MTTR, mean time to resolution, is the average interval between an error first appearing in production and that error being marked fixed, measured across a set of items over a window of time.
MTTR = total resolution time across N items / N
Example
The average hides where the time goes, so split it into four intervals:
detection error occurs -> someone notices 14 min
triage someone notices -> item assigned 46 min
diagnosis item assigned -> root cause known 3h 20m
repair root cause known -> fix deployed 1h 05m
MTTR = 5h 25m
In this example, diagnosis takes 3 hours 20 minutes of the 5 hours 25 minutes, more than detection, triage, and repair combined. An MTTR number with no split tells you the total and nothing about which interval to attack.
One caution on the name: DORA replaced mean time to restore with failed deployment recovery time in its five software delivery metrics, and its guidance warns against treating any single metric as the one that matters. Track the distribution alongside the mean.
What Rollbar does about MTTR
Rollbar shortens the diagnosis interval by showing the stack trace with code context pulled from your repository, the telemetry timeline of what happened just before the error, and the session replay when one was captured, all on the same item page.
Rollbar closes the loop from the other end too. Put fixes rb#2 in a commit message and report the deploy, and Rollbar resolves the referenced item against the deployed revision. Rollbar Resolve goes further, taking a production error, reviewing the codebase, applying a change in an isolated environment, running your tests, and opening a pull request you review.
Related terms
See how Resolve fixes production errors.
Sources
- Rollbar Docs, Resolve via commits: https://docs.rollbar.com/docs/resolve-via-commits
- Rollbar Docs, Enable Code Context in a Traceback: https://docs.rollbar.com/docs/code-context
- Rollbar Docs, JavaScript Telemetry: https://docs.rollbar.com/docs/rollbarjs-telemetry
- DORA, DORA’s software delivery performance metrics: https://dora.dev/guides/dora-metrics-four-keys/
