Ability to disable built-in tags for sendDistributionMetric function. about datadog-lambda-js

[PatrykMilewski]

@tianchu Thank you for response!

I thought that unique combinations of tags billing works a little bit different. Now I agree, that from biling perspective, there is no point in disabling this.

But still it adds some unneeded noise to all of the metrics.

Maybe let's keep this issue as open and if somebody else find it as a problem, then we can get back to it? 😄

[pinkerton]

Hi @PatrykMilewski, thanks for filing an issue.

The custom metrics you submit with the Datadog Lambda Layer / package are Distribution metrics. These are unique in that you control which aggregations and percentiles you want. To disable a tag like dd_lambda_layer, you can navigate to Metrics > Distribution Metrics > your.custom.metric and change the aggregations there.

Docs: https://docs.datadoghq.com/metrics/distributions/#customize-tagging

[PatrykMilewski]

Thank you @pinkerton, it worked!

[PatrykMilewski]

@pinkerton I think I have to reopen this issue. The workaround that you proposed works, but if I publish tens of metrics, then I have to click through them and for each of them disable dd_lambda_layer tag, which is time consuming and annoying.

My point is, that it could be avoided, since for my use case this tag is really not important and could be disabled, since I'm not getting any value of having it in my DataDog.

I did look into the code and it's only about possibility to force getRuntimeTag() to return nothing by some flag that can be provided with configuration.

export function sendDistributionMetric(name: string, value: number, ...tags: string[]) {
  tags = [...tags, getRuntimeTag()];

  if (currentMetricsListener !== undefined) {
    currentMetricsListener.sendDistributionMetric(name, value, ...tags);
  } else {
    logError("handler not initialized");
  }
}

[tianchu]

@PatrykMilewski I agree this request makes sense, as that tag was added mostly for tracking/debugging, we are working on a better solution and we can get rid of this tag in a future release.

However, to clarify, unless you emit the metric from multiple Lambda functions using different versions of Datadog layers, this extra tag won't increase # of billed custom metrics, as its cardinality is 1. Say, if the # of unique combinations of other tags is 12, then 12 * 1 is still 12.

This doc might be helpful: https://docs.datadoghq.com/account_management/billing/custom_metrics/?tab=distribution

Let me know if I missed anything.

[PatrykMilewski]

I no longer need of removing this default tag, that's why I'm closing this issue.