Default OpenSearch source serverless search context to point_in_time (#6756)

Signed-off-by: Srikanth Padakanti <srikanth_padakanti@apple.com>
Co-authored-by: Srikanth Padakanti <srikanth_padakanti@apple.com>

Author: srikanthpadakanti

data-prepper-plugins/opensearch/src/main/java/org/opensearch/dataprepper/plugins/source/opensearch/worker/client/SearchAccessorStrategy.java

@@ -145,9 +145,9 @@ public SearchAccessor getSearchAccessor() {
 
     private SearchAccessor createSearchAccessorForServerlessCollection(final PluginComponentRefresher clientRefresher) {
         if (Objects.isNull(openSearchSourceConfiguration.getSearchConfiguration().getSearchContextType())) {
-            LOG.info("Configured with AOS serverless flag as true, defaulting to search_context_type as 'none', which uses search_after");
+            LOG.info("Configured with AOS serverless flag as true, defaulting to search_context_type as 'point_in_time'");
             return new OpenSearchAccessor(clientRefresher,
-                    SearchContextType.NONE);
+                    SearchContextType.POINT_IN_TIME);
         } else {
             if ( SearchContextType.SCROLL.equals(openSearchSourceConfiguration.getSearchConfiguration().getSearchContextType())) {
                 throw new InvalidPluginConfigurationException("A search_context_type of scroll is not supported for serverless collections");

data-prepper-plugins/opensearch/src/test/java/org/opensearch/dataprepper/plugins/source/opensearch/worker/client/SearchAccessStrategyTest.java

@@ -210,7 +210,7 @@ void search_context_type_set_to_none_uses_that_search_context_regardless_of_vers
     }
 
     @Test
-    void serverless_flag_true_defaults_to_search_context_type_none() {
+    void serverless_flag_true_defaults_to_search_context_type_point_in_time() {
 
         final AwsAuthenticationConfiguration awsAuthenticationConfiguration = mock(AwsAuthenticationConfiguration.class);
         when(awsAuthenticationConfiguration.isServerlessCollection()).thenReturn(true);
@@ -222,7 +222,7 @@ void serverless_flag_true_defaults_to_search_context_type_none() {
         final SearchAccessor searchAccessor = createObjectUnderTest().getSearchAccessor();
 
         assertThat(searchAccessor, notNullValue());
-        assertThat(searchAccessor.getSearchContextType(), equalTo(SearchContextType.NONE));
+        assertThat(searchAccessor.getSearchContextType(), equalTo(SearchContextType.POINT_IN_TIME));
         verifyNoInteractions(pluginConfigObservable);
     }
 
@@ -244,7 +244,7 @@ void serverless_flag_true_throws_InvalidPluginConfiguration_if_search_context_ty
     }
 
     @ParameterizedTest
-    @ValueSource(strings = {"NONE"})
+    @ValueSource(strings = {"NONE", "POINT_IN_TIME"})
     void serverless_flag_true_uses_search_context_type_from_config(final String searchContextType) {
 
         final AwsAuthenticationConfiguration awsAuthenticationConfiguration = mock(AwsAuthenticationConfiguration.class);