Add logging for OpenTelemetry integration

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Features
+
+- Add logging for OpenTelemetry integration ([#2425](https://github.com/getsentry/sentry-java/pull/2425))
+
 ### Dependencies
 
 - Bump Native SDK from v0.5.2 to v0.5.3 ([#2423](https://github.com/getsentry/sentry-java/pull/2423))

sentry-opentelemetry/sentry-opentelemetry-core/src/main/java/io/sentry/opentelemetry/OpenTelemetryLinkErrorEventProcessor.java

@@ -6,22 +6,36 @@
 import io.sentry.EventProcessor;
 import io.sentry.Hint;
 import io.sentry.HubAdapter;
+import io.sentry.IHub;
 import io.sentry.ISpan;
 import io.sentry.Instrumenter;
 import io.sentry.SentryEvent;
+import io.sentry.SentryLevel;
 import io.sentry.SentrySpanStorage;
 import io.sentry.SpanContext;
 import io.sentry.protocol.SentryId;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.TestOnly;
 
 public final class OpenTelemetryLinkErrorEventProcessor implements EventProcessor {
 
+  private final @NotNull IHub hub;
   private final @NotNull SentrySpanStorage spanStorage = SentrySpanStorage.getInstance();
 
+  public OpenTelemetryLinkErrorEventProcessor() {
+    this(HubAdapter.getInstance());
+  }
+
+  @TestOnly
+  OpenTelemetryLinkErrorEventProcessor(final @NotNull IHub hub) {
+    this.hub = hub;
+  }
+
   @Override
   public @Nullable SentryEvent process(final @NotNull SentryEvent event, final @NotNull Hint hint) {
-    if (Instrumenter.OTEL.equals(HubAdapter.getInstance().getOptions().getInstrumenter())) {
+    final @NotNull Instrumenter instrumenter = hub.getOptions().getInstrumenter();
+    if (Instrumenter.OTEL.equals(instrumenter)) {
       @NotNull final Span otelSpan = Span.current();
       @NotNull final String traceId = otelSpan.getSpanContext().getTraceId();
       @NotNull final String spanId = otelSpan.getSpanContext().getSpanId();
@@ -41,8 +55,42 @@ public final class OpenTelemetryLinkErrorEventProcessor implements EventProcesso
                   null);
 
           event.getContexts().setTrace(spanContext);
+          hub.getOptions()
+              .getLogger()
+              .log(
+                  SentryLevel.DEBUG,
+                  "Linking Sentry event %s to span %s created via OpenTelemetry (trace %s).",
+                  event.getEventId(),
+                  spanId,
+                  traceId);
+        } else {
+          hub.getOptions()
+              .getLogger()
+              .log(
+                  SentryLevel.DEBUG,
+                  "Not linking Sentry event %s to any transaction created via OpenTelemetry as none has been found for span %s (trace %s).",
+                  event.getEventId(),
+                  spanId,
+                  traceId);
         }
+      } else {
+        hub.getOptions()
+            .getLogger()
+            .log(
+                SentryLevel.DEBUG,
+                "Not linking Sentry event %s to any transaction created via OpenTelemetry as traceId %s or spanId %s are invalid.",
+                event.getEventId(),
+                traceId,
+                spanId);
       }
+    } else {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not linking Sentry event %s to any transaction created via OpenTelemetry as instrumenter is set to %s.",
+              event.getEventId(),
+              instrumenter);
     }
 
     return event;

sentry-opentelemetry/sentry-opentelemetry-core/src/main/java/io/sentry/opentelemetry/SentryPropagator.java

@@ -10,7 +10,10 @@
 import io.opentelemetry.context.propagation.TextMapSetter;
 import io.sentry.Baggage;
 import io.sentry.BaggageHeader;
+import io.sentry.HubAdapter;
+import io.sentry.IHub;
 import io.sentry.ISpan;
+import io.sentry.SentryLevel;
 import io.sentry.SentrySpanStorage;
 import io.sentry.SentryTraceHeader;
 import io.sentry.exception.InvalidSentryTraceHeaderException;
@@ -26,6 +29,15 @@ public final class SentryPropagator implements TextMapPropagator {
   private static final @NotNull List<String> FIELDS =
       Arrays.asList(SentryTraceHeader.SENTRY_TRACE_HEADER, BaggageHeader.BAGGAGE_HEADER);
   private final @NotNull SentrySpanStorage spanStorage = SentrySpanStorage.getInstance();
+  private final @NotNull IHub hub;
+
+  public SentryPropagator() {
+    this(HubAdapter.getInstance());
+  }
+
+  SentryPropagator(final @NotNull IHub hub) {
+    this.hub = hub;
+  }
 
   @Override
   public Collection<String> fields() {
@@ -37,10 +49,22 @@ public <C> void inject(final Context context, final C carrier, final TextMapSett
     final @NotNull Span otelSpan = Span.fromContext(context);
     final @NotNull SpanContext otelSpanContext = otelSpan.getSpanContext();
     if (!otelSpanContext.isValid()) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not injecting Sentry tracing information for invalid OpenTelemetry span.");
       return;
     }
     final @Nullable ISpan sentrySpan = spanStorage.get(otelSpanContext.getSpanId());
     if (sentrySpan == null || sentrySpan.isNoOp()) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not injecting Sentry tracing information for span %s as no Sentry span has been found or it is a NoOp (trace %s). This might simply mean this is a request to Sentry.",
+              otelSpanContext.getSpanId(),
+              otelSpanContext.getTraceId());
       return;
     }
 
