Retry and Backoff

Understand attempts, exponential backoff, and terminal failure handling.

How retries work

A delivery attempt fails when DispatchQ gets a non-2xx response, network error, or timeout. If attempts remain, the job returns to pending with next_retry_at.

Backoff formula

backoff_seconds = min(2^attempt * 10, 3600)

attempt is 1-based after each failed attempt.

Backoff table

Failed attempt	Delay before next try
1	20s
2	40s
3	80s
4	160s
5	320s
…	capped at 3600s

max_attempts

• Set per job (1 to 100, default 3).
• Once attempts are exhausted, job becomes failed.

Failure callbacks

If callback_url is set, DispatchQ sends a failure callback with status: failed and last_error when the job reaches terminal failure.

Monitoring retries

Use job reads/listing fields:

• retries_remaining: attempts left
• next_retry_in_seconds: countdown to next attempt
• last_error: most recent failure reason