add span stacktrace config option (#1414)

Co-authored-by: jackshirazi <[email protected]>

Author: SylvainJuge

span-stacktrace/README.md

@@ -20,26 +20,38 @@ section below to configure it.
 ### Manual SDK setup
 
 Here is an example registration of `StackTraceSpanProcessor` to capture stack trace for all
-the spans that have a duration >= 1000 ns. The spans that have an `ignorespan` string attribute
+the spans that have a duration >= 1 ms. The spans that have an `ignorespan` string attribute
 will be ignored.
 
 ```java
 InMemorySpanExporter spansExporter = InMemorySpanExporter.create();
 SpanProcessor exportProcessor = SimpleSpanProcessor.create(spansExporter);
 
+Map<String, String> configMap = new HashMap<>();
+configMap.put("otel.java.experimental.span-stacktrace.min.duration", "1ms");
+ConfigProperties config = DefaultConfigProperties.createFromMap(configMap);
+
 Predicate<ReadableSpan> filterPredicate = readableSpan -> {
   if(readableSpan.getAttribute(AttributeKey.stringKey("ignorespan")) != null){
     return false;
   }
   return true;
 };
 SdkTracerProvider tracerProvider = SdkTracerProvider.builder()
-    .addSpanProcessor(new StackTraceSpanProcessor(exportProcessor, 1000, filterPredicate))
+    .addSpanProcessor(new StackTraceSpanProcessor(exportProcessor, config, filterPredicate))
     .build();
 
 OpenTelemetrySdk sdk = OpenTelemetrySdk.builder().setTracerProvider(tracerProvider).build();
 ```
 
+### Configuration
+
+The `otel.java.experimental.span-stacktrace.min.duration` configuration option (defaults to 5ms) allows configuring
+the minimal duration for which spans should have a stacktrace captured.
+
+Setting `otel.java.experimental.span-stacktrace.min.duration` to zero will include all spans, and using a negative
+value will disable the feature.
+
 ## Component owners
 
 - [Jack Shirazi](https://github.com/jackshirazi), Elastic

span-stacktrace/build.gradle.kts

@@ -10,5 +10,10 @@ dependencies {
   api("io.opentelemetry:opentelemetry-sdk")
   testImplementation("io.opentelemetry:opentelemetry-sdk-testing")
 
+  compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
+  compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
+  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+
   testImplementation("io.opentelemetry.semconv:opentelemetry-semconv-incubating")
 }

span-stacktrace/src/main/java/io/opentelemetry/contrib/stacktrace/StackTraceSpanProcessor.java

@@ -8,16 +8,22 @@
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.contrib.stacktrace.internal.AbstractSimpleChainingSpanProcessor;
 import io.opentelemetry.contrib.stacktrace.internal.MutableSpan;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.trace.ReadableSpan;
 import io.opentelemetry.sdk.trace.SpanProcessor;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.time.Duration;
 import java.util.function.Predicate;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 public class StackTraceSpanProcessor extends AbstractSimpleChainingSpanProcessor {
 
+  private static final String CONFIG_MIN_DURATION =
+      "otel.java.experimental.span-stacktrace.min.duration";
+  private static final Duration CONFIG_MIN_DURATION_DEFAULT = Duration.ofMillis(5);
+
   // inlined incubating attribute to prevent direct dependency on incubating semconv
   private static final AttributeKey<String> SPAN_STACKTRACE =
       AttributeKey.stringKey("code.stacktrace");
@@ -38,10 +44,27 @@ public StackTraceSpanProcessor(
     super(next);
     this.minSpanDurationNanos = minSpanDurationNanos;
     this.filterPredicate = filterPredicate;
-    logger.log(
-        Level.FINE,
-        "Stack traces will be added to spans with a minimum duration of {0} nanos",
-        minSpanDurationNanos);
+    if (minSpanDurationNanos < 0) {
+      logger.log(Level.FINE, "Stack traces capture is disabled");
+    } else {
+      logger.log(
+          Level.FINE,
+          "Stack traces will be added to spans with a minimum duration of {0} nanos",
+          minSpanDurationNanos);
+    }
+  }
+
+  /**
+   * @param next next span processor to invoke
+   * @param config configuration
+   * @param filterPredicate extra filter function to exclude spans if needed
+   */
+  public StackTraceSpanProcessor(
+      SpanProcessor next, ConfigProperties config, Predicate<ReadableSpan> filterPredicate) {
+    this(
+        next,
+        config.getDuration(CONFIG_MIN_DURATION, CONFIG_MIN_DURATION_DEFAULT).toNanos(),
+        filterPredicate);
   }
 
   @Override
@@ -56,7 +79,7 @@ protected boolean requiresEnd() {
 
   @Override
   protected ReadableSpan doOnEnd(ReadableSpan span) {
-    if (span.getLatencyNanos() < minSpanDurationNanos) {
+    if (minSpanDurationNanos < 0 || span.getLatencyNanos() < minSpanDurationNanos) {
       return span;
     }
     if (span.getAttribute(SPAN_STACKTRACE) != null) {

span-stacktrace/src/test/java/io/opentelemetry/contrib/stacktrace/StackTraceSpanProcessorTest.java

