otel: add null checks for retry instrumentation

Author: AgraVator

opentelemetry/src/main/java/io/grpc/opentelemetry/GrpcOpenTelemetry.java

@@ -65,8 +65,8 @@ public Stopwatch get() {
   };
 
   @VisibleForTesting
-  static boolean ENABLE_OTEL_TRACING = GrpcUtil.getFlag("GRPC_EXPERIMENTAL_ENABLE_OTEL_TRACING",
-      false);
+  static boolean ENABLE_OTEL_TRACING =
+      GrpcUtil.getFlag("GRPC_EXPERIMENTAL_ENABLE_OTEL_TRACING", false);
 
   private final OpenTelemetry openTelemetrySdk;
   private final MeterProvider meterProvider;
@@ -242,8 +242,7 @@ static OpenTelemetryMetricsResource createMetricInstruments(Meter meter,
               .build());
     }
 
-    if (isMetricEnabled("grpc.client.call.retries", enableMetrics,
-        disableDefault)) {
+    if (isMetricEnabled("grpc.client.call.retries", enableMetrics, disableDefault)) {
       builder.clientCallRetriesCounter(
           meter.histogramBuilder(
                   "grpc.client.call.retries")
@@ -254,14 +253,13 @@ static OpenTelemetryMetricsResource createMetricInstruments(Meter meter,
               .build());
     }
 
-    if (isMetricEnabled("grpc.client.call.retry_delay", enableMetrics,
-        disableDefault)) {
+    if (isMetricEnabled("grpc.client.call.retry_delay", enableMetrics, disableDefault)) {
       builder.clientCallRetryDelayCounter(
           meter.histogramBuilder(
                   "grpc.client.call.retry_delay")
               .setUnit("s")
-              .setDescription("Total time of delay while there is no active attempt during the " +
-                  "client call")
+              .setDescription("Total time of delay while there is no active attempt during the "
+                  + "client call")
               .setExplicitBucketBoundariesAdvice(LATENCY_BUCKETS)
               .build());
     }

opentelemetry/src/main/java/io/grpc/opentelemetry/OpenTelemetryMetricsModule.java

@@ -416,29 +416,32 @@ void recordFinishedCall() {
       }
       callLatencyNanos = callStopWatch.elapsed(TimeUnit.NANOSECONDS);
 
-      if (module.resource.clientCallDurationCounter() != null) {
-        long retriesPerCall = 0;
-        long attempts = attemptsPerCall.get();
-        if (attempts > 0) {
-          retriesPerCall = attempts - 1;
-        }
-
-        // Base attributes
-        io.opentelemetry.api.common.Attributes baseAttributes =
-            io.opentelemetry.api.common.Attributes.of(
-                METHOD_KEY, fullMethodName,
-                TARGET_KEY, target
-        );
+      // Base attributes
+      io.opentelemetry.api.common.Attributes baseAttributes =
+          io.opentelemetry.api.common.Attributes.of(
+              METHOD_KEY, fullMethodName,
+              TARGET_KEY, target
+          );
 
-        // Duration
+      // Duration
+      if (module.resource.clientCallDurationCounter() != null) {
         module.resource.clientCallDurationCounter().record(
             callLatencyNanos * SECONDS_PER_NANO,
             baseAttributes.toBuilder()
                 .put(STATUS_KEY, status.getCode().toString())
                 .build()
         );
+      }
+
+      // Retry counts
+      if (module.resource.clientCallRetriesCounter() != null) {
+
+        long retriesPerCall = 0;
+        long attempts = attemptsPerCall.get();
+        if (attempts > 0) {
+          retriesPerCall = attempts - 1;
+        }
 
-        // Retry counts
         module.resource.clientCallRetriesCounter().record(
             retriesPerCall,
             baseAttributes.toBuilder()
@@ -452,8 +455,10 @@ void recordFinishedCall() {
                 .put(RETRY_TYPE_KEY, OpenTelemetryConstants.RetryType.TRANSPARENT.getValue())
                 .build()
         );
+      }
 
-        // Retry delay
+      // Retry delay
+      if (module.resource.clientCallRetryDelayCounter() != null) {
         module.resource.clientCallRetryDelayCounter().record(
             retryDelayNanos / NANOS_PER_SEC,
             baseAttributes