PERCONA-TOOLKIT(1p) User Contributed Perl Documentation PERCONA-TOOLKIT(1p)
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/>.
TOOLS
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:
o Whitespace followed by a hash sign (#) signifies that the rest of the line is a comment. This is deleted. For example:
o Whitespace is stripped from the beginning and end of all lines.
o Empty lines are ignored.
o 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.
o Only long options are recognized.
o 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:
o Perl v5.8 or newer
o Bash v3 or newer
o Core Perl modules like Time::HiRes
Tools that connect to MySQL require:
o Perl modules DBI and DBD::mysql
o 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:
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.)
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
perl v5.14.2 2012-06-15 PERCONA-TOOLKIT(1p)