NAME¶
pt-find - Find MySQL tables and execute actions, like GNU find.
SYNOPSIS¶
Usage: pt-find [OPTIONS] [DATABASES]
pt-find searches for MySQL tables and executes actions, like GNU find. The
default action is to print the database and table name.
Find all tables created more than a day ago, which use the MyISAM engine, and
print their names:
pt-find --ctime +1 --engine MyISAM
Find InnoDB tables and convert them to MyISAM:
pt-find --engine InnoDB --exec "ALTER TABLE %D.%N ENGINE=MyISAM"
Find tables created by a process that no longer exists, following the
name_sid_pid naming convention, and remove them.
pt-find --connection-id '\D_\d+_(\d+)$' --server-id '\D_(\d+)_\d+$' --exec-plus "DROP TABLE %s"
Find empty tables in the test and junk databases, and delete them:
pt-find --empty junk test --exec-plus "DROP TABLE %s"
Find tables more than five gigabytes in total size:
pt-find --tablesize +5G
Find all tables and print their total data and index size, and sort largest
tables first (sort is a different program, by the way).
pt-find --printf "%T\t%D.%N\n" | sort -rn
As above, but this time, insert the data back into the database for posterity:
pt-find --noquote --exec "INSERT INTO sysdata.tblsize(db, tbl, size) VALUES('%D', '%N', %T)"
RISKS¶
Percona Toolkit is mature, proven in the real world, and well tested, but all
database tools can pose a risk to the system and the database server. Before
using this tool, please:
- •
- Read the tool's documentation
- •
- Review the tool's known "BUGS"
- •
- Test the tool on a non-production server
- •
- Backup your production server and verify the backups
DESCRIPTION¶
pt-find looks for MySQL tables that pass the tests you specify, and executes the
actions you specify. The default action is to print the database and table
name to STDOUT.
pt-find is simpler than GNU find. It doesn't allow you to specify complicated
expressions on the command line.
pt-find uses SHOW TABLES when possible, and SHOW TABLE STATUS when needed.
OPTION TYPES¶
There are three types of options: normal options, which determine some behavior
or setting; tests, which determine whether a table should be included in the
list of tables found; and actions, which do something to the tables pt-find
finds.
pt-find uses standard Getopt::Long option parsing, so you should use double
dashes in front of long option names, unlike GNU find.
OPTIONS¶
This tool accepts additional command-line arguments. Refer to the
"SYNOPSIS" and usage information for details.
- --ask-pass
- Prompt for a password when connecting to MySQL.
- --case-insensitive
- Specifies that all regular expression searches are case-insensitive.
- --charset
- short form: -A; type: string
Default character set. 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.
- --config
- type: Array
Read this comma-separated list of config files; if specified, this must be
the first option on the command line.
- --database
- short form: -D; type: string
Connect to this database.
- --day-start
- Measure times (for "--mmin", etc) from the beginning of today
rather than from the current time.
- --defaults-file
- short form: -F; type: string
Only read mysql options from the given file. You must give an absolute
pathname.
- --help
- Show help and exit.
- --host
- short form: -h; type: string
Connect to host.
- --or
- Combine tests with OR, not AND.
By default, tests are evaluated as though there were an AND between them.
This option switches it to OR.
Option parsing is not implemented by pt-find itself, so you cannot specify
complicated expressions with parentheses and mixtures of OR and AND.
- --password
- short form: -p; type: string
Password to use when connecting.
- --pid
- type: string
Create the given PID file. The tool won't start if the PID file already
exists and the PID it contains is different than the current PID. However,
if the PID file exists and the PID it contains is no longer running, the
tool will overwrite the PID file with the current PID. The PID file is
removed automatically when the tool exits.
- --port
- short form: -P; type: int
Port number to use for connection.
- --[no]quote
- default: yes
Quotes MySQL identifier names with MySQL's standard backtick character.
Quoting happens after tests are run, and before actions are run.
