[opentelemetry-exporter]: provide an option for max attribute value (currently it's hardcoded to 128 bytes)

[mzahor]

Currently opentelemetry-exporter has a limit of 128 bytes for span's attribute value:

opentelemetry-js/packages/opentelemetry-exporter-collector/src/transform.ts

Line 23 in 4627892

const OT_MAX_STRING_LENGTH = 128;

We have a use case where we need it to be bigger (we use our own exporter on the backend that sends all the data to Kinesis for further processing, so bigger values are not an issue for us).
I suggest to provide an optional config property called maxAttributeSize inside of this interface:

opentelemetry-js/packages/opentelemetry-exporter-collector/src/CollectorExporter.ts

Line 29 in 4627892

export interface CollectorExporterConfig {

and then pass it down to the function is responsible for truncating:

opentelemetry-js/packages/opentelemetry-exporter-collector/src/transform.ts

Line 29 in 4627892

export function toCollectorTruncatableString(

If you like the approach, I can prepare a PR today or tomorrow.
If you have any other ideas how to overcome this limitation - let's discuss them.

[dyladan]

The exporter is changing to use the OTLP format in #901. I think we should address this after that merges?

[mayurkale22]

I think this has already been addressed in #901. This limitations/restrictions were there due to old OpenCensus protos, now in latest OpenTelemetry proto they got ride of TruncatableString type.

[mayurkale22]

@obecny could you please confirm the same?

[obecny]

@mayurkale22 It looks like it got rid it is not used anymore

[dyladan]

I was going to close but this issue should be closed by #901

[mzahor]

Thanks @dyladan. The new exporter should solve the issue with attribute value length. As far as I can see the collector already has otlp receiver, is there anything else we need in order for #901 to be released?

[dyladan]

We're just waiting for reviews and to be confident in it before we release as it is a large change. Should be soon