.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "PT-SLAVE-DELAY 1p" .TH PT-SLAVE-DELAY 1p "2020-08-30" "perl v5.30.3" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" pt\-slave\-delay \- Make a MySQL slave server lag behind its master. .SH "SYNOPSIS" .IX Header "SYNOPSIS" Usage: pt-slave-delay [\s-1OPTIONS\s0] \s-1SLAVE_DSN\s0 [\s-1MASTER_DSN\s0] .PP pt-slave-delay starts and stops a slave server as needed to make it lag behind the master. The \s-1SLAVE_DSN\s0 and \s-1MASTER_DSN\s0 use \s-1DSN\s0 syntax, and values are copied from the \s-1SLAVE_DSN\s0 to the \s-1MASTER_DSN\s0 if omitted. .PP To hold slavehost one minute behind its master for ten minutes: .PP .Vb 1 \& pt\-slave\-delay \-\-delay 1m \-\-interval 15s \-\-run\-time 10m slavehost .Ve .SH "RISKS" .IX Header "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: .IP "\(bu" 4 Read the tool's documentation .IP "\(bu" 4 Review the tool's known \*(L"\s-1BUGS\*(R"\s0 .IP "\(bu" 4 Test the tool on a non-production server .IP "\(bu" 4 Backup your production server and verify the backups .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\f(CW\*(C`pt\-slave\-delay\*(C'\fR watches a slave and starts and stops its replication \s-1SQL\s0 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 \&\*(L"\-\-delay\*(R" and \*(L"\-\-delay\*(R" + \*(L"\-\-interval\*(R" behind the master. .PP 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 \s-1IO\s0 thread doesn't lag the master much, which is typical in most replication setups; the \s-1IO\s0 thread lag is usually milliseconds on a fast network. If your \&\s-1IO\s0 thread's lag is too large for your purposes, \f(CW\*(C`pt\-slave\-delay\*(C'\fR can also connect to the master for information about binlog positions. .PP If the slave's I/O thread reports that it is waiting for the \s-1SQL\s0 thread to free some relay log space, \f(CW\*(C`pt\-slave\-delay\*(C'\fR will automatically connect to the master to find binary log positions. If \*(L"\-\-ask\-pass\*(R" and \*(L"\-\-daemonize\*(R" 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 \&\*(L"\-\-use\-master\*(R" explicitly when daemonizing, or don't specify \*(L"\-\-ask\-pass\*(R". .PP The \s-1SLAVE_DSN\s0 and optional \s-1MASTER_DSN\s0 are both DSNs. See \*(L"\s-1DSN OPTIONS\*(R"\s0. Missing \s-1MASTER_DSN\s0 values are filled in with values from \s-1SLAVE_DSN,\s0 so you don't need to specify them in both places. \f(CW\*(C`pt\-slave\-delay\*(C'\fR 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. .PP \&\f(CW\*(C`pt\-slave\-delay\*(C'\fR tries to exit gracefully by trapping signals such as Ctrl-C. You cannot bypass \*(L"\-\-[no]continue\*(R" with a trappable signal. .SH "PRIVILEGES" .IX Header "PRIVILEGES" pt-slave-delay requires the following privileges: \s-1PROCESS, REPLICATION CLIENT,\s0 and \s-1SUPER.\s0 .SH "OUTPUT" .IX Header "OUTPUT" If you specify \*(L"\-\-quiet\*(R", there is no output. Otherwise, the normal output is a status message consisting of a timestamp and information about what \&\f(CW\*(C`pt\-slave\-delay\*(C'\fR is doing: starting the slave, stopping the slave, or just observing. .SH "OPTIONS" .IX Header "OPTIONS" This tool accepts additional command-line arguments. Refer to the \&\*(L"\s-1SYNOPSIS\*(R"\s0 and usage information for details. .IP "\-\-ask\-pass" 4 .IX Item "--ask-pass" Prompt for a password when connecting to MySQL. .IP "\-\-charset" 4 .IX Item "--charset" short form: \-A; type: string .Sp Default character set. If the value is utf8, sets Perl's binmode on \&\s-1STDOUT\s0 to utf8, passes the mysql_enable_utf8 option to DBD::mysql, and runs \s-1SET NAMES UTF8\s0 after connecting to MySQL. Any other value sets binmode on \s-1STDOUT\s0 without the utf8 layer, and runs \s-1SET NAMES\s0 after connecting to MySQL. .IP "\-\-config" 4 .IX Item "--config" type: Array .Sp Read this comma-separated list of config files; if specified, this must be the first option on the command line. .IP "\-\-[no]continue" 4 .IX Item "--[no]continue" default: yes .Sp Continue replication normally on exit. After exiting, restart the slave's \s-1SQL\s0 thread with no \s-1UNTIL\s0 condition, so it will run as usual and catch up to the master. This is enabled by default and works even if you terminate \&\f(CW\*(C`pt\-slave\-delay\*(C'\fR