| # Data Lifecycle. Time To Live (TTL) |
| Time To Live (TTL) is a mechanism to automatically delete data that is older than the specified time. |
| |
| In SkyWalking, there are two types of observability data: |
| 1. Records include traces, logs, topN sampled statements and alarm. `recordDataTTL` applies to **record** data. |
| 1. Metrics include all metrics for service, instance, endpoint, and topology map. Metadata(lists of services, instances, or endpoints) also belongs to metrics. `metricsDataTTL` applies to **Metrics** data. |
| |
| These are the settings for the different types: |
| ```yaml |
| # Set a timeout on metrics data. After the timeout has expired, the metrics data will automatically be deleted. |
| recordDataTTL: ${SW_CORE_RECORD_DATA_TTL:3} # Unit is day |
| metricsDataTTL: ${SW_CORE_METRICS_DATA_TTL:7} # Unit is day |
| ``` |
| |
| ## BanyanDB TTL |
| |
| BanyanDB has a TTL mechanism to automatically delete data that is older than the specified time. When you use BanyanDB |
| as the storage backend, `recordDataTTL` and `metricsDataTTL` are not used. Instead, you should configure the TTL |
| settings in `storage.banyandb`. |
| |
| Please refer to the [Storage BanyanDB](storages/banyandb.md) and [BanyanDB's Progressive TTL](../../banyandb/ttl.md) |
| documents for more information. |
