Talk will try to cover deployment of PostgreSQL inside of Kubernetes with accent on high availability.

1. DEPLOYMENT OF
POSTGRES IN KUBERNETES
WITH HIGH AVAILABILITY
BY ARMIN NESIREN

2. ABOUT
ME AND MY
COMPANY
■ Who is Armin Nesiren?
■ Who is CYBERTEC?

3. ARMIN NESIREN
Database engineer
● work on Postgresql HA since 8.3
● working for CYBERTEC since 2017
M A I L armin.nesiren@cybertec.at

4. DATABASE SERVICES
DATA Science
▪ Artificial Intelligence
▪ Machine Learning
▪ Big Data
▪ Business Intelligence
▪ Data Mining
▪ etc.
POSTGRESQL Services
▪ 24/7 Support
▪ Training
▪ Consulting
▪ Performance Tuning
▪ Clustering
▪ etc.

6. ▪ ICT
▪ University
▪ Government
▪ Automotive
▪ Industry
▪ Trade
▪ Finance
▪ etc.
CLIENT
SECTORS

7. WHY
PostgreSQL in
Kubernetes
Service oriented
architecture - SOA
Future of Kubernetes
Test it home - IT’S FREE
PostgreSQL available for
everyone, QUICKLY

8. WHAT I WILL
TALK ABOUT
● A little about containers and their role
● Containers managed by K8s
● (A little about) Kubernetes storages
● Deploying PostgreSQL inside kubernetes simple way *
● About K8s operators
● Deploying PostgreSQL automated with operator
● Handling failover & recovery
● Handling backups

9. CONTAINERS IN
GENERAL
● We love them because
○ they ‘cost’ us less
○ lightweight
○ standalone
○ they run the same on any env

10. CONTAINERS
IN KUBERNETES
● Kubernetes is dealing with containers
● Kubernetes helps you avoid downtime
● Service discovery and load balancing
● Storage orchestration
● Automated rollouts and rollbacks
● Self-healing
● Secret and configuration management

11. BARE METAL
VS PROVIDERS
● Providers
○ less stress but some limitations
● Bare metal
○ as low as 3-5 servers
○ storage options
○ exposing of services

12. K8s -
SIMPLE
ARCHITECTURE

13. HOW TO “TALK”
TO K8S
● kubectl
○ command line
○ via yaml
● Client library
○ Go, Python, Java, dotnet and more

14. YAML example

15. SIMPLE DEPLOYMENT OF
POSTGRESQL IN K8S
● define postgresql container and pass parameters
● it would be a long YAML to manage
● Pretty hard to configure
● Not easy to manipulate with clusters (update, delete…)
● Manual generation of DB objects after setup

16. WHAT IF THERE IS...
● … small docker image with just what we need
● Multiple versions of PostgreSQL inside one image
● Plenty of extensions (pg_partman, pg_cron, postgis…)
● Additional tools (pgq, pgbouncer, wal-e/wal-g)
● Environment-variables based configuration
● Light! ~120MB

17. AND WE WANT IT ALL...
● …. so we add Patroni
● Automatic failover solution for streaming replication
● A python daemon that manages one PostgreSQL instance
● Keeps the cluster state in DCS (etcd, zookeeper, consul)
○ Uses DCS for leader election
● Helps automate things like
○ new cluster deployment
○ scaling out and in
○ PostgreSQL configuration management

18. SPILO & PATRONI TOGETHER

19. POSTGRESQL TYPICAL
LIFECYCLE

20. KUBERNETES OPERATOR
● Encapsulates knowledge of a human operating the service
● Fully automated:
○ deployments
○ cluster upgrades
○ user management

21. Kubernetes operator
image source: container-solutions.com

22. ZALANDO OPERATOR
● Defines CDR (Postgresql)
● Watches instances, creates/updates/deletes
● Create DB objects, roles, passwords. . .
● Allows updating of resources (memory, cpu, volumes),
postgresql configuration
● Auto-repairs, smart rolling updates

23. POSTGRESQL MANIFEST

24. FINAL OPERATOR CHART

25. SCALE AND CONFIG
● Adding more nodes is easy
● as well as removing them
● Changing configuration is also easy
● It is all matter of changing Postgresql CDR
manifest

26. BACKUP
● Backup can be done multiple way
● Logical (pg_dump) or streaming (WAL-E or WAL-G)
● PITR available
● Restore is easy

27. DEMO