邵阳住建部网站,阳原网站建设,脱贫地区农副产品网络销售平台,华为应用市场下载安装文章目录 1.流复制介绍2.异步流复制2.1.主库部署2.2.备库部署2.3.测试 3.同步复制3.1.主库部署3.2.备库部署3.3.测试 4.主备切换 开源中间件 # PostgreSQLhttps://iothub.org.cn/docs/middleware/ https://iothub.org.cn/docs/middleware/postgresql/postgres-stream/1.流复制… 文章目录 1.流复制介绍2.异步流复制2.1.主库部署2.2.备库部署2.3.测试 3.同步复制3.1.主库部署3.2.备库部署3.3.测试 4.主备切换 开源中间件 # PostgreSQLhttps://iothub.org.cn/docs/middleware/ https://iothub.org.cn/docs/middleware/postgresql/postgres-stream/1.流复制介绍 流复制其原理为备库不断的从主库同步相应的数据并在备库apply每个WAL record这里的流复制每次传输单位是WAL日志的record。 PostgreSQL物理流复制按照同步方式分为两类 异步流复制同步流复制 物理流复制具有以下特点 延迟极低不怕大事务支持断点续传支持多副本配置简单备库与主库物理完全一致并支持只读 2.异步流复制 2.1.主库部署 安装postgresql # yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm# yum install -y postgresql11-server # 关闭防火墙 firewall-cmd --state #查看默认防火墙状态关闭后显示notrunning开启后显示running systemctl stop firewalld.service #停止firewall systemctl start firewalld.service #开启防火墙 systemctl disable firewalld.service #禁止firewall开机启动 systemctl enable firewalld.service #开启firewall开机启动初始化数据库 主库初始化 # /usr/pgsql-11/bin/postgresql-11-setup initdb启动服务 # systemctl start postgresql-11 服务自启动 # systemctl enable postgresql-11切换用户设置数据库密码 # su - postgres $ psql # ALTER USER postgres with encrypted password postgres; 创建用于主从同步的用户 用户名replica, 密码replica # CREATE ROLE replica login replication encrypted password replica;postgres# \q #-bash-4.2$ exit修改配置文件 1.修改连接权限 # vim /var/lib/pgsql/11/data/pg_hba.conf# 客户端访问 host all all all md5 # replica是用来做备份的用户172.51.216.82/32是备的IP地址 host replication replica 172.51.216.82/32 md5# 完整配置 # TYPE DATABASE USER ADDRESS METHOD# local is for Unix domain socket connections only local all all peer # IPv4 local connections: host all all 127.0.0.1/32 ident # IPv6 local connections: host all all ::1/128 ident # Allow replication connections from localhost, by a user with the # replication privilege. local replication all peer host replication all 127.0.0.1/32 ident host replication all ::1/128 identhost all all all md5 host replication replica 172.51.216.82/32 md52.修改数据库配置 # vim /var/lib/pgsql/11/data/postgresql.conf同步增加配置 synchronous_commit on # synchronization level; synchronous_standby_names msalisten_addresses * # what IP address(es) to listen on; port 5432 # (change requires restart) max_connections 512 # (change requires restart) shared_buffers 128MB # min 128kB dynamic_shared_memory_type posix # the default is the first option wal_level hot_standby # minimal, replica, or logical archive_mode on # enables archiving; off, on, or always archive_command cp %p /var/lib/pgsql/11/data/pg_archive/%f # command to use to archive a logfile segment max_wal_senders 6 # max number of walsender processes wal_keep_segments 256 # in logfile segments, 16MB each; 0 disables wal_sender_timeout 60s # in milliseconds; 0 disables log_directory log # directory where log files are written 修改完要创建刚刚配置的一些目录结构 # mkdir /var/lib/pgsql/11/data/pg_archive/ # chown -R postgres.postgres /var/lib/pgsql/11/data重启主库服务 # systemctl restart postgresql-11 # systemctl status postgresql-11 2.2.