MONIT-40224: fix error span

Author: Yang Zeng

proxy/src/main/java/com/wavefront/agent/sampler/EbpfSampler.java

@@ -1,6 +1,5 @@
 package com.wavefront.agent.sampler;
 
-import static com.wavefront.common.TraceConstants.PARENT_KEY;
 import static com.wavefront.sdk.common.Constants.*;
 
 import com.github.benmanes.caffeine.cache.Caffeine;
@@ -16,7 +15,6 @@
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import javax.annotation.Nonnull;
-import org.apache.commons.lang.StringUtils;
 import wavefront.report.Annotation;
 import wavefront.report.Span;
 
@@ -139,7 +137,7 @@ public boolean sample(@Nonnull Span span) {
     stats.edgeCount.getAndIncrement();
     if (!stats.isSignificant()) sampled = true;
 
-    if (annotationMap.containsKey(ERROR_TAG_KEY)) {
+    if (annotationMap.containsKey(ERROR_TAG_KEY) && "true".equalsIgnoreCase(annotationMap.get(ERROR_TAG_KEY))) {
       stats.errorCount.getAndIncrement();
       if (!sampled && stats.getErrorRatio() < 0.5) sampled = true;
     }