Worker and cache¶
Correlation worker and cache¶
Correlation calculation runs outside the normal render path. To avoid fully materializing long histories on every start, the worker may store a derived cache in the meta store.
flowchart LR
OLD[finalized older days] --> CACHE[derived daily-value cache]
NEW[last four editable days] --> RECALC[always recalculate]
CACHE --> ROWS[combined daily rows]
RECALC --> ROWS
ROWS --> COR[correlation analysis]
Important boundaries:
- Only days outside the four-day backfill window are reused.
- The cache signature includes metric definitions and labels; relevant configuration changes invalidate it.
- The cache contains only derived numeric daily values.
- Tracking data remains the sole source of truth.
- The cache is transient, is not backed up and is removed after a restore.
- When the evaluated time range changes, no rows outside the range are retained.