Trace id can't be decoded by agent due to being transmitted as float

[datadog]

Trace id can't be decoded by agent due to being transmitted as float

[realark]

@aesy Thank you so much for the fix! This will ship in our 0.17.0 release (estimated to go out next week).

Will close this issue once the release ships.

[tylerbenson]

@aesy Thanks for the report. From your investigation, do you see something that can be changed inside the java tracer to improve the situation besides waiting for better handling in msgpack-java?

[aesy]

The issue is only present when serializing string numbers, like such:

dd-trace-java/dd-trace-ot/src/main/java/datadog/opentracing/DDSpan.java

Lines 330 to 346 in 6b0e43b

	@JsonGetter("trace_id")
	@JsonSerialize(using = UInt64IDStringSerializer.class)
	public String getTraceId() {
	return context.getTraceId();
	}
	@JsonGetter("span_id")
	@JsonSerialize(using = UInt64IDStringSerializer.class)
	public String getSpanId() {
	return context.getSpanId();
	}
	@JsonGetter("parent_id")
	@JsonSerialize(using = UInt64IDStringSerializer.class)
	public String getParentId() {
	return context.getParentId();
	}

dd-trace-java/dd-trace-ot/src/main/java/datadog/opentracing/DDSpan.java

Lines 408 to 424 in 6b0e43b

	protected static class UInt64IDStringSerializer extends StdSerializer<String> {
	public UInt64IDStringSerializer() {
	this(null);
	}
	public UInt64IDStringSerializer(final Class<String> stringClass) {
	super(stringClass);
	}
	@Override
	public void serialize(
	final String value, final JsonGenerator gen, final SerializerProvider provider)
	throws IOException {
	gen.writeNumber(value);
	}
	}

I think this could be circumvented by storing the id's as BigInteger rather than String. Maybe this would result in worse performance, as discussed here, I don't know.

I can make a pull request if you think think this would be a good solution.

[realark]

@aesy trace/span identifiers are sometimes logged in performance sensitive areas. We wanted to avoid paying the penalty of conversion for such cases.

Serialization to the agent is less of a concern (only happens once). Do you think we could accomplish the same thing with changes to UInt64IDStringSerializer?

[aesy]

Ah I see.

Yeah, that would work. And there wouldn't need to be any validation since that's already been done at an earlier stage.

[tylerbenson]

Fix is included in 0.17.0.