centos环境下运行多实例mysql

There are numerous advantages to run multiple database instances on the save physical server. Here are some reasons that I would like to point out :

1. Utilize existing hardware properly

2. Long lead times to provide physical hardware

3. Reduce Licensing Hardware / OS costs

4. Smaller/manageable data center foot print

5. Reduced overhead

To run multiple instances using MySQL we need to have a couple of things separate from the initial install on MySQL like data directory, init script and config file. It is quite that simple and here is how we do it, I will subscript 2 for all the files/directories that I am going to create to indicate this new second instance:

1. Create a new data directory [/var/lib/mysql2] and make mysql user own it.

mkdir /var/lib/mysql2

chown mysql.mysql /var/lib/mysql2/

2. Create / copy existing mysql configuration file, call it my2.cnf and update data directory/port values

cp /etc/my.cnf /etc/my2.cnf

vi /etc/my2.cnf

Update the lines as shown in the screenshot above [If you have a custom path, use it]:

datadir=/var/lib/mysql2port=3307

3. Create/copy existing mysql init file to start/stop/reload etc on this new instance

cp /etc/init.d/mysql /etc/init.d/mysql2

4. Edit the init file and make some minor changes to make it this instance specific [Four edits required]

vi /etc/init.d/mysql2

Edit 1: Add the following line after line 138 for the init script to handle ports

--port=*)     port=`echo "$arg"  sed -e 's/^[^=]*=//'` ;;

Edit 2: At line 215 update my.cnf to point to the new config file my2.cnf for this instance

conf=/etc/my2.cnf

Edit 3: At line 257 add -c flag to the arguments to read this config file while parsing server arguments

parse_server_arguments `$print_defaults $extra_args mysqld server mysql_server mysql.server -c/etc/my2.cnf`

Edit 4: Add port argument to mysql_safe command on line 284

$bindir/mysqld_safe --defaults-file=/etc/my2.cnf --datadir="$datadir" --pid-file="$mysqld_pid_file_path" --port="$port" --socket="$datadir"/mysql2.sock $other_args >/dev/null 2>&1 &

You final init script looks like the following:

