feat: Multiple Feature Ideas I had after playing with the tool for a minute

[tdarwin]

Thought I'd just load up some of the ideas we discussed in Slack so that I don't forget about them

• Add an option for interjecting a percentage of spans that would have an error field
• Being able to add custom fields and values that you want to see at X rate so that we can build refinery rules around specific span attributes
• A way to hook it up to Lambda's that could be called via the API Gateway to spin up multple loadgens generating different kind of traffic.

Some extra ideas I thought of on top of things

These might be things we can do with running via multiple lambdas, but would be cool in the tool as well

• Outlier options - being able to add outlier traces that are generated randomly in the midst of your loadgen data.
  • span count (creating a trace with a super high span count compared to others)
  • duration (either exceptionally short duration spans or long duration spans)
  • missing parent spans or trace root spans
  • multi-service traces (maybe a list of services as the option, even better if it can be a hash with service names and weights)
  • read in a CSV or JSON or YAML or something containing a list of attributes each with a list/array of values you want to exist
  • Be able to give specific field names for extra span attribute fields but still have the tool generate values for the fields.

[kentquirk]

• Error field -- please tell me exactly what field name(s) you want to generate; I considered this and I couldn't easily find documentation on what we consider to be errors.
• I don't understand the "X rate" part of the custom fields. Can you elaborate?
• Lambda: the way it's built, the traces are generated by individual goroutines that are running (well, mostly sleeping) for the full duration of a trace. Doing that in lambda is going to be expensive. At the moment, I can't quite think of a way to do this with lambda that makes sense.

Extras:

• Most of the outliers I think are better handled by running a separate instance of loadgen with different parameters. Otherwise it's going to be a nightmare to configure.
• But missing spans is maybe a "drop every 100th span" option?
• I originally designed it as multi-service and then felt like it just got too complicated to specify. If you can give me a sample command line or two with some commentary on interpretation, I'd be happy to consider it again.
• Explicit attributes is something I've considered. I'll chew on it a bit more. I think both explicit and automatic values are possible.

[kentquirk]

I just added generators for custom fields and changed the default number of extras to 0. Check it out in the readme and let me know what you think.

[MikeGoldsmith]

We believe we've added enough for now.