标签:size via 要求 recovery 进程 col app environ ssh登录
简介:
MHA(Master High Availability)目前在MySQL高可用方面是一个相对成熟的解决方案,它由日本DeNA公司youshimaton(现就职于Facebook公司)开发,是一套优秀的作为MySQL高可用性环境下故障切换和主从提升的高可用软件。在MySQL故障切换过程中,MHA能做到在0~30秒之内自动完成数据库的故障切换操作,并且在进行故障切换的过程中,MHA能在最大程度上保证数据的一致性,以达到真正意义上的高可用。
该软件由两部分组成:MHA Manager(管理节点)和MHA Node(数据节点)。MHA Manager可以单独部署在一台独立的机器上管理多个master-slave集群,也可以部署在一台slave节点上。MHA Node运行在每台MySQL服务器上,MHA Manager会定时探测集群中的master节点,当master出现故障时,它可以自动将最新数据的slave提升为新的master,然后将所有其他的slave重新指向新的master。整个故障转移过程对应用程序完全透明。
在MHA自动故障切换过程中,MHA试图从宕机的主服务器上保存二进制日志,最大程度的保证数据的不丢失,但这并不总是可行的。例如,如果主服务器硬件故障或无法通过ssh访问,MHA没法保存二进制日志,只进行故障转移而丢失了最新的数据。使用MySQL 5.5的半同步复制,可以大大降低数据丢失的风险。MHA可以与半同步复制结合起来。如果只有一个slave已经收到了最新的二进制日志,MHA可以将最新的二进制日志应用于其他所有的slave服务器上,因此可以保证所有节点的数据一致性。
目前MHA主要支持一主多从的架构,要搭建MHA,要求一个复制集群中必须最少有三台数据库服务器,一主二从,即一台充当master,一台充当备用master,另外一台充当从库,因为至少需要三台服务器,出于机器成本的考虑,淘宝也在该基础上进行了改造,目前淘宝TMHA已经支持一主一从。另外对于想快速搭建的可以参考:MHA快速搭建
我们自己使用其实也可以使用1主1从,但是master主机宕机后无法切换,以及无法补全binlog。master的mysqld进程crash后,还是可以切换成功,以及补全binlog的。
官方介绍:https://code.google.com/p/mysql-master-ha/
图01展示了如何通过MHA Manager管理多组主从复制。可以将MHA工作原理总结为如下:
( 图01 )
(1)从宕机崩溃的master保存二进制日志事件(binlog events);
(2)识别含有最新更新的slave;
(3)应用差异的中继日志(relay log)到其他的slave;
(4)应用从master保存的二进制日志事件(binlog events);
(5)提升一个slave为新的master;
(6)使其他的slave连接新的master进行复制;
MHA软件由两部分组成,Manager工具包和Node工具包,具体的说明如下。
Manager工具包主要包括以下几个工具:
masterha_check_ssh 检查MHA的SSH配置状况 masterha_check_repl 检查MySQL复制状况 masterha_manger 启动MHA masterha_check_status 检测当前MHA运行状态 masterha_master_monitor 检测master是否宕机 masterha_master_switch 控制故障转移(自动或者手动) masterha_conf_host 添加或删除配置的server信息
Node工具包(这些工具通常由MHA Manager的脚本触发,无需人为操作)主要包括以下几个工具:
save_binary_logs 保存和复制master的二进制日志 apply_diff_relay_logs 识别差异的中继日志事件并将其差异的事件应用于其他的slave filter_mysqlbinlog 去除不必要的ROLLBACK事件(MHA已不再使用这个工具) purge_relay_logs 清除中继日志(不会阻塞SQL线程)
注意:
为了尽可能的减少主库硬件损坏宕机造成的数据丢失,因此在配置MHA的同时建议配置成MySQL 5.5的半同步复制。关于半同步复制原理各位自己进行查阅。(不是必须)
接下来部署MHA,具体的搭建环境如下(所有操作系统均为centos 7 1804,不是必须,slave1和slave2是maset的从,复制环境搭建后面会简单演示,但是相关的安全复制不会详细说明,需要的童鞋请参考前面的文章,MySQL Replication需要注意的问题):
角色 ip地址 server_id 类型 Monitor host 192.168.134.191 - 监控复制组 Master 192.168.134.193 1 写入 slave1 192.168.134.2 2 读 Slave2 192.168.134.194 3 读
其中master对外提供写服务,备选master提供读服务,也提供相关的读服务,一旦master宕机,将会把备选master(slave1/2)提升为新的master,slave1/2指向新的master(slave2/1)
因为事先下载好的
yum install mha4mysql-*
查看MHA提供了多少东西
