NAME¶
percona-toolkit - Advanced command-line tools used by Percona for MySQL support
and consulting
DESCRIPTION¶
Percona Toolkit is a collection of advanced command-line tools used by Percona
(<
http://www.percona.com/>) support staff to perform a variety of MySQL
and system tasks that are too difficult or complex to perform manually.
These tools are ideal alternatives to private or "one-off" scripts
because they are professionally developed, formally tested, and fully
documented. They are also fully self-contained, so installation is quick and
easy and no libraries are installed.
Percona Toolkit is derived from Maatkit and Aspersa, two of the best-known
toolkits for MySQL server administration. It is developed and supported by
Percona Inc. For more information and other free, open-source software
developed by Percona, visit <
http://www.percona.com/software/>.
This release of Percona Toolkit includes the following tools:
- pt-align
- Align output from other tools to columns.
- pt-archiver
- Archive rows from a MySQL table into another table or a
file.
- pt-config-diff
- Diff MySQL configuration files and server variables.
- pt-deadlock-logger
- Extract and log MySQL deadlock information.
- pt-diskstats
- An interactive I/O monitoring tool for GNU/Linux.
- pt-duplicate-key-checker
- Find duplicate indexes and foreign keys on MySQL
tables.
- pt-fifo-split
- Split files and pipe lines to a fifo without really
splitting.
- pt-find
- Find MySQL tables and execute actions, like GNU find.
- pt-fingerprint
- Convert queries into fingerprints.
- pt-fk-error-logger
- Extract and log MySQL foreign key errors.
- pt-heartbeat
- Monitor MySQL replication delay.
- pt-index-usage
- Read queries from a log and analyze how they use
indexes.
- pt-ioprofile
- Watch process IO and print a table of file and I/O
activity.
- pt-kill
- Kill MySQL queries that match certain criteria.
- pt-log-player
- Replay MySQL query logs.
- pt-mext
- Look at many samples of MySQL "SHOW GLOBAL
STATUS" side-by-side.
- pt-mysql-summary
- Summarize MySQL information nicely.
- pt-online-schema-change
- ALTER tables without locking them.
- pt-pmp
- Aggregate GDB stack traces for a selected program.
- pt-query-advisor
- Analyze queries and advise on possible problems.
- pt-query-digest
- Analyze query execution logs and generate a query report,
filter, replay, or transform queries for MySQL, PostgreSQL, memcached, and
more.
- pt-show-grants
- Canonicalize and print MySQL grants so you can effectively
replicate, compare and version-control them.
- pt-sift
- Browses files created by pt-collect.
- pt-slave-delay
- Make a MySQL slave server lag behind its master.
- pt-slave-find
- Find and print replication hierarchy tree of MySQL
slaves.
- pt-slave-restart
- Watch and restart MySQL replication after errors.
- pt-stalk
- Gather forensic data about MySQL when a problem
occurs.
- pt-summary
- Summarize system information nicely.
- pt-table-checksum
- Verify MySQL replication integrity.
- pt-table-sync
- Synchronize MySQL table data efficiently.
- pt-table-usage
- Analyze how queries use tables.
- pt-tcp-model
- Transform tcpdump into metrics that permit performance and
scalability modeling.
- pt-trend
- Compute statistics over a set of time-series data
points.
- pt-upgrade
- Execute queries on multiple servers and check for
differences.
- pt-variable-advisor
- Analyze MySQL variables and advise on possible
problems.
- pt-visual-explain
- Format EXPLAIN output as a tree.
For more free, open-source software developed Percona, visit
<
http://www.percona.com/software/>.
CONFIGURATION FILES¶
Percona Toolkit tools can read options from configuration files. The
configuration file syntax is simple and direct, and bears some resemblances to
the MySQL command-line client tools. The configuration files all follow the
same conventions.
Internally, what actually happens is that the lines are read from the file and
then added as command-line options and arguments to the tool, so just think of
the configuration files as a way to write your command lines.