with Control-C. .IP "\-\-daemonize" 4 .IX Item "--daemonize" Fork to the background and detach from the shell. \s-1POSIX\s0 operating systems only. .IP "\-\-database" 4 .IX Item "--database" short form: \-D; type: string .Sp The database to use for the connection. .IP "\-\-defaults\-file" 4 .IX Item "--defaults-file" short form: \-F; type: string .Sp Only read mysql options from the given file. You must give an absolute pathname. .IP "\-\-delay" 4 .IX Item "--delay" type: time; default: 1h .Sp How far the slave should lag its master. .IP "\-\-help" 4 .IX Item "--help" Show help and exit. .IP "\-\-host" 4 .IX Item "--host" short form: \-h; type: string .Sp Connect to host. .IP "\-\-interval" 4 .IX Item "--interval" type: time; default: 1m .Sp How frequently \f(CW\*(C`pt\-slave\-delay\*(C'\fR should check whether the slave needs to be started or stopped. .IP "\-\-log" 4 .IX Item "--log" type: string .Sp Print all output to this file when daemonized. .IP "\-\-password" 4 .IX Item "--password" short form: \-p; type: string .Sp Password to use when connecting. If password contains commas they must be escaped with a backslash: \*(L"exam\e,ple\*(R" .IP "\-\-pid" 4 .IX Item "--pid" type: string .Sp Create the given \s-1PID\s0 file. The tool won't start if the \s-1PID\s0 file already exists and the \s-1PID\s0 it contains is different than the current \s-1PID.\s0 However, if the \s-1PID\s0 file exists and the \s-1PID\s0 it contains is no longer running, the tool will overwrite the \s-1PID\s0 file with the current \s-1PID.\s0 The \s-1PID\s0 file is removed automatically when the tool exits. .IP "\-\-port" 4 .IX Item "--port" short form: \-P; type: int .Sp Port number to use for connection. .IP "\-\-quiet" 4 .IX Item "--quiet" short form: \-q .Sp Don't print informational messages about operation. See \s-1OUTPUT\s0 for details. .IP "\-\-run\-time" 4 .IX Item "--run-time" type: time .Sp How long \f(CW\*(C`pt\-slave\-delay\*(C'\fR should run before exiting. The default is to run forever. .IP "\-\-set\-vars" 4 .IX Item "--set-vars" type: Array .Sp Set the MySQL variables in this comma-separated list of \f(CW\*(C`variable=value\*(C'\fR pairs. .Sp By default, the tool sets: .Sp .Vb 1 \& wait_timeout=10000 .Ve .Sp Variables specified on the command line override these defaults. For example, specifying \f(CW\*(C`\-\-set\-vars wait_timeout=500\*(C'\fR overrides the defaultvalue of \f(CW10000\fR. .Sp The tool prints a warning and continues if a variable cannot be set. .IP "\-\-socket" 4 .IX Item "--socket" short form: \-S; type: string .Sp Socket file to use for connection. .IP "\-\-use\-master" 4 .IX Item "--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 \s-1MASTER_DSN\s0 on the command line, \f(CW\*(C`pt\-slave\-delay\*(C'\fR examines the slave's \s-1SHOW SLAVE STATUS\s0 to determine the hostname and port for connecting to the master. .Sp \&\f(CW\*(C`pt\-slave\-delay\*(C'\fR uses only the \s-1MASTER_HOST\s0 and \s-1MASTER_PORT\s0 values from \s-1SHOW SLAVE STATUS\s0 for the master connection. It does not use the \s-1MASTER_USER\s0 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 \s-1MASTER_DSN\s0 option explicitly on the command line. .IP "\-\-user" 4 .IX Item "--user" short form: \-u; type: string .Sp User for login if not current user. .IP "\-\-version" 4 .IX Item "--version" Show version and exit. .IP "\-\-[no]version\-check" 4 .IX Item "--[no]version-check" default: yes .Sp Check for the latest version of Percona Toolkit, MySQL, and other programs. .Sp This is a standard \*(L"check for updates automatically\*(R" feature, with two additional features. First, the tool checks its own version and also the versions of the following software: operating system, Percona Monitoring and Management (\s-1PMM\s0), MySQL, Perl, MySQL driver for Perl (DBD::mysql), and Percona Toolkit. 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. .Sp A secure connection to Percona’s Version Check database server is done to perform these checks. Each request is logged by the server, including software version numbers and unique \s-1ID\s0 of the checked system. The \s-1ID\s0 is generated by the Percona Toolkit installation script or when the Version Check database call is done for the first time. .Sp Any updates or known problems are printed to \s-1STDOUT\s0 before the tool's normal output. This feature should never interfere with the normal operation of the tool. .Sp For more information, visit . .SH "DSN OPTIONS" .IX Header "DSN OPTIONS" These \s-1DSN\s0 options are used to create a \s-1DSN.