- --set-vars
- type: Array
Set the MySQL variables in this comma-separated list of
"variable=value" pairs.
By default, the tool sets:
wait_timeout=10000
Variables specified on the command line override these defaults. For
example, specifying "--set-vars wait_timeout=500" overrides the
defaultvalue of 10000.
The tool prints a warning and continues if a variable cannot be set.
- --socket
- short form: -S; type: string
Socket file to use for connection.
- --user
- short form: -u; type: string
User for login if not current user.
- --version
- Show version and exit.
- --[no]version-check
- default: yes
Check for the latest version of Percona Toolkit, MySQL, and other programs.
This is a standard "check for updates automatically" feature, with
two additional features. First, the tool checks the version of other
programs on the local system in addition to its own version. For example,
it checks the version of every MySQL server it connects to, Perl, and the
Perl module DBD::mysql. Second, it checks for and warns about versions
with known problems. For example, MySQL 5.5.25 had a critical bug and was
re-released as 5.5.25a.
Any updates or known problems are printed to STDOUT before the tool's normal
output. This feature should never interfere with the normal operation of
the tool.
For more information, visit
<https://www.percona.com/version-check>.
TESTS¶
Most tests check some criterion against a column of SHOW TABLE STATUS output.
Numeric arguments can be specified as +n for greater than n, -n for less than
n, and n for exactly n. All numeric options can take an optional suffix
multiplier of k, M or G (1_024, 1_048_576, and 1_073_741_824 respectively).
All patterns are Perl regular expressions (see 'man perlre') unless specified
as SQL LIKE patterns.
Dates and times are all measured relative to the same instant, when pt-find
first asks the database server what time it is. All date and time manipulation
is done in SQL, so if you say to find tables modified 5 days ago, that
translates to SELECT DATE_SUB(CURRENT_TIMESTAMP, INTERVAL 5 DAY). If you
specify "--day-start", if course it's relative to CURRENT_DATE
instead.
However, table sizes and other metrics are not consistent at an instant in time.
It can take some time for MySQL to process all the SHOW queries, and pt-find
can't do anything about that. These measurements are as of the time they're
taken.
If you need some test that's not in this list, file a bug report and I'll
enhance pt-find for you. It's really easy.
- --autoinc
- type: string; group: Tests
Table's next AUTO_INCREMENT is n. This tests the Auto_increment column.
- --avgrowlen
- type: size; group: Tests
Table avg row len is n bytes. This tests the Avg_row_length column. The
specified size can be "NULL" to test where Avg_row_length IS
NULL.
- --checksum
- type: string; group: Tests
Table checksum is n. This tests the Checksum column.
- --cmin
- type: size; group: Tests
Table was created n minutes ago. This tests the Create_time column.
- --collation
- type: string; group: Tests
Table collation matches pattern. This tests the Collation column.
- --column-name
- type: string; group: Tests
A column name in the table matches pattern.
- --column-type
- type: string; group: Tests
A column in the table matches this type (case-insensitive).
Examples of types are: varchar, char, int, smallint, bigint, decimal, year,
timestamp, text, enum.
- --comment
- type: string; group: Tests
Table comment matches pattern. This tests the Comment column.
- --connection-id
- type: string; group: Tests
Table name has nonexistent MySQL connection ID. This tests the table name
for a pattern. The argument to this test must be a Perl regular expression
that captures digits like this: (\d+). If the table name matches the
pattern, these captured digits are taken to be the MySQL connection ID of
some process. If the connection doesn't exist according to SHOW FULL
PROCESSLIST, the test returns true. If the connection ID is greater than
pt-find's own connection ID, the test returns false for safety.
Why would you want to do this? If you use MySQL statement-based replication,
you probably know the trouble temporary tables can cause. You might choose
to work around this by creating real tables with unique names, instead of
temporary tables. One way to do this is to append your connection ID to
the end of the table, thusly: scratch_table_12345. This assures the table
name is unique and lets you have a way to find which connection it was
associated with. And perhaps most importantly, if the connection no longer
exists, you can assume the connection died without cleaning up its tables,
and this table is a candidate for removal.