备库部署 安装postgresql # yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm# yum install -y postgresql11-server # 关闭防火墙 firewall-cmd --state #查看默认防火墙状态关闭后显示notrunning开启后显示running systemctl stop firewalld.service #停止firewall systemctl start firewalld.service #开启防火墙 systemctl disable firewalld.service #禁止firewall开机启动 systemctl enable firewalld.service #开启firewall开机启动初始化数据库 主库初始化 # /usr/pgsql-11/bin/postgresql-11-setup initdb启动服务 # systemctl start postgresql-11 服务自启动 # systemctl enable postgresql-11拷贝主库数据 1.进入data目录,清空从节点数据 # su - postgres $ cd /var/lib/pgsql/11/data/ $ rm -rf *2.把主节点所有的数据文件都会拷贝过来 -bash-4.2$ pg_basebackup -h 172.51.216.81 -U replica -D /var/lib/pgsql/11/data/ -X stream -P Password: replica 修改配置文件 1、修改从库配置文件 -bash-4.2$ vim /var/lib/pgsql/11/data/postgresql.conf listen_addresses * # what IP address(es) to listen on; port 5432 # (change requires restart) max_connections 1000 # (change requires restart) shared_buffers 128MB # min 128kB dynamic_shared_memory_type posix # the default is the first option wal_level replica # minimal, replica, or logical archive_mode on # enables archiving; off, on, or always archive_command cp %p /var/lib/pgsql/11/data/pg_archive/%f # command to use to archive a logfile segment wal_sender_timeout 60s # in milliseconds; 0 disables hot_standby on # on allows queries during recovery max_standby_streaming_delay 30s # max delay before canceling queries wal_receiver_status_interval 10s # send replies at least this often hot_standby_feedback on # send info from standby to prevent log_directory log # directory where log files are written,2.创建恢复文件recovery.conf -bash-4.2$ cp /usr/pgsql-11/share/recovery.conf.sample /var/lib/pgsql/11/data/recovery.conf -bash-4.2$ vim /var/lib/pgsql/11/data/recovery.conf# 修改参数 recovery_target_timeline latest #同步到最新数据 standby_mode on #指明从库身份 trigger_file failover.now primary_conninfo host172.51.216.81 port5432 userreplica passwordreplica #连接到主库信息 切换到root用户 $ exit重启从库服务 # systemctl restart postgresql-11 # systemctl start postgresql-11 # systemctl status postgresql-11# netstat -lntp # netstat -nat2.3.测试 进入主节点 su - postgres psql在主库上运行以下命令 postgres# select client_addr,sync_state from pg_stat_replication;postgres# select client_addr,sync_state from pg_stat_replication;client_addr | sync_state ---------------------------172.51.216.82 | async (1 row)postgres# \x Expanded display is on. postgres# select * from pg_stat_replication; -[ RECORD 1 ]---------------------------------- pid | 8437 usesysid | 16384 usename | replica application_name | walreceiver client_addr | 172.51.216.82 client_hostname | client_port | 37542 backend_start | 2021-03-12 13:28:55.81823908 backend_xmin | 572 state | streaming sent_lsn | 0/C01DE30 write_lsn | 0/C01DE30 flush_lsn | 0/C01DE30 replay_lsn | 0/C01DE30 write_lag | flush_lag | replay_lag | sync_priority | 0 sync_state | async# 方法-1 在主库端检查说明89服务器是从节点在接收流而且是异步流复制 postgres# select usename , application_name , client_addr,sync_state from pg_stat_replication; -[ RECORD 1 ]------------------ usename | replica application_name | walreceiver client_addr | 172.51.216.89 sync_state | async# 方法-2 在主、从节点分别执行如下命令# 主 postgres 34833 11712 0 14:14 ? 00:00:00 postgres: walsender replica 172.51.216.89(51848) streaming 0/9024250# 从 postgres 77147 77128 0 14:14 ? 00:00:03 postgres: walreceiver streaming 0/90242503.同步复制 3.1.