MHA 高可用架构部署
一, MHA 介绍
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。
二, MHA搭建前
MHA搭建前必须要完成一主多从的主从复制项目:
环境:
|
db01 |
主 | 10.0.0.51 |
| db02 | 从 | 10.0.0.52 |
| db03 | 从 | 10.0.0.53 |
三台节点配置:
vim /etc/my.cnf
[mysqld]
basedir=/application/mysql
datadir=/application/mysql/data
socket=/tmp/mysql.sock
log-error=/var/log/mysql.log
log_bin=/data/mysql/mysql-bin
binlog_format=row
skip-name-resolve
server-id=51
gtid-mode=on
enforce-gtid-consistency=true
log-slave-updates=1
[client]
socket=/tmp/mysql.sock slave1：10.0.0.52 vim /etc/my.cnf
[mysqld]
basedir=/application/mysql
datadir=/application/mysql/data
socket=/tmp/mysql.sock
log-error=/var/log/mysql.log
log_bin=/data/mysql/mysql-bin
binlog_format=row
skip-name-resolve
server-id=52
gtid-mode=on
enforce-gtid-consistency=true
log-slave-updates=1
[client]
socket=/tmp/mysql.sock slave2：10.0.0.53
vim /etc/my.cnf
[mysqld]
basedir=/application/mysql
datadir=/application/mysql/data
socket=/tmp/mysql.sock
log-error=/var/log/mysql.log
log_bin=/data/mysql/mysql-bin
binlog_format=row
skip-name-resolve
server-id=53
gtid-mode=on
enforce-gtid-consistency=true
log-slave-updates=1
[client]
socket=/tmp/mysql.sock 3.重新初始化三台机器数据 /application/mysql/scripts/mysql_install_db --basedir=/application/mysql/ --datadir=/application/mysql/data --user=mysql 4. 分别启动三台数据库服务器
/etc/init.d/mysqld start
三. MHA部署开始
构建GTID:
51节点:
grant replication slave on *.* to repl@'10.0.0.%' identified by '123'; 52\53节点: change master to master_host='10.0.0.51',master_user='repl',master_password='123' ,MASTER_AUTO_POSITION=1;
start slave;
密钥乱发:
主节点配值:
rm -rf /root/.ssh
ssh-keygen cd /root/.ssh
mv id_rsa.pub authorized_keys
scp -r /root/.ssh 10.0.0.52
scp -r /root/.ssh 10.0.0.53
各个节点密钥完成无密码两两互联
51节点:
ssh 10.0.0.51 date
ssh 10.0.0.52 date
ssh 10.0.0.53 date 52节点:
ssh 10.0.0.51 date
ssh 10.0.0.52 date
ssh 10.0.0.53 date 53节点:
ssh 10.0.0.51 date
ssh 10.0.0.52 date
ssh 10.0.0.53 date
数据库配置:
51节点 52节点 53节点配置 set global relay_log_purge = 0; 52节点 53节点配置
set global read_only=1;
服务器配置
ln -s /application/mysql/bin/mysqlbinlog /usr/bin/mysqlbinlog
ln -s /application/mysql/bin/mysql /usr/bin/mysql
软件下载:
下载mha软件，mha官网：https://code.google.com/archive/p/mysql-master-ha/
安装依赖包:
yum install perl-DBD-MySQL -y
安装node
所有节点
rpm -ivh mha4mysql-node-0.57-0.el7.noarch.rpm
主库创建MHA用户
grant all privileges on *.* to mha@'10.0.0.%' identified by 'mha';
53节点配置MHA
yum install -y perl-Config-Tiny epel-release perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes
rpm -ivh mha4mysql-manager-0.57-0.el7.noarch.rpm
53节点配置文件配置
#创建配置文件目录
mkdir -p /etc/mha #创建日志目录
mkdir -p /var/log/mha/app1 #编辑mha配置文件
vim /etc/mha/app1.cnf [server default]
manager_log=/var/log/mha/app1/manager
manager_workdir=/var/log/mha/app1
master_binlog_dir=/data/mysql/
user=mha
password=mha
ping_interval=2
repl_password=123
repl_user=repl
ssh_user=root [server1]
hostname=10.0.0.51
port=3306 [server2]
hostname=10.0.0.52
port=3306 [server3]
hostname=10.0.0.53
port=3306
MHA 检查:
masterha_check_ssh --conf=/etc/mha/app1.cnf
全部ok为正常
主从状态:
masterha_check_repl --conf=/etc/mha/app1.cnf
启动MHA
nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mha/app1/manager.log 2>&1 &
四, 故障演练
某一天主库宕机了
pkill mysqld
同时MHA架构日志:
Mon Nov :: - [warning] Got error on MySQL select ping: (MySQL server has gone away)
Mon Nov :: - [info] Executing SSH check script: exit
Mon Nov :: - [warning] Got error on MySQL connect: (Can't connect to MySQL server on '10.0.0.51' (111))
Mon Nov 26 17:31:12 2018 - [warning] Connection failed 2 time(s)..
