PostgreSQL HA
- 1. PostgreSQL - High Availability Muhammad Haroon PUG August 2016, Islamabad
- 2. Agenda ● A typical workflow in DR ● Why does everyone talk about it ? ● What is HA after all ? ● PostgreSQL HA ● PostgreSQL HA + Linux modus vivendi
- 3. Who am I ?? ● Working in PostgreSQL space @ 2ndQuadrant ● Part of PostgreSQL family for over 10 years ● Work in almost all areas around PostgreSQL from development to professional services ● Past stints with PostgreSQL family include ○ EnterpriseDB ○ OpenSCG ● Headed Engineering & IT efforts @ IBEX ● Served as Principal Architect/Product Owner @ TRG Email: haroon@2ndQuadrant.com : contact.mharoon@gmail.com Skype: contact.haroon
- 4. Where does it all begin ?
- 5. Downtime ???
- 6. Downtime ● Planned downtime ○ Software maintenance activity (upgrades etc) ○ Hardware maintenance activity (changes, upgrades etc) ● Unplanned downtime ○ Software crash ○ Hardware crash ○ Network failure ○ Human error
- 9. HA - Availability Levels
- 10. What is HA after all ? ● RTO - Recovery Time Objective ○ The time interval it will take to restore ... ● RPO - Recovery Point Objective ○ The amount of data that you will lose ...
- 12. RPO ● Backups ○ Logical Backups ■ Database dumps ● SQL script + data ○ Physical backups ■ Online ● Basebackups (provides base for PITR) ■ Offline ● Stop PostgreSQL, take backup ■ Filesystem snapshots ○ WAL archiving
- 14. PostgreSQL & RTO
- 15. PostgreSQL HA - Replication ● Streaming Replication ○ Synchronous ○ Asynchronous ○ Master, slave(s) ○ Master, slave(s), cascaded slaves(s) ● WAL shipping
- 16. PostgreSQL HA - Failover Scenario Primary/Master Standby 4 Standby 3 Standby 1 App server Standby 2
- 17. PostgreSQL HA - Failover Scenario (cont.) Primary/Master Standby 4 Standby 3 Standby 1 App server Standby 2
- 18. PostgreSQL HA - Failover Scenario (cont.) Old primary/master Standby 4 Standby 3 Primary/Master App server Standby 2
- 19. PostgreSQL HA - Failover Scenario (cont.) Standby 4 Standby 3 Primary/Master Old primary/master App server Standby 2
- 20. PostgreSQL HA - Failover Scenario (cont.) Standby 4 Standby 3 Primary/Master Standby 1 App server Standby 2
- 21. PostgreSQL HA + Open source PG community tools + Linux Free & Open source complete HA
- 22. PostgreSQL HA - Streaming Replication Primary/Master Standby 4 Standby 3 Standby 1 App server Proxy Standby 2
- 23. PostgreSQL HA - Streaming Replication Old Primary/Master Standby 4 Standby 3 Primary App server Proxy Standby 2
- 24. Old primary - STONITH Shoot The Other Node In The Head image courtesy ourobengr.com
- 25. Further reading - Barman: http://www.pgbarman.org - Repmgr: http://www.repmgr.org - Repmgrd: http://www.repmgr.org - Pgbouncer: https://pgbouncer.github.io - pgPool: http://www.pgpool.net/mediawiki/index.php/Main_Page - pgBackRest: https://github.com/pgbackrest/pgbackrest - CoroSync: http://corosync.github.io/corosync/ - Various other tools available to work with postgres
- 26. Special Thanks!!
- 27. Questions Thank you for your time Questions ? ● Need customized PostgreSQL suited to your needs? ● Looking for PostgreSQL training ? ● Need help migrating to PostgreSQL ? ● Need PostgreSQL production support ? ● Got specific PostgreSQL needs ? ● Looking for cloud and/or hybrid high availability clusters ? Let us help you! Email: haroon@2ndQuadrant.com Skype: contact.haroon
- 28. ● PostgreSQL News ○ PostgreSQL 9.6 Beta4 Released - August 11, 2016 ○ MariaDB license change ○ PGConf.ASIA - Tokyo (2-3 December 2016) ● 2ndQuadrant News ○ repmgr 3.1.5 ○ Postgres-XL 9.5 R1.3 ○ BDR9.4 1.0 ○ 2UDA 9.6 Beta4