Add transaction.span_count.started (#198)

implements elastic/apm-server#1241

Author: felixbarny

apm-agent-core/src/main/java/co/elastic/apm/impl/ElasticApmTracer.java

@@ -198,17 +198,17 @@ private Span createRealSpan(Transaction transaction, @Nullable Span parentSpan,
         if (isTransactionSpanLimitReached(transaction)) {
             // TODO only drop leaf spans
             dropped = true;
-            transaction.getSpanCount().getDropped().increment();
+            transaction.getSpanCount().getDropped().incrementAndGet();
         } else {
             dropped = false;
+            transaction.getSpanCount().getStarted().incrementAndGet();
         }
-        transaction.getSpanCount().increment();
         span.start(transaction, parentSpan, nanoTime, dropped);
         return span;
     }
 
     private boolean isTransactionSpanLimitReached(Transaction transaction) {
-        return coreConfiguration.getTransactionMaxSpans() <= transaction.getSpanCount().getTotal();
+        return coreConfiguration.getTransactionMaxSpans() <= transaction.getSpanCount().getStarted().get();
     }
 
     public void captureException(@Nullable Throwable e) {

apm-agent-core/src/main/java/co/elastic/apm/impl/transaction/Dropped.java

@@ -26,24 +26,20 @@
 
 public class SpanCount implements Recyclable {
 
-    private final Dropped dropped = new Dropped();
-    private final AtomicInteger total = new AtomicInteger(0);
+    private final AtomicInteger dropped = new AtomicInteger(0);
+    private final AtomicInteger started = new AtomicInteger(0);
 
-    public Dropped getDropped() {
+    public AtomicInteger getDropped() {
         return dropped;
     }
 
-    public void increment() {
-        total.incrementAndGet();
-    }
-
-    public int getTotal() {
-        return total.get();
+    public AtomicInteger getStarted() {
+        return started;
     }
 
     @Override
     public void resetState() {
-        dropped.resetState();
-        total.set(0);
+        dropped.set(0);
+        started.set(0);
     }
 }

apm-agent-core/src/main/java/co/elastic/apm/impl/transaction/SpanCount.java

@@ -431,7 +431,11 @@ private void serializeTransaction(final Transaction transaction) {
         writeField("duration", transaction.getDuration());
         writeField("result", transaction.getResult());
         serializeContext(transaction.getContext());
-        serializeSpanCount(transaction.getSpanCount());
+        if (distributedTracing) {
+            serializeSpanCountV2(transaction.getSpanCount());
+        } else {
+            serializeSpanCountV1(transaction.getSpanCount());
+        }
         serializeSpans(transaction.getSpans());
         // TODO marks
         writeLastField("sampled", transaction.isSampled());
@@ -574,18 +578,27 @@ private void serializeSpanContext(SpanContext context) {
         jw.writeByte(COMMA);
     }
 
-    private void serializeSpanCount(final SpanCount spanCount) {
+    private void serializeSpanCountV1(final SpanCount spanCount) {
         writeFieldName("span_count");
         jw.writeByte(OBJECT_START);
         writeFieldName("dropped");
         jw.writeByte(OBJECT_START);
         writeFieldName("total");
-        NumberConverter.serialize(spanCount.getDropped().getTotal(), jw);
+        NumberConverter.serialize(spanCount.getDropped().get(), jw);
         jw.writeByte(OBJECT_END);
         jw.writeByte(OBJECT_END);
         jw.writeByte(COMMA);
     }
 
+    private void serializeSpanCountV2(final SpanCount spanCount) {
+        writeFieldName("span_count");
+        jw.writeByte(OBJECT_START);
+        writeField("dropped", spanCount.getDropped().get());
+        writeLastField("started", spanCount.getStarted().get());
+        jw.writeByte(OBJECT_END);
+        jw.writeByte(COMMA);
+    }
+
     private void serializeContext(final TransactionContext context) {
         writeFieldName("context");
         jw.writeByte(OBJECT_START);
@@ -820,6 +833,17 @@ private void writeField(final String fieldName, final long value) {
         jw.writeByte(COMMA);
     }
 
+    private void writeField(final String fieldName, final int value) {
+        writeFieldName(fieldName);
+        NumberConverter.serialize(value, jw);
+        jw.writeByte(COMMA);
+    }
+
+    private void writeLastField(final String fieldName, final int value) {
+        writeFieldName(fieldName);
+        NumberConverter.serialize(value, jw);
+    }
+
     private void writeField(final String fieldName, final boolean value) {
         writeFieldName(fieldName);
         BoolConverter.serialize(value, jw);

apm-agent-core/src/main/java/co/elastic/apm/report/serialize/DslJsonSerializer.java

@@ -85,7 +85,7 @@
             "type": ["object", "null"],
             "properties": {
                 "dropped": {
-                    "type": ["object", "null"],
+                    "type": ["object", "integer", "null"],
                     "properties": {
                         "total": {
                             "type": ["integer","null"],

apm-agent-core/src/main/resources/schema/transactions/transaction.json

@@ -196,8 +196,8 @@ void testEnableDropSpans() {
             transaction.end();
         }
         assertThat(reporter.getFirstTransaction().isSampled()).isTrue();
-        assertThat(reporter.getFirstTransaction().getSpanCount().getDropped().getTotal()).isEqualTo(1);
-        assertThat(reporter.getFirstTransaction().getSpanCount().getTotal()).isEqualTo(2);
+        assertThat(reporter.getFirstTransaction().getSpanCount().getDropped().get()).isEqualTo(1);
+        assertThat(reporter.getFirstTransaction().getSpanCount().getStarted().get()).isEqualTo(1);
         assertThat(reporter.getSpans()).hasSize(1);
     }
 

apm-agent-core/src/test/java/co/elastic/apm/impl/ElasticApmTracerTest.java

@@ -118,13 +118,15 @@ private void validate(TransactionPayload payload) throws IOException {
         DslJsonSerializer serializer = new DslJsonSerializer(coreConfiguration.isDistributedTracingEnabled(), mock(StacktraceConfiguration.class));
 
         final String content = serializer.toJsonString(payload);
+        System.out.println(content);
         Set<ValidationMessage> errors = schema.validate(objectMapper.readTree(content));
         assertThat(errors).isEmpty();
 
         when(coreConfiguration.isDistributedTracingEnabled()).thenReturn(true);
         serializer = new DslJsonSerializer(coreConfiguration.isDistributedTracingEnabled(), mock(StacktraceConfiguration.class));
         transformForDistributedTracing(payload);
         final String contentInDistributedTracingFormat = serializer.toJsonString(payload);
+        System.out.println(contentInDistributedTracingFormat);
         Set<ValidationMessage> distributedTracingFormatErrors = schema.validate(objectMapper.readTree(contentInDistributedTracingFormat));
         assertThat(distributedTracingFormatErrors).isEmpty();
     }