SYNTAX¶
The syntax of the configuration files is as follows:
- •
- Whitespace followed by a hash sign (#) signifies that the
rest of the line is a comment. This is deleted. For example:
- •
- Whitespace is stripped from the beginning and end of all
lines.
- •
- Empty lines are ignored.
- •
- Each line is permitted to be in either of the following
formats:
option
option=value
Do not prefix the option with "--". Do not quote the values, even
if it has spaces; value are literal. Whitespace around the equals sign is
deleted during processing.
- •
- Only long options are recognized.
- •
- A line containing only two hyphens signals the end of
option parsing. Any further lines are interpreted as additional arguments
(not options) to the program.
EXAMPLE¶
This config file for pt-stalk,
# Config for pt-stalk
variable=Threads_connected
cycles=2 # trigger if problem seen twice in a row
--
--user daniel
is equivalent to this command line:
pt-stalk --variable Threads_connected --cycles 2 -- --user daniel
Options after "--" are passed literally to mysql and mysqladmin.
READ ORDER¶
The tools read several configuration files in order:
- 1.
- The global Percona Toolkit configuration file,
/etc/percona-toolkit/percona-toolkit.conf. All tools read this
file, so you should only add options to it that you want to apply to all
tools.
- 2.
- The global tool-specific configuration file,
/etc/percona-toolkit/TOOL.conf, where "TOOL" is a tool
name like "pt-query-digest". This file is named after the
specific tool you're using, so you can add options that apply only to that
tool.
- 3.
- The user's own Percona Toolkit configuration file,
$HOME/.percona-toolkit.conf. All tools read this
file, so you should only add options to it that you want to apply to all
tools.
- 4.
- The user's tool-specific configuration file,
$HOME /.TOOL.conf, where "TOOL" is a tool
name like "pt-query-digest". This file is named after the
specific tool you're using, so you can add options that apply only to that
tool.
SPECIFYING¶
There is a special "--config" option, which lets you specify which
configuration files Percona Toolkit should read. You specify a comma-separated
list of files. However, its behavior is not like other command-line options.
It must be given
first on the command line, before any other options.
If you try to specify it anywhere else, it will cause an error. Also, you
cannot specify "--config=/path/to/file"; you must specify the option
and the path to the file separated by whitespace
without an equal sign
between them, like:
--config /path/to/file
If you don't want any configuration files at all, specify "--config
''" to provide an empty list of files.
DSN (DATA SOURCE NAME) SPECIFICATIONS¶
Percona Toolkit tools use DSNs to specify how to create a DBD connection to a
MySQL server. A DSN is a comma-separated string of "key=value"
parts, like:
h=host1,P=3306,u=bob
The standard key parts are shown below, but some tools add additional key parts.
See each tool's documentation for details.
Some tools do not use DSNs but still connect to MySQL using options like
"--host", "--user", and "--password". Such tools
uses these options to create a DSN automatically, behind the scenes.
Other tools uses both DSNs and options like the ones above. The options provide
defaults for all DSNs that do not specify the option's corresponding key part.
For example, if DSN "h=host1" and option "--port=12345"
are specified, then the tool automatically adds "P=12345" to DSN.
ESCAPING VALUES¶
DSNs are usually specified on the command line, so shell quoting and escaping
must be taken into account. Special characters, like asterisk ("*"),
need to be quoted and/or escaped properly to be passed as literal characters
in DSN values.
Since DSN parts are separated by commas, literal commas in DSN values must be
escaped with a single backslash ("\"). And since a backslash is the
escape character for most shells, two backslashes are required to pass a
literal backslash. For example, if the username is literally
"my,name", it must be specified as "my\\,name" on most
shells. This applies to DSNs and DSN-related options like "--user".
KEY PARTS¶
Many of the tools add more parts to DSNs for special purposes, and sometimes
override parts to make them do something slightly different. However, all the
tools support at least the following:
- A
- Specifies the default character set for the connection.
