Skip to content

[Durable Objects] Adding warning for calling setAlarm from inside the constructor #22746

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jun 4, 2025
Merged

[Durable Objects] Adding warning for calling setAlarm from inside the constructor #22746

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
dfb4112
Adding warning for calling setAlarm from inside
Oxyjun May 29, 2025
655025a
Clarification of wording
Oxyjun May 29, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 6 additions & 0 deletions src/content/docs/durable-objects/api/alarms.mdx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,12 @@ Alarms can be used to build distributed primitives, like queues or batching of w
- Set the time for the alarm to run. Specify the time as the number of milliseconds elapsed since the UNIX epoch.
- If you call `setAlarm` when there is already one scheduled, it will override the existing alarm.

:::caution[Calling `setAlarm` inside the constructor]
If you wish to call `setAlarm` inside the constructor of a Durable Object, ensure that you are first checking whether an alarm has already been set.

This is due to the fact that, if the Durable Object wakes up after being inactive, the constructor is invoked before the [`alarm` handler](/durable-objects/api/alarms/#alarm). Therefore, if the constructor calls `setAlarm`, it could interfere with the next alarm which has already been set.
:::

### `deleteAlarm`

- `deleteAlarm()`: <Type text='void' />
Expand Down
Loading