change aggregation temporality to DELTA instead of CUMULATIVE (#4111)

Author: Blazer-007

gobblin-metrics-libs/gobblin-metrics/src/main/java/org/apache/gobblin/metrics/OpenTelemetryMetrics.java

@@ -33,6 +33,7 @@
 import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporterBuilder;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
 import io.opentelemetry.sdk.metrics.SdkMeterProvider;
+import io.opentelemetry.sdk.metrics.export.AggregationTemporalitySelector;
 import io.opentelemetry.sdk.metrics.export.MetricExporter;
 import io.opentelemetry.sdk.metrics.export.PeriodicMetricReader;
 import io.opentelemetry.sdk.resources.Resource;
@@ -86,6 +87,7 @@ protected MetricExporter initializeMetricExporter(State state) {
         httpExporterBuilder.addHeader(header.getKey(), header.getValue());
       }
     }
+    httpExporterBuilder.setAggregationTemporalitySelector(AggregationTemporalitySelector.deltaPreferred());
     return httpExporterBuilder.build();
   }
 

gobblin-temporal/src/main/java/org/apache/gobblin/temporal/workflows/metrics/TemporalMetricsHelper.java

@@ -33,6 +33,7 @@
 
 import io.micrometer.core.instrument.Clock;
 import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.registry.otlp.AggregationTemporality;
 import io.micrometer.registry.otlp.OtlpConfig;
 import io.micrometer.registry.otlp.OtlpMeterRegistry;
 import io.temporal.common.reporter.MicrometerClientStatsReporter;
@@ -91,6 +92,12 @@ public String prefix() {
         return GobblinTemporalConfigurationKeys.TEMPORAL_METRICS_OTLP_PREFIX_WITHOUT_DOT;
       }
 
+      @NotNull
+      @Override
+      public AggregationTemporality aggregationTemporality() {
+        return AggregationTemporality.DELTA;
+      }
+
       @NotNull
       @Override
       public Map<String, String> headers() {