Rename IgnoreNoResponseMetricsCollector (elastic#125934)

Originally this metrics collector was just there to ignore API calls
that didn't make it all the way to S3, but (a) it doesn't really do that
because it also apparently ignores 4xx responses and (b) it also does a
bunch of other metrics collection too. `IgnoreNoResponseMetricsCollector`
is definitely the wrong name these days so this commit renames it to
something more general.

Author: DaveCTurner

modules/repository-s3/src/internalClusterTest/java/org/elasticsearch/repositories/s3/S3BlobStoreRepositoryTests.java

@@ -285,7 +285,7 @@ public void testMetrics() throws Exception {
             final BlobStore blobStore = blobStoreRepository.blobStore();
             final BlobStore delegateBlobStore = ((BlobStoreWrapper) blobStore).delegate();
             final S3BlobStore s3BlobStore = (S3BlobStore) delegateBlobStore;
-            final Map<S3BlobStore.StatsKey, S3BlobStore.IgnoreNoResponseMetricsCollector> statsCollectors = s3BlobStore
+            final Map<S3BlobStore.StatsKey, S3BlobStore.ElasticsearchS3MetricsCollector> statsCollectors = s3BlobStore
                 .getStatsCollectors().collectors;
 
             final var plugins = internalCluster().getInstance(PluginsService.class, nodeName)

modules/repository-s3/src/main/java/org/elasticsearch/repositories/s3/S3BlobStore.java

@@ -143,16 +143,17 @@ public TimeValue getCompareAndExchangeAntiContentionDelay() {
         return service.compareAndExchangeAntiContentionDelay;
     }
 
-    // metrics collector that ignores null responses that we interpret as the request not reaching the S3 endpoint due to a network
-    // issue
-    class IgnoreNoResponseMetricsCollector extends RequestMetricCollector {
+    /**
+     * A {@link RequestMetricCollector} that processes the metrics related to each API invocation attempt according to Elasticsearch's needs
+     */
+    class ElasticsearchS3MetricsCollector extends RequestMetricCollector {
 
         final LongAdder requests = new LongAdder();
         final LongAdder operations = new LongAdder();
         private final Operation operation;
         private final Map<String, Object> attributes;
 
-        private IgnoreNoResponseMetricsCollector(Operation operation, OperationPurpose purpose) {
+        private ElasticsearchS3MetricsCollector(Operation operation, OperationPurpose purpose) {
             this.operation = operation;
             this.attributes = RepositoriesMetrics.createAttributesMap(repositoryMetadata, purpose, operation.getKey());
         }
@@ -582,7 +583,7 @@ public String toString() {
     }
 
     class StatsCollectors {
-        final Map<StatsKey, IgnoreNoResponseMetricsCollector> collectors = new ConcurrentHashMap<>();
+        final Map<StatsKey, ElasticsearchS3MetricsCollector> collectors = new ConcurrentHashMap<>();
 
         RequestMetricCollector getMetricCollector(Operation operation, OperationPurpose purpose) {
             return collectors.computeIfAbsent(new StatsKey(operation, purpose), k -> buildMetricCollector(k.operation(), k.purpose()));
@@ -605,8 +606,8 @@ Map<String, BlobStoreActionStats> statsMap(boolean isStateless) {
             }
         }
 
-        IgnoreNoResponseMetricsCollector buildMetricCollector(Operation operation, OperationPurpose purpose) {
-            return new IgnoreNoResponseMetricsCollector(operation, purpose);
+        ElasticsearchS3MetricsCollector buildMetricCollector(Operation operation, OperationPurpose purpose) {
+            return new ElasticsearchS3MetricsCollector(operation, purpose);
         }
     }