Orchestrator+Proxysql 实现自动导换+应用透明读写分离

增加一个定时任务

脚本做如下检查

• read_only=ON – mysql服务器是否为 read-only (Slave，read-only为ON)
• repl_lag  is NULL – Master，这个参数值应该为NULL (如果seconds_behind_master没有定义, ProxySQL 会报告repl_lag 为 NULL)

如果 read_only=ON, 这意味者，这台服务器当前不是master。但如果repl_lag=NULL, 这就意味得服务器没有开启复制，而且很有可能以前是master. 所以，就必须把它从Hostgroup内移除.

INSERT  INTO scheduler (id,interval_ms,filename,arg1) values (10,2000,"/var/lib/proxysql/server_monitor.pl","-u=admin -p=admin -h=127.0.0.1 -G=601 -P=6032 --debug=0  --log=/var/lib/proxysql/server_check");

LOAD SCHEDULER TO RUNTIME;SAVE SCHEDULER TO DISK;

检查mysql服务器状态

当host01重新启动后。

如下，可以看到host01（192.168.56.103）的状态是在线，但是hostgroup修改成为了9601（server_monitor.pl脚本实现就是通过修改   New hostgroup=9000+ old hostgroup）。如此一来，发往601只读hostgroup里，就排除了host01。

mysql> select * from mysql_servers;

+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| hostgroup_id | hostname       | port | gtid_port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment |

+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| 9601         | 192.168.56.103 | 3306 | 0         | ONLINE | 1000   | 0           | 1000            | 60                  | 0       | 0              |         |

| 600          | 192.168.56.104 | 3306 | 0         | ONLINE | 1000   | 0           | 1000            | 60                  | 0       | 0              |         |

| 601          | 192.168.56.105 | 3306 | 0         | ONLINE | 1000   | 0           | 1000            | 60                  | 0       | 0              |         |

| 601          | 192.168.56.104 | 3306 | 0         | ONLINE | 1000   | 0           | 1000            | 60                  | 0       | 0              |         |

+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

4 rows in set (0.00 sec)

server_monitor.pl完整脚本

#!/usr/bin/perl

# This tool is "fat-packed": most of its dependent modules are embedded

# in this file. 

package remove_old_master;

use Time::HiRes qw(gettimeofday);

use strict;

use DBI;

use Getopt::Long;

use Pod::Usage;

use Data::Dumper;

$Getopt::Long::ignorecase = 0;

my $Param = {};

my $user = "admin";

my $pass = "admin";

my $help = '';

my $host = 'localhot' ;

my $debug = 0 ;

my %hostgroups;

my %processState;

my %processCommand;

my @HGIds;

######################################################################

#Local functions

######################################################################

sub URLDecode {

my $theURL = $_[0];

$theURL =~ tr/+/ /;

$theURL =~ s/%([a-fA-F0-9]{2,2})/chr(hex($1))/eg;

$theURL =~ s/<!--(.|\n)*-->//g;

return $theURL;

}

sub URLEncode {

my $theURL = $_[0];

$theURL =~ s/([\W])/"%" . uc(sprintf("%2.2x",ord($1)))/eg;

return $theURL;

}

# return a proxy object

sub get_proxy($$$$){

my $dns = shift;

my $user = shift;

my $pass = shift;

my $debug = shift;

my $proxynode = ProxySqlNode->new();

$proxynode->dns($dns);

$proxynode->user($user);

$proxynode->password($pass);

$proxynode->debug($debug);

return $proxynode;

}

sub main{

# ============================================================================

#+++++ INITIALIZATION

# ============================================================================

if($#ARGV < 3){

#given a ProxySQL scheduler

#limitation we will pass the whole set of params as one

# and will split after

@ARGV = split('\ ',$ARGV[0]);

}

$Param->{user} = '';

$Param->{log} = undef ;

$Param->{password} = '';

$Param->{host} = '';

