一、說(shuō)明
前面我們說(shuō)了mysql的安裝配置,mysql語(yǔ)句使用以及備份恢復(fù)mysql數(shù)據(jù);本次要介紹的是mysql的主從復(fù)制,讀寫(xiě)分離;及高可用MHA;
環(huán)境如下:
master:CentOS7_x64 mysql5.721 172.16.3.175 db1
slave1:CentOS7_x64 mysql5.7.21 172.16.3.235 db2
slave2:CentOS7_x64 mysql5.7.21 172.16.3.235 db3
proxysql/MHA:CentOS7_x64 mysql5.7.21 172.16.3.235 proxysql
架構(gòu)圖:

說(shuō)明:
配置測(cè)試時(shí)為了方便關(guān)閉了防火墻頭,selinux安全策略;
現(xiàn)實(shí)中請(qǐng)開(kāi)放防火墻策略;myslqdb的安裝已經(jīng)有腳本一鍵安裝并配置好;這里就不在重復(fù)配置;只對(duì)對(duì)應(yīng)的角色貼出對(duì)應(yīng)的配置或安裝與之相關(guān)的軟件;
二、主從復(fù)制配置
一臺(tái)主數(shù)據(jù)庫(kù),N從節(jié)點(diǎn);從節(jié)點(diǎn)開(kāi)啟兩個(gè)線程,通過(guò)Slave_IO_Running線程和主節(jié)點(diǎn)上有權(quán)限的賬號(hào)從 主數(shù)據(jù)庫(kù)節(jié)點(diǎn)復(fù)制binlog日志到本地,能過(guò)Slave_SQL_Running線程在本地執(zhí)行binlog日志,達(dá)到主從節(jié)點(diǎn)內(nèi)容同步;
master配置:
egrep -v '(^$|^#)' /usr/local/mysql/etc/my.cnf[mysqld]datadir=/data1/mysqldbsocket=/tmp/mysql.sockkey_buffer_size = 16Mmax_allowed_packet = 16Mthread_stack = 192Kthread_cache_size = 8query_cache_limit = 1Mquery_cache_size = 64Mquery_cache_type = 1symbolic-links=0innodb_file_per_table=ONskip_name_resolve=ONserver-id = 1log_bin = /data1/mysqldb/mysql-bin.log[mysqld_safe]log-error=/usr/local/mysql/logs/error.logpid-file=/data1/mysqldb/mysql.pid!includedir /usr/local/mysql/etc/my.cnf.d
創(chuàng)建從節(jié)點(diǎn)同步賬號(hào):
mysql > grant replication client,replication slave on *.* to 'repluser'@'172.16.3.%' identified by 'replpass';mysql > flush privileges;mysql >show master logs;+------------------+-----------+| Log_name | File_size |+------------------+-----------+| mysql-bin.000001 | 622 |
主節(jié)點(diǎn)上的binlog日志文件及位置;請(qǐng)記下;從節(jié)點(diǎn)第一次同步時(shí)需要用;slave節(jié)點(diǎn):
egrep -v '(^$|^#)' /usr/local/mysql/etc/my.cnf[mysqld]datadir=/data1/mysqldbsocket=/data1/mysqldb/mysql.sockkey_buffer_size = 16Mmax_allowed_packet = 16Mthread_stack = 192Kthread_cache_size = 8query_cache_limit = 1Mquery_cache_size = 64Mquery_cache_type = 1symbolic-links=0innodb_file_per_table=ONskip_name_resolve=ONserver-id = 11 #從節(jié)點(diǎn)標(biāo)識(shí)ID 各從節(jié)點(diǎn)均不一樣 relay_log = relay-logread_only=ON[mysqld_safe]log-error=/usr/local/mysql/log/error.logpid-file=/var/run/mysql/mysql.pid!includedir /usr/local/mysql/etc/my.cnf.d
啟動(dòng)mysq數(shù)據(jù)庫(kù)
注意:兩臺(tái)從節(jié)點(diǎn)的server-id 值不一樣;其他的都一樣;因此從節(jié)點(diǎn)只展示一個(gè)配置文件;
登錄數(shù)據(jù)庫(kù)并同步數(shù)據(jù)啟動(dòng)slave
兩臺(tái)slave均要同步并啟動(dòng)
mysql > CHANGE MASTER TO MASTER_HOST="172.16.3.175",MASTER_USER="repluser",MASTER_PASSWORD="replpass",MASTER_PORT=3306,MASTER_LOG_FILE="mysql-bin.000001",MASTER_LOG_POS=622;mysql > start slave; #啟動(dòng)從節(jié)點(diǎn)()#查看從節(jié)點(diǎn)狀態(tài)mysql > SHOW SLAVE STATUS;*************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 172.16.3.175 #主節(jié)點(diǎn) Master_User: repluser #同步賬號(hào) Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000001 Read_Master_Log_Pos: 622 Relay_Log_File: relay-log.000001 Relay_Log_Pos: 582 Relay_Master_Log_File: