AWN-194549

en/google/compute/disk-multiaz.md

@@ -0,0 +1,31 @@
+[![CloudSploit](https://cloudsploit.com/img/logo-new-big-text-100.png "CloudSploit")](https://cloudsploit.com)
+
+# GOOGLE / Compute / Disk MultiAz
+
+## Quick Info
+
+| | |
+|-|-|
+| **Plugin Title** | Disk MultiAz |
+| **Cloud** | GOOGLE |
+| **Category** | Compute |
+| **Description** | Building HA database services using regional persistent disks |
+| **More Info** | You can use regional persistent disks (PDs) to build high availability (HA) services. |
+| **GOOGLE Link** | https://cloud.google.com/compute/docs/disks/high-availability-regional-persistent-disk |
+| **Recommended Action** | Build HA solutions for stateful database services. |
+
+## Detailed Remediation Steps
+This section covers high level concepts for building HA solutions for stateful database services (MySQL, Postgres, etc.) using regional persistent disks and Compute Engine.
+
+If there are broad outages in Google Cloud, for example, if a whole region becomes unavailable, your application might become unavailable. Depending on your needs, consider [cross-regional replication techniques](https://cloud.google.com/architecture/disaster-recovery#how_to_leverage_zones_and_regions_to_achieve_reliability) for even higher availability.
+
+Database HA configurations typically have at least two VM instances. Preferably these instances are part of one or more [managed instance groups](https://cloud.google.com/compute/docs/instance-groups/creating-groups-of-managed-instances):
+
+-   A primary VM instance in the primary zone
+-   A standby VM instance in a secondary zone
+
+A primary VM instance has at least two persistent disks: a boot disk, and a regional persistent disk. The regional persistent disk contains database data and any other mutable data that should be preserved to another zone in case of an outage.
+
+A standby VM instance requires a separate boot disk to be able to recover from configuration-related outages, which could result from an operating system upgrade, for example. You cannot force attach a boot disk to another VM during a failover.
+
+The primary and standby VM instances are configured to use a load balancer with the traffic directed to the primary VM based on health check signals. This configuration is also known as a hot standby. The [disaster recovery scenario for data](https://cloud.google.com/solutions/dr-scenarios-for-data) outlines other failover configurations, which might be more appropriate for your scenario.