Postgresql in Education
- 1. Postgresql in Education AICT, University of Alberta
- 3. Academic Information & Communication Technologies http://www.aict.ualberta.ca
- 4. Application Hosting Currently 6 people taking care of • Shared Oracle environment with about 120 databases and applications • Shared SQL Server environment with about 150+ databases and applications • Individual databases and applications ~200 (oracle, sql server, mysql, postgresql, tomcat, alfresco, AIM, moodle, etc.) • SLA’s from on-incident support, business hours to 24x7 support. • Dealing with Financial data and private (FOIP protected) data • Go to team for application / database errors for people we do not directly support. • Transitioning and consolidating applications and databases from around 75 departments.
- 6. Why am I here? In 2010 University of Alberta was looking for a new Learning Content Management System. Our existing system was Blackboard Vista running on Oracle. Objectives: - Reduce licensing costs - Create a service people want to use - Improve service reliability - Collaborate with other institutions across the province and beyond We selected Moodle (Open Source) on Postgresql (9.0). Migration took around 2 years.
- 7. Central Learning Management System
- 8. Upcoming and existing projects using Postgresql OTRS Ticketing System Primary Secondary (used for searching) Reporting DB Jaspersoft Business Intelligence Enterprise Document and Records Management System • Business critical records like land titles, contracts, billing, student records • Expected size in 1 year – 1.5 TB (DB + FS) with 3 departments on board. • 73 more departments to go New Shared Postgresql Environment • 24x7 managed shared environment • Automated replication to TEST / UAT • Service reporting for clients?
- 9. Core considerations • We are not particularly big or busy • We do care about our data (and jobs!) • People are expensive • Incidents are expensive and disruptive • Reliability is important, up to a point. • KISS. Over-engineering usually comes with high maintenance costs.
- 10. Lessons Learned • Only change things you absolutely need. • vm.dirty_bytes and vm.dirty_background_bytes • Autovacuum is usually just fine (but give it more maintenance memory) • Iptables and pg_hba.conf. Only allow specific ip’s access to your database servers. • To pool or not to pool? • Omnipitr is your friend
- 12. Monitoring • CPU • RAM • Disk • Presence of postgresql process • Backups (including temporary space) • Replication status • Long running queries • ?
- 13. Load Replication ideas / procedure TEST / UAT environments never see the same level of traffic as production. 1. Query pg_stat_activity on a schedule 2. Get a sampling of all the queries being run (caveats) 3. Generate statistics on the data (order by times a given query was run) 4. Create a pgbench script to be used against your test / uat. 5. include write queries as well as read for better testing.
- 14. 0 20 40 60 80 100 120 140 160 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 Average tps, 500 users, Read/write workload on SSD, 50 GB DB. Average tps Example performance run
- 15. Upgrading Option 1: pg_upgrade: • ~ 24 hours to perform upgrade – not acceptable Option 2: Dump / restore • time pg_dump -p 5434 -Fc moodle > moodle.dump (9m 30 sec) • time pg_restore -C -e -j 4 -v -d postgres moodle.dump (131 m) Option 3: Upgrade standby and setup replication? • Needs testing
- 16. Challenges moving into hosting a multi-tenant environment. • Identifying problem queries and clients • Isolating problem clients (limiting cpu / ram) • Generating client usage reports • Better upgrade procedure • Minimizing maintenance tasks – setting up schedules for test / uat.
- 17. Challenges moving into hosting a multi-tenant environment. • Identifying problem queries and clients • Isolating problem clients (limiting cpu / ram, disk) • Generating client usage reports • Migrating from other systems? Oracle? SQL Server? MySQL?
- 18. Closing notes • Slides, documentation and scripts available at http://www.ualberta.ca/~dostatni/pgcon2013 • Please contact me if you have any questions. I am happy to help – [email protected] • Questions?