redpanda-data / redpanda-data/benthos

metric processor: `Handler error: value … is negative`

Open
#339 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Go
Stars
571
Forks
120
Avg merge
2d 1h
Merged PRs (30d)
18

Description

      metric:
        name: indicator
        type: gauge
        labels:
          indicator_name: ${! json("indicator") }
        value: ${! json("value") }

The above processor gives me errors like: Handler error: value -0.000091 is negative. Also the doc says it must be a positive number. But it's perfectly correct for a gauge metric to have negative values. The Prometheus spec says:

value is a float represented as required by Go's ParseFloat() function. In addition to standard numerical values, NaN, +Inf, and -Inf are valid values representing not a number, positive infinity, and negative infinity, respectively.

rpk connect --version
Version: 4.75.0
Date: 2025-12-15T20:23:55Z

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start in internal/impl/pure/processor_metric.go, linked from the issue, and inspect how metric values are validated for gauge metrics. Compare that behavior with the Prometheus value format described in the issue, then verify that a negative gauge value such as -0.000091 is accepted without a handler error.

Written by the indexing model from the issue text.

Assessment

Tech stack
go
Domain
observability
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
52/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.