---
title: Internal time series databases
slug: reference/internal-time-series-databases
docTags: 
createdAt: 2025-09-05T11:20:15.121Z
---

`_internal_factry` is a time series database used to store historian and collector logs and statistics. This database gets configured during the “First time setup” after installing the historian. The database is initialized with a retention policy named `_internal_factry_rp` of 12 weeks which means that data older than 12 weeks is not kept.

## Logs

InfluxDB measurement: `logs`.

You can view these logs in the historian.

Only `message` is an InfluxDB field, plus `error` when the log entry carries one. Everything else below is a tag, which matters when querying: tags can be used in `GROUP BY` and are indexed, fields cannot.

**Common tags**

- application (2 options, reflects the type of the log)
  - historian-server
  - historian-collector
- level
- log\_type, derived from the entity the entry relates to: system, event, forwarder, measurement, collector, worker\_pool, timeseries\_database or organization

### Server logs

Logs from the historian server. They always carry the `version` and `build` tags. Which logs are stored are defined by the LOG\_LEVEL [environmental variable](docId\:sWKCAYy17F7TL9mntIDrj) .

Where possible server logs are linked to the relevant entity by a `<entity type>_uuid` tag; eg. `collector_uuid`, `measurement_uuid`, `event_configuration_uuid`,...

### Collector logs

Logs sent by the collectors. Which logs get sent depends on the [LogLevel](docId\:im-7Bhp1Lmte9WPvndn_Y) setting on the collector.

Extra tags:

- collector\_name
- collector\_type
- collector\_uuid
- measurement\_uuid
- version

## Statistics

InfluxDB measurement: `statistics`.

Statistics are written by both the historian server and the collectors, and the two write different field sets. Server points carry the tags `application` (value `historian`) and `version`. Collector points carry `collector_uuid`, `collector_name`, `collector_type` and `version`, and no `application` tag, so the two are told apart by the presence of the collector tags rather than by `application`.

Both producers write once per minute.

### System

The two producers write different fields, so not every field below is present on every point.

### Written by the historian server

- cpu\_usage (%): average over the last minute
- memory\_usage (%): the instantaneous used percentage at the last refresh, not an average
- system\_uptime (seconds)
- uptime (seconds): Uptime of the Historian
- points\_written: Points written per second, refreshed at most every 10 seconds
- cpu\_count: Amount of cpu’s on machine
- cpu\_load: Average cpu load
- memory\_total: Total available memory
- memory\_free: Available memory
- the cache\_\* fields described under [Memory cache](docId:0xToy0ZQv0HO4dhJB-JL4)

The server also writes one extra point per mounted filesystem, tagged with `mount_point`, carrying total\_disk\_space, free\_disk\_space, read\_count, write\_count, read\_bytes and write\_bytes. Free disk space is only reported on these per-mount points.

### Written by the collectors

- cpu\_usage (%)
- memory\_usage (%)
- free\_disk\_space (bytes): Free disk space of the drive the collector is installed on
- system\_uptime (seconds)

### Collector

- collector\_name
- collector\_type
- collector\_uuid
- collector\_uptime (seconds)
- version
- bad\_points: amount per minute
- good\_points: amount per minute
- points\_sent: amount per minute

### Buffer

- buffer\_current\_size: amount of items held in memory across all five collector buffers (logs, statistics, points, measurements and health), not points alone
- buffer\_error\_files: amount of invalid buffer files
- buffer\_disk\_flushes: amount of disk flushes since last statistics update