#!/bin/sh# Copyright Abandoned 1996 TCX DataKonsult AB & Monty Program KB & Detron HB# This file is public domain and comes with NO WARRANTY of any kind# MySQL daemon start/stop script.# Usually this is put in /etc/init.d (at least on machines SYSV R4 based# systems) and linked to /etc/rc3.d/S99mysql and /etc/rc0.d/K01mysql.# When this is done the mysql server will be started when the machine is# started and shut down when the systems goes down.# Comments to support chkconfig on RedHat Linux# chkconfig: 2345 64 36# description: A very fast and reliable SQL database engine.# Comments to support LSB init script conventions### BEGIN INIT INFO# Provides: mysqls# Required-Start: $local_fs $network $remote_fs# Should-Start: ypbind nscd ldap ntpd xntpd# Required-Stop: $local_fs $network $remote_fs# Default-Start:  2 3 4 5# Default-Stop: 0 1 6# Short-Description: start and stop MySQL# Description: MySQL is a very fast and reliable SQL database engine.### END INIT INFO# If you change base dir, you must also change datadir. These may get# overwritten by settings in the MySQL configuration files.basedir=datadir=# Default value, in seconds, afterwhich the script should timeout waiting# for server start.# Value here is overriden by value in my.cnf.# 0 means don't wait at all# Negative numbers mean to wait indefinitelyservice_startup_timeout=900# Lock directory for RedHat / SuSE.lockdir='/var/lock/subsys'lock_file_path="$lockdir/mysql"# The following variables are only set for letting mysql.server find things.# Set some defaultsmysqld_pid_file_path=if test -z "$basedir"then  basedir=/usr  bindir=/usr/bin  if test -z "$datadir"  then    datadir=/var/lib/mysql  fi  sbindir=/usr/sbin  libexecdir=/usr/sbinelse  bindir="$basedir/bin"  if test -z "$datadir"  then    datadir="$basedir/data"  fi  sbindir="$basedir/sbin"  libexecdir="$basedir/libexec"fi# datadir_set is used to determine if datadir was set (and so should be# *not* set inside of the --basedir= handler.)datadir_set=## Use LSB init script functions for printing messages, if possible#lsb_functions="/lib/lsb/init-functions"if test -f $lsb_functions ; then  . $lsb_functionselse  log_success_msg()  {    echo " SUCCESS! $@"  }  log_failure_msg()  {    echo " ERROR! $@"  }fiPATH="/sbin:/usr/sbin:/bin:/usr/bin:$basedir/bin"export PATHmode=$1    # start or stop[ $# -ge 1 ] && shiftother_args="$*"   # uncommon, but needed when called from an RPM upgrade action           # Expected: "--skip-networking --skip-grant-tables"           # They are not checked here, intentionally, as it is the resposibility           # of the "spec" file author to give correct arguments only.case `echo "testing\c"`,`echo -n testing` in    *c*,-n*) echo_n=   echo_c=     ;;    *c*,*)   echo_n=-n echo_c=     ;;    *)       echo_n=   echo_c='\c' ;;esacparse_server_arguments() {  for arg do    case "$arg" in      --basedir=*)  basedir=`echo "$arg" | sed -e 's/^[^=]*=//'`                    bindir="$basedir/bin"                    if test -z "$datadir_set"; then                      datadir="$basedir/data"                    fi                    sbindir="$basedir/sbin"                    libexecdir="$basedir/libexec"        ;;      --datadir=*)  datadir=`echo "$arg" | sed -e 's/^[^=]*=//'`                    datadir_set=1        ;;      --pid-file=*) mysqld_pid_file_path=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;      --port=*)     port=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;      --service-startup-timeout=*) service_startup_timeout=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;    esac  done}wait_for_pid () {  verb="$1"           # created | removed  pid="$2"            # process ID of the program operating on the pid-file  pid_file_path="$3" # path to the PID file.  i=0  avoid_race_condition="by checking again"  while test $i -ne $service_startup_timeout ; do    case "$verb" in      'created')        # wait for a PID-file to pop into existence.        test -s "$pid_file_path" && i='' && break        ;;      'removed')        # wait for this PID-file to disappear        test ! -s "$pid_file_path" && i='' && break        ;;      *)        echo "wait_for_pid () usage: wait_for_pid created|removed pid pid_file_path"        exit 1        ;;    esac    # if server isn't running, then pid-file will never be updated    if test -n "$pid"; then      if kill -0 "$pid" 2>/dev/null; then        :  # the server still runs      else        # The server may have exited between the last pid-file check and now.        if test -n "$avoid_race_condition"; then          avoid_race_condition=""          continue  # Check again.        fi        # there's nothing that will affect the file.        log_failure_msg "The server quit without updating PID file ($pid_file_path)."        return 1  # not waiting any more.      fi    fi    echo $echo_n ".$echo_c"    i=`expr $i + 1`    sleep 1  done  if test -z "$i" ; then    log_success_msg    return 0  else    log_failure_msg    return 1  fi}# Get arguments from the my.cnf file,# the only group, which is read from now on is [mysqld]if test -x ./bin/my_print_defaultsthen  print_defaults="./bin/my_print_defaults"elif test -x $bindir/my_print_defaultsthen  print_defaults="$bindir/my_print_defaults"elif test -x $bindir/mysql_print_defaultsthen  print_defaults="$bindir/mysql_print_defaults"else  # Try to find basedir in /etc/my.cnf  conf=/etc/my2.cnf  print_defaults=  if test -r $conf  then    subpat='^[^=]*basedir[^=]*=\(.