public boolean shouldSample(SegmentObject segmentObject, int duration) {
        int sample = Math.abs(segmentObject.getTraceId().hashCode()) % 10000;
        String serviceName = segmentObject.getService();
        return traceSamplingPolicyWatcher.shouldSample(serviceName, sample, duration);
    }
The sampler makes the sampling mechanism works at backend side. Sample result: [0,sampleRate) sampled, (sampleRate,~)
ignored
oap-server/analyzer/agent-analyzer/src/main/java/org/apache/skywalking/oap/server/analyzer/provider/trace/parser/listener/TraceSegmentSampler.java