review comments

Author: surbhigarg92

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

@@ -690,7 +690,7 @@ private static boolean isEmulatorEnabled(SpannerOptions options, String emulator
   }
 
   public static boolean isEnableAFEServerTiming() {
-    return !Boolean.parseBoolean(System.getenv("SPANNER_DISABLE_AFE_SERVER_TIMING"));
+    return "false".equalsIgnoreCase(System.getenv("SPANNER_DISABLE_AFE_SERVER_TIMING"));
   }
 
   private static final RetrySettings ADMIN_REQUESTS_LIMIT_EXCEEDED_RETRY_SETTINGS =

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

@@ -72,7 +72,7 @@ class HeaderInterceptor implements ClientInterceptor {
   private static final Metadata.Key<String> SERVER_TIMING_HEADER_KEY =
       Metadata.Key.of("server-timing", Metadata.ASCII_STRING_MARSHALLER);
   private static final String GFE_TIMING_HEADER = "gfet4t7";
-  private static final String AFE_TIMING_HEADER = "afet4t7";
+  private static final String AFE_TIMING_HEADER = "afe";
   private static final Metadata.Key<String> GOOGLE_CLOUD_RESOURCE_PREFIX_KEY =
       Metadata.Key.of("google-cloud-resource-prefix", Metadata.ASCII_STRING_MARSHALLER);
   private static final Pattern SERVER_TIMING_PATTERN =

google-cloud-spanner/src/test/java/com/google/cloud/spanner/AbstractNettyMockServerTest.java

@@ -76,7 +76,7 @@ public void sendHeaders(Metadata headers) {
                             headers.put(
                                 Metadata.Key.of("server-timing", Metadata.ASCII_STRING_MARSHALLER),
                                 String.format(
-                                    "afet4t7; dur=%d, gfet4t7; dur=%d",
+                                    "afe; dur=%d, gfet4t7; dur=%d",
                                     fakeAFEServerTiming.get(), fakeServerTiming.get()));
                             super.sendHeaders(headers);
                           }

google-cloud-spanner/src/test/java/com/google/cloud/spanner/OpenTelemetryBuiltInMetricsTracerTest.java

@@ -209,18 +209,8 @@ public void testMetricsSingleUseQuery() {
     long gfeLatencyValue = getAggregatedValue(gfeLatencyMetricData, expectedAttributes);
     assertEquals(fakeServerTiming.get(), gfeLatencyValue, 0);
 
-    MetricData afeLatencyMetricData =
-        getMetricData(metricReader, BuiltInMetricsConstant.AFE_LATENCIES_NAME);
-    long afeLatencyValue = getAggregatedValue(afeLatencyMetricData, expectedAttributes);
-    assertEquals(fakeAFEServerTiming.get(), afeLatencyValue, 0);
-
-    MetricData gfeConnectivityMetricData =
-        getMetricData(metricReader, BuiltInMetricsConstant.GFE_CONNECTIVITY_ERROR_NAME);
-    assertThat(getAggregatedValue(gfeConnectivityMetricData, expectedAttributes)).isEqualTo(0);
-
-    MetricData afeConnectivityMetricData =
-        getMetricData(metricReader, BuiltInMetricsConstant.AFE_CONNECTIVITY_ERROR_NAME);
-    assertThat(getAggregatedValue(afeConnectivityMetricData, expectedAttributes)).isEqualTo(0);
+    assertFalse(checkIfMetricExists(metricReader, BuiltInMetricsConstant.AFE_LATENCIES_NAME));
+    assertFalse(checkIfMetricExists(metricReader, BuiltInMetricsConstant.AFE_CONNECTIVITY_ERROR_NAME));
   }
 
   @Test
@@ -400,10 +390,7 @@ public void testNoServerTimingHeader() throws IOException, InterruptedException
     MetricData gfeConnectivityMetricData =
         getMetricData(metricReader, BuiltInMetricsConstant.GFE_CONNECTIVITY_ERROR_NAME);
     assertThat(getAggregatedValue(gfeConnectivityMetricData, expectedAttributes)).isEqualTo(1);
-
-    MetricData afeConnectivityMetricData =
-        getMetricData(metricReader, BuiltInMetricsConstant.AFE_CONNECTIVITY_ERROR_NAME);
-    assertThat(getAggregatedValue(afeConnectivityMetricData, expectedAttributes)).isEqualTo(1);
+    assertFalse(checkIfMetricExists(metricReader, BuiltInMetricsConstant.AFE_CONNECTIVITY_ERROR_NAME));
     spannerNoHeader.close();
     serverNoHeader.shutdown();
     serverNoHeader.awaitTermination();
@@ -442,6 +429,27 @@ private MetricData getMetricData(InMemoryMetricReader reader, String metricName)
     return null;
   }
 
+  private boolean checkIfMetricExists(InMemoryMetricReader reader, String metricName) {
+    String fullMetricName = BuiltInMetricsConstant.METER_NAME + "/" + metricName;
+
+    for (int attemptsLeft = 1000; attemptsLeft > 0; attemptsLeft--) {
+      boolean exists = reader.collectAllMetrics().stream()
+          .anyMatch(md -> md.getName().equals(fullMetricName));
+      if (exists) {
+        return true;
+      }
+      try {
+        Thread.sleep(1);
+      } catch (InterruptedException e) {
+        Thread.currentThread().interrupt();
+        throw new RuntimeException(e);
+      }
+    }
+
+    return false;
+  }
+
+
   private long getAggregatedValue(MetricData metricData, Attributes attributes) {
     switch (metricData.getType()) {
       case HISTOGRAM: