MySQL HA Percona cluster @ MySQL meetup Mumbai
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The document discusses MySQL High Availability (HA) solutions, focusing on the Percona Cluster and Galera technology. It outlines the principles of distributed computing, features of Galera such as synchronous and parallel replication, as well as node recovery methods. Additionally, it highlights the importance of avoiding single points of failure and ensuring site reliability through various replication strategies.
MySQL HA Percona cluster @ MySQL meetup Mumbai
- 1. 1 MySQL HA Solution - Percona Cluster
- 2. Agenda • Need for HA • Principle of Distributed computing. • MySQL HA Solutions Available. • Introduction to Galera. • Percona Cluster. • Node Recovery. • Things to be considered. 2
- 3. 3 • Senior MySQL DBA Yahoo! • Focus MySQL HA and Sharding • MySQL Experience 4 Years • Student MS ( FOSS ) MIT • Blogger remotemysqldba.blogspot.in About Myself : P.R.KarthiK
- 4. Need For HA • Site Reliability • Failover • Disaster Recovery • Scheduled / Unscheduled downtime. • Avoid Single Point Failure 4
- 5. Principle of Distributed Computing CAP Theorem 5
- 6. Principle of Distributed Computing CAP Theorem •Only Two out of three AP – MySQL Replication CA – Galera Cluster 6
- 7. MySQL HA Solutions Available • Master – Slave • Master – Master • Single Writer • NDB Cluster ( MySQL ) • Galera Cluster • Tungsten Replicator • Storage Level Replication ( DRDB) 7
- 8. Introduction To Galera • Founded By Codership • Synchronous Replication • Parallel Replication • Multi-Threaded • Automated node recovery • Zero slave lag • Read/ Write Scalable • WAN Based Optimization. • A True Open Source. 8
- 9. Introduction To Galera What is Galera ? Galera is a replication plugin for the synchronous and multi-master replication to achieve HA. “Wsrep_provider_options” controls library. Percona Cluster MariaDB Cluster Used over MySQL 9
- 10. Introduction To Galera • Shared nothing Architecture. • Network is the heart. What is wsrep ? (Write Set REPlication ) It is an API to connect the Galera library and control characteristics. It helps to implement synchronous replication and certification based multi-master- replication. 10
- 11. Introduction To Galera Simple Architecture 11
- 12. Percona Cluster • Use Galera Library • XtraDB • Xtrabackup + + 12
- 13. Percona Cluster Why Percona Server ? •Enhanced InnoDB (XtraDB ) •Performance Improvement •Xtrabackup ( Makes SST better ) •A better MySQL 13
- 14. Transaction in Galera. • Transaction is handled by Galera Plugin. • Uses traditional dual phase commit. • It also handles locking. • Uses the optimistic locking method. • The commits are based on certifications (keys). • Smaller transaction are always better. • Increase in network latency increases query time. 14
- 16. Transaction in Galera. • Synchronous ( Virtual ) Replication. • Wsrep_causal_reads=ON ( true synchronous) • Auto_increment is handled by cluster. • Uses GTID for Transaction. 16
- 17. Node Recovery 17 • Node recovery is automated. • Validates the gcache for state files. • Chooses the State Transfer method 1) IST (Incremental State Transfer) 2)SST (State Snapshot Transfer )
- 18. Node Recovery 18 IST : •Recover from write sets in gcache. •Faster recovery method. •Have good gcache size.
- 19. Node Recovery 19 SST : State Snapshot Transfer the complete transfer ( Cloning ) of data to recreate a node. *when not in Gcache *Adding a new node Different Methods of SST Xtrabackup (best ) , rsync , mysqldump .
- 20. Node Recovery 20 Validate Node after recovery Wsrep_local_state_Comment 1)Joining 2)Donor/desynced 3)Joined 4)Synced
- 21. Things should be considered. 21 • Support only Transactional engines. • Row Based replication. • Read commited Isolation. • Innodb_autoinc_lock_mode=2. • Avoid huge transactions. • Wsrep_max_ws_rows (128K) • Wsrep_max_ws_size. (1G) • Network is the heart. • Keep the DB design simple
- 22. IMAGE Courtesy •Galera and Percona cluster documentation •http://opentodo.net/2012/12/mysql-multi-master- replication-with-galera/ 22