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If you use Oracle MySQL or Percona Server, I would recommend to try group replication[1], no third-party software required. MariaDB can use something similar c

If you use Oracle MySQL or Percona Server, I would recommend to try group replication[1], no third-party software required. MariaDB can use something similar called Galera Cluster. Percona also has its own version, called Percona XtraCluster (PXC). For more traditional MySQL/MariaDB replication typologies, Orchestrator[2] is a great tool. For postgres, I have heard a lot of good words about Patroni[3], although I never used it myself. [1]: https://dev.mysql.com/doc/refman/8.0/en/group-replication.html https://dev.mysql.com/doc/refman/8.0/en/group-replication.ht... [2]: https://github.com/openark/orchestrator https://github.com/openark/orchestrator [3]: https://github.com/zalando/patroni https://github.com/zalando/patroni

hu3 5y ago
Hi! I'm interested in scaling MariaDb with active-active replicas. They call it ring replication: https://mariadb.com/kb/en/replication-overview/ https://mariadb.com/kb/en/replication-overview/ I would appreciate any comments. Specially on the upsides and downsides.
- ericyan 5y ago
  That's a footgun. For ring replication to work, it requires all replication sources (aka. "masters") to be online at all times. This never happens in real life, so it is just a matter of time that you get a nasty split-brain. Star replication tries to mitigate this by a crazy setup with replication filters that is painful to maintain and probably will break after some DDL statements. Moreover, neither of these can handle conflicts. If a row gets updated on different hosts at the same time, you will get broken replication and/or split-brain. To scale writes, sharding is usually the way to go and Vitess can be handy for that. By the way, MySQL group replication has multi-primary mode that is safer. Galera Cluster/PXC probably has something similar but I am not completely sure.
  - samlambert 5y ago
    This.
  - hu3 5y ago
    Thank you! I'll be looking into Galera then.

hu3 5y ago

Hi! I'm interested in scaling MariaDb with active-active replicas. They call it ring replication: https://mariadb.com/kb/en/replication-overview/ https://mariadb.com/kb/en/replication-overview/ I would appreciate any comments. Specially on the upsides and downsides.

ericyan 5y ago
That's a footgun. For ring replication to work, it requires all replication sources (aka. "masters") to be online at all times. This never happens in real life, so it is just a matter of time that you get a nasty split-brain. Star replication tries to mitigate this by a crazy setup with replication filters that is painful to maintain and probably will break after some DDL statements. Moreover, neither of these can handle conflicts. If a row gets updated on different hosts at the same time, you will get broken replication and/or split-brain. To scale writes, sharding is usually the way to go and Vitess can be handy for that. By the way, MySQL group replication has multi-primary mode that is safer. Galera Cluster/PXC probably has something similar but I am not completely sure.
- samlambert 5y ago
  This.
- hu3 5y ago
  Thank you! I'll be looking into Galera then.