xenial (1) pt-config-diff.1p.gz

Provided by: percona-toolkit_2.2.16-1_all bug

NAME

       pt-config-diff - Diff MySQL configuration files and server variables.

SYNOPSIS

       Usage: pt-config-diff [OPTIONS] CONFIG CONFIG [CONFIG...]

       pt-config-diff diffs MySQL configuration files and server variables.  CONFIG can be a filename or a DSN.
       At least two CONFIG sources must be given.  Like standard Unix diff, there is no output if there are no
       differences.

       Diff host1 config from SHOW VARIABLES against host2:

         pt-config-diff h=host1 h=host2

       Diff config from [mysqld] section in my.cnf against host1 config:

         pt-config-diff /etc/my.cnf h=host1

       Diff the [mysqld] section of two option files:

          pt-config-diff /etc/my-small.cnf /etc/my-large.cnf

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-config-diff diffs MySQL configurations by examining the values of server system variables from two or
       more CONFIG sources specified on the command line.  A CONFIG source can be a DSN or a filename containing
       the output of "mysqld --help --verbose", "my_print_defaults", "SHOW VARIABLES", or an option file (e.g.
       my.cnf).

       For each DSN CONFIG, pt-config-diff connects to MySQL and gets variables and values by executing "SHOW
       /*!40103 GLOBAL*/ VARIABLES".  This is an "active config" because it shows what server values MySQL is
       actively (currently) running with.

       Only variables that all CONFIG sources have are compared because if a variable is not present then we
       cannot know or safely guess its value.  For example, if you compare an option file (e.g. my.cnf) to an
       active config (i.e. SHOW VARIABLES from a DSN CONFIG), the option file will probably only have a few
       variables, whereas the active config has every variable.  Only values of the variables present in both
       configs are compared.

       Option file and DSN configs provide the best results.

OUTPUT

       There is no output when there are no differences.  When there are differences, pt-config-diff prints a
       report to STDOUT that looks similar to the following:

         2 config differences
         Variable                  my.master.cnf   my.slave.cnf
         ========================= =============== ===============
         datadir                   /tmp/12345/data /tmp/12346/data
         port                      12345           12346

       Comparing MySQL variables is difficult because there are many variations and subtleties across the many
       versions and distributions of MySQL.  When a comparison fails, the tool prints a warning to STDERR, such
       as the following:

         Comparing log_error values (mysqld.log, /tmp/12345/data/mysqld.log)
         caused an error: Argument "/tmp/12345/data/mysqld.log" isn't numeric
         in numeric eq (==) at ./pt-config-diff line 2311.

       Please report these warnings so the comparison functions can be improved.

EXIT STATUS

       pt-config-diff exits with a zero exit status when there are no differences, and 1 if there are.

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.

       --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.  (This option does not specify a CONFIG; it's equivalent to "--defaults-file".)

       --database
           short form: -D; type: string

           Connect to this database.

       --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.

       --[no]ignore-case
           default: yes

           Compare the variables case-insensitively.

       --ignore-variables
           type: array

           Ignore, do not compare, these variables.

       --password
           short form: -p; type: string

           Password to use for connection.

       --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]report
           default: yes

           Print the MySQL config diff report to STDOUT.  If you just want to check if the given configs are
           different or not by examining the tool's exit status, then specify "--no-report" to suppress the
           report.

       --report-width
           type: int; default: 78

           Truncate report lines to this many characters.  Since some variable values can be long, or when
           comparing multiple configs, it may help to increase the report width so values are not truncated
           beyond readability.

       --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

           MySQL user 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>.

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.  If password contains commas they must be escaped with a backslash:
           "exam\,ple"

       •   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-config-diff ... > 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-config-diff>.

       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 and Daniel Nichter

ABOUT PERCONA TOOLKIT

       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 2011-2015 Percona LLC and/or its affiliates.

       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-config-diff 2.2.16