Mon Nov 26 17:31:14 2018 - [warning] Got error on MySQL connect: 2003 (Can't connect to MySQL server on '10.0.0.51' ())
Mon Nov :: - [warning] Connection failed time(s)..
Mon Nov :: - [warning] HealthCheck: Got timeout on checking SSH connection to 10.0.0.51! at /usr/share/perl5/vendor_perl/MHA/HealthCheck.pm line .
Mon Nov :: - [warning] Got error on MySQL connect: (Can't connect to MySQL server on '10.0.0.51' (111))
Mon Nov 26 17:31:16 2018 - [warning] Connection failed 4 time(s)..
Mon Nov 26 17:31:16 2018 - [warning] Master is not reachable from health checker!
Mon Nov 26 17:31:16 2018 - [warning] Master 10.0.0.51(10.0.0.51:3306) is not reachable!
Mon Nov 26 17:31:16 2018 - [warning] SSH is NOT reachable.
Mon Nov 26 17:31:16 2018 - [info] Connecting to a master server failed. Reading configuration file /etc/masterha_default.cnf and /etc/mha/app1.cnf again, and trying to connect to all servers to check server status..
Mon Nov 26 17:31:16 2018 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Mon Nov 26 17:31:16 2018 - [info] Reading application default configuration from /etc/mha/app1.cnf..
Mon Nov 26 17:31:16 2018 - [info] Reading server configuration from /etc/mha/app1.cnf..
Mon Nov 26 17:31:17 2018 - [info] GTID failover mode = 1
Mon Nov 26 17:31:17 2018 - [info] Dead Servers:
Mon Nov 26 17:31:17 2018 - [info] 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:17 2018 - [info] Alive Servers:
Mon Nov 26 17:31:17 2018 - [info] 10.0.0.52(10.0.0.52:3306)
Mon Nov 26 17:31:17 2018 - [info] 10.0.0.53(10.0.0.53:3306)
Mon Nov 26 17:31:17 2018 - [info] Alive Slaves:
Mon Nov 26 17:31:17 2018 - [info] 10.0.0.52(10.0.0.52:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:17 2018 - [info] GTID ON
Mon Nov 26 17:31:17 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:17 2018 - [info] 10.0.0.53(10.0.0.53:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:17 2018 - [info] GTID ON
Mon Nov 26 17:31:17 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:17 2018 - [info] Checking slave configurations..
Mon Nov 26 17:31:17 2018 - [info] Checking replication filtering settings..
Mon Nov 26 17:31:17 2018 - [info] Replication filtering check ok.
Mon Nov 26 17:31:17 2018 - [info] Master is down!
Mon Nov 26 17:31:17 2018 - [info] Terminating monitoring script.
Mon Nov 26 17:31:17 2018 - [info] Got exit code 20 (Master dead).
Mon Nov 26 17:31:17 2018 - [info] MHA::MasterFailover version 0.57.
Mon Nov 26 17:31:17 2018 - [info] Starting master failover.
Mon Nov 26 17:31:17 2018 - [info]
Mon Nov 26 17:31:17 2018 - [info] * Phase 1: Configuration Check Phase..