主库部署 安装postgresql # yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm# yum install -y postgresql11-server # 关闭防火墙 firewall-cmd --state #查看默认防火墙状态关闭后显示notrunning开启后显示running systemctl stop firewalld.service #停止firewall systemctl start firewalld.service #开启防火墙 systemctl disable firewalld.service #禁止firewall开机启动 systemctl enable firewalld.service #开启firewall开机启动初始化数据库 主库初始化 # /usr/pgsql-11/bin/postgresql-11-setup initdb启动服务 # systemctl start postgresql-11 服务自启动 # systemctl enable postgresql-11切换用户设置数据库密码 # su - postgres $ psql # ALTER USER postgres with encrypted password postgres; 创建用于主从同步的用户 用户名replica, 密码replica # CREATE ROLE replica login replication encrypted password replica;postgres# \q #-bash-4.2$ exit修改配置文件 1.修改连接权限 # vim /var/lib/pgsql/11/data/pg_hba.conf# 客户端访问 host all all all md5 # replica是用来做备份的用户172.51.216.82/32是备的IP地址 host replication replica 172.51.216.82/32 md5#完成配置 # TYPE DATABASE USER ADDRESS METHOD# local is for Unix domain socket connections only local all all peer # IPv4 local connections: host all all 127.0.0.1/32 ident # IPv6 local connections: host all all ::1/128 ident # Allow replication connections from localhost, by a user with the # replication privilege. local replication all peer host replication all 127.0.0.1/32 ident host replication all ::1/128 identhost all all all md5 host replication replica 172.51.216.82/32 md52.修改数据库配置 # vim /var/lib/pgsql/11/data/postgresql.conf同步增加配置 synchronous_commit on # synchronization level; synchronous_standby_names msalisten_addresses * # what IP address(es) to listen on; port 5432 # (change requires restart) max_connections 512 # (change requires restart) shared_buffers 128MB # min 128kB dynamic_shared_memory_type posix # the default is the first option wal_level hot_standby # minimal, replica, or logical archive_mode on # enables archiving; off, on, or always archive_command cp %p /var/lib/pgsql/11/data/pg_archive/%f # command to use to archive a logfile segment max_wal_senders 6 # max number of walsender processes wal_keep_segments 256 # in logfile segments, 16MB each; 0 disables wal_sender_timeout 60s # in milliseconds; 0 disables log_directory log # directory where log files are written 修改完要创建刚刚配置的一些目录结构 # mkdir /var/lib/pgsql/11/data/pg_archive/ # chown -R postgres.postgres /var/lib/pgsql/11/data重启主库服务 # systemctl restart postgresql-11 # systemctl status postgresql-11 3.2.备库部署 安装postgresql # yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm# yum install -y postgresql11-server # 关闭防火墙 firewall-cmd --state #查看默认防火墙状态关闭后显示notrunning开启后显示running systemctl stop firewalld.service #停止firewall systemctl start firewalld.service #开启防火墙 systemctl disable firewalld.service #禁止firewall开机启动 systemctl enable firewalld.service #开启firewall开机启动初始化数据库 主库初始化 # /usr/pgsql-11/bin/postgresql-11-setup initdb启动服务 # systemctl start postgresql-11 服务自启动 # systemctl enable postgresql-11拷贝主库数据 1.进入data目录,清空从节点数据 # su - postgres $ cd /var/lib/pgsql/11/data/ $ rm -rf *2.