Manpage of PATTERNS

PATTERNS

Section: User Commands (1) Updated: Feb 10, 1992 Return to Library's README

NAME

patterns -- summarize file access patterns in a trace

SYNOPSIS

patterns [ -v ] [ -d ] [ -f filterfile ] file

DESCRIPTION

patterns reads a trace and prints a summary of file access patterns based on close records occurring in the trace file. The summary includes the number of read-only, write-only, and read-write accesses to files, as well as bytes transferred for each access type. In addition, each of these access type is further broken down into whole-file tranfer, other sequential access, and random access. Only close records with a reference count of 1 are used in this summary, because the statistics reported on close are cumulative.

OPTIONS

: -d Prints library debugging information. Lots of it.
: -f filterfile Apply the filter in filterfile to the trace.
: -v Verbose mode. Prints information on what the library is doing.

DIAGNOSTICS

The following are frequently encountered errors:

can't process file file -- the file wasn't there or if a filter file was specified, it couldn't be applied.

BUGS

The summary access information in CLOSE records (number of bytes read, written) is cumulative. For example, if a file is open and the descriptor is dup'ed, and then the file is manipulated by both agents, the statistics reported will be the sum of their accesses, and there is no way to tell from the final close who did which accesses. (One can tell by tracking the intermediate closes, but this program does not do that.) So if one if the agents only reads the file, and the other only writes, the complete session, from data in the last CLOSE record, will be reported as a read-write access.

AUTHOR

Lily B. Mummert

This document was created on Time: 05:25:52 GMT, October 10, 1998