PT-PMP(1) User Contributed Perl Documentation PT-PMP(1)NAMEpt-pmp - Aggregate GDB stack traces for a selected program.
SYNOPSIS
Usage: pt-pmp [OPTIONS] [FILES]
pt-pmp is a poor man's profiler, inspired by
<http://poormansprofiler.org>. It can create and summarize full stack
traces of processes on Linux. Summaries of stack traces can be an
invaluable tool for diagnosing what a process is waiting for.
RISKS
Percona Toolkit is mature, proven in the real world, and well tested,
but all database tools can pose a risk to the system and the database
server. 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
DESCRIPTIONpt-pmp performs two tasks: it gets a stack trace, and it summarizes the
stack trace. If a file is given on the command line, the tool skips
the first step and just aggregates the file.
To summarize the stack trace, the tool extracts the function name
(symbol) from each level of the stack, and combines them with commas.
It does this for each thread in the output. Afterwards, it sorts
similar threads together and counts how many of each one there are,
then sorts them most-frequent first.
pt-pmp is a read-only tool. However, collecting GDB stacktraces is
achieved by attaching GDB to the program and printing stack traces from
all threads. This will freeze the program for some period of time,
ranging from a second or so to much longer on very busy systems with a
lot of memory and many threads in the program. In the tool's default
usage as a MySQL profiling tool, this means that MySQL will be
unresponsive while the tool runs, although if you are using the tool to
diagnose an unresponsive server, there is really no reason not to do
this. In addition to freezing the server, there is also some risk of
the server crashing or performing badly after GDB detaches from it.
OPTIONS--binary
short form: -b; type: string; default: mysqld
Which binary to trace.
--help
Show help and exit.
--interval
short form: -s; type: int; default: 0
Number of seconds to sleep between "--iterations".
--iterations
short form: -i; type: int; default: 1
How many traces to gather and aggregate.
--lines
short form: -l; type: int; default: 0
Aggregate only first specified number of many functions;
0=infinity.
--pid
short form: -p; type: int
Process ID of the process to trace; overrides "--binary".
--save-samples
short form: -k; type: string
Keep the raw traces in this file after aggregation.
--version
Show version and exit.
ENVIRONMENT
This tool does not use any environment variables.
SYSTEM REQUIREMENTS
This tool requires Bash v3 or newer. If no backtrace files are given,
then gdb is also required to create backtraces for the process
specified on the command line.
BUGS
For a list of known bugs, see <http://www.percona.com/bugs/pt-pmp>.
Please report bugs at <https://bugs.launchpad.net/percona-toolkit>.
Include the following information in your bug report:
· Complete command-line used to run the tool
· Tool "--version"
· 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
"PTDEBUG"; see "ENVIRONMENT".
DOWNLOADING
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:
wget percona.com/get/TOOL
Replace "TOOL" with the name of any tool.
AUTHORS
Baron Schwartz, based on a script by Domas Mituzas
(<http://poormansprofiler.org/>)
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 2011-2015 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.
VERSIONpt-pmp 2.2.14
perl v5.20.2 2015-04-10 PT-PMP(1)