[root@c1 ~]# rpm -ql mha4mysql-manager ./usr/bin/masterha_check_repl /usr/bin/masterha_check_ssh /usr/bin/masterha_check_status /usr/bin/masterha_conf_host /usr/bin/masterha_manager /usr/bin/masterha_master_monitor /usr/bin/masterha_master_switch /usr/bin/masterha_secondary_check /usr/bin/masterha_stop /usr/share/man/man1/masterha_check_repl.1.gz /usr/share/man/man1/masterha_check_ssh.1.gz /usr/share/man/man1/masterha_check_status.1.gz /usr/share/man/man1/masterha_conf_host.1.gz /usr/share/man/man1/masterha_manager.1.gz /usr/share/man/man1/masterha_master_monitor.1.gz /usr/share/man/man1/masterha_master_switch.1.gz /usr/share/man/man1/masterha_secondary_check.1.gz /usr/share/man/man1/masterha_stop.1.gz /usr/share/perl5/vendor_perl/MHA/Config.pm /usr/share/perl5/vendor_perl/MHA/DBHelper.pm /usr/share/perl5/vendor_perl/MHA/FileStatus.pm /usr/share/perl5/vendor_perl/MHA/HealthCheck.pm /usr/share/perl5/vendor_perl/MHA/ManagerAdmin.pm /usr/share/perl5/vendor_perl/MHA/ManagerAdminWrapper.pm /usr/share/perl5/vendor_perl/MHA/ManagerConst.pm /usr/share/perl5/vendor_perl/MHA/ManagerUtil.pm /usr/share/perl5/vendor_perl/MHA/MasterFailover.pm /usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm /usr/share/perl5/vendor_perl/MHA/MasterRotate.pm /usr/share/perl5/vendor_perl/MHA/SSHCheck.pm /usr/share/perl5/vendor_perl/MHA/Server.pm /usr/share/perl5/vendor_perl/MHA/ServerManager.pm
注意:binlog-do-db 和 replicate-ignore-db 设置必须相同。 MHA 在启动时候会检测过滤规则,如果过滤规则不同,MHA 不启动监控和故障转移。
mysqldump -A -B --master-data=2 --events > all.sql
--master-data[=#]: 此选项须启用二进制日志 1:所备份的数据之前加一条记录为CHANGE MASTER TO语句,非注释,不指定#,默认为1 2:记录为注释的CHANGE MASTER TO语句 --events:备份相关的所有event scheduler
mysql>grant all on *.* to mhauser@‘192.168.134.%‘ identified by ‘centos‘; 监控用户
mysql>grant replication slave on *.* to repluser@‘192.168.134.%‘ identified by ‘centos‘; 复制用户
MariaDB [(none)]> show master logs; +--------------------+-----------+ | Log_name | File_size | +--------------------+-----------+ | mariadb-bin.000001 | 8749 | | mariadb-bin.000002 | 245 | +--------------------+-----------+
scp all.sql 192.168.134.2: scp all.sql 192.168.134.194:
mysql < all.sql
mysql > CHANGE MASTER TO MASTER_HOST=‘192.168.134.193‘, MASTER_USER=‘repluser‘, MASTER_PASSWORD=‘centos‘, MASTER_PORT=3306, MASTER_LOG_FILE=‘mariadb-bin.000002‘, MASTER_LOG_POS=245;
查看状态MariaDB [(none)]> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.134.193 Master_User: repluser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mariadb-bin.000002 Read_Master_Log_Pos: 245 Relay_Log_File: mariadb-relay-bin.000002 Relay_Log_Pos: 531 Relay_Master_Log_File: mariadb-bin.000002 Slave_IO_Running: Yes Slave_SQL_Running: Yes
vim /etc/my.cnf [mysqld] skip_name_resolve 禁止主机名解析,建议使用 innodb_file_per_table 可以修改InnoDB为独立表空间模式,每个数据库的每个表都会生成一个数据空间。 read_only relay_log_purge=0 MHA可通过purge_relay_logs禁用自动删除功能以及定期清理 server_id=3 log_bin
[server default]
user=mhauser
password=centos
manager_workdir=/data/mastermha/app1/ //设置manager的工作目录
manager_log=/data/mastermha/app1/manager.log //设置manager的日志
