The document discusses the implementation of configuration management (CM) for MariaDB Galera Clusters, emphasizing the need for modern orchestration capabilities that go beyond classical CM. It introduces tools like Ansible, SaltStack, and Puppet for automated provisioning, updating, and bootstrapping of cluster nodes, along with practical examples of Ansible playbooks. Additionally, it provides guidance on rolling updates and related operational tasks, with source links for further information.

1. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
CM for MariaDB Galera cluster

2. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
About Adfinis SyGroup
● OpenSource service provider for 15 years
● based in Switzerland (Bern/Basel/Zurich)
● Software development and System Engineering
● multiple partners in the OSS community

3. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Why Configuration Management
● automate and standardize configuration of services/servers
● Provisioning
● automate changes on services/servers
● Deployment / Orchestration
● Infrastructure as Code

4. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Classical CM is not enough
● used for provisioning
● can't handle node interdependencies
● can't handle states from other nodes
● no timed execution
We need more than configuration management!

5. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
What defines a modern CM
● Orchestration capabilities
● run commands on a set of hosts
● Configuration Management + Orchestration
● apply changes to a set of hosts in a defined manner
● defined manner is important for clusters!

6. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
CM for clusters
● Provision: initialize all hosts to a defined state
● install packages, add configuration
● Bootstrap: initialize the cluster
● run commands on specific hosts in specific order
● Update: update/reconfigure the cluster
● run commands on specific hosts in specific order

7. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Which tools can handle batches
● Ansible
● serial per playbook (numeric or percentage)
● from 2.0: execution strategies
● Saltstack
● batch-size as CLI option (numeric or percentage)
● from Boron: option in orchestrate runner
● Puppet Enterprise (MCollective)
● batch as CLI option (numeric or percentage)

8. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Quick Ansible introduction
● Agentless – tasks are executed via SSH
● Ad-Hoc commands
ansible webserver -m apt -a "name=nginx state=latest"
● Playbooks
ansible-playbook galera.yml
● powerful language for more complex tasks
● Playbooks contain tasks to be executed in order
● Tasks can notify handlers (e.g. reload configuration)
● Roles are used to structure complex playbooks

9. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Orchestration with Ansible
● batch size for rolling updates
● only update a number of hosts at a time
● maximum failure percentage
● stop after a percentage of hosts have failed
● delegation
● delegate a task to another node
● conditional execution
● only run a task under certain conditions

10. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
MariaDB Galera cluster with Ansible
● Playbooks for provisioning, bootstrap and rolling update
● Roles for
● package installation
● firewall
● MariaDB Galera configuration
● MariaDB privileges
● MariaDB Galera cluster bootstrapping
currently tested on RHEL/CentOS 7

11. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Provisioning
● open ports on the firewall
● add repositories (MariaDB, EPEL)
● install packages
● MariaDB Galera
● Percona Xtrabackup v2 (SST)
● configure MariaDB Galera

12. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Bootstrapping
● only two tasks in the playbook
● bootstrap MariaDB Galera cluster
– first node in group
● restart MariaDB and join cluster
– rest of group
● tasks run one node at a time (serial: 1)

13. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Bootstrapping
galera-db-01
service mysql bootstrap
galera-db-02
service mysql start
initialer SST
galera-db-03
service mysql start
initialer SST

14. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Rolling Update
● role galera_conf can also handle rolling updates
● variable bootstrapped: yes needs to be set
● enables restart handler
● serial set to 49%
● no loss of quorum
● execution strategies enable more advanced behaviour

15. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Rolling Update
galera-db-01
service mysql restart
galera-db-02
service mysql restart
galera-db-03
service mysql restart

16. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Demo
● Preparation
● Reset VM's
● git clone https://github.com/adfinis-sygroup/mariadb-ansible-galera-cluster
● Installing requirements
# ansible-playbook -i galera.hosts galera.yml --tags setup
● Configure MariaDB Galera cluster
# ansible-playbook -i galera.hosts galera.yml --skip-tags setup
● Bootstrapping MariaDB Galera cluster
# ansible-playbook -i galera.hosts galera_bootstrap.yml
● Rolling MariaDB Galera cluster updates
# ansible-playbook -i galera.hosts galera_rolling_update.yml

17. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Questions?

18. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Sources and Links
● Ansible - https://docs.ansible.com/ansible/
● SaltStack - https://docs.saltstack.com/
● Puppet - https://docs.puppetlabs.com/
● MariaDB Galera Cluster Ansible Playbook -
https://github.com/adfinis-sygroup/mariadb-ansible-galera-cluster
● Adfinis SyGroup - https://adfinis-sygroup.ch/

19. 30.11.2016 CM for MariaDB Galera Cluster 30.11.2016
Adfinis SyGroup AG
Lukas Grossar
@lukasgrossar
lukas.grossar@adfinis-sygroup.ch
Check out our techblog:
https://blog.adfinis-sygroup.ch/ https://git.io/vwPJ2