mysql-bin.000001 Slave_IO_Running: Yes #同步線程正常 Slave_SQL_Running: Yes #本地寫(xiě)線程正常 Replicate_Do_DB: #同步過(guò)濾為空(可以只同步某個(gè)或某些庫(kù)) Replicate_Ignore_DB: #不同步的庫(kù) Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 #最后同步的錯(cuò)誤 0表示正常同步 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 622 Relay_Log_Space: 615 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 1 Master_UUID: 57017c43-36e3-11e8-ac76-080027393fc7 Master_Info_File: /data1/mysqldb/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)ERROR: No query specified
測(cè)試主從同步
在master導(dǎo)入測(cè)試數(shù)據(jù);修改數(shù)據(jù)并查看slave 中的數(shù)據(jù)是否一致;
[root@db1 ~]# mysql < Testdb.sql登錄數(shù)據(jù)庫(kù)[root@db1 ~]# mysql -uroot -pmysql> show databases;+--------------------+| Database |+--------------------+ study |+--------------------+5 rows in set (0.00 sec)###study測(cè)試數(shù)據(jù)庫(kù)導(dǎo)入成功mysql> use study;Database changedmysql> show tables;+-----------------+| Tables_in_study |+-----------------+| class || course || part || score || student || tb31 || tb32 || teacher || test1 || test2 || user_info |+-----------------+11 rows in set (0.00 sec)#刪除test1 test2表
slave從節(jié)點(diǎn)上查看
mysql> show tables;+-----------------+| Tables_in_study |+-----------------+| class || course || part || score || student || tb31 || tb32 || teacher || user_info |+-----------------+9 rows in set (0.00 sec)
數(shù)據(jù)已經(jīng)可以正常同步;注意主從同步只需要第一次手動(dòng)啟動(dòng);之后都隨mysql服務(wù)自動(dòng)啟動(dòng);主從同步架構(gòu)只方便了數(shù)據(jù)的同步,此時(shí)如果沒(méi)有 第三方工具介入想做到讀寫(xiě)分離就需要在程序中去做,難免出錯(cuò);而出錯(cuò)了,就需要手動(dòng)同步數(shù)據(jù);這里通過(guò)proxysql來(lái)做讀寫(xiě)分離;
三、proxysql之讀寫(xiě)分離
以上已經(jīng)完成了主從復(fù)制配置;然而這只是一個(gè)基本配置,加上一個(gè)proxysql實(shí)現(xiàn)mysql讀寫(xiě)分離,proxysql類(lèi)似haproxy七層代理路由功能且支持MySQL 協(xié)議的的數(shù)據(jù)庫(kù)代理;是dba開(kāi)發(fā)給dba使用的;用戶(hù)請(qǐng)求發(fā)向proxysql,如果是寫(xiě)請(qǐng)求發(fā)往主節(jié)點(diǎn);讀請(qǐng)求發(fā)下從節(jié)點(diǎn)組中;以此實(shí)現(xiàn)讀寫(xiě)分離;一定程序上減輕了主數(shù)據(jù)庫(kù)的io壓力;
下載安裝proxysql
目前最新版本是1.4.7-1(由于最新版本有問(wèn)題)
我們這里下載使用1.3.6-1的基于CentOS7的rpm包;下載到本地并yum安裝
[root@proxysql ~]# yum install proxysql-1.3.6-1-centos7.x86_64.rpm -y[root@proxysql ~]# rpm -ql proxysql/etc/init.d/proxysql/etc/proxysql.cnf #主配置文件/usr/bin/proxysql/usr/share/proxysql/tools/proxysql_galera_checker.sh/usr/share/proxysql/tools/proxysql_galera_writer.pl
配置如下:
在配置proxysql之前需要在主節(jié)點(diǎn)配置授權(quán)賬號(hào)以作proxysql對(duì)主從節(jié)點(diǎn)操作;另外proxysql上的mysql客戶(hù)端工具需要和主從節(jié)點(diǎn)上的保持一致;
在主節(jié)點(diǎn)master上授權(quán)登錄賬號(hào):
mysql > GRANT ALL ON *.* TO 'myadmin'@'172.16.3.%' identified by 'mypass';proxysql.cnf配置