$Param->{port} = '127.0.0.1';

$Param->{debug} = 0;

$Param->{processlist} = 0;

$Param->{OS} = $^O;

$Param->{main_segment} = 0;

$Param->{retry_up} = 0;

$Param->{retry_down} = 0;

$Param->{print_execution} = 0;

$Param->{development} = 0;

$Param->{hgid} = 0;

my $run_pid_dir = "/tmp" ;

#if (

GetOptions(

'user|u:s' => \$Param->{user},

'password|p:s' => \$Param->{password},

'host|h:s' => \$host,

'port|P:i' => \$Param->{port},

'debug|d:i' => \$Param->{debug},

'log:s' => \$Param->{log},

'main_segment|S:s'=> \$Param->{main_segment},

'retry_up:i' => \$Param->{retry_up},

'retry_down:i' => \$Param->{retry_down},

'execution_time:i' => \$Param->{print_execution},

'development:i' => \$Param->{development},

'active_failover' => \$Param->{active_failover},

'hgid|G:i' => \$Param->{hgid},

'help|?' => \$Param->{help}

) or pod2usage(2);

pod2usage(-verbose => 2) if $Param->{help};

die print Utils->print_log(1,"Option --hgid not specified.\n") unless defined($Param->{hgid});

die print Utils->print_log(1,"Option --host not specified.\n") unless defined $Param->{host};

die print Utils->print_log(1,"Option --user not specified.\n") unless defined $Param->{user};

die print Utils->print_log(1,"Option --port not specified.\n") unless defined $Param->{port};

die "Option --log not specified. We need a place to log what is going on, don't we?\n" unless defined $Param->{log};

print Utils->print_log(2,"Option --log not specified. We need a place to log what is going on, don't we?\n") unless defined $Param->{log};

if($Param->{debug}){

Utils::debugEnv();

}

$Param->{host} = URLDecode($host);

my $dsn = "DBI:mysql:host=$Param->{host};port=$Param->{port}";

if(defined $Param->{user}){

$user = "$Param->{user}";

}

if(defined $Param->{password}){

$pass = "$Param->{password}";

}

my $hg =$Param->{hgid};

$hg =~ s/[\:,\,]/_/g;

my $base_path = "${run_pid_dir}/proxysql_galera_check_${hg}.pid";

#============================================================================

# Execution

#============================================================================

if(defined $Param->{log}){

open(FH, '>>', $Param->{log}."_".$hg.".log") or die Utils->print_log(1,"cannot open file");

#select FH;

}

if($Param->{development} < 1){

if(!-e $base_path){

`echo "$$ : $hg" > $base_path`

}

else{

print Utils->print_log(1,"Another process is running using the same HostGroup and settings,\n Or orphan pid file. check in $base_path");

exit 1;

}

}

# for test only purpose comment for prod

#my $xx =1;

#my $y =0;

#$xx=20000000 if($Param->{development} > 0);

#while($y < $xx){

#++$y ;

my $start = gettimeofday();

if($Param->{debug} >= 1){

print Utils->print_log(3,"START EXECUTION\n");

}

my $proxy_sql_node = get_proxy($dsn, $user, $pass ,$Param->{debug}) ;

$proxy_sql_node->retry_down($Param->{retry_down});

$proxy_sql_node->move_node($proxy_sql_node,$Param->{hgid});

$proxy_sql_node->connect();

my $end = gettimeofday();

print Utils->print_log(3,"END EXECUTION Total Time:".($end - $start) * 1000 ."\n\n") if $Param->{print_execution} >0;

$proxy_sql_node->disconnect();

#debug braket

sleep 2 if($Param->{development} > 0);

}

if(defined $Param->{log}){

close FH; # in the end

}

`rm -f $base_path`;

exit(0);

}

# ############################################################################

# Run the program.

# ############################################################################

exit main(@ARGV);