Enables character set settings in Perl and MySQL. If the value is
"utf8", sets Perl's binmode on STDOUT to utf8, passes the
"mysql_enable_utf8" option to DBD::mysql, and runs "SET
NAMES UTF8" after connecting to MySQL. Any other value sets binmode
on STDOUT without the utf8 layer, and runs "SET NAMES" after
connecting to MySQL.
Unfortunately, there is no way from within Perl itself to specify the client
library's character set. "SET NAMES" only affects the server; if
the client library's settings don't match, there could be problems. You
can use the defaults file to specify the client library's character set,
however. See the description of the F part below.
- D
- Specifies the connection's default database.
- F
- Specifies a defaults file the mysql client library (the C
client library used by DBD::mysql, not Percona Toolkit itself)
should read. The tools all read the [client] section within the defaults
file. If you omit this, the standard defaults files will be read in the
usual order. "Standard" varies from system to system, because
the filenames to read are compiled into the client library. On Debian
systems, for example, it's usually /etc/mysql/my.cnf then ~/.my.cnf. If
you place the following into ~/.my.cnf, tools will Do The Right Thing:
[client]
user=your_user_name
pass=secret
Omitting the F part is usually the right thing to do. As long as you have
configured your ~/.my.cnf correctly, that will result in tools connecting
automatically without needing a username or password.
You can also specify a default character set in the defaults file. Unlike
the "A" part described above, this will actually instruct the
client library (DBD::mysql) to change the character set it uses
internally, which cannot be accomplished any other way as far as I know,
except for "utf8".
- h
- Hostname or IP address for the connection.
- p
- Password to use when connecting.
- P
- Port number to use for the connection. Note that the usual
special-case behaviors apply: if you specify "localhost" as your
hostname on Unix systems, the connection actually uses a socket file, not
a TCP/IP connection, and thus ignores the port.
- S
- Socket file to use for the connection (on Unix
systems).
- u
- User for login if not current user.
BAREWORD¶
Many of the tools will let you specify a DSN as a single word, without any
"key=value" syntax. This is called a 'bareword'. How this is handled
is tool-specific, but it is usually interpreted as the "h" part. The
tool's "--help" output will tell you the behavior for that tool.
PROPAGATION¶
Many tools will let you propagate values from one DSN to the next, so you don't
have to specify all the parts for each DSN. For example, if you want to
specify a username and password for each DSN, you can connect to three hosts
as follows:
h=host1,u=fred,p=wilma host2 host3
This is tool-specific.
ENVIRONMENT¶
The environment variable "PTDEBUG" enables verbose debugging output to
STDERR. To enable debugging and capture all output to a file, run the tool
like:
PTDEBUG=1 pt-table-checksum ... > FILE 2>&1
Be careful: debugging output is voluminous and can generate several megabytes of
output.
SYSTEM REQUIREMENTS¶
Most tools require:
- •
- Perl v5.8 or newer
- •
- Bash v3 or newer
- •
- Core Perl modules like Time::HiRes
Tools that connect to MySQL require:
- •
- Perl modules DBI and DBD::mysql
- •
- MySQL 5.0 or newer
Percona Toolkit is only tested on UNIX systems, primarily Debian and Red Hat
derivatives; other operating systems are not supported.
Tools that connect to MySQL may work with MySQL v4.1, but this is not test or
supported.
BUGS¶
Please report bugs at
https://bugs.launchpad.net/percona-toolkit
<
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".
AUTHORS¶
Percona Toolkit is primarily developed by Baron Schwartz and Daniel Nichter,
both of whom are employed by Percona Inc. See each program's documentation for
details.
COPYRIGHT, LICENSE, AND WARRANTY¶
Percona Toolkit is copyright 2011-2012 Percona Inc. and others. See each
program's documentation for complete copyright notices.
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.
VERSION¶
Percona Toolkit v2.1.2 released 2012-06-12