pt-config-diff(1p)
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 2011-2016 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 2.2.20
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