Telegraf: CSV parser includes csv_measurement_name as a field

[shantanoo-desai]

Relevant telegraf.conf:

[agent]
  interval = "1m"
  round_interval = true
  metric_batch_size = 5000
  metric_buffer_limit = 5000000
  # collection_jitter = "0s"
  # flush_interval = "10s"
  # flush_jitter = "0s"
  precision = "us"
  debug = true
  quiet = false
  logfile = ""
  hostname = ""
  omit_hostname = true

[[outputs.influxdb]]

  urls = ["http://localhost:8086"]
  database = "pressure"
  skip_database_creation = false
  ## Timeout for HTTP messages.
  timeout = "10s"

[[inputs.file]]

  ## Files to parse each interval.
  files = ["../datasets/data/PressureSensor1.csv"]

  data_format = "csv"
  csv_header_row_count = 1
  csv_skip_columns = 0
  csv_measurement_column = "measurement_name"
  csv_field_columns = ["damage", "value", "warning"]
  csv_tag_columns = ["description", "datatype"]
  csv_timestamp_column = "time"
  csv_timestamp_format = "unix_us"

System info:

__Telegraf Version__: Telegraf 1.13.4 (git: HEAD ffabd6b5)
__OS__: Windows 10

Steps to reproduce:

1. I have a csv file as the following:

    measurement_name,description,datatype,damage,value,warning,time
    Machine,Left,pressure,130.0,203.0,230.0,1581677425059610
   

2. On Windows within the telegraf directory:

    telegraf.exe --config .\csvconfig.conf
   

Expected behavior:

In chronograf

when the measurement Machine is clicked the fields should be:

damage, value, warning

Actual behavior:

Event though the fields are specifically mentioned in the array (e.g. ["damage", "value", "warning"])

Based on InfluxData's Blog about Write Points from CSV.

Additional info:

I have tried adding skip_csv_columns=1 to skip the measurment_name but that still add it as a field.

[danielnelson]

The csv_field_columns doesn't appear to be a supported option, we actually should be producing an error when it is set. I believe we may be accepting this option as a leftover bit of code from development, but the option is not hooked up and does nothing. We ought to clean up any documentation that references it, where did you learn about this option?

I do think the plugin should exclude the csv_measurement_column and csv_timestamp_column columns from the fields. We may need to add options to preserve backwards compatiblity, or perhaps this is enough like a bug to just change.

As a workaround you should be able to use fielddrop to remove these columns:
```
[[inputs.file]]
## Files to parse each interval.
files = ["../datasets/data/PressureSensor1.csv"]

data_format = "csv"
csv_header_row_count = 1
csv_skip_columns = 0
csv_measurement_column = "measurement_name"
csv_field_columns = ["damage", "value", "warning"]
csv_tag_columns = ["description", "datatype"]
csv_timestamp_column = "time"
csv_timestamp_format = "unix_us"
fielddrop = ["measurement_name"]

[shantanoo-desai]

@danielnelson As a quick hack I tried fielddrop but then the measurement is turned to file as opposed to what it needs to be. However checking it now.

Also I believe I might be barking up the wrong tree. Is tail a better option for inserting historical data set in csv format?

[shantanoo-desai]

Okay you are right fielddrop=["measurement_name"] worked for me.

[danielnelson]

Is tail a better option for inserting historical data set in csv format?

Yes, you will want to set from_beginning = true, because tail will process the file once while the file input will attempt to reprocess it every interval.

One thing to keep in mind for historical data is that currently the tail plugin will attempt to process as fast as it can, and for large files it will quickly outpace the output plugin, fill the metric buffer, and metrics can be dropped.

[HarshitOnGitHub]

@danielnelson Willing to pick this up next, can you assign me? :)