Add undeclared Azure settings, modify test to exercise them

docs/changelog/118634.yaml

@@ -0,0 +1,5 @@
+pr: 118634
+summary: "Add undeclared Azure settings, modify test to exercise them"
+area: Snapshot/Restore
+type: bug
+issues: []

modules/repository-azure/src/internalClusterTest/java/org/elasticsearch/repositories/azure/AzureBlobStoreRepositoryTests.java

@@ -31,6 +31,7 @@
 import org.elasticsearch.common.unit.ByteSizeUnit;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.core.SuppressForbidden;
+import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.plugins.PluginsService;
 import org.elasticsearch.repositories.RepositoriesService;
@@ -41,6 +42,7 @@
 import org.elasticsearch.telemetry.Measurement;
 import org.elasticsearch.telemetry.TestTelemetryPlugin;
 import org.elasticsearch.test.BackgroundIndexer;
+import org.elasticsearch.threadpool.ThreadPool;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -53,6 +55,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Predicate;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
@@ -75,6 +78,8 @@ public class AzureBlobStoreRepositoryTests extends ESMockAPIBasedRepositoryInteg
     protected static final String DEFAULT_ACCOUNT_NAME = "account";
     protected static final Predicate<String> LIST_PATTERN = Pattern.compile("GET /[a-zA-Z0-9]+/[a-zA-Z0-9]+\\?.+").asMatchPredicate();
     protected static final Predicate<String> GET_BLOB_PATTERN = Pattern.compile("GET /[a-zA-Z0-9]+/[a-zA-Z0-9]+/.+").asMatchPredicate();
+    private static final AtomicInteger MAX_CONNECTION_SETTING = new AtomicInteger(-1);
+    private static final AtomicInteger EVENT_LOOP_THREAD_COUNT_SETTING = new AtomicInteger(-1);
 
     @Override
     protected String repositoryType() {
@@ -132,9 +137,17 @@ protected Settings nodeSettings(int nodeOrdinal, Settings otherSettings) {
 
         // see com.azure.storage.blob.BlobUrlParts.parseIpUrl
         final String endpoint = "ignored;DefaultEndpointsProtocol=http;BlobEndpoint=" + httpServerUrl() + "/" + accountName;
+
+        // The first node configured sets these for all nodes
+        MAX_CONNECTION_SETTING.compareAndSet(-1, randomIntBetween(10, 30));
+        EVENT_LOOP_THREAD_COUNT_SETTING.compareAndSet(-1, randomIntBetween(1, 3));
         return Settings.builder()
             .put(super.nodeSettings(nodeOrdinal, otherSettings))
             .put(AzureStorageSettings.ENDPOINT_SUFFIX_SETTING.getConcreteSettingForNamespace("test").getKey(), endpoint)
+            .put(AzureClientProvider.EVENT_LOOP_THREAD_COUNT.getKey(), EVENT_LOOP_THREAD_COUNT_SETTING.get())
+            .put(AzureClientProvider.MAX_OPEN_CONNECTIONS.getKey(), MAX_CONNECTION_SETTING.get())
+            .put(AzureClientProvider.MAX_IDLE_TIME.getKey(), TimeValue.timeValueSeconds(randomIntBetween(10, 30)))
+            .put(AzureClientProvider.OPEN_CONNECTION_TIMEOUT.getKey(), TimeValue.timeValueSeconds(randomIntBetween(10, 30)))
             .setSecureSettings(secureSettings)
             .build();
     }
@@ -262,6 +275,16 @@ private boolean isPutBlockList(String request) {
         }
     }
 
+    public void testSettingsTakeEffect() {
+        AzureClientProvider azureClientProvider = internalCluster().getInstance(AzureClientProvider.class);
+        assertEquals(MAX_CONNECTION_SETTING.get(), azureClientProvider.getConnectionProvider().maxConnections());
+        ThreadPool nodeThreadPool = internalCluster().getInstance(ThreadPool.class);
+        assertEquals(
+            EVENT_LOOP_THREAD_COUNT_SETTING.get(),
+            nodeThreadPool.info(AzureRepositoryPlugin.NETTY_EVENT_LOOP_THREAD_POOL_NAME).getMax()
+        );
+    }
+
     public void testLargeBlobCountDeletion() throws Exception {
         int numberOfBlobs = randomIntBetween(257, 2000);
         try (BlobStore store = newBlobStore()) {

modules/repository-azure/src/main/java/org/elasticsearch/repositories/azure/AzureClientProvider.java

@@ -265,6 +265,11 @@ protected void doStop() {
     @Override
     protected void doClose() {}
 
+    // visible for testing
+    ConnectionProvider getConnectionProvider() {
+        return connectionProvider;
+    }
+
     static class RequestMetrics {
         private volatile long totalRequestTimeNanos = 0;
         private volatile int requestCount;

modules/repository-azure/src/main/java/org/elasticsearch/repositories/azure/AzureRepositoryPlugin.java

@@ -97,6 +97,10 @@ AzureStorageService createAzureStorageService(Settings settingsToUse, AzureClien
     @Override
     public List<Setting<?>> getSettings() {
         return Arrays.asList(
+            AzureClientProvider.EVENT_LOOP_THREAD_COUNT,
+            AzureClientProvider.MAX_OPEN_CONNECTIONS,
+            AzureClientProvider.OPEN_CONNECTION_TIMEOUT,
+            AzureClientProvider.MAX_IDLE_TIME,
             AzureStorageSettings.ACCOUNT_SETTING,
             AzureStorageSettings.KEY_SETTING,
             AzureStorageSettings.SAS_TOKEN_SETTING,