[root@proxysql ~]# egrep -v '(^$|^#)' /etc/proxysql.cnfdatadir="/var/lib/proxysql"admin_variables={ admin_credentials="admin:admin" #proxysql自己的管理用戶(hù)名密碼 mysql_ifaces="127.0.0.1:6032;/tmp/proxysql_admin.sock"}mysql_variables={ threads=4 #線程數(shù),建議和cpu核心數(shù)一致 max_connections=2048 #最大連接 default_query_delay=0 default_query_timeout=36000000 have_compress=true poll_timeout=2000 interfaces="0.0.0.0:3306;/tmp/proxysql.sock" #對(duì)外接口 default_schema="information_schema" stacksize=1048576 server_version="5.5.30" connect_timeout_server=3000 monitor_username="monitor" monitor_password="monitor" monitor_history=600000 monitor_connect_interval=60000 monitor_ping_interval=10000 monitor_read_only_interval=1500 monitor_read_only_timeout=500 ping_interval_server_msec=120000 ping_timeout_server=500 commands_stats=true sessions_sort=true connect_retries_on_failure=10}#####主從節(jié)點(diǎn)的配置mysql_servers = ( { address = "172.16.3.175" # no default, required . If port is 0 , address is interpred as a Unix Socket Domain port = 3306 # no default, required . If port is 0 , address is interpred as a Unix Socket Domain hostgroup = 1 # 設(shè)置組號(hào) status = "ONLINE" # default: ONLINE weight = 1 # default: 1 compression = 0 # default: 0 max_connections = 200 ###定義最大的連接 }, { address = "172.16.3.235" # no default, required . If port is 0 , address is interpred as a Unix Socket Domain port = 3306 # no default, required . If port is 0 , address is interpred as a Unix Socket Domain hostgroup = 2 # no default, required status = "ONLINE" # default: ONLINE weight = 1 # default: 1 compression = 0 # default: 0 max_connections=1000 }, { address = "172.16.3.241" # no default, required . If port is 0 , address is interpred as a Unix Socket Domain port = 3306 # no default, required . If port is 0 , address is interpred as a Unix Socket Domain hostgroup = 2 # no default, required status = "ONLINE" # default: ONLINE weight = 1 # default: 1 compression = 0 # default: 0 max_connections=1000 })mysql_users:( { username = "myadmin" # no default , required password = "mypass" # default: '' default_hostgroup = 1 # default: 0 max_connections=1000 default_schema="test" active = 1 #是否激活 })mysql_query_rules:()scheduler=()mysql_replication_hostgroups=( { writer_hostgroup=1 #定義寫(xiě)組號(hào)1 reader_hostgroup=2 #定義讀組號(hào)2 comment="test repl 1" #注釋內(nèi)容 })啟動(dòng)proxysql服務(wù)
[root@proxysql ~]# service proxysql start
測(cè)試proxysql
模擬通過(guò)proxysql使用數(shù)據(jù)庫(kù)[root@proxysql ]# mysql -h172.16.3.175 -umyadmin -pmypassmysql: [Warning] Using a password on the command line interface can be insecure.Welcome to the MySQL monitor. Commands end with ; or /g.Your MySQL connection id is 17406Server version: 5.7.21-log MySQL Community Server (GPL)Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '/h' for help. Type '/c' to clear the current input statement.mysql> mysql > show databases;mysql> show databases;+--------------------+| Database |+--------------------+| information_schema || mysql || performance_schema || study || sys |+--------------------+5 rows in set (0.00 sec)###刪除study數(shù)據(jù)庫(kù)user_info中6 -12之間的數(shù)據(jù)刪除之前:mysql> select * from user_info;+-----+-------+------+--------+----------+| nid | name | age | gender | part_nid |+-----+-------+------+--------+----------+| 1 | san | 20 | 男 | 1 || 2 | dong | 29 | 男 | 