|o||Read the tools documentation|
|o||Review the tools known BUGS|
|o||Test the tool on a non-production server|
|o||Backup your production server and verify the backups|
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 doesnt allow you to specify complicated expressions on the command line.
pt-find uses SHOW TABLES when possible, and SHOW TABLE STATUS when needed.
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.
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 Perls 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 wont 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 MySQLs 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:
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 --version Show version and exit. --[no]version-check default: yes
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 tools normal output. This feature should never interfere with the normal operation of the tool.
For more information, visit <https://www.percona.com/version-check>.
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 its 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 cant do anything about that. These measurements are as of the time theyre taken.
If you need some test thats not in this list, file a bug report and Ill enhance pt-find for you. Its really easy.
--autoinc type: string; group: Tests
Tables 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).
--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 doesnt exist according to SHOW FULL PROCESSLIST, the test returns true. If the connection ID is greater than pt-finds 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 thats 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). Its 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 theyre 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 theyre created on. This prevents a table from being accidentally dropped on a slave while its 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 theres no such connection 12345. But if you also force the name to match the server ID with --server-id \D_(\d+)_\d+$, the table wont 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.
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 Ill 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
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 cant add any special formatting instructions, like field widths or alignment (though Im 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 doesnt 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
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.
dsn: charset; copy: yes
Default character set.
dsn: database; copy: yes
dsn: mysql_read_default_file; copy: yes
Only read default options from the given file
dsn: host; copy: yes
Connect to host.
dsn: password; copy: yes
Password to use when connecting.
dsn: port; copy: yes
Port number to use for connection.
dsn: mysql_socket; copy: yes
Socket file to use for connection.
dsn: user; copy: yes
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.
You need Perl, DBI, DBD::mysql, and some core packages that ought to be installed in any reasonably new version of Perl.
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:
If possible, include debugging output by running the tool with PTDEBUG; see ENVIRONMENT.
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.)
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:
Replace TOOL with the name of any tool.
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.
This program is copyright 2011-2015 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.
|perl v5.20.3||PT-FIND (1)||2015-04-10|