KingbaseES R6 集群创建流复制只读副本库案例

一、环境概述

[kingbase@node2 bin]$ ./ksql -U system test
ksql (V8.0)
Type "help" for help.

test=# select version();
                                                       version
----------------------------------------------------------------------------------------------------------
 KingbaseES V008R006C003B0010 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46), 64-bit
(1 row)

在kingbaseES R6集群已经部署了一主一备的架构下，现因业务需求，客户需要再构建一个只读的副本（流复制备库），此备库不需要纳入repmgr的管理。

集群架构：由于设备所限，新增的流复制与primary放在同一Server上

二、查看原集群节点状态和流复制状态

1、查看集群节点状态

[kingbase@node1 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+--------
 1  | node248 | standby |   running | node249  | default  | 100      | 6        | host=192.168.7.248 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node249 | primary | * running |          | default  | 100      | 6        | host=192.168.7.249 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

2、查看流复制状态

test=# select * from sys_stat_replication;
  pid  | usesysid | usename | application_name |  client_addr  | client_hostname | client_port |         backend_start         | backend_xmin |   state   |  sent_lsn  | write_lsn  | flush_lsn  | replay_lsn | write_lag | flush_lag | replay_lag | sync_priority | sync_state |          reply_time
-------+----------+---------+------------------+---------------+-----------------+-------------+-
 32701 |    16384 | esrep   | node248          | 192.168.7.248 |                 |       40835 | 2021-03-01 14:14:46.302306+08 |              | streaming | 2/21000060 | 2/21000060 | 2/21000060 | 2/21000060 |           |           |            |             1 | quorum     | 2021-03-01 17:35:03.927948+08
(1 row)

三、在主库生成检查点

[kingbase@node2 bin]$ ./ksql -U system test
ksql (V8.0)
Type "help" for help.

test=# checkpoint;
CHECKPOINT

四、创建新的流复制备库（sys_basebackup）

在249主机上：

[kingbase@node2 kingbase]$ pwd
/home/kingbase/cluster/R6HA/KHA/kingbase

[kingbase@node2 kingbase]$ mkdir data1

[kingbase@node2 bin]$ ./sys_basebackup -h 127.0.0.1  -D /home/kingbase/cluster/R6HA/KHA/kingbase/data1 -F p -X stream -v -P -U system  -p 54321
sys_basebackup: initiating base backup, waiting for checkpoint to complete
sys_basebackup: checkpoint completed
sys_basebackup: write-ahead log start point: 2/20000028 on timeline 6
sys_basebackup: starting background WAL receiver
sys_basebackup: created temporary replication slot "sys_basebackup_11798"
540366/540366 kB (100%), 1/1 tablespace
sys_basebackup: write-ahead log end point: 2/20000138
sys_basebackup: waiting for background process to finish streaming ...
sys_basebackup: syncing data to disk ...
sys_basebackup: base backup completed

[kingbase@node2 kingbase]$ chmod 700 data1

五、在新备库data下生成standby.signal文件

注意：此文件标识此节点是备库，一定在启动备库数据库服务前创建；否则数据库服务启动，默认为主库，将无法再加入流复制集群。此文件可以用vi创建，也可以从原备库拷贝。

[kingbase@node1 data]$ scp standby.signal node2:/home/kingbase/cluster/R6HA/KHA/kingbase/data1
standby.signal  

[kingbase@node2 data1]$ ls -lh standby.signal
-rw------- 1 kingbase kingbase 20 Mar  1 17:45 standby.signal

[kingbase@node2 data1]$ cat standby.signal
# created by repmgr

六、编辑kingbase.auto.conf连接主库

[kingbase@node2 data1]$ cat kingbase.auto.conf
# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command.
primary_conninfo = 'user=esrep connect_timeout=10 host=192.168.7.249 port=54321 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3'
recovery_target_timeline = 'latest'
primary_slot_name = 'repmgr_slot_3'
wal_retrieve_retry_interval = '5000'
synchronous_standby_names = 'ANY 1(*)'

注意：此处填写主库的ip信息，对应的复制槽要在主库创建。

七、创建复制槽和启动备库数据库服务

1、查看已有的复制槽信息

test=# select * from sys_replication_slots;
   slot_name   | plugin | slot_type | datoid | database | temporary | active | active_pid | xmin | catalog_xmin | restart_lsn | confirmed_flush_lsn
---------------+--------+-----------+--------+----------+-----------+--------+------------+------
 repmgr_slot_1 |        | physical  |        |          | f         | t      |      32701 |      |              | 2/21000060  |
(1 row)

2、创建复制槽

test=# select sys_create_physical_replication_slot('repmgr_slot_3');
 sys_create_physical_replication_slot
--------------------------------------
 (repmgr_slot_3,)
(1 row)

test=# select * from sys_replication_slots;
   slot_name   | plugin | slot_type | datoid | database | temporary | active | active_pid | xmin | catalog_xmin | restart_lsn | confirmed_flush_lsn
---------------+--------+-----------+--------+----------+-----------+--------+------------+------+--------------+-------------+---------------------
 repmgr_slot_1 |        | physical  |        |          | f         | t      |      32701 |      |              | 2/21000148  |
 repmgr_slot_3 |        | physical  |        |          | f         | f      |            |      |              |
            |
(2 rows)

