01 - InfluxDB: First Steps and Guide-Lines

InfluxLine Protocol

InfluxDB line protocol is a text based format for writing points to InfluxDB.

Syntax

<measurement>,<tag_key>=<tag_value>,<tag_key>=<tag_value> <field_key>=<field_value>,<field_key>=<field_value> <timestamp>

The whitespace between the tags and the fields are required!

Example:

win_process_usage,ProcessName=ClusSvc,ID=1333 Handles=200,PagedmemorySize=102400,CPU=7

Measurement = win_process_usace
Tags = ProcessName, ID
Fields = Handles, PagedmemorySize, CPU

Syntax description

Element	Optional/Required	Description	Type
Measurement	Required	The measurement name. InfluxDB accepts one measurement per point.	String
Tag set	Optional	All tag key-value pairs for the point.	Tag keys and tag values are both strings.
Field set	Required. Points must have at least one field.	All field key-value pairs for the point.	Field keys are strings. Field values can be floats, integers, strings, or Booleans.
Timestamp	Optional. InfluxDB uses the server’s local nanosecond timestamp in UTC if the timestamp is not included with the point.	The timestamp for the data point. InfluxDB accepts one timestamp per point.	Unix nanosecond timestamp. Specify alternative precisions with the InfluxDB API.

PowerShell-Example to write metrics directly to an InfluxDB v1.x

Invoke-WebRequest 'http://<your_InfluxDB_server>:8086/write?db=<yourdb>' -Method POST -Body 'test_measurement_cpu,host=server01,os=windows cpuload=33 1587646932000000000'

If the response statuscode is 204 this means, it was a success!
The Timestamp is optional. (1587646932000000000 means 23. April 2020, 14:02:12.)

PowerShell-Example to write metrics directly to an InfluxDB v2.x

$Header = @{Authorization = "Token <YOUR_AUTH_TOKEN>"}
Invoke-WebRequest -Uri 'http://<your_InfluxDB_server>:8086/api/v2/write?org=<INFLUX_YOUR_ORG>&bucket=<YOUR_BUCKET>' -Header $Header -Method POST -Body 'test_measurement_cpu,host=server01,os=windows cpuload=33 1587646932000000000'

If the response statuscode is 204 this means, it was a success!
The Timestamp is optional. (1587646932000000000 means 23. April 2020, 14:02:12.)

PowerShell-Example to write metrics with the Telegraf Agent to an InfluxDB

Telegraf configuration name "inputs.exec.process.conf"

 [[inputs.exec]]
 commands = ['powershell -NoProfile -file "C:\Program Files\Telegraf\scripts\input.process.ps1"']
 timeout = "1m"
 data_format = "influx" 

PowerShell-Skript named "input.process.ps1"

$Processes = Get-Process -Name * | Select-Object ProcessName, Id, Handles, PagedmemorySize, CPU
 
ForEach ($Process in $Processes) {
    Write-Output "win_process_usage,ProcessName=$($Process.ProcessName) ID=$($Process.Id),Handles=$($Process.Handles),PagedmemorySize=$($Process.PagedmemorySize),CPU=$($Process.CPU)"
}

Testing the Telegraf configuration and the PowerShell script

telegraf.exe --config "C:\Program Files\Telegraf\telegraf.d\inputs.exec.process.conf" --test

More informations: https://docs.influxdata.com/influxdb/v1.8/write_protocols/line_protocol_reference/

Useful Queries / Snippets

Count unique tag values

// Count unique values for each tag in a bucket
import "influxdata/influxdb/schema"

cardinalityByTag = (bucket) =>
  schema.tagKeys(bucket: bucket)
    |> map(fn: (r) => ({
      tag: r._value,
      _value:
        if contains(set: ["_stop","_start"], value:r._value) then 0
        else (schema.tagValues(bucket: bucket, tag: r._value)
          |> count()
          |> findRecord(fn: (key) => true, idx: 0))._value
    }))
    |> group(columns:["tag"])
    |> sum()

cardinalityByTag(bucket: "<YOUR_BUCKET>")

Time (Docs: https://www.influxdata.com/blog/tldr-tech-tips-flux-timestamps)

Convert function "now" to Epoche Timestamp (Unix) in ns

uint(v: now())
// Returns 1568808000000000000

Convert Epoche Timestamp (Unix) to ISO Format (RFC3339)

uint(v: 1568808000000000000)
// Returns 2019-09-18T12:00:00.000000000Z

Find letters in _value

from(bucket: "<YOUR_BUCKET>")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r._value =~ /\d/)