This is how I manage scratch tables, and that's why I included this test in
pt-find.
The argument I use to "--connection-id" is "\D_(\d+)$".
That finds tables with a series of numbers at the end, preceded by an
underscore and some non-number character (the latter criterion prevents me
from examining tables with a date at the end, which people tend to do:
baron_scratch_2007_05_07 for example). It's better to keep the scratch
tables separate of course.
If you do this, make sure the user pt-find runs as has the PROCESS
privilege! Otherwise it will only see connections from the same user, and
might think some tables are ready to remove when they're still in use. For
safety, pt-find checks this for you.
See also "--server-id".
- --createopts
- type: string; group: Tests
Table create option matches pattern. This tests the Create_options
column.
- --ctime
- type: size; group: Tests
Table was created n days ago. This tests the Create_time column.
- --datafree
- type: size; group: Tests
Table has n bytes of free space. This tests the Data_free column. The
specified size can be "NULL" to test where Data_free IS
NULL.
- --datasize
- type: size; group: Tests
Table data uses n bytes of space. This tests the Data_length column. The
specified size can be "NULL" to test where Data_length IS
NULL.
- --dblike
- type: string; group: Tests
Database name matches SQL LIKE pattern.
- --dbregex
- type: string; group: Tests
Database name matches this pattern.
- --empty
- group: Tests
Table has no rows. This tests the Rows column.
- --engine
- type: string; group: Tests
Table storage engine matches this pattern. This tests the Engine column, or
in earlier versions of MySQL, the Type column.
- --function
- type: string; group: Tests
Function definition matches pattern.
- --indexsize
- type: size; group: Tests
Table indexes use n bytes of space. This tests the Index_length column. The
specified size can be "NULL" to test where Index_length IS
NULL.
- --kmin
- type: size; group: Tests
Table was checked n minutes ago. This tests the Check_time column.
- --ktime
- type: size; group: Tests
Table was checked n days ago. This tests the Check_time column.
- --mmin
- type: size; group: Tests
Table was last modified n minutes ago. This tests the Update_time
column.
- --mtime
- type: size; group: Tests
Table was last modified n days ago. This tests the Update_time column.
- --procedure
- type: string; group: Tests
Procedure definition matches pattern.
- --rowformat
- type: string; group: Tests
Table row format matches pattern. This tests the Row_format column.
- --rows
- type: size; group: Tests
Table has n rows. This tests the Rows column. The specified size can be
"NULL" to test where Rows IS NULL.
- --server-id
- type: string; group: Tests
Table name contains the server ID. If you create temporary tables with the
naming convention explained in "--connection-id", but also add
the server ID of the server on which the tables are created, then you can
use this pattern match to ensure tables are dropped only on the server
they're created on. This prevents a table from being accidentally dropped
on a slave while it's in use (provided that your server IDs are all
unique, which they should be for replication to work).
For example, on the master (server ID 22) you create a table called
scratch_table_22_12345. If you see this table on the slave (server ID 23),
you might think it can be dropped safely if there's no such connection
12345. But if you also force the name to match the server ID with
"--server-id '\D_(\d+)_\d+$'", the table won't be dropped on the
slave.
- --tablesize
- type: size; group: Tests
Table uses n bytes of space. This tests the sum of the Data_length and
Index_length columns.
- --tbllike
- type: string; group: Tests
Table name matches SQL LIKE pattern.
- --tblregex
- type: string; group: Tests
Table name matches this pattern.
- --tblversion
- type: size; group: Tests
Table version is n. This tests the Version column.
- --trigger
- type: string; group: Tests
Trigger action statement matches pattern.
- --trigger-table
- type: string; group: Tests
"--trigger" is defined on table matching pattern.
- --view
- type: string; group: Tests
CREATE VIEW matches this pattern.