@@ -82,8 +106,18 @@ public <C> Context extract(
       Span wrappedSpan = Span.wrap(otelSpanContext);
       modifiedContext = modifiedContext.with(wrappedSpan);
 
+      hub.getOptions()
+          .getLogger()
+          .log(SentryLevel.DEBUG, "Continuing Sentry trace %s", sentryTraceHeader.getTraceId());
+
       return modifiedContext;
     } catch (InvalidSentryTraceHeaderException e) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.ERROR,
+              "Unable to extract Sentry tracing information from invalid header.",
+              e);
       return context;
     }
   }

sentry-opentelemetry/sentry-opentelemetry-core/src/main/java/io/sentry/opentelemetry/SentrySpanProcessor.java

@@ -19,6 +19,7 @@
 import io.sentry.ISpan;
 import io.sentry.ITransaction;
 import io.sentry.Instrumenter;
+import io.sentry.SentryLevel;
 import io.sentry.SentrySpanStorage;
 import io.sentry.SentryTraceHeader;
 import io.sentry.SpanId;
@@ -48,7 +49,7 @@ public SentrySpanProcessor() {
     this(HubAdapter.getInstance());
   }
 
-  SentrySpanProcessor(@NotNull IHub hub) {
+  SentrySpanProcessor(final @NotNull IHub hub) {
     this.hub = hub;
   }
 
@@ -58,22 +59,44 @@ public void onStart(final @NotNull Context parentContext, final @NotNull ReadWri
       return;
     }
 
+    final @NotNull TraceData traceData = getTraceData(otelSpan, parentContext);
+
     if (isSentryRequest(otelSpan)) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not forwarding OpenTelemetry span %s to Sentry as this looks like a span for a request to Sentry (trace %s).",
+              traceData.getSpanId(),
+              traceData.getTraceId());
       return;
     }
-
-    final @NotNull TraceData traceData = getTraceData(otelSpan, parentContext);
     final @Nullable ISpan sentryParentSpan =
         traceData.getParentSpanId() == null ? null : spanStorage.get(traceData.getParentSpanId());
 
     if (sentryParentSpan != null) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Creating Sentry child span for OpenTelemetry span %s (trace %s). Parent span is %s.",
+              traceData.getSpanId(),
+              traceData.getTraceId(),
+              traceData.getParentSpanId());
       final @NotNull Date startDate =
           DateUtils.nanosToDate(otelSpan.toSpanData().getStartEpochNanos());
       final @NotNull ISpan sentryChildSpan =
           sentryParentSpan.startChild(
               otelSpan.getName(), otelSpan.getName(), startDate, Instrumenter.OTEL);
       spanStorage.store(traceData.getSpanId(), sentryChildSpan);
     } else {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Creating Sentry transaction for OpenTelemetry span %s (trace %s).",
+              traceData.getSpanId(),
+              traceData.getTraceId());
       final @NotNull String transactionName = otelSpan.getName();
       final @NotNull TransactionNameSource transactionNameSource = TransactionNameSource.CUSTOM;
       final @Nullable String op = otelSpan.getName();
@@ -124,18 +147,48 @@ public void onEnd(final @NotNull ReadableSpan otelSpan) {
     final @Nullable ISpan sentrySpan = spanStorage.removeAndGet(traceData.getSpanId());
 
     if (sentrySpan == null) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Unable to find Sentry span for OpenTelemetry span %s (trace %s).",
+              traceData.getSpanId(),
+              traceData.getTraceId());
       return;
     }
 
     if (isSentryRequest(otelSpan)) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not forwarding OpenTelemetry span %s to Sentry as this looks like a span for a request to Sentry (trace %s).",
+              traceData.getSpanId(),
+              traceData.getTraceId());
       return;
     }
 
     if (sentrySpan instanceof ITransaction) {
-      ITransaction sentryTransaction = (ITransaction) sentrySpan;
+      final @NotNull ITransaction sentryTransaction = (ITransaction) sentrySpan;
       updateTransactionWithOtelData(sentryTransaction, otelSpan);
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Finishing Sentry transaction %s for OpenTelemetry span %s (trace %s).",
+              sentryTransaction.getEventId(),
+              traceData.getSpanId(),
+              traceData.getTraceId());
     } else {
       updateSpanWithOtelData(sentrySpan, otelSpan);
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Finishing Sentry span for OpenTelemetry span %s (trace %s). Parent span is %s.",
+              traceData.getSpanId(),
+              traceData.getTraceId(),
+              traceData.getParentSpanId());
     }
 
     final @NotNull SpanStatus sentryStatus = mapOtelStatus(otelSpan);
@@ -151,15 +204,32 @@ public boolean isEndRequired() {
 
   private boolean ensurePrerequisites(final @NotNull ReadableSpan otelSpan) {
     if (!hasSentryBeenInitialized()) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not forwarding OpenTelemetry span to Sentry as Sentry has not yet been initialized.");
       return false;
     }
 
-    if (!Instrumenter.OTEL.equals(hub.getOptions().getInstrumenter())) {
+    final @NotNull Instrumenter instrumenter = hub.getOptions().getInstrumenter();
+    if (!Instrumenter.OTEL.equals(instrumenter)) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not forwarding OpenTelemetry span to Sentry as instrumenter has been set to %s.",
+              instrumenter);
       return false;
     }
 
     final @NotNull SpanContext otelSpanContext = otelSpan.getSpanContext();
     if (!otelSpanContext.isValid()) {
+      hub.getOptions()
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Not forwarding OpenTelemetry span to Sentry as the span is invalid.");
       return false;
     }