Implement dropped attribute count in logs (#4697)

* Implement dropped attribute count in logs

* PR feedback

* PR feedback

exporters/otlp/common/src/main/java/io/opentelemetry/exporter/internal/otlp/logs/LogMarshaler.java

@@ -50,8 +50,7 @@ final class LogMarshaler extends MarshalerWithSize {
         MarshalerUtil.toBytes(logData.getSeverityText()),
         anyValueMarshaler,
         attributeMarshalers,
-        // TODO (trask) implement droppedAttributesCount in LogRecord
-        0,
+        logData.getTotalAttributeCount() - logData.getAttributes().size(),
         spanContext.getTraceFlags(),
         spanContext.getTraceId().equals(INVALID_TRACE_ID) ? null : spanContext.getTraceId(),
         spanContext.getSpanId().equals(INVALID_SPAN_ID) ? null : spanContext.getSpanId());

exporters/otlp/common/src/test/java/io/opentelemetry/exporter/internal/otlp/logs/LogsRequestMarshalerTest.java

@@ -69,6 +69,7 @@ class LogsRequestMarshalerTest {
                         SpanContext.create(
                             TRACE_ID, SPAN_ID, TraceFlags.getDefault(), TraceState.getDefault()))
                     .setAttributes(Attributes.of(AttributeKey.booleanKey("key"), true))
+                    .setTotalAttributeCount(2)
                     .setEpoch(12345, TimeUnit.NANOSECONDS)
                     .build()));
 
@@ -111,6 +112,7 @@ class LogsRequestMarshalerTest {
                         SpanContext.create(
                             TRACE_ID, SPAN_ID, TraceFlags.getDefault(), TraceState.getDefault()))
                     .setAttributes(Attributes.of(AttributeKey.booleanKey("key"), true))
+                    .setTotalAttributeCount(2)
                     .setEpoch(12345, TimeUnit.NANOSECONDS)
                     .build()));
 
@@ -124,6 +126,7 @@ class LogsRequestMarshalerTest {
                 .setKey("key")
                 .setValue(AnyValue.newBuilder().setBoolValue(true).build())
                 .build());
+    assertThat(logRecord.getDroppedAttributesCount()).isEqualTo(1);
     assertThat(logRecord.getTimeUnixNano()).isEqualTo(12345);
   }
 
@@ -148,6 +151,7 @@ class LogsRequestMarshalerTest {
         .isEqualTo(Severity.UNDEFINED_SEVERITY_NUMBER.getSeverityNumber());
     assertThat(logRecord.getBody()).isEqualTo(AnyValue.newBuilder().setStringValue("").build());
     assertThat(logRecord.getAttributesList()).isEmpty();
+    assertThat(logRecord.getDroppedAttributesCount()).isZero();
     assertThat(logRecord.getTimeUnixNano()).isEqualTo(12345);
   }
 

sdk/logs-testing/src/main/java/io/opentelemetry/sdk/testing/assertj/LogDataAssert.java

@@ -163,4 +163,17 @@ public class LogDataAssert extends AbstractAssert<LogDataAssert, LogData> {
     // implementations.
     return actual.getAttributes().asMap().equals(attributes.asMap());
   }
+
+  /** Asserts the log has the given total attributes. */
+  public LogDataAssert hasTotalAttributeCount(int totalAttributeCount) {
+    isNotNull();
+    if (actual.getTotalAttributeCount() != totalAttributeCount) {
+      failWithActualExpectedAndMessage(
+          actual.getTotalAttributeCount(),
+          totalAttributeCount,
+          "Expected log to have recorded <%s> total attributes but did not",
+          totalAttributeCount);
+    }
+    return this;
+  }
 }

sdk/logs-testing/src/main/java/io/opentelemetry/sdk/testing/logs/TestLogData.java

@@ -31,7 +31,8 @@ public abstract class TestLogData implements LogData {
         .setSpanContext(SpanContext.getInvalid())
         .setSeverity(Severity.UNDEFINED_SEVERITY_NUMBER)
         .setBody("")
-        .setAttributes(Attributes.empty());
+        .setAttributes(Attributes.empty())
+        .setTotalAttributeCount(0);
   }
 
   TestLogData() {}
@@ -86,5 +87,8 @@ public abstract class TestLogData implements LogData {
 
     /** Set the attributes. */
     public abstract Builder setAttributes(Attributes attributes);
+
+    /** Set the total attribute count. */
+    public abstract Builder setTotalAttributeCount(int totalAttributeCount);
   }
 }

sdk/logs-testing/src/test/java/io/opentelemetry/sdk/testing/assertj/LogAssertionsTest.java

