Fix IllegalArgumentException in PrometheusMetricConverter and NaN value...

Fix IllegalArgumentException in PrometheusMetricConverter and NaN value samples in SampleFamily (#7349)

CHANGES.md

@@ -113,6 +113,8 @@ Release Notes.
   new timeout mechanism is designed for avoiding this specific case.
 * Fix Kafka transport topics are created duplicated with and without namespace issue
 * Fix possible version_conflict_engine_exception in bulk execution.
+* Fix PrometheusMetricConverter may throw an `IllegalArgumentException` when convert metrics to SampleFamily
+* Filtering NaN value samples when build SampleFamily  
 
 #### UI
 

oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/dsl/SampleFamily.java

@@ -74,6 +74,7 @@ public class SampleFamily {
 
     static SampleFamily build(RunningContext ctx, Sample... samples) {
         Preconditions.checkNotNull(samples);
+        samples = Arrays.stream(samples).filter(sample -> !Double.isNaN(sample.getValue())).toArray(Sample[]::new);
         Preconditions.checkArgument(samples.length > 0);
         return new SampleFamily(samples, Optional.ofNullable(ctx).orElseGet(RunningContext::instance));
     }

oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/prometheus/PrometheusMetricConverter.java

@@ -88,7 +88,7 @@ public class PrometheusMetricConverter {
         return metricStream
             .peek(metric -> log.debug("Prom metric to be convert to SampleFamily: {}", metric))
             .flatMap(this::convertMetric)
-            .filter(t -> t != NIL)
+            .filter(t -> t != NIL && t._2.samples.length > 0)
             .peek(t -> log.debug("SampleFamily: {}", t))
             .collect(toImmutableMap(Tuple2::_1, Tuple2::_2, (a, b) -> {
                 log.debug("merge {} {}", a, b);