Adjusting the sampling rate according to HTTP Status Code

[kworkbee]

Hello, I would like to create a custom Sampler and a custom SpanProcessor using SDK to give the sampling rate according to http.response.status_code among span attributes. However, it seems that http.response.status_code is found to be null inside the span attributes.

    @Override
    public SamplingResult shouldSample(
        Context parentContext,
        String traceId,
        String name,
        SpanKind spanKind,
        Attributes attributes,
        List<LinkData> parentLinks) {

        Long statusCode = attributes.get(AttributeKey.longKey("http.response.status_code"));
        double ratio = determineRatio(profile, statusCode);
        return Sampler.traceIdRatioBased(ratio)
                .shouldSample(parentContext, traceId, name, spanKind, attributes, parentLinks);
    }

[trask]

hi @kworkbee! sampling is done when the span starts and the http response status code isn't available until the span ends

there is support for "tail sampling" in the OpenTelemetry Collector if you need that functionality