Mon Nov 26 17:31:17 2018 - [info]
Mon Nov 26 17:31:18 2018 - [info] GTID failover mode = 1
Mon Nov 26 17:31:18 2018 - [info] Dead Servers:
Mon Nov 26 17:31:18 2018 - [info] 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:18 2018 - [info] Checking master reachability via MySQL(double check)...
Mon Nov 26 17:31:18 2018 - [info] ok.
Mon Nov 26 17:31:18 2018 - [info] Alive Servers:
Mon Nov 26 17:31:18 2018 - [info] 10.0.0.52(10.0.0.52:3306)
Mon Nov 26 17:31:18 2018 - [info] 10.0.0.53(10.0.0.53:3306)
Mon Nov 26 17:31:18 2018 - [info] Alive Slaves:
Mon Nov 26 17:31:18 2018 - [info] 10.0.0.52(10.0.0.52:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:18 2018 - [info] GTID ON
Mon Nov 26 17:31:18 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:18 2018 - [info] 10.0.0.53(10.0.0.53:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:18 2018 - [info] GTID ON
Mon Nov 26 17:31:18 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:18 2018 - [info] Starting GTID based failover.
Mon Nov 26 17:31:18 2018 - [info]
Mon Nov 26 17:31:18 2018 - [info] ** Phase 1: Configuration Check Phase completed.
Mon Nov 26 17:31:18 2018 - [info]
Mon Nov 26 17:31:18 2018 - [info] * Phase 2: Dead Master Shutdown Phase..
Mon Nov 26 17:31:18 2018 - [info]
Mon Nov 26 17:31:18 2018 - [info] Forcing shutdown so that applications never connect to the current master..
Mon Nov 26 17:31:18 2018 - [warning] master_ip_failover_script is not set. Skipping invalidating dead master IP address.
Mon Nov 26 17:31:18 2018 - [warning] shutdown_script is not set. Skipping explicit shutting down of the dead master.
Mon Nov 26 17:31:19 2018 - [info] * Phase 2: Dead Master Shutdown Phase completed.
Mon Nov 26 17:31:19 2018 - [info]
Mon Nov 26 17:31:19 2018 - [info] * Phase 3: Master Recovery Phase..
Mon Nov 26 17:31:19 2018 - [info]
Mon Nov 26 17:31:19 2018 - [info] * Phase 3.1: Getting Latest Slaves Phase..
Mon Nov 26 17:31:19 2018 - [info]
Mon Nov 26 17:31:19 2018 - [info] The latest binary log file/position on all slaves is mysql-bin.000003:792
Mon Nov 26 17:31:19 2018 - [info] Retrieved Gtid Set: b54af3fb-f133-11e8-825d-00505628e54f:1-3
Mon Nov 26 17:31:19 2018 - [info] Latest slaves (Slaves that received relay log files to the latest):
Mon Nov 26 17:31:19 2018 - [info] 10.0.0.52(10.0.0.52:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:19 2018 - [info] GTID ON
Mon Nov 26 17:31:19 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:19 2018 - [info] 10.0.0.53(10.0.0.53:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:19 2018 - [info] GTID ON
Mon Nov 26 17:31:19 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:19 2018 - [info] The oldest binary log file/position on all slaves is mysql-bin.000003:792
Mon Nov 26 17:31:19 2018 - [info] Retrieved Gtid Set: b54af3fb-f133-11e8-825d-00505628e54f:1-3
Mon Nov 26 17:31:19 2018 - [info] Oldest slaves:
Mon Nov 26 17:31:19 2018 - [info] 10.0.0.52(10.0.0.52:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:19 2018 - [info] GTID ON
Mon Nov 26 17:31:19 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:19 2018 - [info] 10.0.0.53(10.0.0.53:3306) Version=5.6.38-log (oldestmajor version between slaves) log-bin:enabled
Mon Nov 26 17:31:19 2018 - [info] GTID ON
Mon Nov 26 17:31:19 2018 - [info] Replicating from 10.0.0.51(10.0.0.51:3306)
Mon Nov 26 17:31:19 2018 - [info]
Mon Nov 26 17:31:19 2018 - [info] * Phase 3.3: Determining New Master Phase..