2 || 4 | Ling | 28 | 男 | 4 || 5 | ling | 28 | 男 | 3 || 6 | dong | 30 | 男 | 1 || 7 | b | 11 | 女 | 1 || 8 | c | 12 | 女 | 1 || 9 | d | 18 | 女 | 4 || 10 | e | 22 | 男 | 3 || 11 | f | 23 | 男 | 2 || 12 | dongy | 22 | 男 | 1 |+-----+-------+------+--------+----------+11 rows in set (0.00 sec)刪除之后:mysql> delete from user_info where nid >6 and nid <12;Query OK, 5 rows affected (0.03 sec)mysql> select * from user_info;+-----+-------+------+--------+----------+| nid | name | age | gender | part_nid |+-----+-------+------+--------+----------+| 1 | san | 20 | 男 | 1 || 2 | dong | 29 | 男 | 2 || 4 | Ling | 28 | 男 | 4 || 5 | ling | 28 | 男 | 3 || 6 | dong | 30 | 男 | 1 || 12 | dongy | 22 | 男 | 1 |+-----+-------+------+--------+----------+6 rows in set (0.00 sec)
到主從節(jié)點(diǎn)上查看,會(huì)發(fā)現(xiàn)以上的查和修改數(shù)據(jù)都被proxysql正確的代理到后端處理了;
以上看了并不直觀;為了查看proxysql與各主從節(jié)點(diǎn)通訊我們?cè)谥鲝墓?jié)點(diǎn)上安裝tcpdump并過(guò)濾包
主節(jié)點(diǎn):類(lèi)似如下:[root@db1 ~]# tcpdump -i enp0s3 -nn tcp port 3306tcpdump: verbose output suppressed, use -v or -vv for full protocol decodelistening on enp0s3, link-type EN10MB (Ethernet), capture size 262144 bytes18:04:34.678861 IP 172.16.3.254.42191 > 172.16.3.175.3306: Flags [S], seq 3385407732, win 29200, options [mss 1460,sackOK,TS val 17576713 ecr 0,nop,wscale 7], length 018:04:34.678908 IP 172.16.3.175.3306 > 172.16.3.254.42191: Flags [S.], seq 1579426335, ack 3385407733, win 28960, options [mss 1460,sackOK,TS val 29413673 ecr 17576713,nop,wscale 7], length 018:04:34.680902 IP 172.16.3.254.42191 > 172.16.3.175.3306: Flags [.], ack 1, win 229, options [nop,nop,TS val 17576715 ecr 29413673], length 018:04:34.681264 IP 172.16.3.175.3306 > 172.16.3.254.42191: Flags [P.], seq 1:83, ack 1, win 227, options [nop,nop,TS val 29413675 ecr 17576715], length 82....從節(jié)點(diǎn):類(lèi)似如下:[root@db2 data1]# tcpdump -i enp0s3 -nn tcp port 3306tcpdump: verbose output suppressed, use -v or -vv for full protocol decodelistening on enp0s3, link-type EN10MB (Ethernet), capture size 262144 bytes18:02:57.932043 IP 172.16.3.254.42733 > 172.16.3.235.3306: Flags [S], seq 76520456, win 29200, options [mss 1460,sackOK,TS val 17479189 ecr 0,nop,wscale 7], length 0...........
proxysql命令行管理接口:支持運(yùn)行時(shí)修改
[root@proxysql]# mysql -u admin -padmin -h 127.0.0.1 -P6032 --prompt='Admin> 'Admin> show databases;+-----+---------+-------------------------------+| seq | name | file |+-----+---------+-------------------------------+| 0 | main | || 2 | disk | /var/lib/proxysql/proxysql.db || 3 | stats | || 4 | monitor | |+-----+---------+-------------------------------+4 rows in set (0.00 sec)
以上stats,monitor,main都從配置文件中獲取的數(shù)據(jù)庫(kù);可以通過(guò)類(lèi)似mysql運(yùn)行時(shí)修改;而不需要重啟;
至此我們基于proxysql主從復(fù)制讀寫(xiě)分離架構(gòu)已經(jīng)完成;
雙主或多主模型是無(wú)須實(shí)現(xiàn)讀寫(xiě)分離,僅需要負(fù)載均衡:haproxy, nginx, lvs等;
proxysql并沒(méi)有解決,當(dāng)主數(shù)據(jù)巖機(jī)時(shí)的問(wèn)題;此時(shí)就需要量MHA來(lái)解決 ;后續(xù)再介紹;
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