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

NAME

       pt-slave-delay - Make a MySQL slave server lag behind its master.

SYNOPSIS

       Usage: pt-slave-delay [OPTIONS] SLAVE_DSN [MASTER_DSN]

       pt-slave-delay starts and stops a slave server as needed to make it lag behind the master.
       The SLAVE_DSN and MASTER_DSN use DSN syntax, and values are copied from the SLAVE_DSN to
       the MASTER_DSN if omitted.

       To hold slavehost one minute behind its master for ten minutes:

          pt-slave-delay --delay 1m --interval 15s --run-time 10m slavehost

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-slave-delay" watches a slave and starts and stops its replication SQL thread as
       necessary to hold it at least as far behind the master as you request.  In practice, it
       will typically cause the slave to lag between "--delay" and "--delay"+"--interval" behind
       the master.

       It bases the delay on binlog positions in the slave's relay logs by default, so there is
       no need to connect to the master.  This works well if the IO thread doesn't lag the master
       much, which is typical in most replication setups; the IO thread lag is usually
       milliseconds on a fast network.  If your IO thread's lag is too large for your purposes,
       "pt-slave-delay" can also connect to the master for information about binlog positions.

       If the slave's I/O thread reports that it is waiting for the SQL thread to free some relay
       log space, "pt-slave-delay" will automatically connect to the master to find binary log
       positions.  If "--ask-pass" and "--daemonize" are given, it is possible that this could
       cause it to ask for a password while daemonized.  In this case, it exits.  Therefore, if
       you think your slave might encounter this condition, you should be sure to either specify
       "--use-master" explicitly when daemonizing, or don't specify "--ask-pass".

       The SLAVE_DSN and optional MASTER_DSN are both DSNs.  See "DSN OPTIONS".  Missing
       MASTER_DSN values are filled in with values from SLAVE_DSN, so you don't need to specify
       them in both places.  "pt-slave-delay" reads all normal MySQL option files, such as
       ~/.my.cnf, so you may not need to specify username, password and other common options at
       all.

       "pt-slave-delay" tries to exit gracefully by trapping signals such as Ctrl-C.  You cannot
       bypass "--[no]continue" with a trappable signal.

PRIVILEGES

       pt-slave-delay requires the following privileges: PROCESS, REPLICATION CLIENT, and SUPER.

OUTPUT

       If you specify "--quiet", there is no output.  Otherwise, the normal output is a status
       message consisting of a timestamp and information about what "pt-slave-delay" is doing:
       starting the slave, stopping the slave, or just observing.

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.

       --[no]continue
           default: yes

           Continue replication normally on exit.  After exiting, restart the slave's SQL thread
           with no UNTIL condition, so it will run as usual and catch up to the master.  This is
           enabled by default and works even if you terminate "pt-slave-delay" with Control-C.

       --daemonize
           Fork to the background and detach from the shell.  POSIX operating systems only.

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

           The database to use for the connection.

       --defaults-file
           short form: -F; type: string

           Only read mysql options from the given file.  You must give an absolute pathname.

       --delay
           type: time; default: 1h

           How far the slave should lag its master.

       --help
           Show help and exit.

       --host
           short form: -h; type: string

           Connect to host.

       --interval
           type: time; default: 1m

           How frequently "pt-slave-delay" should check whether the slave needs to be started or
           stopped.

       --log
           type: string

           Print all output to this file when daemonized.

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

           Password to use when connecting.  If password contains commas they must be escaped
           with a backslash: "exam\,ple"

       --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.

       --quiet
           short form: -q

           Don't print informational messages about operation.  See OUTPUT for details.

       --run-time
           type: time

           How long "pt-slave-delay" should run before exiting.  The default is to run forever.

       --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.

       --use-master
           Get binlog positions from master, not slave.  Don't trust the binlog positions in the
           slave's relay log.  Connect to the master and get binlog positions instead.  If you
           specify this option without giving a MASTER_DSN on the command line, "pt-slave-delay"
           examines the slave's SHOW SLAVE STATUS to determine the hostname and port for
           connecting to the master.

           "pt-slave-delay" uses only the MASTER_HOST and MASTER_PORT values from SHOW SLAVE
           STATUS for the master connection.  It does not use the MASTER_USER value.  If you want
           to specify a different username for the master than the one you use to connect to the
           slave, you should specify the MASTER_DSN option explicitly on the command line.

       --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>.

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-slave-delay ... > 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-slave-delay>.

       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

       Sergey Zhuravlev and Baron Schwartz

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, 2007-2011 Sergey
       Zhuravle and 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-slave-delay 2.2.16