Mon Nov 26 17:31:19 2018 - [info]
Mon Nov 26 17:31:19 2018 - [info] Searching new master from slaves..
Mon Nov 26 17:31:19 2018 - [info] Candidate masters from the configuration file:
Mon Nov 26 17:31:19 2018 - [info] Non-candidate masters:
Mon Nov 26 17:31:19 2018 - [info] New master is 10.0.0.52(10.0.0.52:3306)
Mon Nov 26 17:31:19 2018 - [info] Starting master failover..
Mon Nov 26 17:31:19 2018 - [info]
From:
10.0.0.51(10.0.0.51:3306) (current master)
+--10.0.0.52(10.0.0.52:3306)
+--10.0.0.53(10.0.0.53:3306) To:
10.0.0.52(10.0.0.52:3306) (new master)
+--10.0.0.53(10.0.0.53:3306)
Mon Nov 26 17:31:19 2018 - [info]
Mon Nov 26 17:31:19 2018 - [info] * Phase 3.3: New Master Recovery Phase..
Mon Nov 26 17:31:19 2018 - [info]
Mon Nov 26 17:31:19 2018 - [info] Waiting all logs to be applied..
Mon Nov 26 17:31:19 2018 - [info] done.
Mon Nov 26 17:31:19 2018 - [info] Getting new master's binlog name and position..
Mon Nov :: - [info] mysql-bin.:
Mon Nov :: - [info] All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=, MASTER_AUTO_POSITION=, MASTER_USER='repl', MASTER_PASSWORD='xxx';
Mon Nov :: - [info] Master Recovery succeeded. File:Pos:Exec_Gtid_Set: mysql-bin., , b54af3fb-f133-11e8-825d-00505628e54f:-
Mon Nov :: - [warning] master_ip_failover_script is not set. Skipping taking over new master IP address.
Mon Nov :: - [info] Setting read_only= on 10.0.0.52(10.0.0.52:)..
Mon Nov :: - [info] ok.
Mon Nov :: - [info] ** Finished master recovery successfully.
Mon Nov :: - [info] * Phase : Master Recovery Phase completed.
Mon Nov :: - [info]
Mon Nov :: - [info] * Phase : Slaves Recovery Phase..
Mon Nov :: - [info]
Mon Nov :: - [info]
Mon Nov :: - [info] * Phase 4.1: Starting Slaves in parallel..
Mon Nov :: - [info]
Mon Nov :: - [info] -- Slave recovery on host 10.0.0.53(10.0.0.53:) started, pid: . Check tmp log /var/log/mha/app1/10.0..53_3306_20181126173117.log if it takes time..
Mon Nov :: - [info]
Mon Nov :: - [info] Log messages from 10.0.0.53 ...
Mon Nov :: - [info]
Mon Nov :: - [info] Resetting slave 10.0.0.53(10.0.0.53:) and startingreplication from the new master 10.0.0.52(10.0.0.52:)..
Mon Nov :: - [info] Executed CHANGE MASTER.
Mon Nov :: - [info] Slave started.
Mon Nov :: - [info] gtid_wait(b54af3fb-f133-11e8-825d-00505628e54f:-) completed on 10.0.0.53(10.0.0.53:). Executed events.
Mon Nov :: - [info] End of log messages from 10.0.0.53.
Mon Nov :: - [info] -- Slave on host 10.0.0.53(10.0.0.53:) started.
Mon Nov :: - [info] All new slave servers recovered successfully.
Mon Nov :: - [info]
Mon Nov :: - [info] * Phase : New master cleanup phase..
Mon Nov :: - [info]
Mon Nov :: - [info] Resetting slave info on the new master..
Mon Nov :: - [info] 10.0.0.52: Resetting slave info succeeded.
Mon Nov :: - [info] Master failover to 10.0.0.52(10.0.0.52:) completed successfully.
Mon Nov :: - [info] Deleted server1 entry from /etc/mha/app1.cnf .
