[CALCITE-6725] The caching mechanism key in ElasticsearchSchemaFactor…

…y is affected by the order of hosts

Update ElasticsearchSchemaFactory.java

Add unit test

add unit test

Modify code implementation and unit test

Reformat code

Test unit is compatible with Java8

Reformat code

Reformat code

Reformat code

Add jira link

elasticsearch/src/main/java/org/apache/calcite/adapter/elasticsearch/ElasticsearchSchemaFactory.java

@@ -45,6 +45,7 @@
 import java.io.IOException;
 import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -159,6 +160,8 @@ public ElasticsearchSchemaFactory() {
         throw new IllegalArgumentException
         ("Both 'coordinates' and 'hosts' is missing in configuration. Provide one of them.");
       }
+      List<HttpHost> sortedHost = getSortedHost(hosts);
+
       final String pathPrefix = (String) map.get("pathPrefix");
 
       // Enable or Disable SSL Verification
@@ -174,7 +177,7 @@ public ElasticsearchSchemaFactory() {
       String username = (String) map.get("username");
       String password = (String) map.get("password");
       final RestClient client =
-          connect(hosts, pathPrefix, username, password, disableSSLVerification);
+          connect(sortedHost, pathPrefix, username, password, disableSSLVerification);
       final String index = (String) map.get("index");
 
       return new ElasticsearchSchema(client, new ObjectMapper(), index);
@@ -183,6 +186,15 @@ public ElasticsearchSchemaFactory() {
     }
   }
 
+  protected static List<HttpHost> getSortedHost(List<HttpHost> hosts) {
+    List<HttpHost> sortedHosts =
+        hosts
+            .stream()
+            .sorted(Comparator.comparing(HttpHost::toString, String::compareTo))
+            .collect(Collectors.toList());
+    return sortedHosts;
+  }
+
   /**
    * Builds Elastic rest client from user configuration.
    *

elasticsearch/src/test/java/org/apache/calcite/adapter/elasticsearch/ElasticSearchAdapterTest.java

@@ -26,6 +26,8 @@
 import org.apache.calcite.util.Bug;
 import org.apache.calcite.util.TestUtil;
 
+import org.apache.http.HttpHost;
+
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.io.LineProcessor;
@@ -53,6 +55,7 @@
 import java.util.Map;
 import java.util.function.Consumer;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import static java.util.Objects.requireNonNull;
@@ -771,4 +774,21 @@ private static Consumer<ResultSet> sortedResultSetChecker(String column,
             "state=AR; EXPR$1=3; EXPR$2=3");
   }
 
+  /**
+   * Test case for
+   * <a href="https://issues.apache.org/jira/browse/CALCITE-6725">[CALCITE-6725]
+   * The caching mechanism key in ElasticsearchSchemaFactory is affected by the order of hosts</a>.
+   */
+  @Test void testSortHosts() {
+    HttpHost host1 = HttpHost.create("192.168.1.200:8080");
+    HttpHost host2 = HttpHost.create("192.168.1.100:8080");
+    HttpHost host3 = HttpHost.create("192.168.1.150:8080");
+    List<HttpHost> hosts = Arrays.asList(host1, host2, host3);
+    List<HttpHost> sortedHosts = ElasticsearchSchemaFactory.getSortedHost(hosts);
+    assertEquals(3, sortedHosts.size());
+    assertEquals("http://192.168.1.100:8080", sortedHosts.get(0).toString());
+    assertEquals("http://192.168.1.150:8080", sortedHosts.get(1).toString());
+    assertEquals("http://192.168.1.200:8080", sortedHosts.get(2).toString());
+  }
+
 }