*\)$'    dirs=`sed -e "/$subpat/!d" -e 's//\1/' $conf`    for d in $dirs    do      d=`echo $d | sed -e 's/[  ]//g'`      if test -x "$d/bin/my_print_defaults"      then        print_defaults="$d/bin/my_print_defaults"        break      fi      if test -x "$d/bin/mysql_print_defaults"      then        print_defaults="$d/bin/mysql_print_defaults"        break      fi    done  fi  # Hope it's in the PATH ... but I doubt it  test -z "$print_defaults" && print_defaults="my_print_defaults"fi## Read defaults file from 'basedir'.   If there is no defaults file there# check if it's in the old (depricated) place (datadir) and read it from there#extra_args=""if test -r "$basedir/my.cnf"then  extra_args="-e $basedir/my.cnf"else  if test -r "$datadir/my.cnf"  then    extra_args="-e $datadir/my.cnf"  fifiparse_server_arguments `$print_defaults $extra_args mysqld server mysql_server mysql.server -c/etc/my2.cnf`## Set pid file if not given#if test -z "$mysqld_pid_file_path"then  mysqld_pid_file_path=$datadir/`hostname`.pidelse  case "$mysqld_pid_file_path" in    /* ) ;;    * )  mysqld_pid_file_path="$datadir/$mysqld_pid_file_path" ;;  esacficase "$mode" in  'start')    # Start daemon    # Safeguard (relative paths, core dumps..)    cd $basedir    echo $echo_n "Starting MySQL"    if test -x $bindir/mysqld_safe    then      # Give extra arguments to mysqld with the my.cnf file. This script      # may be overwritten at next upgrade.      $bindir/mysqld_safe --defaults-file=/etc/my2.cnf --datadir="$datadir" --pid-file="$mysqld_pid_file_path" --port="$port" --socket="$datadir"/mysql2.sock $other_args >/dev/null 2>&1 &      wait_for_pid created "$!" "$mysqld_pid_file_path"; return_value=$?      # Make lock for RedHat / SuSE      if test -w "$lockdir"      then        touch "$lock_file_path"      fi      exit $return_value    else      log_failure_msg "Couldn't find MySQL server ($bindir/mysqld_safe)"    fi    ;;  'stop')    # Stop daemon. We use a signal here to avoid having to know the    # root password.    if test -s "$mysqld_pid_file_path"    then      mysqld_pid=`cat "$mysqld_pid_file_path"`      if (kill -0 $mysqld_pid 2>/dev/null)      then        echo $echo_n "Shutting down MySQL"        kill $mysqld_pid        # mysqld should remove the pid file when it exits, so wait for it.        wait_for_pid removed "$mysqld_pid" "$mysqld_pid_file_path"; return_value=$?      else        log_failure_msg "MySQL server process #$mysqld_pid is not running!"        rm "$mysqld_pid_file_path"      fi      # Delete lock for RedHat / SuSE      if test -f "$lock_file_path"      then        rm -f "$lock_file_path"      fi      exit $return_value    else      log_failure_msg "MySQL server PID file could not be found!"    fi    ;;  'restart')    # Stop the service and regardless of whether it was    # running or not, start it again.    if $0 stop  $other_args; then      $0 start $other_args    else      log_failure_msg "Failed to stop running server, so refusing to try to start."      exit 1    fi    ;;  'reload'|'force-reload')    if test -s "$mysqld_pid_file_path" ; then      read mysqld_pid < "$mysqld_pid_file_path"      kill -HUP $mysqld_pid && log_success_msg "Reloading service MySQL"      touch "$mysqld_pid_file_path"    else      log_failure_msg "MySQL PID file could not be found!"      exit 1    fi    ;;  'status')    # First, check to see if pid file exists    if test -s "$mysqld_pid_file_path" ; then      read mysqld_pid < "$mysqld_pid_file_path"      if kill -0 $mysqld_pid 2>/dev/null ; then        log_success_msg "MySQL running ($mysqld_pid)"        exit 0      else        log_failure_msg "MySQL is not running, but PID file exists"        exit 1      fi    else      # Try to find appropriate mysqld process      mysqld_pid=`pidof $libexecdir/mysqld`      if test -z $mysqld_pid ; then        if test -f "$lock_file_path" ; then          log_failure_msg "MySQL is not running, but lock file ($lock_file_path) exists"          exit 2        fi        log_failure_msg "MySQL is not running"        exit 3      else        log_failure_msg "MySQL is running but PID file could not be found"        exit 4      fi    fi    ;;    *)      # usage      basename=`basename "$0"`      echo "Usage: $basename  {start|stop|restart|reload|force-reload|status}  [ MySQL server options ]"      exit 1    ;;esacexit 0

If you plan on deploying more instances you just need to work through edit 2 and 3 mentioned above after you copy the above init file.

5. Install default tables for this new database instance

mysql_install_db --datadir=/var/lib/mysql2 --defaults-file=/etc/my2.cnf --user=mysql

6. Start the new instance

service mysql2 start

7. Set password for this instance and connect to this new instance

/usr/bin/mysqladmin -u root -h127.0.0.1 -P3307 password 'opensourcedbmsadmin'mysql -uroot -h127.0.0.1 -P3307 -p

8. Finally add it to server start-up list

chkconfig --add mysql2chkconfig mysql2 --level 2345 on

If you want to deploy more instances change the subscript and follow above. Make sure that you properly manage memory and processor allocations when running multiple mysql instances on the same server. Please post any questions below and I will answer as soon as I can. 

refer: https://opensourcedbms.com/dbms/running-multiple-mysql-5-6-instances-on-one-server-in-centos-6rhel-6fedora/

https://dev.mysql.com/doc/refman/5.7/en/multiple-unix-servers.html

https://dev.mysql.com/doc/refman/5.7/en/multiple-servers.html