Mon Nov :: - [info] ----- Failover Report ----- app1: MySQL Master failover 10.0.0.51(10.0.0.51:) to 10.0.0.52(10.0.0.52:) succeeded Master 10.0.0.51(10.0.0.51:) is down! Check MHA Manager logs at db03:/var/log/mha/app1/manager for details. Started automated(non-interactive) failover.
Selected 10.0.0.52(10.0.0.52:) as a new master.
10.0.0.52(10.0.0.52:): OK: Applying all logs succeeded.
10.0.0.53(10.0.0.53:): OK: Slave started, replicating from 10.0.0.52(10.0.0.52:)
10.0.0.52(10.0.0.52:): Resetting slave info succeeded.
Master failover to 10.0.0.52(10.0.0.52:) completed successfully.
可以发现主库实现漂移自动转到53节点
恢复机器:
再MHA的日志这里可以看见他说明了要恢复服务器的内容
而且
vim /etc/mha/app1.cnf
配置文件中不需要的服务器自动删除
重新启动服务器的话需要把配置文件重新配置
[server default]
manager_log=/var/log/mha/app1/manager
manager_workdir=/var/log/mha/app1
master_binlog_dir=/data/mysql/
password=mha
ping_interval=
repl_password=
repl_user=repl
ssh_user=root
user=mha [server1]
hostname=10.0.0.51
port= [server2]
hostname=10.0.0.52
port= [server3]
hostname=10.0.0.53
port=
再宕机的服务器重新配置slave
CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123'; start slave;
MHA重新启动
重新检测:
[root@db03 ~]# masterha_check_ssh --conf=/etc/mha/app1.cnf
Mon Nov :: - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Mon Nov :: - [info] Reading application default configuration from /etc/mha/app1.cnf..
Mon Nov :: - [info] Reading server configuration from /etc/mha/app1.cnf..
Mon Nov :: - [info] Starting SSH connection tests..
Mon Nov :: - [debug]
Mon Nov :: - [debug] Connecting via SSH from root@10.0.0.51(10.0.0.51:) to root@10.0.0.52(10.0.0.52:)..
Mon Nov :: - [debug] ok.
Mon Nov :: - [debug] Connecting via SSH from root@10.0.0.51(10.0.0.51:) to root@10.0.0.53(10.0.0.53:)..
Mon Nov :: - [debug] ok.
Mon Nov :: - [debug]
Mon Nov :: - [debug] Connecting via SSH from root@10.0.0.52(10.0.0.52:) to root@10.0.0.51(10.0.0.51:)..
Mon Nov :: - [debug] ok.
Mon Nov :: - [debug] Connecting via SSH from root@10.0.0.52(10.0.0.52:) to root@10.0.0.53(10.0.0.53:)..
Mon Nov :: - [debug] ok.
Mon Nov :: - [debug]
Mon Nov :: - [debug] Connecting via SSH from root@10.0.0.53(10.0.0.53:) to root@10.0.0.51(10.0.0.51:)..
Mon Nov :: - [debug] ok.
Mon Nov :: - [debug] Connecting via SSH from root@10.0.0.53(10.0.0.53:) to root@10.0.0.52(10.0.0.52:)..
Mon Nov :: - [debug] ok.
Mon Nov :: - [info] All SSH connection tests passed successfully.
[root@db03 ~]#
nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover< /dev/null > /var/log/mha/app1/manager.log >& &
MHA 高可用架构部署的更多相关文章
- MHA高可用架构与Atlas读写分离
1.1 MHA简介 1.1.1 MHA软件介绍 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 ...
- linux下mysql5.7的MHA高可用架构搭建
一.MHA简介 MHA(Master High Availability)目前在mysql高可用方面比较成熟.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 ...
- MySQL集群搭建(5)-MHA高可用架构
1 概述 1.1 MHA 简介 MHA - Master High Availability 是由 Perl 实现的一款高可用程序,出现故障时,MHA 以最小的停机时间(通常10-30秒)执行 mas ...
