Shulou(Shulou.com)05/31 Report--

This article mainly introduces "how MySQL5.7 realizes the manual smooth switching of one master and two slaves MHA online". In daily operation, I believe that many people have doubts about how MySQL5.7 realizes the manual smooth switching of one master and two slaves MHA online. Xiaobian consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful for everyone to answer the doubts of "how to achieve a master and two slaves MHA online manual smooth switching". Next, please follow the editor to study!

Database architecture: one master and two slaves

Master:192.168.8.57

Slave1:192.168.8.58

Slave2:192.168.8.59

Manager:192.168.8.60

MHA Toolkit:

Mha4mysql-manager-0.58.tar.gz

Mha4mysql-node-0.58.tar.gz

I. modify the content of master_ip_online_change

#! / usr/bin/env perl# Copyright (C) 2011 DeNA Co.,Ltd.## 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; either version 2 of the License, or# (at your option) any later version.## This program is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU General Public License for more details.## 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.,# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USAuse strict;use warnings FATAL = > 'all';use Getopt::Long qw (: config pass_through); use Pod::Usage;use MHA::MasterMonitor;use MHA::MasterFailover;use MHA::MasterRotate;use MHA::ManagerConst;my $master_state = "; my $help My $version;$ | = 1 exit_code GetOptions ('help' = >\ $help,' version' = >\ $version, 'master_state=s' = >\ $master_state); my $exit_code = 1 exit_code if ($version) {print "masterha_master_switch version $MHA::ManagerConst::VERSION.\ n"; exit 0;} if ($help) {pod2usage (0);} if ($master_state eq "dead") {$exit_code = MHA::MasterFailover::main (@ ARGV) } elsif ($master_state eq "alive") {$exit_code = MHA::MasterRotate::main (@ ARGV);} else {pod2usage (1);} exit $exit_code # Documentation# # # # # = pod=head1 NAMEmasterha_master_switch-Switching MySQL master server to one of other slave servers=head1 SYNOPSIS# For master failovermasterha_master_switch-- master_state=dead-- global_conf=/etc/masterha_default.cnf-- conf=/usr/local/masterha/conf/app1.cnf-- dead_master_host=host1 # For online master switchmasterha_master_switch-- master_state=alive- Global_conf=/etc/masterha_default.cnf-conf=/usr/local/masterha/conf/app1.cnfSee online reference (http://code.google.com/p/mysql-master-ha/wiki/masterha_master_switch) for details.=head1 DESCRIPTIONSee online reference (http://code.google.com/p/mysql-master-ha/wiki/masterha_master_switch) for details. [root@manager MHA] # [root@manager MHA] # [root@manager MHA] # cat / usr/local Binding perl# Copyright (C) 2011 DeNA Co. Ltd.## 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; either version 2 of the License, or# (at your option) any later version.## This program is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU General Public License for more details.## 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.,# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA## Note: This is a sample script and is not complete. Modify the script based on your environment.use strict;use warnings FATAL = > 'all';use Getopt::Long;use MHA::DBHelper;use MHA::NodeUtil;use Time::HiRes qw (sleep gettimeofday tv_interval); use Data::Dumper;my $_ tstart;my $_ running_interval = 0.1 My ($command, $orig_master_is_new_slave, $orig_master_host, $orig_master_ip, $orig_master_port, $orig_master_user, $orig_master_password, $orig_master_ssh_user, $new_master_host, $new_master_ip, $new_master_port, $new_master_user, $new_master_password, $new_master_ssh_user,) GetOptions ('command=s' = >\ $command,' orig_master_is_new_slave' = >\ $orig_master_is_new_slave, 'orig_master_host=s' = >\ $orig_master_host,' orig_master_ip=s' = >\ $orig_master_ip, 'orig_master_port=i' = >\ $orig_master_port,' orig_master_user=s' = >\ $orig_master_user 'orig_master_password=s' = >\ $orig_master_password,' orig_master_ssh_user=s' = >\ $orig_master_ssh_user, 'new_master_host=s' = >\ $new_master_host,' new_master_ip=s' = >\ $new_master_ip, 'new_master_port=i' = >\ $new_master_port,' new_master_user=s' = >\ $new_master_user 'new_master_password=s' = >\ $new_master_password,' new_master_ssh_user=s' = >\ $new_master_ssh_user,) Exit & main (); sub current_time_us {my ($sec, $microsec) = gettimeofday (); my $curdate = localtime ($sec); return $curdate. "". Sprintf ("d", $microsec);} sub sleep_until {my $elapsed = tv_interval ($_ tstart); if ($_ running_interval > $elapsed) {sleep ($_ running_interval-$elapsed);}} sub get_threads_util {my $dbh = shift; my $my_connection_id = shift; my $running_time_threshold = shift; my $type = shift $running_time_threshold = 0 unless ($running_time_threshold); $type = 0 unless ($type); my @ threads; my $sth = $dbh- > prepare ("SHOW PROCESSLIST"); $sth- > execute (); while (my $ref = $sth- > fetchrow_hashref ()) {my $id = $ref- > {Id}; my $user = $ref- > {User}; my $host = $ref- > {Host} My $command = $ref- > {Command}; my $state = $ref- > {State}; my $query_time = $ref- > {Time}; my $info = $ref- > {Info}; $info = ~ s / ^\ s * (. *?)\ s steps 1 / if defined ($info); next if ($my_connection_id = = $id); next if (defined ($query_time) & $query_time)

