Principle:Apache Druid Spec Management Troubleshooting
| Knowledge Sources | |
|---|---|
| Domains | Streaming_Ingestion, Operations, Troubleshooting |
| Last Updated | 2026-02-10 00:00 GMT |
Overview
A supervisor spec versioning and troubleshooting principle that tracks configuration changes and enables comparison between supervisor spec versions.
Description
Spec Management and Troubleshooting provides version control for streaming supervisor specifications. When a supervisor spec is updated (via hot-swap), Druid retains the history of all previous versions. This enables:
- Version tracking: See all historical spec versions with ISO timestamps
- Diff comparison: Compare adjacent versions to identify exactly what changed
- Rollback understanding: Know what configuration was active during incidents
- Audit trail: Track who changed what and when
The history is accessible via the Supervisor action dialog's "History" tab and fetched from the Druid Supervisor history API endpoint.
Usage
Use this principle when troubleshooting streaming ingestion issues. Comparing the current spec with a previous working version can quickly identify misconfiguration. Also useful for audit and compliance purposes.
Theoretical Basis
Spec management follows a append-only version log pattern:
GET /druid/indexer/v1/supervisor/{id}/history?count=100
→ SupervisorHistoryEntry[] = [
{ version: ISO_timestamp, spec: IngestionSpec },
{ version: ISO_timestamp, spec: IngestionSpec },
...
]
Versions ordered newest-first
Diff computed client-side between adjacent entries