{

package ProxySqlNode;

sub new {

my $class = shift;

my $SQL_get_monitor = "select variable_name name,variable_value value from global_variables where variable_name in( 'mysql-monitor_username','mysql-monitor_password','mysql-monitor_read_only_timeout' ) order by 1";

my $SQL_get_hostgroups = "select distinct hostgroup_id hg_isd from mysql_servers order by 1;";

my $SQL_get_rep_hg = "select writer_hostgroup,reader_hostgroup from mysql_replication_hostgroups order by 1;";

# Variable section for looping values

#Generalize object for now I have conceptualize as:

# Proxy (generic container)

# Proxy->{DNS} conenction reference

# Proxy->{PID} processes pid (angel and real)

# Proxy->{hostgroups}

# Proxy->{user} This is the user name

# Proxy->{password}

# Proxy->{port} node status (OPEN 0,Primary 1,Joiner 2,Joined 3,Synced 4,Donor 5)

my $self = {

_dns => undef,

_pid => undef,

_user => undef,

_password => undef,

_port => undef,

_hgid => undef,

_monitor_user => undef,

_monitor_password => undef,

_SQL_get_monitor => $SQL_get_monitor,

_SQL_get_hg=> $SQL_get_hostgroups,

_SQL_get_replication_hg=> $SQL_get_rep_hg,

_dbh_proxy => undef,

_check_timeout => 100, #timeout in ms

_retry_down => 0, # number of retry on a node before declaring it as failed.

};

bless $self, $class;

return $self;

}

sub retry_down{

my ( $self, $in ) = @_;

$self->{_retry_down} = $in if defined($in);

return $self->{_retry_down};

}

sub debug{

my ( $self, $debug ) = @_;

$self->{_debug} = $debug if defined($debug);

return $self->{_debug};

}

sub dns {

my ( $self, $dns ) = @_;

$self->{_dns} = $dns if defined($dns);

return $self->{_dns};

}

sub dbh_proxy{

my ( $self, $dbh_proxy ) = @_;

$self->{_dbh_proxy} = $dbh_proxy if defined($dbh_proxy);

return $self->{_dbh_proxy};

}

sub pid {

my ( $self, $pid ) = @_;

$self->{_pid} = $pid if defined($pid);

return $self->{_pid};

}

sub user{

my ( $self, $user ) = @_;

$self->{_user} = $user if defined($user);

return $self->{_user};

}

sub password {

my ( $self, $password ) = @_;

$self->{_password} = $password if defined($password);

return $self->{_password};

}

sub monitor_user{

my ( $self, $monitor_user ) = @_;

$self->{_monitor_user} = $monitor_user if defined($monitor_user);

return $self->{_monitor_user};

}

sub monitor_password {

my ( $self, $monitor_password ) = @_;

$self->{_monitor_password} = $monitor_password if defined($monitor_password);

return $self->{_monitor_password};

}

sub port {

my ( $self, $port ) = @_;

$self->{_port} = $port if defined($port);

return $self->{_port};

}

sub hgid {

my ( $self, $hgid ) = @_;

$self->{_hgid} = $hgid if defined($hgid);

print Dumper($hgid);

return $self->{_hgid};

}

sub check_timeout{

my ( $self, $check_timeout ) = @_;

$self->{_check_timeout} = $check_timeout if defined($check_timeout);

return $self->{_check_timeout};

}

sub move_node{

my ( $self,$proxynode,$hgid ) = @_;

my $dbh = Utils::get_connection($self->{_dns}, $self->{_user}, $self->{_password},' ');

$self->{_dbh_proxy} = $dbh;

my $SQL_get_old_master= "SELECT ro.hostname,

 ro.port,

 ms.hostgroup_id

 FROM (select *, max(time_start_us) from monitor.mysql_server_read_only_log group by hostname,port) as ro

 LEFT JOIN (select *,max(time_start_us) from monitor.mysql_server_replication_lag_log group by hostname,port ) as lag ON ro.hostname=lag.hostname

