=pod
=head1 NAME
percona-toolkit - Advanced command-line tools for MySQL
=head1 DESCRIPTION
Percona Toolkit is a collection of advanced command-line tools used by
Percona (L) 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 L.
=head1 TOOLS
This release of Percona Toolkit includes the following tools:
=over
=item pt-align
Align output from other tools to columns.
=item pt-archiver
Archive rows from a MySQL table into another table or a file.
=item pt-config-diff
Diff MySQL configuration files and server variables.
=item pt-deadlock-logger
Log MySQL deadlocks.
=item pt-diskstats
An interactive I/O monitoring tool for GNU/Linux.
=item pt-duplicate-key-checker
Find duplicate indexes and foreign keys on MySQL tables.
=item pt-fifo-split
Split files and pipe lines to a fifo without really splitting.
=item pt-find
Find MySQL tables and execute actions, like GNU find.
=item pt-fingerprint
Convert queries into fingerprints.
=item pt-fk-error-logger
Log MySQL foreign key errors.
=item pt-heartbeat
Monitor MySQL replication delay.
=item pt-index-usage
Read queries from a log and analyze how they use indexes.
=item pt-ioprofile
Watch process IO and print a table of file and I/O activity.
=item pt-kill
Kill MySQL queries that match certain criteria.
=item pt-mext
Look at many samples of MySQL C side-by-side.
=item pt-mysql-summary
Summarize MySQL information nicely.
=item pt-online-schema-change
ALTER tables without locking them.
=item pt-pmp
Aggregate GDB stack traces for a selected program.
=item pt-query-digest
Analyze MySQL queries from logs, processlist, and tcpdump.
=item pt-show-grants
Canonicalize and print MySQL grants so you can effectively replicate, compare and version-control them.
=item pt-sift
Browses files created by pt-stalk.
=item pt-slave-delay
Make a MySQL slave server lag behind its master.
=item pt-slave-find
Find and print replication hierarchy tree of MySQL slaves.
=item pt-slave-restart
Watch and restart MySQL replication after errors.
=item pt-stalk
Collect forensic data about MySQL when problems occur.
=item pt-summary
Summarize system information nicely.
=item pt-table-checksum
Verify MySQL replication integrity.
=item pt-table-sync
Synchronize MySQL table data efficiently.
=item pt-table-usage
Analyze how queries use tables.
=item pt-upgrade
Verify that query results are identical on different servers.
=item pt-variable-advisor
Analyze MySQL variables and advise on possible problems.
=item pt-visual-explain
Format EXPLAIN output as a tree.
=back
For more free, open-source software developed Percona, visit
L.
=head1 SPECIAL OPTION TYPES
Tool options use standard types (C, C, etc.) as well as
these special types:
=over
=item time
Time values are seconds by default. For example, C<--run-time 60> means
60 seconds. Time values support an optional suffix: s (seconds),
m (minutes), h (hours), d (days). C<--run-time 1m> means 1 minute
(the same as 60 seconds).
=item size
Size values are bytes by default. For example, C<--disk-space-free 1024>
means 1 Kibibyte. Size values support an optional suffix: k (Kibibyte),
M (Mebibyte), G (Gibibyte).
=item DSN
See L<"DSN (DATA SOURCE NAME) SPECIFICATIONS">.
=item Hash, hash, Array, array
Hash, hash, Array, and array values are comma-separated lists of values.
For example, C<--ignore-tables foo,bar> ignores tables C and C.
=back
=head1 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.
=head2 SYNTAX
The syntax of the configuration files is as follows:
=over
=item *
Whitespace followed by a hash sign (#) signifies that the rest of the line is a
comment. This is deleted. For example:
=item *
Whitespace is stripped from the beginning and end of all lines.
=item *
Empty lines are ignored.
=item *
Each line is permitted to be in either of the following formats:
option
option=value
Do not prefix the option with C<-->. Do not quote the values, even if
it has spaces; value are literal. Whitespace around the equals sign is
deleted during processing.
=item *
Only long options are recognized.
=item *
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.
=back
=head2 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 C<--> are passed literally to mysql and mysqladmin.
=head2 READ ORDER
The tools read several configuration files in order:
=over
=item 1.
The global Percona Toolkit configuration file,
F. All tools read this file,
so you should only add options to it that you want to apply to all tools.
=item 2.
The global tool-specific configuration file, F,
where C is a tool name like C. This file is named
after the specific tool you're using, so you can add options that apply
only to that tool.
=item 3.
The user's own Percona Toolkit configuration file,
F<$HOME/.percona-toolkit.conf>. All tools read this file, so you should only
add options to it that you want to apply to all tools.
=item 4.
The user's tool-specific configuration file, F<$HOME/.TOOL.conf>,
where C is a tool name like C. This file is named
after the specific tool you're using, so you can add options that apply
only to that tool.
=back
=head2 SPECIFYING
There is a special C<--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 B 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 C<--config=/path/to/file>;
you must specify the option and the path to the file separated by whitespace
I between them, like:
--config /path/to/file
If you don't want any configuration files at all, specify C<--config ''> to
provide an empty list of files.
=head1 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 C 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
C<--host>, C<--user>, and C<--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 C and option C<--port=12345> are
specified, then the tool automatically adds C to DSN.
=head2 ESCAPING VALUES
DSNs are usually specified on the command line, so shell quoting and escaping
must be taken into account. Special characters, like asterisk (C<*>), 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 (C<\>). 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 C,
it must be specified as C on most shells. This applies to DSNs
and DSN-related options like C<--user>.
=head2 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:
=over
=item A
Default character set for the connection (C).
Enables character set settings in Perl and MySQL. If the value is C,
sets Perl's binmode on STDOUT to utf8, passes the C option
to DBD::mysql, and runs C after connecting to MySQL. Other
values set binmode on STDOUT without the utf8 layer and run C after
connecting to MySQL.
Unfortunately, there is no way from within Perl itself to specify the client
library's character set. C 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.
=item D
Default database to use when connecting. Tools may C