在物理复制中,Master节点会运行多个wal send进程;Standby节点会运行多个wal recv进程和startup进程,send是master发送wal日志的进程;recv进程是standby节点接受wal日志的进程,startup进程是standby节点apply wal日志的进程。 基于SQL的逻辑Replication:基本原理是应用端发出更改请求,master不断的产生日志,紧接着master的send...
iMac:slavehs$ pg_ctl -D . start server starting LOG: database system was interrupted; last known up at 2013-03-17 21:08:39 CET LOG: creating missing WAL directory "pg_XLOG/archive_status" LOG: entering standby mode LOG: streaming replication successfully connected to primary LOG: redo st...
AI代码解释 pg_ctl start-D~/12/data/
walsender进程是用来发送WAL日志记录的,执行顺序如下:PostgresMain()->exec_replication_command()->StartReplication()->WalSndLoop()->XLogSendPhysical()walreceiver进程是用来接收WAL日志记录的,执行顺序如下:sigusr1_handler()->StartWalReceiver()->AuxiliaryProcessMain()->WalReceiverMain()->walrcv_receive()...
exec_replication_command(cmd_string = 0x1812418 "START_REPLICATION SLOT \"test_for_recvlogical\" LOGICAL 0/0") C++ (gdb) PostgresMain(argc = 1, argv = 0x18407b0, dbname = 0x1840720 "postgres", username = 0x1840708 "zjh") C++ (gdb) ...
Once we have configured our master and taken a base backup, we can start configuring our slave system. Let's assume for the sake of simplicity that we are using only a single slave; we will not cascade replication to other systems. 我们只需要在从服务器上更改 postgresql.conf 中的一行: We...
hostreplicationrep_user192.168.0.22/32md5 1. 配置备节点 步骤1:备份主节点 要配置备用节点,需要用 pg_basebackup 程序生成主节点的备份,这将作为备用节点的起点。命令如下: 复制 pg_basebackp-D-h-Xstream-cfast-Urep_user-W 1. 上述语法中使用的参数如下: ...
pg_ctl -D /pgdata start 三、发现问题 通过ps -ef|grep postgres，已经可以看到主库和备库的walsender和walreciver进程都已经启动，流复制已经搭建好。但是，通过pg_stat_replication进行查看，发现当前数据库状态仍然还是异步流复制状态：postgres=# select * from pg_stat_replication;-[ RECORD 2 ]---+---...
sudo systemctl start postgresql 1 验证配置 在主服务器上检查复制状态 在主服务器上运行以下 SQL 查询,检查从服务器是否连接: SELECT * FROM pg_stat_replication; 1 在从服务器上检查日志 检查从服务器的 PostgreSQL 日志,以确保没有错误并且流复制正常运行。
start-up:见上图5~6 catch-up:上图7 streaming:上图8 backup:因为备份发送整个数据库集群的文件,比如PG_basebackup工具 通过PG_stat_replication视图可以查看: testdb=# SELECT application_name,state FROM pg_stat_replication;application_name|state---+---standby1|streaming standby2|streaming pg_basebackup...