Maintenance Windows
Maintenance windows are used to perform necessary updates and upgrades regarding security and management layers of your Exoscale DBaaS services. They are not used to perform major service version upgrades, refer to the section upgrades on how to upgrade versions.
NOTE
Urgent upgrades including vulnerability updates will happen before the maintenance window in order to keep the services safe.
By default, an arbitrary slot will be assigned when creating your service. You can control the weekly maintenance window of each service to ensure maintenance occurs during a window with lower traffic levels.
Changing the Maintenance Window of a Service
To adapt the maintenance window of a service, you need to pass
a new day of week and associated time with the update command
exo dbaas update -z de-fra-1 test-pg --maintenance-dow=tuesday --maintenance-time=10:10:10
Updating Database Service "test-pg"...
┼───────────────────────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼
│ DATABASE SERVICE │ │
┼───────────────────────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼
│ Zone │ de-fra-1 │
│ Name │ test-pg │
│ Type │ pg │
│ Plan │ hobbyist-1 │
│ Disk Size │ 8.0 GiB │
│ State │ running │
│ Creation Date │ 2021-10-21 08:42:40 +0000 UTC │
│ Update Date │ 2021-11-01 09:25:27 +0000 UTC │
│ Nodes │ 1 │
│ Node CPUs │ 2 │
│ Node Memory │ 2.0 GiB │
│ Termination Protected │ true │
│ Maintenance │ tuesday (10:10:10) │
│ Backup Schedule │ 20:28 │
│ URI │ postgres://avnadmin:xxxxx@test-pg-exoscale-08b0165e-ef03-47ec-926f-f01163d557ed.aivencloud.com:21699/defaultdb?sslmode=require │
│ IP Filter │ 0.0.0.0/0 │
│ Components │ │
│ │ pg test-pg-exoscale-08b0165e-ef03-47ec-926f-f01163d557ed.aivencloud.com:21699 route:dynamic usage:primary │
│ │ pgbouncer test-pg-exoscale-08b0165e-ef03-47ec-926f-f01163d557ed.aivencloud.com:21700 route:dynamic usage:primary │
│ │ │
│ Users │ avnadmin (primary) │
┼───────────────────────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼The maintenance window can also be specified at creation time with the same parameters.
This parameter can also be checked and adjusted within the Portal
under the maintenance tab of a service. The same tab also lists
the upcoming updates to be applied at the next scheduled maintenance
or manually within the page.
How Maintenance and Upgrades Work
Upgrades are performed as rolling upgrades where completely new instances are built alongside the old ones. After the new instances are running and synced with the old instances, a controlled automatic failover is performed to switch the service to use the new upgraded instances. The old servers are retired automatically after the new instances have taken over for providing the service.
The controlled failover is very quick and safe - it takes less than a minute to get clients connected again. Typically, we see a 5-10 second period during which the clients are unable to re-establish the connection. Single node plans will however see a longer downtime.
Best practices for client configuration:
- Do not cache IP addresses of services.
- Make sure your client can automatically reconnect to a service.
- Make sure the DNS name of a service stays the same after the upgrade.