ACTIONS¶
The "--exec-plus" action happens after everything else, but otherwise
actions happen in an indeterminate order. If you need determinism, file a bug
report and I'll add this feature.
- --exec
- type: string; group: Actions
Execute this SQL with each item found. The SQL can contain escapes and
formatting directives (see "--printf").
- --exec-dsn
- type: string; group: Actions
Specify a DSN in key-value format to use when executing SQL with
"--exec" and "--exec-plus". Any values not specified
are inherited from command-line arguments.
- --exec-plus
- type: string; group: Actions
Execute this SQL with all items at once. This option is unlike
"--exec". There are no escaping or formatting directives; there
is only one special placeholder for the list of database and table names,
%s. The list of tables found will be joined together with commas and
substituted wherever you place %s.
You might use this, for example, to drop all the tables you found:
DROP TABLE %s
This is sort of like GNU find's "-exec command {} +" syntax. Only
it's not totally cryptic. And it doesn't require me to write a
command-line parser.
- --print
- group: Actions
Print the database and table name, followed by a newline. This is the
default action if no other action is specified.
- --printf
- type: string; group: Actions
Print format on the standard output, interpreting '\' escapes and '%'
directives. Escapes are backslashed characters, like \n and \t. Perl
interprets these, so you can use any escapes Perl knows about. Directives
are replaced by %s, and as of this writing, you can't add any special
formatting instructions, like field widths or alignment (though I'm musing
over ways to do that).
Here is a list of the directives. Note that most of them simply come from
columns of SHOW TABLE STATUS. If the column is NULL or doesn't exist, you
get an empty string in the output. A % character followed by any character
not in the following list is discarded (but the other character is
printed).
CHAR DATA SOURCE NOTES
---- ------------------ ------------------------------------------
a Auto_increment
A Avg_row_length
c Checksum
C Create_time
D Database The database name in which the table lives
d Data_length
E Engine In older versions of MySQL, this is Type
F Data_free
f Innodb_free Parsed from the Comment field
I Index_length
K Check_time
L Collation
M Max_data_length
N Name
O Comment
P Create_options
R Row_format
S Rows
T Table_length Data_length+Index_length
U Update_time
V Version
DSN OPTIONS¶
These DSN options are used to create a DSN. Each option is given like
"option=value". The options are case-sensitive, so P and p are not
the same option. There cannot be whitespace before or after the "="
and if the value contains whitespace it must be quoted. DSN options are
comma-separated. See the percona-toolkit manpage for full details.
- •
- A
dsn: charset; copy: yes
Default character set.
- •
- D
dsn: database; copy: yes
Default database.
- •
- F
dsn: mysql_read_default_file; copy: yes
Only read default options from the given file
- •
- h
dsn: host; copy: yes
Connect to host.
- •
- p
dsn: password; copy: yes
Password to use when connecting.
- •
- P
dsn: port; copy: yes
Port number to use for connection.
- •
- S
dsn: mysql_socket; copy: yes
Socket file to use for connection.
- •
- u
dsn: user; copy: yes
User for login if not current user.
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-find ... > FILE 2>&1
Be careful: debugging output is voluminous and can generate several megabytes of
output.
SYSTEM REQUIREMENTS¶
You need Perl, DBI, DBD::mysql, and some core packages that ought to be
installed in any reasonably new version of Perl.
BUGS¶
For a list of known bugs, see <
http://www.percona.com/bugs/pt-find>.
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".
DOWNLOADING¶
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:
wget percona.com/get/percona-toolkit.tar.gz
wget percona.com/get/percona-toolkit.rpm
wget percona.com/get/percona-toolkit.deb
You can also get individual tools from the latest release:
wget percona.com/get/TOOL
Replace "TOOL" with the name of any tool.
AUTHORS¶
Baron Schwartz
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.
COPYRIGHT, LICENSE, AND WARRANTY¶
This program is copyright 2011-2014 Percona LLC and/or its affiliates, 2007-2011
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.
VERSION¶
pt-find 2.2.11