[processor/tailsamplingprocessor] Is it possible to pass an array of numbers to policy

[koungkub]

Component(s)

processor/tailsampling

Describe the issue you're reporting

I'd like to pass an array of numbers on the numeric_attribute policy. for instance

policies:
    [
        {
            name: array_of_numbers
            type: xxx
            xxx: {key: yyy, values: [2, 4, 12, 13, 14]}
        }
    ]

[github-actions]

Pinging code owners:

• processor/tailsampling: @jpkrohling

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[jiekun]

I would like to check if the OTTL policy could meet your needs later. I think it should work like:

policies:
    [
        {
              name: ottl-test,
              type: ottl_condition,
              ottl_condition: {
                   error_mode: ignore,
                   span: [
                        "attributes[\"test_attr_key_1\"] == 2",
                        "attributes[\"test_attr_key_2\"] == 4",
                   ]
              }
         }
    ]

But maybe we could write a more concise OTTL expression.

[koungkub]

@jiekun It's better if we have a condition that accepted an array of numbers.

[jiekun]

@jiekun It's better if we have a condition that accepted an array of numbers.

@koungkub I think OTTL could handle array. You could check it here: https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/pkg/ottl#lists

I'm sorry that I cannot do some test myself yesterday due to limited time. I will add some test example. And maybe you could read the OTTL doc to see if it met your expectation as well.

[koungkub]

@jiekun It's better if we have a condition that accepted an array of numbers.

@koungkub I think OTTL could handle array. You could check it here: https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/pkg/ottl#lists

I'm sorry that I cannot do some test myself yesterday due to limited time. I will add some test example. And maybe you could read the OTTL doc to see if it met your expectation as well.

Thanks

[jiekun]

Alright I think the boolean expression support those operation:

The valid operators are:

Equal (==). Tests if the left and right Values are equal (see the Comparison Rules below).
Not Equal (!=). Tests if the left and right Values are not equal.
Less Than (<). Tests if left is less than right.
Greater Than (>). Tests if left is greater than right.
Less Than or Equal To (<=). Tests if left is less than or equal to right.
Greater Than or Equal to (>=). Tests if left is greater than or equal to right.

The list value is acceptable for an OTTL function tho.

I would like to ping OTTL master @TylerHelmuth for help. :P

[TylerHelmuth]

OTTL supports passing lists in the grammar, but doesn't have in or contains functionality.

If I am understanding the problem statement correctly, you want to check if an attribute with a numeric value is one of several possible values. This is achievable with the OTTL condition policy exactly as @jiekun suggested:

policies:
    [
        {
              name: ottl-test,
              type: ottl_condition,
              ottl_condition: {
                   error_mode: ignore,
                   span: [
                        attributes["yyy"] == 2,
                        attributes["yyy"] == 4,
                        attributes["yyy"] == 12,
                        attributes["yyy"] == 13,
                        attributes["yyy"] == 14,
                   ]
              }
         }
    ]

If any of the statements is true the policy will resolve to true. This is functionally equivalent to

policies:
    [
        {
            name: array_of_numbers
            type: xxx
            xxx: {key: yyy, values: [2, 4, 12, 13, 14]}
        }
    ]

With some improvements to pkg/ottl we can make the statement more precise, but the functionality wouldn't change.

[koungkub]

@jiekun @TylerHelmuth Thank you so much. It's working correctly.

[koungkub]

@TylerHelmuth I agree with you about the precise statement of ottl. It should be accepted array of either strings or numbers

[TylerHelmuth]

@koungkub if you'd like please open a new issue for pkg/ottl requesting that enhancement. Since the problem statement for this issue is solved I am going to close this issue, but ping me if you think it should be reopened.