# InfluxDB (0.9 and newer) Persistence

This service allows you to persist and query states using the InfluxDB and InfluxDB 2.0 time series database. The persisted values can be queried from within openHAB. There also are nice tools on the web for visualizing InfluxDB time series, such as Grafana and new Influx DB 2.0 version introduces powerful data processing features.

# Database Structure

  • This service allows you to persist and query states using the time series database.

  • The states of an item are persisted in measurements points with names equal to the name of the item, or the alias, if one is provided. In both variants, a tag named "item" is added, containing the item name. All values are stored in a field called "value" using the following types:

    • float for DecimalType and QuantityType
    • integer for OnOffType and OpenClosedType (values are stored using 0 or 1) and DateTimeType (milliseconds since 1970-01-01T00:00:00Z)
    • string for the rest of types
  • If configured, extra tags for item category, label or type can be added fore each point.

Some example entries for an item with the name "speedtest" without any further configuration would look like this:

> Query using Influx DB 2.0 syntax for 1.0 is different
> from(bucket: "default")
    |> range(start: -30d)
    |> filter(fn: (r) => r._measurement == "speedtest")
name: speedtest

_time               _item     _value
-----               -----     ------
1558302027124000000 speedtest 123289369.0
1558332852716000000 speedtest 80423789.0

# Prerequisites

First of all you have to setup and run an InfluxDB 1.X or 2.X server. This is very easy and you will find good documentation on it on the InfluxDB web site for 2.X version and InfluxDB web site for 1.X version.

# Configuration

Property Default Required Description
version V1 No InfluxDB database version V1 for 1.X and V2 for 2.x
url http://127.0.0.1:8086 No database URL
user openhab No name of the database user, e.g. openhab
password No(*) password of the database user you choose
token No(*) token to authenticate the database (only for V2) Intructions about how to create one
db openhab No name of the database for V1 and name of the organization for V2
retentionPolicy autogen No name of the retention policy for V1 and name of the bucket for V2

(*) For 1.X version you must provide user and password, for 2.X you can use also user and password or a token. That means that if you use all default values at minimum you must provide a password or a token.

All item- and event-related configuration is defined in the file persistence/influxdb.persist.