Juttle InfluxDB Adapter

InfluxDB adapter for the Juttle data flow language, with read & write support.

Currently supports InfluxDB 0.9 and 0.10.

Examples

Read entries from the cpu measurement where the host tag is www123:

read influx -db 'test' name='cpu' host='www123' | view text

Perform an equivalent query using the -raw option:

read influx -db 'test' -raw "SELECT * FROM cpu where host='www123' | view text

Write a single point into the cpu measurement:

emit -points [{ value: 0.01, host: 'www123', name: 'cpu' }] | write influx -db 'test'

An end-to-end example is described here and deployed to the demo system demo.juttle.io.

Installation

Like Juttle itself, the adapter is installed as a npm package. Both Juttle and the adapter need to be installed side-by-side:

$ npm install juttle
$ npm install juttle-influx-adapter

Configuration

The adapter needs to be registered and configured so that it can be used from within Juttle. To do so, add the following to your ~/.juttle/config.json file:

{
    "adapters": {
        "influx": {
            "url": "http://localhost:8086/"
        }
    }
}

The URL in the url key should point to the API url of your InfluxDB instance.

Authentication

Influx adapter supports HTTP basic authentication. To use it, modify the url key to include the username and password:

{
    "adapters": {
        "influx": {
            "url": "http://username:password@localhost:8086/"
        }
    }
}

Usage

Read options

When reading data, most of the InfluxQL SELECT syntax is expressible through Juttle filter expressions.

Alternatively, raw queries are also available as a fallback.

Name	Type	Required	Description
db	string	yes	database to use
raw	string	no	send a raw InfluxQL query to InfluxDB
fields	string	no	fields to select from the measurement (default: all)
nameField	string	no	if specified, measurement name will be saved in a point field with this name (default: 'name')
from	moment	no	select points after this time (inclusive)
to	moment	no	select points before this time (exclusive)

The filter expressions can be placed after the above options in read influx. Supported filters are:

• fieldname = value for both tags and field values (also, !=, and </> for numbers)
• fieldname ~ '*glob*' wildcard matching (also, !~) for string fields
• fieldname =~ /regex/ regex matching (also, !~) for string fields
• fieldname in [v1, v2] array inclusion
• combining filter expressions with AND, OR, NOT

Influx adapter does not support full text search, or nullness checks.

Write options

Name	Type	Required	Description
db	string	yes	database to use
intFields	array	no	lists fields to be stored as integers instead of floats (default: none)
valFields	array	no	lists fields to be stored as values instead of tags (default: all non-string fields)
nameField	string	no	points will be checked for this field and its value will be used as the measurement name (default: 'name')

Note: when storing points, the following conventions are used:

1. All fields whose values are strings are treated as tags. and all fields with numeric types are treated as fields. You can override this behavior using the valueFields option. For example, ... | write influx -valueFields 'foo', 'bar' will treat foo and bar as fields, not tags.

2. InfluxDB distinguishes between integers and floating point numeric types. By default, the adapter stores all numeric fields as floats. This can be changed by enumerating integer fields via intFields option.

Optimizations

Whenever the influx adapter can shape the entire Juttle flowgraph or its portion into an InfluxDB query, it will do so, sending the execution to InfluxDB, so only the matching data will come back into Juttle runtime. The portion of the program expressed in read influx is always executed as an InfluxDB query; the downstream Juttle processors may be optimized as well.

List of optimized operations:

• any filter expression as part of read influx (note: read influx | filter ... is not optimized)
• head or tail

Other operations such as reduce and sort are not currently optimized.

In case of unexpected behavior with optimized reads, add -optimize false option to read influx to disable optimizations, and kindly report the problem as a GitHub issue.

Contributing

Want to contribute? Awesome! Don’t hesitate to file an issue or open a pull request.