Heroku Postgres Maintenance Windows

Last updated 21 March 2017

From time to time, Heroku must take your database offline to perform maintenance tasks. Typical tasks include upgrading the underlying infrastructure of the database (for example, patching the operating system or required libraries) or upgrading Postgres itself. This maintenance is handled automatically by Heroku.

Checking if maintenance is required for your database

You can check if maintenance is required on a database by using pg:info.

$ heroku pg:info
Plan:           Standard 4
Status:         Available
Data Size:      26.1 MB
...
Maintenance:    required by 2014-02-01 00:00:00 +0000

Setting a maintenance window

Some database plans support maintenance windows that can be set. Users can specify the day-of-week and time (UTC) at which the maintenance will occur:

$ heroku pg:maintenance:window DATABASE "Sunday 14:30"

Setting a maintenance window allows you to minimize the impact on your application and users. We recommend selecting a time during which maintenance would have the least impact on your business. Maintenance windows are 4 hours long starting at the time you specify. The actual time required for maintenance depends on exactly what’s taking place, but it will usually require your database to be offline for only a few minutes.

Running a maintenance

For databases that support a maintenance window and have a maintenance that needs to occur, that maintenance can be run prior to the maintenance window. This will allow for the maintenance to occur on a time frame that you prefer if it happens to be outside the maintenance window.

Putting application in maintenance mode

$ heroku maintenance:on -a sushi
Enabling maintenance mode for ⬢ sushi... done

$ heroku pg:maintenance:run DATABASE -a sushi
Starting maintenance for postgresql-clean-29349... done

$ heroku maintenance:off -a sushi
Disabling maintenance mode for ⬢ sushi... done

Forcing a maintenance

Forcing a maintenance is an action that should be used with extreme caution. If the maintenance were to require some down time, your application could see errors from being unable to connect to the database.

$ heroku pg:maintenance:run DATABASE --force -a sushi

Limitations

Maintenance windows that can be set and manual maintenance runs are only available on standard, premium and enterprise plans.

Heroku will make the best effort to honor your maintenance window request but it is not guaranteed. If there is an emergency where the security or integrity of your data is threatened, we may perform the maintenance outside of your regular window at our discretion.