 AND ro.port=lag.port

 LEFT JOIN mysql_servers ms ON ro.hostname=ms.hostname

 AND ro.port=ms.port,

 mysql_replication_hostgroups hg

 WHERE read_only=1

 AND repl_lag IS NULL

 AND ms.hostgroup_id='$hgid'

 AND ms.hostgroup_id = hg.reader_hostgroup

 AND ms.status='ONLINE'

 GROUP BY ro.hostname,

 ro.port;";

my $sth = $dbh->prepare($SQL_get_old_master);

my $ref;

$sth->execute();

while ($ref = $sth->fetchrow_arrayref()) {

print "@$ref[0] @$ref[1]\n";

if (@$ref[0] ne '') {

move_node_down_hg_change($proxynode,@$ref[0],@$ref[1],$Param->{hgid});

}

}

}

#Connect method connect an populate the cluster returns the Galera cluster

sub connect{

my ( $self, $port ) = @_;

my $dbh = Utils::get_connection($self->{_dns}, $self->{_user}, $self->{_password},' ');

$self->{_dbh_proxy} = $dbh;

# get monitor user/pw

my $cmd = $self->{_SQL_get_monitor};

my $sth = $dbh->prepare($cmd);

$sth->execute();

while (my $ref = $sth->fetchrow_hashref()) {

if($ref->{'name'} eq 'mysql-monitor_password' ){$self->{_monitor_password} = $ref->{'value'};}

if($ref->{'name'} eq 'mysql-monitor_username' ) {$self->{_monitor_user} = $ref->{'value'};}

if($ref->{'name'} eq 'mysql-monitor_read_only_timeout' ) {$self->{_check_timeout} = $ref->{'value'};}

}

if($self->debug >=1){print Utils->print_log(3," Connecting to ProxySQL " . $self->{_dns}. "\n" ); }

}

sub disconnect{

my ( $self, $port ) = @_;

$self->{_dbh_proxy}->disconnect;

}

#move a node to a maintenance HG ((9000 + HG id))

sub move_node_down_hg_change{

my ($proxynode, $host,$port,$hgid) = @_;

if($hgid > 9000) {return 1;}

my $node_sql_command = "SET GLOBAL READ_ONLY=1;";

my $proxy_sql_command =" UPDATE mysql_servers SET hostgroup_id=".(9000 + $hgid)." WHERE hostgroup_id=$hgid AND hostname='$host' AND port='$port'";

print "$proxy_sql_command\n";

$proxynode->{_dbh_proxy}->do($proxy_sql_command) or die "Couldn't execute statement: " . $proxynode->{_dbh_proxy}->errstr;

$proxynode->{_dbh_proxy}->do("LOAD MYSQL SERVERS TO RUNTIME") or die "Couldn't execute statement: " . $proxynode->{_dbh_proxy}->errstr;

print Utils->print_log(2," Move node:"

." SQL:" .$proxy_sql_command

."\n" );

}

}

{

package ProxySqlHG;

sub new {

my $class = shift;

my $self = {

_id => undef, #

_type => undef, # available types: w writer; r reader ; mw maintance writer; mr maintenance reader

_size => 0,

};

bless $self, $class;

return $self;

}

sub id {

my ( $self, $id ) = @_;

$self->{_id} = $id if defined($id);

return $self->{_id};

}

sub type {

my ( $self, $type ) = @_;

$self->{_type} = $type if defined($type);

return $self->{_type};

}

sub size {

my ( $self, $size ) = @_;

$self->{_size} = $size if defined($size);

return $self->{_size};

}

}

{

package Utils;

use Time::HiRes qw(gettimeofday);

