SkyWalking
Progressive TTL
Progressive TTL provides a capability to manage data retention with different TTL settings and Segment Creation Policies based on the time granularity of metrics.
BanyanDB employs a Time-To-Live (TTL) mechanism to automatically delete data older than the specified duration. When using BanyanDB as the storage backend, the recordDataTTL and metricsDataTTL configurations are deprecated. Instead, TTL settings should be configured directly within storage.banyandb.
For detailed information, please refer to the Storage BanyanDB documentation.
How TTL works in BanyanDB
BanyanDB uses time-based rotation with two key settings per group (and per stage, if enabled):
- segmentInterval (days): How often a new segment is created.
- ttl (days): How long data is retained before automatic deletion.
Some groups support progressive stages:
- hot (default stage, always present)
- warm (optional, used in the default query if present)
- cold (optional)
When warm/cold stages are enabled, data flows hot → warm → cold as it ages, each stage having its own ttl, segmentInterval, and placement (nodeSelector).
Default TTLs by kind (from bydb.yml)
Warm and Cold are disabled by default. The values listed for warm/cold apply if you enable those stages.
- ttl: retention (days) in the hot stage
- warm ttl / cold ttl: retention (days) in warm/cold stages
| Kind (group) | ttl | warm ttl | cold ttl |
|---|---|---|---|
| records | 3 | 7 | 30 |
| trace | 3 | 7 | 30 |
| zipkinTrace | 3 | 7 | 30 |
| recordsLog | 3 | 7 | 30 |
| recordsBrowserErrorLog | 3 | 7 | 30 |
| metricsMinute | 7 | 15 | 60 |
| metricsHour | 15 | 30 | 120 |
| metricsDay | 15 | 30 | 120 |
| metadata (index-mode) | 15 | — | — |
| property | — | — | — |
Notes:
- “—” = not specified in the default bydb.yml. Metadata don’t support warm/cold stages.
- Property kind does not have TTL because it uses a different KV-engine mechanism.
- The metadata group should have ttl greater than or equal to the maximum ttl of your metrics groups to ensure index coverage for retained data.
For more details on configuring segmentIntervalDays and ttlDays, refer to the BanyanDB Rotation documentation.