Using CoundDownLatch

Signed-off-by: Dharmesh 💤 <sdharms@amazon.com>

server/src/main/java/org/opensearch/action/admin/cluster/remotestore/RemoteStoreService.java

@@ -26,8 +26,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Supplier;
 
@@ -86,23 +85,28 @@ public RemoteStoreService(Supplier<RepositoriesService> repositoriesService, Thr
     public void verifyRepository(List<Repository> repositories, DiscoveryNode localNode) {
         for (Repository repository : repositories) {
             String verificationToken = repository.startVerification();
-            ExecutorService executor = threadPool.executor(ThreadPool.Names.GENERIC);
-            executor.execute(() -> {
+            String repositoryName = repository.getMetadata().name();
+            CountDownLatch repositoryVerificationLatch = new CountDownLatch(1);
+            threadPool.executor(ThreadPool.Names.GENERIC).execute(() -> {
                 try {
                     repository.verify(verificationToken, localNode);
+                    logger.info(() -> new ParameterizedMessage("successfully verified [{}] repository", repositoryName));
+                    repositoryVerificationLatch.countDown();
                 } catch (Exception e) {
                     logger.warn(() -> new ParameterizedMessage("[{}] failed to verify repository", repository), e);
-                    throw new RepositoryVerificationException(repository.getMetadata().name(), e.getMessage());
+                    throw new RepositoryVerificationException(repositoryName, e.getMessage());
                 }
             });
 
             // TODO: See if using listener here which is async makes sense, made this sync as
-            //  we need the repository registration for remote store node to be completed before the bootstrap
-            //  completes.
+            // we need the repository registration for remote store node to be completed before the bootstrap
+            // completes.
             try {
-                if(executor.awaitTermination(5000, TimeUnit.MILLISECONDS)) {
-                    throw new RepositoryVerificationException(repository.getMetadata().name(), "could not complete " +
-                        "repository verification within timeout.");
+                if (repositoryVerificationLatch.await(1000, TimeUnit.MILLISECONDS) == false) {
+                    throw new RepositoryVerificationException(
+                        repository.getMetadata().name(),
+                        "could not complete " + "repository verification within timeout."
+                    );
                 }
             } catch (InterruptedException e) {
                 throw new RepositoryVerificationException(repository.getMetadata().name(), e.getMessage());