IL-0551 Atlassian · 2025-05-08database
Bitbucket Cloud's overloaded primary database failed over, and the website, API and Pipelines were slow for almost a day
On 8 May 2025 a high-scale backfill job run by an internal Atlassian service put excessive load on certain Bitbucket Cloud API endpoints. Those endpoints ran resource-intensive queries and operations against the primary database, the database became overloaded, and the website and API slowed down from 15:26 UTC. Monitoring caught the problem immediately, the backfill job was stopped, and the primary database failed over automatically, so Bitbucket services recovered within 15 minutes.
The failover did not end the incident. Services that depend on the database had built up a backlog of retries, and that extra load kept database performance down, with intermittent failures and latency on the website, the API and Bitbucket Pipelines. Engineers applied several measures to shed database load, and Bitbucket Cloud was fully operational at 11:19 UTC on 9 May. Atlassian's testing had not caught the problem because it came from this particular high-scale backfill job and the expensive queries it set off.
- Severity
- –
- Scope
- Bitbucket Cloud website, API and Bitbucket Pipelines: increased latency and intermittent failures from 15:26 UTC on 8 May to 11:19 UTC on 9 May 2025
- Users affected
- –
- Region
- –
- Time to detect
- –
- Time to resolve
- 19h 53m
Symptoms
At 15:26 UTC on 8 May 2025, the Bitbucket Cloud website and API became slow because the primary database was overloaded. Atlassian's real-time monitoring detected the problem at once.
The primary database failed over automatically, and Bitbucket services recovered within 15 minutes. After the failover, a backlog of retries from downstream services kept loading the database, and customers saw intermittent errors and slow responses on the website, the API and Bitbucket Pipelines until 11:19 UTC on 9 May.
Root cause
Root cause Capacity exhaustion
- Trigger
- A high-scale backfill job run by an internal Atlassian service sent a large volume of calls to certain Bitbucket API endpoints, which ran expensive queries against the primary database.
Detection
Atlassian's real-time monitoring detected the incident as soon as it started.
Remediation
- Stopped the high-intensity backfill job
- Primary database failed over automatically, and Bitbucket services recovered within 15 minutes
- Applied several measures after the failover to shed database load
Action items
- Route more reads to read replicas instead of the write primary database
- Adjust rate limits for internal API endpoints that run resource-intensive database operations
- Optimise database queries so they run more efficiently
- Tune the retry policies of downstream services
Lessons
–
Sources
- https://bitbucket.status.atlassian.com/incidents/z1lk6hmkp9gt · official-status
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