Galera Availability

Overview

The following availability details pertain to SkySQL's MariaDB Platform for Transactions in a Galera topology.

MariaDB Platform for Transactions in a Galera topology offers horizontal read scaling for transactional workloads.

Read Scaling with MariaDB Enterprise Cluster

MariaDB Platform for Transactions in a Galera topology uses MariaDB Enterprise Cluster, which provides high availability for transactional workloads:

  • Uses the InnoDB storage engine to store data

  • Replicates InnoDB data between nodes using virtually synchronous, certificated-based replication

  • When the primary node fails, failover occurs automatically

MariaDB Enterprise Cluster refers to the combination of MariaDB Enterprise Server with Galera Cluster.

Automatic Failover with MariaDB MaxScale

MariaDB Platform for Transactions in a Galera topology uses MariaDB MaxScale for automatic failover.

MaxScale's Galera Monitor (galeramon) provides automatic failover:

  • MaxScale's Galera Monitor continuously checks the status of all nodes.

  • If the current primary node fails, MaxScale chooses another node to be the new primary.

SkySQL also provides failover for MaxScale itself:

  • If the MaxScale instance fails, it is restarted or replaced, depending on the specific issue.

  • If one an instance fails, it is restarted or replaced, depending on the specific issue.

Redundant MaxScale instances are also supported as optional configuration option. For additional information, see "MaxScale Redundancy".

Google Infrastructure

MariaDB SkySQL services on GCP rely on Google Kubernetes Engine (GKE), which is a component of Google Cloud Platform (GCP). MariaDB SkySQL inherits many availability features from GKE and GCP:

  • The resiliency of regional GKE Kubernetes clusters which include multiple zones within a region.

  • The auto-healing functionality of Kubernetes.

  • Google's goal to have 99.5% up-time, as mentioned in the SLA for GKE.

Powered by Kubernetes

MariaDB SkySQL services run in containers powered by Kubernetes. MariaDB SkySQL inherits many availability features from Kubernetes' self-healing functionality:

  • Failed containers are automatically restarted.

  • Unhealthy containers are automatically killed.

  • Dead containers are automatically replaced.

  • All of this happens in a way that is transparent to the user.

  • If the MaxScale instance fails it is restarted or replaced, depending on the specific issue.

  • If one of the MariaDB Enterprise Server instances fails, it is restarted or replaced, depending on the specific issue.

Production Readiness

MariaDB Platform for Transactions in a Galera topology is designed for resiliency. It is built on MariaDB Enterprise Server with Galera Cluster, which provides certification-based replication and High Availability (HA) with the InnoDB storage engine.