|o||Read the tools documentation|
|o||Review the tools known BUGS|
|o||Test the tool on a non-production server|
|o||Backup your production server and verify the backups|
pt-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 tools 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.
--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.
This tool does not use any environment variables.
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.
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:
If possible, include debugging output by running the tool with PTDEBUG; see ENVIRONMENT.
o Complete command-line used to run the tool o Tool --version o MySQL version of all servers involved o Output from the tool including STDERR o Input files (log/dump/config files, etc.)
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:
Replace TOOL with the name of any tool.
Baron Schwartz, based on a script by Domas Mituzas (<http://poormansprofiler.org/>)
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.
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.
|perl v5.20.3||PT-PMP (1)||2015-04-10|