3、修改服务端口号（因为此备库和主库在同一个主机，所以需要修改服务端口号，同时启动两个实例）

[kingbase@node2 data1]$ cat kingbase.conf |grep port
port = 54322                            # (change requires restart)

4、启动数据库服务

[kingbase@node2 bin]$ ./sys_ctl start -D ../data1
waiting for server to start....2021-03-01 17:52:22.990 CST [16562] LOG:  sepapower extension initialized
2021-03-01 17:52:22.991 CST [16562] LOG:  starting KingbaseES V008R006C003B0010 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46), 64-bit
2021-03-01 17:52:22.991 CST [16562] LOG:  listening on IPv4 address "0.0.0.0", port 54322
2021-03-01 17:52:22.991 CST [16562] LOG:  listening on IPv6 address "::", port 54322
2021-03-01 17:52:23.070 CST [16562] LOG:  listening on Unix socket "/tmp/.s.KINGBASE.54322"
2021-03-01 17:52:23.212 CST [16562] LOG:  redirecting log output to logging collector process
2021-03-01 17:52:23.212 CST [16562] HINT:  Future log output will appear in directory "sys_log".
. done
server started

[kingbase@node2 bin]$ ps -ef |grep kingbase
kingbase   539 32623  0 14:14 ?        00:00:08 kingbase: esrep esrep 192.168.7.248(40847) idle
kingbase   688 32623  0 14:14 ?        00:00:19 kingbase: esrep esrep 192.168.7.249(53332) idle
kingbase   691     1  0 14:14 ?        00:00:04 /home/kingbase/cluster/R6HA/KHA/kingbase/bin/repmgrd -d -v -f /home/kingbase/cluster/R6HA/KHA/kingbase/bin/../etc/repmgr.conf
kingbase  1073     1  0 14:15 ?        00:00:01 /home/kingbase/cluster/R6HA/KHA/kingbase/bin/kbha -A daemon -f /home/kingbase/cluster/R6HA/KHA/kingbase/bin/../etc/repmgr.conf
kingbase  1354     1  0 14:15 ?        00:00:00 /home/kingbase/cluster/R6HA/KHA/kingbase/bin/../share/node_exporter
kingbase  1355     1  0 14:15 ?        00:00:00 /home/kingbase/cluster/R6HA/KHA/kingbase/bin/../share/postgres_exporter
kingbase  1409 32623  0 14:15 ?        00:00:00 kingbase: system test ::1(61541) idle
kingbase  9680 27531  0 17:23 pts/1    00:00:00 ./ksql -U system test
kingbase  9681 32623  0 17:23 ?        00:00:00 kingbase: system test [local] idle
kingbase 16562     1  0 17:52 ?        00:00:00 /home/kingbase/cluster/R6HA/KHA/kingbase/bin/kingbase -D ../data1
kingbase 16563 16562  0 17:52 ?        00:00:00 kingbase: logger
kingbase 16564 16562  1 17:52 ?        00:00:00 kingbase: startup   recovering 000000060000000200000023
kingbase 16567 16562  0 17:52 ?        00:00:00 kingbase: checkpointer
kingbase 16568 16562  0 17:52 ?        00:00:00 kingbase: background writer
kingbase 16569 16562  0 17:52 ?        00:00:00 kingbase: stats collector
kingbase 16570 16562  0 17:52 ?        00:00:00 kingbase: walreceiver   streaming 2/23000060
kingbase 16571 32623  0 17:52 ?        00:00:00 kingbase: walsender esrep 192.168.7.249(59875) streaming 2/23000060

八、查看流复制状态

test=# select * from sys_stat_replication;
  pid  | usesysid | usename | application_name |  client_addr  | client_hostname | client_port |         backend_start         | backend_xmin |   state   |  sent_lsn  | write_lsn  | flush_lsn  | replay_lsn | write_lag | flush_lag | replay_lag | sync_priority | sync_state |          reply_time
-------+----------+---------+------------------+---------------+-----------------+-------------+
 32701 |    16384 | esrep   | node248          | 192.168.7.248 |                 |       40835 | 2021-03-01 14:14:46.302306+08 |              | streaming | 2/23000060 | 2/23000060 | 2/23000060 | 2/23000060 |           |           |            |             1 | quorum     | 2021-03-01 17:54:12.970131+08
 16571 |    16384 | esrep   | walreceiver      | 192.168.7.249 |                 |       59875 | 2021-03-01 17:52:24.644390+08 |              | streaming | 2/23000060 | 2/23000060 | 2/23000060 | 2/23000060 |           |           |            |             1 | quorum     | 2021-03-01 17:53:04.788830+08
(2 rows)

九、验证数据同步