Send spans if they are too long (#225)

src/main/kotlin/io/emeraldpay/dshackle/config/spans/export.kt

@@ -3,7 +3,9 @@ package io.emeraldpay.dshackle.config.spans
 import brave.handler.MutableSpan
 import io.emeraldpay.dshackle.commons.SPAN_ERROR
 import io.emeraldpay.dshackle.commons.SPAN_NO_RESPONSE_MESSAGE
+import org.springframework.beans.factory.annotation.Value
 import org.springframework.stereotype.Component
+import java.util.concurrent.TimeUnit
 
 interface SpanExportable {
     fun isExportable(span: MutableSpan): Boolean
@@ -18,3 +20,15 @@ class ErrorSpanExportable : SpanExportable {
 class NoResponseSpanExportable : SpanExportable {
     override fun isExportable(span: MutableSpan): Boolean = span.tags().containsKey(SPAN_NO_RESPONSE_MESSAGE)
 }
+
+@Component
+class LongResponseSpanExportable(
+    @Value("\${spans.collect.provider.long-span-threshold}")
+    private val longSpanThreshold: Long? = null
+) : SpanExportable {
+
+    override fun isExportable(span: MutableSpan): Boolean {
+        val duration = span.finishTimestamp() - span.startTimestamp()
+        return TimeUnit.SECONDS.convert(duration, TimeUnit.MICROSECONDS) >= longSpanThreshold!!
+    }
+}

src/main/resources/application.yml

@@ -22,5 +22,6 @@ spans:
     enabled: ${ENABLE_COLLECT_SPANS:false}
     provider:
       enabled: ${ENABLE_PROVIDER_COLLECT_SPANS:true}
+      long-span-threshold: ${LONG_SPAN_THRESHOLD:1}
     main:
       enabled: ${ENABLE_MAIN_COLLECT_SPANS:false}