Updating the developer guide

Signed-off-by: Vacha Shah <vachshah@amazon.com>

DEVELOPER_GUIDE.md

@@ -67,10 +67,10 @@ Run integration tests after starting OpenSearch cluster:
 
 #### AWS Transport Integration Tests
 
-To run integration tests for the AWS transport client, ensure working AWS credentials and specify your OpenSearch domain and region as follows:
+To run integration tests for the AWS transport client, ensure working AWS credentials in `/.aws/credentials` and specify your OpenSearch domain and region as follows:
 
 ```
-./gradlew integrationTest --tests "*AwsSdk2*" -Dtests.awsSdk2support.domainHost=search-...us-west-2.es.amazonaws.com -Dtests.awsSdk2support.domainRegion=us-west-2
+./gradlew integrationTest --tests "*AwsSdk2*" -Dtests.awsSdk2support.domainHost=search-...us-west-2.es.amazonaws.com -Dtests.awsSdk2support.domainRegion=us-west-2 -Dtests.awsSdk2support.serviceName=es
 ```
 
 For OpenSearch Serverless, change the signing service name.

java-client/src/test/java/org/opensearch/client/opensearch/integTest/aws/AwsSdk2SearchIT.java

@@ -56,7 +56,8 @@ void testClient(boolean async) throws Exception {
         addDoc(client, "id2", doc2);
         SimplePojo doc3 = getLongDoc("Long Document 3", 1000000);
         addDoc(client, "id3", doc3);
-
+
+        // wait for the document to index
         Thread.sleep(1000);
 
         SearchResponse<SimplePojo> response = query(client, "NotPresent", null);
@@ -86,8 +87,9 @@ void testClientAsync(boolean async) throws Exception {
         CompletableFuture<IndexResponse> add3 = CompletableFuture.allOf(add1, add2).thenCompose(
                 unused -> addDoc(client, "id3", doc3));
 
+        // wait for the document to index
         Thread.sleep(1000);
-        
+
         List<SearchResponse<SimplePojo>> results = add3.thenCompose(unused -> {
             CompletableFuture<SearchResponse<SimplePojo>> r1 = query(client, "NotPresent", null);
             CompletableFuture<SearchResponse<SimplePojo>> r2 = query(client, "Document", null);