file associated with the file record has been modified; and

b) determining whether additional memory space should be added to the current cache size when the file associated with the file record has not been modified.

8. The computer-implemented method as recited in claim 7, further including the step of determining whether the filesystem continues to cache modified files when the file associated with the file record has been modified.

9. A computer system configured to implement the method of claim 1.

23. A computer-implemented method as recited in claim 1, wherein the step of determining the size of the file cache includes the computer-implemented step of accessing and utilizing the stored records of certain filesystem transactions to the filesystem log file.

24. A computer-implemented method as recited in claim 1, further including the computer-implemented step of setting the file cache size to an appropriate size based upon a user work load during the user work cycle.

25. A computer-implemented method as recited in claim 1 wherein the appropriate file cache size includes a near-optimal file cache size.

26. A computer-implemented method as recited in claim 1 wherein the user work cycle is defined by a user on one computer for a length of time set by the user.

10. A computer system for determining the size of a file cache, the computer system comprising:

a file cache for storing at least a portion of at least one computer file;

a filesystem log file for storing records of filesystem transactions;

a filesystem logging mechanism that monitors filesystem transactions performed during a user work cycle and stores records of certain filesystem transactions to the filesystem log file; and

a filesystem log file processing mechanism for determining an appropriate size of the file cache based at least in part on the records stored in the filesystem log file.

11. The computer system as recited in claim 10, wherein the computer system comprises a computer coupled to a computer network including a fileserver, the file cache is located in memory associated with the computer, and the filesystem transactions monitored by the filesystem logging mechanism include copying at least a portion of a least one file stored on the fileserver to the file cache.

12. The computer system as recited in claim 11, wherein the file cache is located in mass storage coupled with the computer.

13. The computer system as recited in claim 12, wherein the filesystem logging mechanism includes:

a) a prior file cache check mechanism to determine whether a prior file cache exists in memory associated with the computer; and

b) a fileserver mounter capable of identifying the file cache as the location for storing data transferred from the fileserver to the computer.

14. The computer system as recited in claim 13, further including a file cache creation mechanism for creating a file cache when a file cache does not already exist in memory associated with the computer.

15. The computer system as recited in claim 14, wherein the logging records include fields for at least a record type, an error status flag and a filesystem identifier.

16. The computer system as recited in claim 10, wherein the filesystem log file processing mechanism comprises:

a) a record type discriminator capable of determining the record type for each record stored in the filesystem log file;

b) a record processing mechanism that is capable of determining the amount of memory occupied by the file associated with the record; and

c) a cache size updating mechanism capable of determining the size of the file cache required to store the data referenced by the records stored in the log file.

17. A computer program product comprising a computer usable medium having computer readable code embodied thereon for determining the size of a file cache, the computer program product comprising:

computer readable program code devices configured to cause a computer to activate a filesystem logging mechanism that operates under computer control to monitor filesystem transactions performed on the computer;

computer readable program code devices configured to cause a computer to provide a file cache for storing a least a portion of at least one computer file therein and a filesystem log file for storing records of filesystem transactions invoked by the computer while the filesystem logging mechanism is monitoring filesystem transactions performed on the computer;

computer readable program code devices configured to cause a computer to store records of certain filesystem transactions invoked by the computer while the filesystem logging mechanism is monitoring filesystem transactions performed on the computer to the filesystem log file; and

computer readable program code devices configured to cause a computer to determine an appropriate size of the file cache based at least in part on the records stored in the filesystem log file.

18. The computer program product as recited in claim 17, wherein the computer is coupled with a computer network including a fileserver, and the filesystem transactions invoked by the computer include copying at least a portion of a least one file stored on the fileserver to the file cache.

19. The computer program product as recited in claim 18, wherein the file cache is located in mass storage coupled with the computer.

20. The computer program product as recited in claim 19, wherein the logging records include fields for at least a record type, an error status flag, a time stamp and a filesystem identifier.

21. The computer program product as recited in claim 17, wherein the computer readable program code devices configured to cause a computer to determine the size of the file cache include:

a) computer readable program code devices configured to cause a computer to determine the record type for each record stored in the filesystem log file;

b) computer readable program code devices configured to cause a computer to process each record stored in the filesystem log file; and

c) computer readable program code devices configured to cause a computer to update a cache size indicator to reflect the size of the file cache required to store the data referenced by the records stored in the log file.

22. A computer system configured to implement the computer program product of claim 17.

27. A computer program product comprising a computer usable medium as recited in claim 17, wherein the computer readable program code devices configured to cause a computer to determine the size of the file cache includes program code devices configured to access and utilize records of certain filesystem transactions stored in the filesystem log file.

28. A computer program product comprising a computer usable medium as recited in claim 17, further including program code devices configured to set the file cache size to an appropriate size based upon a user work load during a user work cycle.

29. A computer program product comprising a computer usable medium as recited in claim 17, further including computer readable program code devices configured to cause a computer to store records of certain filesystem transactions to a filesystem log file during a user work cycle.

30. A computer program product comprising a computer usable medium as recited in claim 17 wherein the appropriate file cache size includes a near-optima file cache size.