@@ -13,73 +13,107 @@
 import io.opentelemetry.context.Scope;
 import io.opentelemetry.contrib.stacktrace.internal.TestUtils;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
 import io.opentelemetry.sdk.testing.exporter.InMemorySpanExporter;
 import io.opentelemetry.sdk.trace.ReadableSpan;
 import io.opentelemetry.sdk.trace.SpanProcessor;
 import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
 import io.opentelemetry.semconv.incubating.CodeIncubatingAttributes;
+import java.time.Duration;
 import java.time.Instant;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 class StackTraceSpanProcessorTest {
 
-  private InMemorySpanExporter spansExporter;
-  private SpanProcessor exportProcessor;
-
-  @BeforeEach
-  public void setup() {
-    spansExporter = InMemorySpanExporter.create();
-    exportProcessor = SimpleSpanProcessor.create(spansExporter);
+  private static long msToNs(int ms) {
+    return Duration.ofMillis(ms).toNanos();
   }
 
   @Test
   void durationAndFiltering() {
+    // on duration threshold
+    checkSpanWithStackTrace(span -> true, "1ms", msToNs(1));
     // over duration threshold
-    testSpan(span -> true, 11, 1);
+    checkSpanWithStackTrace(span -> true, "1ms", msToNs(2));
     // under duration threshold
-    testSpan(span -> true, 9, 0);
+    checkSpanWithoutStackTrace(span -> true, "2ms", msToNs(1));
 
     // filtering out span
-    testSpan(span -> false, 20, 0);
+    checkSpanWithoutStackTrace(span -> false, "1ms", 20);
+  }
+
+  @Test
+  void defaultConfig() {
+    long expectedDefault = msToNs(5);
+    checkSpanWithStackTrace(span -> true, null, expectedDefault);
+    checkSpanWithStackTrace(span -> true, null, expectedDefault + 1);
+    checkSpanWithoutStackTrace(span -> true, null, expectedDefault - 1);
+  }
+
+  @Test
+  void disabledConfig() {
+    checkSpanWithoutStackTrace(span -> true, "-1", 5);
   }
 
   @Test
   void spanWithExistingStackTrace() {
-    testSpan(
+    checkSpan(
         span -> true,
-        20,
-        1,
+        "1ms",
+        Duration.ofMillis(1).toNanos(),
         sb -> sb.setAttribute(CodeIncubatingAttributes.CODE_STACKTRACE, "hello"),
         stacktrace -> assertThat(stacktrace).isEqualTo("hello"));
   }
 
-  private void testSpan(
-      Predicate<ReadableSpan> filterPredicate, long spanDurationNanos, int expectedSpansCount) {
-    testSpan(
+  private static void checkSpanWithStackTrace(
+      Predicate<ReadableSpan> filterPredicate, String configString, long spanDurationNanos) {
+    checkSpan(
         filterPredicate,
+        configString,
         spanDurationNanos,
-        expectedSpansCount,
         Function.identity(),
         (stackTrace) ->
             assertThat(stackTrace)
                 .describedAs("span stack trace should contain caller class name")
                 .contains(StackTraceSpanProcessorTest.class.getCanonicalName()));
   }
 
-  private void testSpan(
+  private static void checkSpanWithoutStackTrace(
+      Predicate<ReadableSpan> filterPredicate, String configString, long spanDurationNanos) {
+    checkSpan(
+        filterPredicate,
+        configString,
+        spanDurationNanos,
+        Function.identity(),
+        (stackTrace) -> assertThat(stackTrace).describedAs("no stack trace expected").isNull());
+  }
+
+  private static void checkSpan(
       Predicate<ReadableSpan> filterPredicate,
+      String configString,
       long spanDurationNanos,
-      int expectedSpansCount,
       Function<SpanBuilder, SpanBuilder> customizeSpanBuilder,
       Consumer<String> stackTraceCheck) {
+
+    // they must be re-created as they are shutdown when the span processor is closed
+    InMemorySpanExporter spansExporter = InMemorySpanExporter.create();
+    SpanProcessor exportProcessor = SimpleSpanProcessor.create(spansExporter);
+
+    Map<String, String> configMap = new HashMap<>();
+    if (configString != null) {
+      configMap.put("otel.java.experimental.span-stacktrace.min.duration", configString);
+    }
+
     try (SpanProcessor processor =
-        new StackTraceSpanProcessor(exportProcessor, 10, filterPredicate)) {
+        new StackTraceSpanProcessor(
+            exportProcessor, DefaultConfigProperties.createFromMap(configMap), filterPredicate)) {
 
       OpenTelemetrySdk sdk = TestUtils.sdkWith(processor);
       Tracer tracer = sdk.getTracer("test");
@@ -96,14 +130,12 @@ private void testSpan(
       }
 
       List<SpanData> finishedSpans = spansExporter.getFinishedSpanItems();
-      assertThat(finishedSpans).hasSize(expectedSpansCount);
+      assertThat(finishedSpans).hasSize(1);
 
-      if (!finishedSpans.isEmpty()) {
-        String stackTrace =
-            finishedSpans.get(0).getAttributes().get(CodeIncubatingAttributes.CODE_STACKTRACE);
+      String stackTrace =
+          finishedSpans.get(0).getAttributes().get(CodeIncubatingAttributes.CODE_STACKTRACE);
 
-        stackTraceCheck.accept(stackTrace);
-      }
+      stackTraceCheck.accept(stackTrace);
     }
   }
 }