< $running_time_threshold ); next if ( defined($command) && $command eq "Binlog Dump" ); next if ( defined($user) && $user eq "system user" ); next if ( defined($command) && $command eq "Sleep" && defined($query_time) && $query_time >

= 1); if ($type > = 1) {next if (defined ($command) & & $command eq "Sleep"); next if (defined ($command) & & $command eq "Connect");} if ($type > = 2) {next if (defined ($info) & & $info = ~ m / ^ select / I); next if (defined ($info) & $info = ~ m / ^ show / I);} push @ threads, $ref;} return @ threads } sub main {if ($command eq "stop") {# Gracefully killing connections on the current master # 1. Set read_only= 1 on the new master # 2. DROP USER so that no app user can establish new connections # 3. Set read_only= 1 on the current master # 4. Kill current queries # * Any database access failure will result in script die. My $exit_code = 1; eval {# Setting read_only=1 on the new master (to avoid accident) my $new_master_handler = new MHA::DBHelper (); # args: hostname, port, user, password, raise_error (die_on_error) _ or_not $new_master_handler- > connect ($new_master_ip, $new_master_port, $new_master_user, $new_master_password, 1); print current_time_us (). "Set read_only on the new master.. "; $new_master_handler- > enable_read_only (); if ($new_master_handler- > is_read_only ()) {print" ok.\ n ";} else {die" Failed!\ n ";} $new_master_handler- > disconnect (); # Connecting to the orig master, die if any database error happens my $orig_master_handler = new MHA::DBHelper () $orig_master_handler- > connect ($orig_master_ip, $orig_master_port, $orig_master_user, $orig_master_password, 1); # # Drop application user so that nobody can connect. Disabling per-session binlog beforehand $orig_master_handler- > disable_log_bin_local (); print current_time_us (). "Drpping app user on the orig master..\ n"; # FIXME_xxx_drop_app_user ($orig_master_handler); # # Waiting for N * 100 milliseconds so that current connections can exit my $time_until_read_only = 15; $_ tstart = [gettimeofday]; my @ threads = get_threads_util ($orig_master_handler- > {dbh}, $orig_master_handler- > {connection_id}) While ($time_until_read_only > 0 & & $# threads > = 0) {if ($time_until_read_only% 5 = = 0) {printf "% s Waiting all running% d threads are disconnected.. (max% d milliseconds)\ n ", current_time_us (), $# threads + 1, $time_until_read_only * 100; if ($# threads

< 5 ) { print Data::Dumper->

New ([$_])-> Indent (0)-> Terse (1)-> Dump. "\ n" foreach (@ threads);}} sleep_until (); $_ tstart = [gettimeofday]; $time_until_read_only--; @ threads = get_threads_util ($orig_master_handler- > {dbh}, $orig_master_handler- > {connection_id}) Setting read_only=1 on the current master so that nobody (except SUPER) can write print current_time_us (). "Set read_only=1 on the orig master.. "; $orig_master_handler- > enable_read_only (); if ($orig_master_handler- > is_read_only ()) {print" ok.\ n ";} else {die" Failed!\ n ";} # # Waiting for M * 100 milliseconds so that current update queries can complete my $time_until_kill_threads = 5 Threads = get_threads_util ($orig_master_handler- > {dbh}, $orig_master_handler- > {connection_id}); while ($time_until_kill_threads > 0 & & $# threads > = 0) {if ($time_until_kill_threads% 5 = = 0) {printf "% s Waiting all running% d queries are disconnected.. (max% d milliseconds)\ n ", current_time_us (), $# threads + 1, $time_until_kill_threads * 100; if ($# threads

< 5 ) { print Data::Dumper->

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