#============================================================================

## get_connection -- return a valid database connection handle (or die)

## $dsn -- a perl DSN, e.g. "DBI:mysql:host=ltsdbwm1;port=3311"

## $user -- a valid username, e.g. "check"

## $pass -- a matching password, e.g. "g33k!"

sub get_connection($$$$) {

my $dsn = shift;

my $user = shift;

my $pass = shift;

my $SPACER = shift;

my $dbh = DBI->connect($dsn, $user, $pass);

if (!defined($dbh)) {

print Utils->get_current_time ."[ERROR] Cannot connect to $dsn as $user\n";

# die();

return undef;

}

return $dbh;

}

#Prrint time from invocation with milliseconds

sub get_current_time{

use POSIX qw(strftime);

my $t = gettimeofday();

my $date = strftime "%Y/%m/%d %H:%M:%S", localtime $t;

$date .= sprintf ".%03d", ($t-int($t))*1000; # without rounding

return $date;

}

#prit all environmnt variables

sub debugEnv{

my $key = keys %ENV;

foreach $key (sort(keys %ENV)) {

print $key, '=', $ENV{$key}, "\n";

}

}

#Print a log entry

sub print_log($$){

my $log_level = $_[1];

my $text = $_[2];

my $log_text = "[ - ] ";

SWITCH: {

if ($log_level == 1) { $log_text= "[ERROR] "; last SWITCH; }

if ($log_level == 2) { $log_text= "[WARN] "; last SWITCH; }

if ($log_level == 3) { $log_text= "[INFO] "; last SWITCH; }

if ($log_level == 4) { $log_text= "[DEBUG] "; last SWITCH; }

}

return Utils::get_current_time.":".$log_text.$text;

}

#trim a string

sub trim {

my $s = shift;

$s =~ s/^\s+|\s+$//g;

return $s

};

}

# ############################################################################

# Documentation

# #################

=pod

=head1 NAME

server_monitor.pl

=head1 OPTIONS

    server_monitor.pl -u=admin -p=admin -h=192.168.1.50 -G=601 -P=3310 --debug=0 --log <full_path_to_file> --help

    sample [options] [file ...]

    Options:

      -u|user user to connect to the proxy

      -p|password Password for the proxy

      -h|host Proxy host

      -G Hostgroup ID with role definition.

      --retry_down The number of loop/test the check has to do before moving a node Down (default 0)

      --debug

      --log Full path to the log file ie (/var/log/proxysql/galera_check_) the check will add the identifier for the specific HG.

      -help help message

=head1 DESCRIPTION

Server monitor is a script to remove the server from the HostGroup which are not part of the replicaset anymore.

The script monitors the read_only flag and the repl_lag. If read_only=1 and repl_lag is NULL it removes the server from the HostGroup.

Why we need this?

Example: If we promote a new master and the old master won't be the a slave of the ne master, the ProxySQL will thought that server now is part of the

read hostgroup and going to send reads. But the old master does not part of the replicaset anymore. ProxySQL should not send any traffic.

=head1 Configure in ProxySQL

INSERT INTO scheduler (id,interval_ms,filename,arg1) values (10,2000,"/var/lib/proxysql/server_monitor.pl","-u=admin -p=admin -h=192.168.1.50 -G=601 -P=3310 --retry_down=2 --debug=0 --log=/var/lib/proxysql/server_check");

LOAD SCHEDULER TO RUNTIME;SAVE SCHEDULER TO DISK;

update scheduler set arg1="-u=admin -p=admin -h=192.168.1.50 -G=601 -P=3310 --debug=1 --log=/var/lib/proxysql/server_check" where id =10;

LOAD SCHEDULER TO RUNTIME;SAVE SCHEDULER TO DISK;

delete from scheduler where id=10;

LOAD SCHEDULER TO RUNTIME;SAVE SCHEDULER TO DISK;

=cut

注意事项

因为proxysql通过read_only变量来进行消息的转发控制，所以我们启动服务器的时候，一定要以read_only方式进行启动(即便是master)。如此就能避免很多类似多点同时写入的问题。

参考资料

https://www.percona.com/blog/2016/11/09/orchestrator-and-proxysql/