@@ -55,6 +55,7 @@ public class LogAssertionsTest {
           .setSeverityText("info")
           .setBody("message")
           .setAttributes(ATTRIBUTES)
+          .setTotalAttributeCount(999)
           .build();
 
   @Test
@@ -109,7 +110,8 @@ public class LogAssertionsTest {
                         attributeEntry("colors", "red", "blue"),
                         attributeEntry("conditions", false, true),
                         attributeEntry("scores", 0L, 1L),
-                        attributeEntry("coins", 0.01, 0.05, 0.1)));
+                        attributeEntry("coins", 0.01, 0.05, 0.1)))
+        .hasTotalAttributeCount(999);
   }
 
   @Test
@@ -179,5 +181,7 @@ public class LogAssertionsTest {
                                     AttributeKey.stringKey("bear"),
                                     value -> assertThat(value).hasSize(2))))
         .isInstanceOf(AssertionError.class);
+    assertThatThrownBy(() -> assertThat(LOG_DATA).hasTotalAttributeCount(11))
+        .isInstanceOf(AssertionError.class);
   }
 }

sdk/logs/src/main/java/io/opentelemetry/sdk/logs/SdkLogData.java

@@ -31,7 +31,8 @@ abstract class SdkLogData implements LogData {
       Severity severity,
       @Nullable String severityText,
       Body body,
-      Attributes attributes) {
+      Attributes attributes,
+      int totalAttributeCount) {
     return new AutoValue_SdkLogData(
         resource,
         instrumentationScopeInfo,
@@ -40,6 +41,7 @@ abstract class SdkLogData implements LogData {
         severity,
         severityText,
         body,
-        attributes);
+        attributes,
+        totalAttributeCount);
   }
 }

sdk/logs/src/main/java/io/opentelemetry/sdk/logs/SdkReadWriteLogRecord.java

@@ -115,7 +115,8 @@ class SdkReadWriteLogRecord implements ReadWriteLogRecord {
           severity,
           severityText,
           body,
-          getImmutableAttributes());
+          getImmutableAttributes(),
+          attributes == null ? 0 : attributes.getTotalAddedValues());
     }
   }
 }

sdk/logs/src/main/java/io/opentelemetry/sdk/logs/data/LogData.java

@@ -8,6 +8,7 @@ package io.opentelemetry.sdk.logs.data;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.sdk.common.InstrumentationScopeInfo;
+import io.opentelemetry.sdk.logs.LogLimits;
 import io.opentelemetry.sdk.resources.Resource;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
@@ -44,4 +45,13 @@ public interface LogData {
 
   /** Returns the attributes for this log, or {@link Attributes#empty()} if unset. */
   Attributes getAttributes();
+
+  /**
+   * Returns the total number of attributes that were recorded on this log.
+   *
+   * <p>This number may be larger than the number of attributes that are attached to this log, if
+   * the total number recorded was greater than the configured maximum value. See {@link
+   * LogLimits#getMaxNumberOfAttributes()}.
+   */
+  int getTotalAttributeCount();
 }

sdk/logs/src/test/java/io/opentelemetry/sdk/logs/SdkLogEmitterTest.java

@@ -17,6 +17,7 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.api.internal.StringUtils;
@@ -104,20 +105,20 @@ class SdkLogEmitterTest {
                 () -> LogLimits.builder().setMaxNumberOfAttributes(maxNumberOfAttrs).build())
             .build();
 
-    AttributesBuilder attributesBuilder = Attributes.builder();
+    LogRecordBuilder builder = logEmitterProvider.get("test").logRecordBuilder();
+    AttributesBuilder expectedAttributes = Attributes.builder();
     for (int i = 0; i < 2 * maxNumberOfAttrs; i++) {
-      attributesBuilder.put("key" + i, i);
+      AttributeKey<Long> key = AttributeKey.longKey("key" + i);
+      builder.setAttribute(key, (long) i);
+      if (i < maxNumberOfAttrs) {
+        expectedAttributes.put(key, (long) i);
+      }
     }
+    builder.emit();
 
-    logEmitterProvider
-        .get("test")
-        .logRecordBuilder()
-        .setAllAttributes(attributesBuilder.build())
-        .emit();
-
-    // NOTE: cannot guarantee which attributes are retained, only that there are no more that the
-    // max
-    assertThat(seenLog.get().toLogData().getAttributes()).hasSize(maxNumberOfAttrs);
+    assertThat(seenLog.get().toLogData())
+        .hasAttributes(expectedAttributes.build())
+        .hasTotalAttributeCount(maxNumberOfAttrs * 2);
   }
 
   @Test