os: centos 7.4
db: postgresql 11.7
pglogical: 2.3.1
pglogical is a logical replication system implemented entirely as a PostgreSQL extension.
Fully integrated, it requires no triggers or external programs.
This alternative to physical replication is a highly efficient method of replicating data using a publish/subscribe model for selective replication.
192.168.56.111 pg1
192.168.56.112 pg2
192.168.56.113 pg3
版本
# cat /etc/centos-release
CentOS Linux release 7.4.1708 (Core)
#
#
# yum list installed |grep -i postgresql
postgresql11.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-contrib.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-debuginfo.x86_64 11.5-1PGDG.rhel7 @pgdg11
postgresql11-devel.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-docs.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-libs.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-llvmjit.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-odbc.x86_64 12.01.0000-1PGDG.rhel7 @pgdg11
postgresql11-plperl.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-plpython.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-plpython3.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-pltcl.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-server.x86_64 11.7-1PGDG.rhel7 @pgdg11
postgresql11-tcl.x86_64 2.4.0-2.rhel7.1 @pgdg11
postgresql11-test.x86_64 11.7-1PGDG.rhel7 @pgdg11
# su - postgres
Last login: Wed Jan 15 18:34:12 CST 2020 on pts/0
$
$
$ psql -c "select version();"
version
---------------------------------------------------------------------------------------------------------
PostgreSQL 11.7 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39), 64-bit
(1 row)
安裝
三個節點都安裝
# vi /etc/hosts
192.168.56.111 pg1
192.168.56.112 pg2
192.168.56.113 pg3
# yum list all|grep -i pglogical
pglogical_11.x86_64 2.3.1-1.rhel7 pgdg11
# yum install pglogical_11;
# vi /var/lib/pgsql/11/data/postgresql.conf
wal_level = 'logical'
max_worker_processes = 20 # one per database needed on provider node
# one per node needed on subscriber node
max_replication_slots = 20 # one per node needed on provider node
max_wal_senders = 20 # one per node needed on provider node
shared_preload_libraries = 'pglogical'
track_commit_timestamp = on # needed for last/first update wins conflict resolution
# property available in PostgreSQL 9.5+
# systemctl restart postgresql-11.service
查看啓動日誌
2020-05-09 14:46:17.340 CST,,,3460,,5eb62b33.d84,3,,2020-05-09 12:01:55 CST,,0,LOG,00000,"received fast shutdown request",,,,,,,,,""
2020-05-09 14:46:17.415 CST,,,3460,,5eb62b33.d84,4,,2020-05-09 12:01:55 CST,,0,LOG,00000,"aborting any active transactions",,,,,,,,,""
2020-05-09 14:46:17.418 CST,,,3460,,5eb62b33.d84,5,,2020-05-09 12:01:55 CST,,0,LOG,00000,"background worker ""logical replication launcher"" (PID 3469) exited with exit code 1",,,,,,,,,""
2020-05-09 14:46:17.418 CST,,,3464,,5eb62b33.d88,3,,2020-05-09 12:01:55 CST,,0,LOG,00000,"shutting down",,,,,,,,,""
2020-05-09 14:46:17.421 CST,,,3464,,5eb62b33.d88,4,,2020-05-09 12:01:55 CST,,0,LOG,00000,"checkpoint starting: shutdown immediate",,,,,,,,,""
2020-05-09 14:46:17.432 CST,,,3464,,5eb62b33.d88,5,,2020-05-09 12:01:55 CST,,0,LOG,00000,"checkpoint complete: wrote 0 buffers (0.0%); 0 WAL file(s) added, 0 removed, 0 recycled; write=0.000 s, sync=0.000 s, total=0.013 s; sync files=0, longest=0.000 s, average=0.000 s; distance=0 kB, estimate=0 kB",,,,,,,,,""
2020-05-09 14:46:17.446 CST,,,3460,,5eb62b33.d84,6,,2020-05-09 12:01:55 CST,,0,LOG,00000,"database system is shut down",,,,,,,,,""
2020-05-09 14:46:17.645 CST,,,13430,,5eb651b9.3476,1,,2020-05-09 14:46:17 CST,,0,LOG,00000,"ending log output to stderr",,"Future log output will go to log destination ""csvlog"".",,,,,,,""
2020-05-09 14:46:17.655 CST,,,13432,,5eb651b9.3478,1,,2020-05-09 14:46:17 CST,,0,LOG,00000,"database system was shut down at 2020-05-09 14:46:17 CST",,,,,,,,,""
2020-05-09 14:46:17.674 CST,,,13430,,5eb651b9.3476,2,,2020-05-09 14:46:17 CST,,0,LOG,00000,"database system is ready to accept connections",,,,,,,,,""
2020-05-09 14:46:17.674 CST,,,13438,,5eb651b9.347e,1,,2020-05-09 14:46:17 CST,,0,LOG,00000,"starting pglogical supervisor",,,,,,,,,"pglogical supervisor"
2020-05-09 14:46:17.900 CST,,"postgres",13440,,5eb651b9.3480,1,"",2020-05-09 14:46:17 CST,4/0,0,LOG,00000,"manager worker [13440] at slot 0 generation 1 detaching cleanly",,,,,,,,,"pglogical manager 13881"
2020-05-09 14:46:18.163 CST,,"template1",13444,,5eb651ba.3484,1,"",2020-05-09 14:46:18 CST,4/0,0,LOG,00000,"manager worker [13444] at slot 0 generation 2 detaching cleanly",,,,,,,,,"pglogical manager 1"
2020-05-09 14:46:18.313 CST,,"pgbenchdb",13445,,5eb651ba.3485,1,"",2020-05-09 14:46:18 CST,4/0,0,LOG,00000,"manager worker [13445] at slot 0 generation 3 detaching cleanly",,,,,,,,,"pglogical manager 41068"
2020-05-09 14:46:18.491 CST,,"yewudb",13446,,5eb651ba.3486,1,"",2020-05-09 14:46:18 CST,4/0,0,LOG,00000,"manager worker [13446] at slot 0 generation 4 detaching cleanly",,,,,,,,,"pglogical manager 50433"
2020-05-09 14:46:18.596 CST,,"pgbench_plprofiler",13447,,5eb651ba.3487,1,"",2020-05-09 14:46:18 CST,4/0,0,LOG,00000,"manager worker [13447] at slot 0 generation 5 detaching cleanly",,,,,,,,,"pglogical manager 57828"
可以看到，每個數據庫啓動了一個 manager worker 進程
參考:
https://www.2ndquadrant.com/en/resources/pglogical/
https://www.2ndquadrant.com/en/resources/pglogical/pglogical-docs/
https://www.2ndquadrant.com/en/resources/pglogical/pglogical-installation-instructions/
https://github.com/2ndQuadrant/pglogical