remote_workdir=/data/mastermha/app1/ //设置master 保存binlog的位置,以便MHA可以找到master的日志,我这里的也就是mysql的数据目录
ssh_user=root //设置ssh的登录用户名
repl_user=repluser //设置复制环境中的复制用户名
repl_password=centos //设置复制环境中的密码
ping_interval=1 //设置监控主库,发送ping包的时间间隔,默认是3秒,尝试三次没有回应的时候自动进行railover
[server1]
hostname=192.168.134.193
candidate_master=1
[server2]
hostname=192.168.134.2
candidate_master=1 //设置为候选master,如果设置该参数以后,发生主从切换以后将会将此从库提升为主库,即使这个主库不是集群中事件最新的slave
[server3]
hostname=192.168.134.194
注意:
MHA在发生切换的过程中,从库的恢复过程中依赖于relay log的相关信息,所以这里要将relay log的自动清除设置为OFF,采用手动清除relay log的方式。在默认情况下,从服务器上的中继日志会在SQL线程执行完毕后被自动删除。但是在MHA环境中,这些中继日志在恢复其他从服务器时可能会被用到,因此需要禁用中继日志的自动删除功能。定期清除中继日志需要考虑到复制延时的问题。在ext3的文件系统下,删除大的文件需要一定的时间,会导致严重的复制延时。为了避免复制延时,需要暂时为中继日志创建硬链接,因为在linux系统中通过硬链接删除大文件速度会很快。(在mysql数据库中,删除大表时,通常也采用建立硬链接的方式)
检查MHA Manger到所有MHA Node的SSH连接状态:
[root@c1 ~]# masterha_check_ssh --conf=/etc/mastermha/app1.cnf Mon Aug 6 18:02:58 2018 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Mon Aug 6 18:02:58 2018 - [info] Reading application default configuration from /etc/mastermha/app1.cnf.. Mon Aug 6 18:02:58 2018 - [info] Reading server configuration from /etc/mastermha/app1.cnf.. Mon Aug 6 18:02:58 2018 - [info] Starting SSH connection tests.. Mon Aug 6 18:03:01 2018 - [debug] Mon Aug 6 18:02:59 2018 - [debug] Connecting via SSH from root@192.168.134.194(192.168.134.194:22) to root@192.168.134.193(192.168.134.193:22).. Mon Aug 6 18:03:00 2018 - [debug] ok. Mon Aug 6 18:03:00 2018 - [debug] Connecting via SSH from root@192.168.134.194(192.168.134.194:22) to root@192.168.134.2(192.168.134.2:22).. Mon Aug 6 18:03:01 2018 - [debug] ok. Mon Aug 6 18:03:06 2018 - [debug] Mon Aug 6 18:02:58 2018 - [debug] Connecting via SSH from root@192.168.134.2(192.168.134.2:22) to root@192.168.134.193(192.168.134.193:22).. Mon Aug 6 18:03:04 2018 - [debug] ok. Mon Aug 6 18:03:04 2018 - [debug] Connecting via SSH from root@192.168.134.2(192.168.134.2:22) to root@192.168.134.194(192.168.134.194:22).. Warning: Permanently added ‘192.168.134.194‘ (ECDSA) to the list of known hosts. Mon Aug 6 18:03:05 2018 - [debug] ok. Mon Aug 6 18:03:10 2018 - [debug] Mon Aug 6 18:02:58 2018 - [debug] Connecting via SSH from root@192.168.134.193(192.168.134.193:22) to root@192.168.134.2(192.168.134.2:22).. Warning: Permanently added ‘192.168.134.2‘ (ECDSA) to the list of known hosts. Mon Aug 6 18:03:09 2018 - [debug] ok. Mon Aug 6 18:03:09 2018 - [debug] Connecting via SSH from root@192.168.134.193(192.168.134.193:22) to root@192.168.134.194(192.168.134.194:22).. Warning: Permanently added ‘192.168.134.194‘ (ECDSA) to the list of known hosts. Mon Aug 6 18:03:10 2018 - [debug] ok. Mon Aug 6 18:03:10 2018 - [info] All SSH connection tests passed successfully.
