address comments

Author: rahul2393

java-spanner/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/EwmaLatencyTracker.java

@@ -127,6 +127,7 @@ public void recordError(Duration penalty) {
   private double calculateTimeBasedAlpha(long nowNanos) {
     long deltaNanos = nowNanos - lastUpdatedAtNanos;
     if (deltaNanos <= 0L) {
+      // concurrent or future samples get full weight.
       return 1.0;
     }
     double alpha = 1.0 - Math.exp(-(double) deltaNanos / (double) tauNanos);

java-spanner/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java

@@ -447,8 +447,15 @@ public GapicSpannerRpc(final SpannerOptions options) {
                 : streamingReadRetryableCodes;
         this.executeQueryRetrySettings =
             options.getSpannerStubSettings().executeStreamingSqlSettings().getRetrySettings();
-        this.executeQueryRetryableCodes =
+        Set<Code> executeStreamingSqlRetryableCodes =
             options.getSpannerStubSettings().executeStreamingSqlSettings().getRetryableCodes();
+        this.executeQueryRetryableCodes =
+            enableLocationApi
+                ? ImmutableSet.<Code>builder()
+                    .addAll(executeStreamingSqlRetryableCodes)
+                    .add(Code.RESOURCE_EXHAUSTED)
+                    .build()
+                : executeStreamingSqlRetryableCodes;
         this.commitRetrySettings =
             options.getSpannerStubSettings().commitSettings().getRetrySettings();
         partitionedDmlRetrySettings =

java-spanner/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpcTest.java

@@ -1081,6 +1081,27 @@ public boolean isEnableLocationApi() {
     }
   }
 
+  @Test
+  public void testExecuteQueryRetryableCodesIncludeResourceExhaustedWhenLocationApiEnabled() {
+    try {
+      SpannerOptions.useEnvironment(
+          new SpannerOptions.SpannerEnvironment() {
+            @Override
+            public boolean isEnableLocationApi() {
+              return true;
+            }
+          });
+      GapicSpannerRpc rpc = new GapicSpannerRpc(createSpannerOptions(), true);
+      try {
+        assertThat(rpc.getExecuteQueryRetryableCodes()).contains(Code.RESOURCE_EXHAUSTED);
+      } finally {
+        rpc.shutdown();
+      }
+    } finally {
+      SpannerOptions.useDefaultEnvironment();
+    }
+  }
+
   @Test
   public void testReadRetryableCodesDoNotAddResourceExhaustedWhenLocationApiDisabled() {
     try {
@@ -1107,6 +1128,32 @@ public boolean isEnableLocationApi() {
     }
   }
 
+  @Test
+  public void testExecuteQueryRetryableCodesDoNotAddResourceExhaustedWhenLocationApiDisabled() {
+    try {
+      SpannerOptions.useEnvironment(
+          new SpannerOptions.SpannerEnvironment() {
+            @Override
+            public boolean isEnableLocationApi() {
+              return false;
+            }
+          });
+      GapicSpannerRpc rpc = new GapicSpannerRpc(createSpannerOptions(), true);
+      try {
+        assertThat(rpc.getExecuteQueryRetryableCodes())
+            .isEqualTo(
+                createSpannerOptions()
+                    .getSpannerStubSettings()
+                    .executeStreamingSqlSettings()
+                    .getRetryableCodes());
+      } finally {
+        rpc.shutdown();
+      }
+    } finally {
+      SpannerOptions.useDefaultEnvironment();
+    }
+  }
+
   @Test
   public void testGrpcGcpExtensionPreservesChannelConfigurator() throws Exception {
     InstantiatingGrpcChannelProvider.Builder channelProviderBuilder =