Add default dimensions for OTEL metrics

src/main/java/com/appsflyer/otelawsmetrics/OtelMetricPublisher.java

@@ -26,6 +26,7 @@
 public class OtelMetricPublisher implements MetricPublisher {
     private static final Logger log = LoggerFactory.getLogger(OtelMetricPublisher.class);
     private static final String DEFAULT_METRIC_PREFIX = "aws.sdk";
+    private final Attributes baseAttributes;
 
     private final Map<String, Map<Boolean, Map<Integer, Attributes>>> perRequestAttributesCache = new ConcurrentHashMap<>();
     private final Map<Attributes, Map<String, Attributes>> perAttemptAttributesCache = new ConcurrentHashMap<>();
@@ -38,25 +39,31 @@ public class OtelMetricPublisher implements MetricPublisher {
     private final Map<String, MetricStrategy> httpMetrics;
 
     public OtelMetricPublisher(OpenTelemetry openTelemetry) {
-        this(openTelemetry, DEFAULT_METRIC_PREFIX);
+        this(openTelemetry, DEFAULT_METRIC_PREFIX,  ForkJoinPool.commonPool(), Attributes.empty());
     }
 
     public OtelMetricPublisher(OpenTelemetry openTelemetry, String metricPrefix) {
-        this(openTelemetry, metricPrefix, ForkJoinPool.commonPool());
+        this(openTelemetry, metricPrefix,  ForkJoinPool.commonPool(), Attributes.empty());
     }
 
     public OtelMetricPublisher(OpenTelemetry openTelemetry, String metricPrefix, Executor executor) {
+        this(openTelemetry, metricPrefix, executor, Attributes.empty());
+    }
+
+    public OtelMetricPublisher(OpenTelemetry openTelemetry, String metricPrefix,
+                               Executor executor, Attributes baseAttributes) {
         Objects.requireNonNull(metricPrefix, "metricPrefix must not be null");
         Objects.requireNonNull(openTelemetry, "openTelemetry must not be null");
+        Objects.requireNonNull(baseAttributes, "baseAttributes must not be null");
 
         if (executor == null) {
             log.warn("An executor is not provided. The metrics will be published synchronously on the calling thread.");
         }
-
         this.metricPrefix = metricPrefix + ".";
         this.executor = executor;
+        this.baseAttributes = baseAttributes;
 
-        Meter meter = openTelemetry.getMeter("aws.sdk");
+        Meter meter = openTelemetry.getMeter(this.metricPrefix);
 
         perRequestMetrics = initializePerRequestStrategies(meter);
         perAttemptMetrics = initializeCoreStrategies(meter);
@@ -267,6 +274,7 @@ private Attributes toPerRequestAttributes(String operationName, boolean isSucces
                         .put("request_operation_name", nullSafeOperationName)
                         .put("request_is_success", isSuccess)
                         .put("request_retry_count", retryCount)
+                        .putAll(this.baseAttributes)
                         .build());
     }
 
@@ -291,4 +299,3 @@ private Attributes toHttpAttributes(Attributes parentAttributes, int httpStatusC
                                 .build());
     }
 }
-

src/test/java/com/appsflyer/otelawsmetrics/OtelMetricPublisherTest.java

@@ -2,6 +2,7 @@
 
 import io.opentelemetry.api.GlobalOpenTelemetry;
 import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
 import io.opentelemetry.sdk.metrics.SdkMeterProvider;
 import io.opentelemetry.sdk.metrics.data.HistogramData;
@@ -30,6 +31,8 @@ class OtelMetricPublisherTest {
     private ExecutorService executor;
     private InMemoryMetricReader metricReader;
     private MetricPublisher metricPublisher;
+    private Attributes baseAttributes;
+    private static String basePrefix = "custom.prefix";
 
     @BeforeEach
     void setUp() {
@@ -39,6 +42,10 @@ void setUp() {
         // Set up an InMemoryMetricReader to capture metrics
         metricReader = InMemoryMetricReader.create();
 
+        // Setup some base attributes
+        baseAttributes = Attributes.of(AttributeKey.stringKey("custom.dimension.key.1"), "CustomDimensionValue.1",
+                AttributeKey.stringKey("custom.dimension.key.2"), "CustomDimensionValue.2");
+
         // Set up the SdkMeterProvider with the metric reader
         SdkMeterProvider sdkMeterProvider = SdkMeterProvider.builder()
                 .registerMetricReader(metricReader)
@@ -53,7 +60,7 @@ void setUp() {
         GlobalOpenTelemetry.set(openTelemetrySdk);
 
         // Create an instance of OtelMetricPublisher
-        metricPublisher = new OtelMetricPublisher(GlobalOpenTelemetry.get(), "aws.sdk", executor);
+        metricPublisher = new OtelMetricPublisher(GlobalOpenTelemetry.get(), basePrefix, executor, baseAttributes);
     }
 
     @Test
@@ -75,7 +82,7 @@ public void testPublishMetrics() throws InterruptedException {
         assertEquals(1, exportedMetrics.size(), "Expected one metric to be exported");
 
         MetricData metricData = exportedMetrics.get(0);
-        assertEquals("aws.sdk.api_call_duration", metricData.getName());
+        assertEquals(basePrefix + ".api_call_duration", metricData.getName());
         assertEquals("The total time taken to finish a request (inclusive of all retries)", metricData.getDescription());
         assertEquals("ns", metricData.getUnit());
 
@@ -90,6 +97,10 @@ public void testPublishMetrics() throws InterruptedException {
         assertEquals("GetItem", point.getAttributes().get(AttributeKey.stringKey("request_operation_name")));
         assertEquals(true, point.getAttributes().get(AttributeKey.booleanKey("request_is_success")));
         assertEquals(0L, point.getAttributes().get(AttributeKey.longKey("request_retry_count")));
+        assertEquals("CustomDimensionValue.1", point.getAttributes()
+                .get(AttributeKey.stringKey("custom.dimension.key.1")));
+        assertEquals("CustomDimensionValue.2", point.getAttributes()
+                .get(AttributeKey.stringKey("custom.dimension.key.2")));
     }
 
     private MetricCollection createMockMetricCollection() {