Move REST test

Author: smalyshev

x-pack/plugin/esql/qa/server/multi-clusters/src/javaRestTest/java/org/elasticsearch/xpack/esql/ccq/MultiClustersIT.java

@@ -12,6 +12,7 @@
 import org.apache.http.HttpHost;
 import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;
+import org.elasticsearch.client.Response;
 import org.elasticsearch.client.RestClient;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
@@ -37,9 +38,11 @@
 
 import static org.elasticsearch.test.MapMatcher.assertMap;
 import static org.elasticsearch.test.MapMatcher.matchesMap;
+import static org.elasticsearch.xpack.esql.ccq.Clusters.REMOTE_CLUSTER_NAME;
 import static org.hamcrest.Matchers.any;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.hamcrest.Matchers.hasKey;
 
 @ThreadLeakFilters(filters = TestClustersThreadFilter.class)
 public class MultiClustersIT extends ESRestTestCase {
@@ -395,6 +398,34 @@ public void testIndexPattern() throws Exception {
         }
     }
 
+    @SuppressWarnings("unchecked")
+    public void testStats() throws IOException {
+        assumeTrue("Older versions do not have ESQL stats", Clusters.localClusterVersion().onOrAfter(Version.V_8_18_0));
+        run("FROM test-local-index,*:test-remote-index | STATS total = SUM(data) BY color | SORT color", includeCCSMetadata());
+        Request stats = new Request("GET", "_cluster/stats");
+        Response statsResponse = client().performRequest(stats);
+        Map<String, Object> result = entityAsMap(statsResponse.getEntity());
+        assertThat(result, hasKey("ccs"));
+        Map<String, Object> ccs = (Map<String, Object>) result.get("ccs");
+        assertThat(ccs, hasKey("_esql"));
+        Map<String, Object> esql = (Map<String, Object>) ccs.get("_esql");
+        assertThat(esql, hasKey("total"));
+        assertThat(esql, hasKey("success"));
+        assertThat(esql, hasKey("took"));
+        assertThat(esql, hasKey("remotes_per_search_max"));
+        assertThat(esql, hasKey("remotes_per_search_avg"));
+        assertThat(esql, hasKey("failure_reasons"));
+        assertThat(esql, hasKey("features"));
+        assertThat(esql, hasKey("clusters"));
+        Map<String, Object> clusters = (Map<String, Object>) esql.get("clusters");
+        assertThat(clusters, hasKey(REMOTE_CLUSTER_NAME));
+        assertThat(clusters, hasKey("(local)"));
+        Map<String, Object> clusterData = (Map<String, Object>) clusters.get(REMOTE_CLUSTER_NAME);
+        assertThat(clusterData, hasKey("total"));
+        assertThat(clusterData, hasKey("skipped"));
+        assertThat(clusterData, hasKey("took"));
+    }
+
     private RestClient remoteClusterClient() throws IOException {
         var clusterHosts = parseClusterHosts(remoteCluster.getHttpAddresses());
         return buildClient(restClientSettings(), clusterHosts.toArray(new HttpHost[0]));