Presentation about Postgresql Master-Slave, point in time recovery and upgrading without downtime using pglogical, all applied on Alfresco.

1. POSTGRESQLPOSTGRESQL
FOR ALFRESCOFOR ALFRESCO
THE PRACTICAL GUIDETHE PRACTICAL GUIDE
Created by Thijs Lemmens

2. Working at Xenit since
2011
Big archiving use cases
Strong interest in
PostgreSQL
ABOUT MEABOUT ME

3. OUTLINEOUTLINE
HA: Master - Slave Failover
Continuous backup - Point-in-time
Recovery
Database upgrade without downtime

4. STREAMING REPLICATIONSTREAMING REPLICATION

6. SYNCHRONOUSSYNCHRONOUS
Data
security
Safe failover
ASYNCHRONOUSASYNCHRONOUS
High
availability
Performance
DILEMMADILEMMA

7. CONFIGURATION: MASTERCONFIGURATION: MASTER
postgresql.conf:
wal_level = hot_standby # or higher
max_wal_senders = 20

8. CONFIGURATION: MASTERCONFIGURATION: MASTER
pg_hba.conf:
host replication repuser 172.18.0.0 255.255.255.0 md5

9. CONFIGURATION: SLAVECONFIGURATION: SLAVE
pg_basebackup --pgdata=datadir --xlog-method=stream
--write-recovery-conf --progress
--dbname="host=pgmaster port=5432 user=repuser password=pwd"

10. CONFIGURATION: ALFRESCOCONFIGURATION: ALFRESCO
jdbc:postgresql://pgmaster:5432,pgslave:5432/alfresco

11. STREAMING BACKUPSTREAMING BACKUP

12. STREAMING BACKUPSTREAMING BACKUP
start from a base backup
archive the wal files
regular bookkeeping (use a
tool)

13. STREAMING BACKUP:STREAMING BACKUP:
CONFIGURATIONCONFIGURATION
postgresql.conf:
archive_mode = on
archive_command = 'test ! -f /wal_archive/%f &&
cp %p /wal_archive/%f'

14. RESTORE: CONFIGURATIONRESTORE: CONFIGURATION
recovery.conf:
restore_command = 'cp /wal_archive/%f %p'
recovery_target_time = '2018-01-09 09:39:50'

15. DEMO: POINT IN TIME RECOVERYDEMO: POINT IN TIME RECOVERY

16. DATABASE UPGRADE WITHOUTDATABASE UPGRADE WITHOUT
DOWNTIMEDOWNTIME

17. addon from 2nd
Quadrant
sql-like replication of
changes to a db
cross version (9.4 -> 10)
built in version in
postgresql 10
per database replication
LOGICAL REPLICATIONLOGICAL REPLICATION

19. LOGICAL REPLICATION SETUP ONLOGICAL REPLICATION SETUP ON
OLD VERSIONOLD VERSION
Dump the database (scheme
only)
Create the extension
Create provider node
Register tables to provider
Register sequences to subscriber

20. LOGICAL REPLICATION SETUP ONLOGICAL REPLICATION SETUP ON
NEW VERSIONNEW VERSION
Restore the database (scheme
only)
Create the extension
Create subscriber node
Register subscription to provider

21. DEMO: DB UPGRADE WITHOUTDEMO: DB UPGRADE WITHOUT
DOWNTIMEDOWNTIME

22. SOURCESSOURCES
https://blog.2ndquadrant.com/evolution-of-fault-tol
erance-in-postgresql-replication-phase/
https://www.postgresql.org/docs
https://rosenfeld.herokuapp.com/en/articles/infrast
ructure/2017-11-10-upgrading-postgresql-from-9-6-
to-10-with-minimal-downtime-using-pglogical

23. THANK YOU!THANK YOU!
https://github.com/thijslemmens/postgres-alfresco-
presentation