把主节点所有的数据文件都会拷贝过来 -bash-4.2$ pg_basebackup -h 172.51.216.81 -U replica -D /var/lib/pgsql/11/data/ -X stream -P Password: replica修改配置文件 1、修改从库配置文件 -bash-4.2$ vim /var/lib/pgsql/11/data/postgresql.conf listen_addresses * # what IP address(es) to listen on; port 5432 # (change requires restart) max_connections 1000 # (change requires restart) shared_buffers 128MB # min 128kB dynamic_shared_memory_type posix # the default is the first option wal_level replica # minimal, replica, or logical archive_mode on # enables archiving; off, on, or always archive_command cp %p /var/lib/pgsql/11/data/pg_archive/%f # command to use to archive a logfile segment wal_sender_timeout 60s # in milliseconds; 0 disables hot_standby on # on allows queries during recovery max_standby_streaming_delay 30s # max delay before canceling queries wal_receiver_status_interval 10s # send replies at least this often hot_standby_feedback on # send info from standby to prevent log_directory log # directory where log files are written,2.创建恢复文件recovery.conf -bash-4.2$ cp /usr/pgsql-11/share/recovery.conf.sample /var/lib/pgsql/11/data/recovery.conf -bash-4.2$ vim /var/lib/pgsql/11/data/recovery.conf# 修改参数 recovery_target_timeline latest #同步到最新数据 standby_mode on #指明从库身份 trigger_file failover.now primary_conninfo host172.51.216.81 port5432 userreplica passwordreplica application_namemsa #连接到主库信息 同步primary_conninfo增加 application_namemsa切换到root用户 $ exit重启从库服务 # systemctl restart postgresql-11 # systemctl start postgresql-11 # systemctl status postgresql-11# netstat -lntp # netstat -nat3.3.测试 # 进入主节点 su - postgres psql在主库上运行以下命令 postgres# select client_addr,sync_state from pg_stat_replication;postgres# select client_addr,sync_state from pg_stat_replication;client_addr | sync_state ---------------------------172.51.216.82 | sync (1 row)postgres# \x Expanded display is on. postgres# select * from pg_stat_replication; -[ RECORD 1 ]---------------------------------- pid | 61092 usesysid | 16384 usename | replica application_name | msa client_addr | 172.51.216.82 client_hostname | client_port | 48152 backend_start | 2021-03-12 14:30:54.52383108 backend_xmin | 573 state | streaming sent_lsn | 0/100000D0 write_lsn | 0/100000D0 flush_lsn | 0/100000D0 replay_lsn | 0/100000D0 write_lag | flush_lag | replay_lag | sync_priority | 1 sync_state | sync# 方法-1 在主库端检查说明89服务器是从节点在接收流而且是异步流复制 postgres# select usename , application_name , client_addr,sync_state from pg_stat_replication; -[ RECORD 1 ]------------------ usename | replica application_name | walreceiver client_addr | 172.51.216.89 sync_state | sync# 方法-2 在主、从节点分别执行如下命令# 主 postgres 34833 11712 0 14:14 ? 00:00:00 postgres: walsender replica 172.51.216.89(51848) streaming 0/9024250# 从 postgres 77147 77128 0 14:14 ? 00:00:03 postgres: walreceiver streaming 0/90242504.主备切换 关闭主库 在主库执行 pg_ctl stop 模拟主库宕机。 pg_ctl stop-bash-4.2$ pg_ctl stop waiting for server to shut down.... done server stopped这时备库日志会报错提示 primary 主库连接不上 2021-03-15 13:22:57.311 CST [66145] FATAL: could not connect to the primary server: could not connect to server: Connection refusedIs the server running on host 172.51.216.81 and acceptingTCP/IP connections on port 5432?激活备库 在备库执行 pg_ctl promote 激活备库 -bash-4.2$ pg_ctl promote waiting for server to promote.... done server promoted备库激活后可以插入数据变为可读写。这时配置文件 recovery.conf 变为 recovery.done。 postgres# SELECT pg_is_in_recovery();pg_is_in_recovery -------------------f (1 row)开源中间件 # PostgreSQLhttps://iothub.org.cn/docs/middleware/ https://iothub.org.cn/docs/middleware/postgresql/postgres-stream/