pt-ioprofile - Watch process IO and print a table of file and I/O activity.
pt-ioprofile [OPTIONS] [FILE]
pt-ioprofile does two things: 1) get lsof+strace for -s seconds, 2) aggregate the result. If you specify a FILE, then step 1) is not performed.
WARNING: pt-ioprofile freezes the server and may crash the process, or make it perform badly after detaching, or leave it in a sleeping state! Before using this tool, please:
- Read the tool’s documentation
- Review the tool’s known “BUGS”
- Test the tool on a non-production server
- Backup your production server and verify the backups
pt-ioprofile should be considered an intrusive tool, and should not be used on production servers unless you understand and accept the risks.
lsof to watch a process’s IO and print out
a table of files and I/O activity. By default, it watches the mysqld
process for 30 seconds. The output is like:
Tue Dec 27 15:33:57 PST 2011 Tracing process ID 1833 total read write lseek ftruncate filename 0.000150 0.000029 0.000068 0.000038 0.000015 /tmp/ibBE5opS
You probably need to run this tool as root.
pt-ioprofile works by attaching
strace to the process using
which will make it run very slowly until
strace detaches. In addition to
freezing the server, there is some risk of the process crashing or performing
strace detaches from it, or of
strace not detaching cleanly
and leaving the process in a sleeping state. As a result, this should be
considered an intrusive tool, and should not be used on production servers
unless you are comfortable with that.
short form: -a; type: string; default: sum
The aggregate function, either
If sum, then each cell will contain the sum of the values in it. If avg, then each cell will contain the average of the values in it.
short form: -c; type: string; default: times
The cell contents.
Valid values are:
VALUE CELLS CONTAIN ===== ======================= count Count of I/O operations sizes Sizes of I/O operations times I/O operation timing
short form: -g; type: string; default: filename
The group-by item.
Valid values are:
VALUE GROUPING ===== ====================================== all Summarize into a single line of output filename One line of output per filename pid One line of output per process ID
Print help and exit.
short form: -b; type: string; default: mysqld
The process name to profile.
type: int; default: 30
How long to profile.
Filename to save samples in; these can be used for later analysis.
Print the tool’s version and exit.
This tool does not use any environment variables.
This tool requires the Bourne shell (/bin/sh).
For a list of known bugs, see http://www.percona.com/bugs/pt-ioprofile.
Please report bugs at https://jira.percona.com/projects/PT. Include the following information in your bug report:
- Complete command-line used to run the tool
- MySQL version of all servers involved
- Output from the tool including STDERR
- Input files (log/dump/config files, etc.)
If possible, include debugging output by running the tool with
Visit http://www.percona.com/software/percona-toolkit/ to download the latest release of Percona Toolkit. Or, get the latest release from the command line:
wget percona.com/get/percona-toolkit.tar.gz wget percona.com/get/percona-toolkit.rpm wget percona.com/get/percona-toolkit.deb
You can also get individual tools from the latest release:
TOOL with the name of any tool.
ABOUT PERCONA TOOLKIT¶
This tool is part of Percona Toolkit, a collection of advanced command-line tools for MySQL developed by Percona. Percona Toolkit was forked from two projects in June, 2011: Maatkit and Aspersa. Those projects were created by Baron Schwartz and primarily developed by him and Daniel Nichter. Visit http://www.percona.com/software/ to learn about other free, open-source software from Percona.
COPYRIGHT, LICENSE, AND WARRANTY¶
This program is copyright 2011-2021 Percona LLC and/or its affiliates, 2010-2011 Baron Schwartz.
THIS PROGRAM IS PROVIDED “AS IS” AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2; OR the Perl Artistic License. On UNIX and similar systems, you can issue `man perlgpl’ or `man perlartistic’ to read these licenses.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.