\s0 Each option is given like \&\f(CW\*(C`option=value\*(C'\fR. The options are case-sensitive, so P and p are not the same option. There cannot be whitespace before or after the \f(CW\*(C`=\*(C'\fR and if the value contains whitespace it must be quoted. \s-1DSN\s0 options are comma-separated. See the percona-toolkit manpage for full details. .IP "\(bu" 4 A .Sp dsn: charset; copy: yes .Sp Default character set. .IP "\(bu" 4 D .Sp dsn: database; copy: yes .Sp Default database. .IP "\(bu" 4 F .Sp dsn: mysql_read_default_file; copy: yes .Sp Only read default options from the given file .IP "\(bu" 4 h .Sp dsn: host; copy: yes .Sp Connect to host. .IP "\(bu" 4 p .Sp dsn: password; copy: yes .Sp Password to use when connecting. If password contains commas they must be escaped with a backslash: \*(L"exam\e,ple\*(R" .IP "\(bu" 4 P .Sp dsn: port; copy: yes .Sp Port number to use for connection. .IP "\(bu" 4 S .Sp dsn: mysql_socket; copy: yes .Sp Socket file to use for connection. .IP "\(bu" 4 u .Sp dsn: user; copy: yes .Sp User for login if not current user. .SH "ENVIRONMENT" .IX Header "ENVIRONMENT" The environment variable \f(CW\*(C`PTDEBUG\*(C'\fR enables verbose debugging output to \s-1STDERR.\s0 To enable debugging and capture all output to a file, run the tool like: .PP .Vb 1 \& PTDEBUG=1 pt\-slave\-delay ... > FILE 2>&1 .Ve .PP Be careful: debugging output is voluminous and can generate several megabytes of output. .SH "SYSTEM REQUIREMENTS" .IX Header "SYSTEM REQUIREMENTS" You need Perl, \s-1DBI,\s0 DBD::mysql, and some core packages that ought to be installed in any reasonably new version of Perl. .SH "BUGS" .IX Header "BUGS" For a list of known bugs, see . .PP Please report bugs at . Include the following information in your bug report: .IP "\(bu" 4 Complete command-line used to run the tool .IP "\(bu" 4 Tool \*(L"\-\-version\*(R" .IP "\(bu" 4 MySQL version of all servers involved .IP "\(bu" 4 Output from the tool including \s-1STDERR\s0 .IP "\(bu" 4 Input files (log/dump/config files, etc.) .PP If possible, include debugging output by running the tool with \f(CW\*(C`PTDEBUG\*(C'\fR; see \*(L"\s-1ENVIRONMENT\*(R"\s0. .SH "DOWNLOADING" .IX Header "DOWNLOADING" Visit to download the latest release of Percona Toolkit. Or, get the latest release from the command line: .PP .Vb 1 \& wget percona.com/get/percona\-toolkit.tar.gz \& \& wget percona.com/get/percona\-toolkit.rpm \& \& wget percona.com/get/percona\-toolkit.deb .Ve .PP You can also get individual tools from the latest release: .PP .Vb 1 \& wget percona.com/get/TOOL .Ve .PP Replace \f(CW\*(C`TOOL\*(C'\fR with the name of any tool. .SH "AUTHORS" .IX Header "AUTHORS" Sergey Zhuravlev and Baron Schwartz .SH "ABOUT PERCONA TOOLKIT" .IX Header "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 to learn about other free, open-source software from Percona. .SH "COPYRIGHT, LICENSE, AND WARRANTY" .IX Header "COPYRIGHT, LICENSE, AND WARRANTY" This program is copyright 2011\-2018 Percona \s-1LLC\s0 and/or its affiliates, 2007\-2011 Sergey Zhuravle and Baron Schwartz. .PP \&\s-1THIS PROGRAM IS PROVIDED \*(L"AS IS\*(R" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.\s0 .PP This program is free software; you can redistribute it and/or modify it under the terms of the \s-1GNU\s0 General Public License as published by the Free Software Foundation, version 2; \s-1OR\s0 the Perl Artistic License. On \s-1UNIX\s0 and similar systems, you can issue `man perlgpl' or `man perlartistic' to read these licenses. .PP You should have received a copy of the \s-1GNU\s0 General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, \s-1MA\s0 02111\-1307 \s-1USA.\s0 .SH "VERSION" .IX Header "VERSION" pt-slave-delay 3.2.1 .SH "POD ERRORS" .IX Header "POD ERRORS" Hey! \fBThe above document had some coding errors, which are explained below:\fR .IP "Around line 4825:" 4 .IX Item "Around line 4825:" Non-ASCII character seen before =encoding in 'Percona’s'. Assuming \s-1UTF\-8\s0