[root@c1 ~]# masterha_check_repl --conf=/etc/mastermha/app1.cnf Mon Aug 6 18:11:54 2018 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Mon Aug 6 18:11:54 2018 - [info] Reading application default configuration from /etc/mastermha/app1.cnf.. Mon Aug 6 18:11:54 2018 - [info] Reading server configuration from /etc/mastermha/app1.cnf.. Mon Aug 6 18:11:54 2018 - [info] MHA::MasterMonitor version 0.56. Mon Aug 6 18:11:55 2018 - [error][/usr/share/perl5/vendor_perl/MHA/ServerManager.pm, ln671] Master 192.168.134.191:3306 from which slave 192.168.134.193(192.168.134.193:3306) replicates is not defined in the configuration file! Mon Aug 6 18:11:55 2018 - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln424] Error happened on checking configurations. at /usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm line 326. Mon Aug 6 18:11:55 2018 - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln523] Error happened on monitoring servers. Mon Aug 6 18:11:55 2018 - [info] Got exit code 1 (Not master dead). MySQL Replication Health is NOT OK! [root@c1 ~]# masterha_check_repl --conf=/etc/mastermha/app1.cnf Mon Aug 6 18:13:27 2018 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Mon Aug 6 18:13:27 2018 - [info] Reading application default configuration from /etc/mastermha/app1.cnf.. Mon Aug 6 18:13:27 2018 - [info] Reading server configuration from /etc/mastermha/app1.cnf.. Mon Aug 6 18:13:27 2018 - [info] MHA::MasterMonitor version 0.56. Mon Aug 6 18:13:29 2018 - [info] GTID failover mode = 0 Mon Aug 6 18:13:29 2018 - [info] Dead Servers: Mon Aug 6 18:13:29 2018 - [info] Alive Servers: Mon Aug 6 18:13:29 2018 - [info] 192.168.134.193(192.168.134.193:3306) Mon Aug 6 18:13:29 2018 - [info] 192.168.134.2(192.168.134.2:3306) Mon Aug 6 18:13:29 2018 - [info] 192.168.134.194(192.168.134.194:3306) Mon Aug 6 18:13:29 2018 - [info] Alive Slaves: Mon Aug 6 18:13:29 2018 - [info] 192.168.134.2(192.168.134.2:3306) Version=5.5.56-MariaDB (oldest major version between slaves) log-bin:enabled Mon Aug 6 18:13:29 2018 - [info] Replicating from 192.168.134.193(192.168.134.193:3306) Mon Aug 6 18:13:29 2018 - [info] Primary candidate for the new Master (candidate_master is set) Mon Aug 6 18:13:29 2018 - [info] 192.168.134.194(192.168.134.194:3306) Version=5.5.56-MariaDB (oldest major version between slaves) log-bin:enabled Mon Aug 6 18:13:29 2018 - [info] Replicating from 192.168.134.193(192.168.134.193:3306) Mon Aug 6 18:13:29 2018 - [info] Current Alive Master: 192.168.134.193(192.168.134.193:3306) Mon Aug 6 18:13:29 2018 - [info] Checking slave configurations.. Mon Aug 6 18:13:29 2018 - [info] Checking replication filtering settings.. Mon Aug 6 18:13:29 2018 - [info] binlog_do_db= , binlog_ignore_db= Mon Aug 6 18:13:29 2018 - [info] Replication filtering check ok. Mon Aug 6 18:13:29 2018 - [info] GTID (with auto-pos) is not supported Mon Aug 6 18:13:29 2018 - [info] Starting SSH connection tests.. Mon Aug 6 18:13:47 2018 - [info] All SSH connection tests passed successfully. Mon Aug 6 18:13:47 2018 - [info] Checking MHA Node version.. Mon Aug 6 18:13:49 2018 - [info] Version check ok. Mon Aug 6 18:13:49 2018 - [info] Checking SSH publickey authentication settings on the current master.. Mon Aug 6 18:13:49 2018 - [info] HealthCheck: SSH to 192.168.134.193 is reachable. Mon Aug 6 18:13:50 2018 - [info] Master MHA Node version is 0.56. Mon Aug 6 18:13:50 2018 - [info] Checking recovery script configurations on 192.168.134.193(192.168.134.193:3306).. Mon Aug 6 18:13:50 2018 - [info] Executing command: save_binary_logs --command=test --start_pos=4 --binlog_dir=/var/lib/mysql,/var/log/mysql --output_file=/data/mastermha/app1//save_binary_logs_test --manager_version=0.56 --start_file=mariadb-bin.000001 Mon Aug 6 18:13:50 2018 - [info] Connecting to root@192.168.134.193(192.168.134.193:22).. Creating /data/mastermha/app1 if not exists.. Creating directory /data/mastermha/app1.. done. ok. Checking output directory is accessible or not.. ok. Binlog found at /var/lib/mysql, up to mariadb-bin.000001 Mon Aug 6 18:13:50 2018 - [info] Binlog setting check done. Mon Aug 6 18:13:50 2018 - [info] Checking SSH publickey authentication and checking recovery script configurations on all alive slave servers.. Mon Aug 6 18:13:50 2018 - [info] Executing command : apply_diff_relay_logs --command=test --slave_user=‘mhauser‘ --slave_host=192.168.134.2 --slave_ip=192.168.134.2 --slave_port=3306 --workdir=/data/mastermha/app1/ --target_version=5.5.56-MariaDB --manager_version=0.56 --relay_log_info=/var/lib/mysql/relay-log.info --relay_dir=/var/lib/mysql/ --slave_pass=xxx Mon Aug 6 18:13:50 2018 - [info] Connecting to root@192.168.134.2(192.168.134.2:22).. Creating directory /data/mastermha/app1/.. done. Checking slave recovery environment settings.. Opening /var/lib/mysql/relay-log.info ... ok. Relay log found at /var/lib/mysql, up to mariadb-relay-bin.000002 Temporary relay log file is /var/lib/mysql/mariadb-relay-bin.000002 Testing mysql connection and privileges.. done. Testing mysqlbinlog output.. done. Cleaning up test file(s).. done. Mon Aug 6 18:13:56 2018 - [info] Executing command : apply_diff_relay_logs --command=test --slave_user=‘mhauser‘ --slave_host=192.168.134.194 --slave_ip=192.168.134.194 --slave_port=3306 --workdir=/data/mastermha/app1/ --target_version=5.5.56-MariaDB --manager_version=0.56 --relay_log_info=/var/lib/mysql/relay-log.info --relay_dir=/var/lib/mysql/ --slave_pass=xxx Mon Aug 6 18:13:56 2018 - [info] Connecting to root@192.168.134.194(192.168.134.194:22).. Creating directory /data/mastermha/app1/.. done. Checking slave recovery environment settings.. Opening /var/lib/mysql/relay-log.info ... ok. Relay log found at /var/lib/mysql, up to mariadb-relay-bin.000002 Temporary relay log file is /var/lib/mysql/mariadb-relay-bin.000002 Testing mysql connection and privileges.. done. Testing mysqlbinlog output.. done. Cleaning up test file(s).. done. Mon Aug 6 18:13:56 2018 - [info] Slaves settings check done. Mon Aug 6 18:13:56 2018 - [info] 192.168.134.193(192.168.134.193:3306) (current master) +--192.168.134.2(192.168.134.2:3306) +--192.168.134.194(192.168.134.194:3306) Mon Aug 6 18:13:56 2018 - [info] Checking replication health on 192.168.134.2.. Mon Aug 6 18:13:56 2018 - [info] ok. Mon Aug 6 18:13:56 2018 - [info] Checking replication health on 192.168.134.194.. Mon Aug 6 18:13:56 2018 - [info] ok. Mon Aug 6 18:13:56 2018 - [warning] master_ip_failover_script is not defined. Mon Aug 6 18:13:56 2018 - [warning] shutdown_script is not defined. Mon Aug 6 18:13:56 2018 - [info] Got exit code 0 (Not master dead). MySQL Replication Health is OK.
通过master_check_status脚本查看Manager的状态:
[root@c1 ~]# masterha_manager --conf=/etc/mastermha/app1.cnf Mon Aug 6 19:10:08 2018 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Mon Aug 6 19:10:08 2018 - [info] Reading application default configuration from /etc/mastermha/app1.cnf.. Mon Aug 6 19:10:08 2018 - [info] Reading server configuration from /etc/mastermha/app1.cnf.. Creating /data/mastermha/app1 if not exists.. ok. Checking output directory is accessible or not.. ok. Binlog found at /var/lib/mysql, up to mariadb-bin.000001
标签:size via 要求 recovery 进程 col app environ ssh登录
原文地址:https://www.cnblogs.com/OrochWang/p/9432981.html