NAME¶
percona-toolkit - Advanced command-line tools for MySQL
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. 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
- Log MySQL deadlocks.
- 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
- 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-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-digest
- Analyze MySQL queries from logs, processlist, and tcpdump.
- 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-stalk.
- 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
- Collect forensic data about MySQL when problems occur.
- 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-upgrade
- Verify that query results are identical on different servers.
- 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/>.
SPECIAL OPTION TYPES¶
Tool options use standard types ("int", "string", etc.) as
well as these special types:
- time
- Time values are seconds by default. For example, "--run-time 60"
means 60 seconds. Time values support an optional suffix: s (seconds), m
(minutes), h (hours), d (days). "--run-time 1m" means 1 minute
(the same as 60 seconds).
- size
- Size values are bytes by default. For example, "--disk-space-free
1024" means 1 Kibibyte. Size values support an optional suffix: k
(Kibibyte), M (Mebibyte), G (Gibibyte).
- DSN
- See "DSN (DATA SOURCE NAME) SPECIFICATIONS".
- Hash, hash, Array, array
- Hash, hash, Array, and array values are comma-separated lists of values.
For example, "--ignore-tables foo,bar" ignores tables
"foo" and "bar".
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
- Default character set for the connection ("SET NAMES").
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. Other values set binmode on
STDOUT without the utf8 layer and run "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
- Default database to use when connecting. Tools may "USE" a
different databases while running.
- F
- Defaults file for the MySQL client library (the C client library used by
DBD::mysql, not Percona Toolkit itself). All 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 in
"~/.my.cnf", you won't have to specify your MySQL username and
password on the command line:
[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.
- h
- MySQL hostname or IP address to connect to.
- L
- Explicitly enable LOAD DATA LOCAL INFILE.
For some reason, some vendors compile libmysql without the
--enable-local-infile option, which disables the statement. This can lead
to weird situations, like the server allowing LOCAL INFILE, but the client
throwing exceptions if it's used.
However, as long as the server allows LOAD DATA, clients can easily
re-enable it; see
<https://dev.mysql.com/doc/refman/5.0/en/load-data-local.html> and
<http://search.cpan.org/~capttofu/DBD-mysql/lib/DBD/mysql.pm>. This
option does exactly that.
- p
- MySQL 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
- MySQL socket file to use for the connection (on Unix systems).
- u
- MySQL username to use when connecting, if not current system 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 officially supports and is tested on many popular Linux
distributions and MySQL 5.0 through 5.6; see
http://goo.gl/srHm7 for the list
of supported platforms and versions.
BUGS¶
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".
AUTHORS¶
- Baron Schwartz
- Baron created Maatkit, from which Percona Toolkit was forked. Many of the
tools and modules were originally written by Baron.
- Daniel Nichter
- Daniel has been the project's lead developer since 2008. He is employed by
Percona.
- Frank Cizmich
- Frank is a full-time Percona Toolkit developer employed by Percona.
- Others
- Many people have contributed code over the years. See each tool's
"AUTHORS" section for details.
COPYRIGHT, LICENSE, AND WARRANTY¶
Percona Toolkit is copyright 2011-2014 Percona LLC and/or its affiliates, et al.
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 v2.2.11 released 2014-09-25