Internal API: remove undocumented ElasticSearch API usage and use documented one (#10031)

docs/en/changes/changes.md

@@ -125,12 +125,13 @@
     25s period.
   * Fix ID conflicts for all JDBC storage implementations. Due to the insert delay, the JDBC storage implementation would
     still generate another new insert statement.
-* [**Breaking Change**] Remove `core/default/enableDatabaseSession` config. 
-* [**Breaking Change**] Add `@BanyanDB.TimestampColumn` to identify `which column in Record` is providing the timestamp(milliseconds) for BanyanDB, 
+* [**Breaking Change**] Remove `core/default/enableDatabaseSession` config.
+* [**Breaking Change**] Add `@BanyanDB.TimestampColumn` to identify `which column in Record` is providing the timestamp(milliseconds) for BanyanDB,
   since BanyanDB stream requires a timestamp in milliseconds.
   For SQL-Database: add new column `timestamp` for tables `profile_task_log/top_n_database_statement`,
   requires altering this column or removing these tables before OAP starts, if bump up from previous releases.
 * Fix Elasticsearch storage: In `No-Sharding Mode`, add specific analyzer to the template before index creation to avoid update index error.
+* Internal API: remove undocumented ElasticSearch API usage and use documented one.
 
 #### UI
 

oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/elasticsearch/ElasticSearchClient.java

@@ -314,7 +314,7 @@ public class ElasticSearchClient implements Client, HealthCheckable {
         indexIds.forEach((indexName, ids) -> {
             map.put(indexNameConverter.apply(indexName), ids);
         });
-        return es.get().documents().mGet(TYPE, map);
+        return es.get().documents().mget(TYPE, map);
     }
 
     /**

oap-server/server-library/library-elasticsearch-client/src/main/java/org/apache/skywalking/library/elasticsearch/client/DocumentClient.java

@@ -86,7 +86,7 @@ public final class DocumentClient {
     }
 
     @SneakyThrows
-    public Optional<Documents> mGet(String type, Map<String, List<String>> indexIds) {
+    public Optional<Documents> mget(String type, Map<String, List<String>> indexIds) {
         final CompletableFuture<Optional<Documents>> future =
             version.thenCompose(
                 v -> client.execute(v.requestFactory().document().mget(type, indexIds))

oap-server/server-library/library-elasticsearch-client/src/main/java/org/apache/skywalking/library/elasticsearch/requests/factory/v7plus/V7DocumentFactory.java

@@ -21,7 +21,6 @@ import com.google.common.collect.ImmutableMap;
 import com.linecorp.armeria.common.HttpRequest;
 import com.linecorp.armeria.common.HttpRequestBuilder;
 import com.linecorp.armeria.common.MediaType;
-import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -106,11 +105,11 @@ final class V7DocumentFactory implements DocumentFactory {
         final Map<String, Iterable<Map<String, String>>> m = ImmutableMap.of("docs", indexIdList);
         final byte[] content = version.codec().encode(m);
         if (log.isDebugEnabled()) {
-            log.debug("mget indexIds request: {}", new String(content, Charset.defaultCharset()));
+            log.debug("mget indexIds request: {}", new String(content));
         }
 
         return HttpRequest.builder()
-                          .get("/_doc/_mget")
+                          .get("/_mget")
                           .content(MediaType.JSON, content)
                           .build();
     }

oap-server/server-library/library-elasticsearch-client/src/test/java/org/apache/skywalking/library/elasticsearch/ITElasticSearchTest.java

@@ -325,7 +325,7 @@ public class ITElasticSearchTest {
                    //test mGet
                    Map<String, List<String>> indexIdsGroup = new HashMap<>();
                    indexIdsGroup.put("test-index", Arrays.asList("id1", "id2"));
-                   Optional<Documents> documents = client.documents().mGet(type, indexIdsGroup);
+                   Optional<Documents> documents = client.documents().mget(type, indexIdsGroup);
                    Map<String, Map<String, Object>> result = new HashMap<>();
                    for (final Document document : documents.get()) {
                        result.put(document.getId(), document.getSource());