- mysql mha高可用架构的安装
MMM无法全然地保证数据的一致性,所以MMM适用于对数据的一致性要求不是非常高.可是又想最大程度的保证业务可用性的场景对于那些对数据一致性要求非常高的业务,非常不建议採用MMM的这样的高可用性架构.那 ...
- 【MySQL】MMM和MHA高可用架构
用途 对MySQL主从复制集群的Master的健康监控. 当Master宕机后把写VIP迁移到新Master. 重新配置集群中的其他Slave从新Master同步 MMM架构 主服务器发生故障时, 1 ...
- Rancher On K3s 高可用架构部署
Rancher 推荐部署架构 k3s 模式 RKE 和 k8s 模式 备注: 我对 RKE 的理解就是 Ansible + kubeadm 的打包,首先 rke 需要到每一个节点都可以免密 ssh , ...
- MySQL 部署 MHA 高可用架构 (二)
实现 MHA VIP 功能 配置 master_ip_failover 脚本(db3) 把 master_ip_failover 上传到 /iba/software 上 master_ip_failo ...
- MySQL 部署 MHA 高可用架构 (一)
MHA 官方网址 Manager : https://github.com/yoshinorim/mha4mysql-manager Node : https://github.com/yoshino ...
- Canal高可用架构部署
一.前言 canal 是阿里的一款开源项目,纯 Java 开发.基于数据库增量日志解析,提供增量数据订阅&消费,目前主要支持了 MySQL(也支持 mariaDB). canal 模拟 mys ...
随机推荐
- Java 核心类库之反射机制
1:什么是反射机制? 2:反射机制它可以做什么呢? 3:反射机制对应的API又是什么? 1):通过反射机制来获取一个对象的全限定名称(完整包名),和类名: 2):实例化Class对象 3):获取对象的 ...
- 如何创建JUnit
这里拿Dynamic项目来演示,首先创建一个Dynamic项目,起名,点next, 继续点next, 将web.xml文件勾选,finish, 接下来在Java Resources->src下创 ...
- MVC - Routing - 网址路由
1. Routing : 路由 主要是比对通过浏览器传来的http要求与响应适当的网址给浏览器. @Html.ActionLink("关于","About", ...
- struts2中错误提示：There is no Action mapped for namespace / and action name
当在struts2中运行时出现如上所述错误时: 1.在src目录下创建struts.xml一定要注意拼写 2.struts.xml文件中引入和extend是否正确 3.在web.xml 中<we ...
- c#递归理解
什么是递归函数? 任何一个方法既可以调用其他方法又可以调用自己,而当这个方法调用自己时,我们就叫它递归函数或者递归方法! 说白了,就是调用自己. 通常递归有两个特点: 1.递归方法一直会调用自 ...
- 【转载】C# DataGridView 通过代码设置样式
// 表格上下左右自适应 dataGridView.Anchor = (AnchorStyles.Top | AnchorStyles.Right | AnchorStyles.Bottom | An ...
- 以太坊系列之六: p2p模块--以太坊源码学习
p2p模块 p2p模块对外暴露了Server关键结构,帮助上层管理复杂的p2p网路,使其集中于Protocol的实现,只关注于数据的传输. Server使用discover模块,在指定的UDP端口管理 ...
- SSH的三个组件ssh、sftp、scp介绍
SSH 包含3个组件 (1) ssh 远程登录节点 : ssh 用户名@IP地址 ① 不允许空密码或错误密码认证登录 ② 不允许root用户登录 ③ 有两个版本 ssh,ssh2安全性更高 (2) ...
- leecode刷题（6）-- 两个数组的交集II
leecode刷题(6)-- 两个数组的交集II 两个数组的交集II 描述: 给定两个数组,编写一个函数来计算它们的交集. 示例: 输入: nums1 = [1,2,2,1], nums2 = [2, ...
- [Swift实际操作]九、完整实例-(1)在iTunesConnect网站中创建产品
本文将通过一个实例项目,演示移动应用开发的所有步骤.首先要做的是打开浏览器,并进入[iTunesConnect网站],需要通过它创建一款自己的应用. 在iTunesConnect的登录页面中,输入自己 ...