[HLRC] Added support for CCR Stats API

client/rest-high-level/src/main/java/org/elasticsearch/client/CcrClient.java

@@ -20,6 +20,8 @@
 package org.elasticsearch.client;
 
 import org.elasticsearch.action.ActionListener;
+import org.elasticsearch.client.ccr.CcrStatsRequest;
+import org.elasticsearch.client.ccr.CcrStatsResponse;
 import org.elasticsearch.client.ccr.DeleteAutoFollowPatternRequest;
 import org.elasticsearch.client.ccr.GetAutoFollowPatternRequest;
 import org.elasticsearch.client.ccr.GetAutoFollowPatternResponse;
@@ -360,4 +362,48 @@ public void getAutoFollowPatternAsync(GetAutoFollowPatternRequest request,
         );
     }
 
+    /**
+     * Gets all CCR stats.
+     *
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ccr-get-stats.html">
+     * the docs</a> for more.
+     *
+     * @param request the request
+     * @param options the request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     * @return the response
+     * @throws IOException in case there is a problem sending the request or parsing back the response
+     */
+    public CcrStatsResponse getCcrStats(CcrStatsRequest request,
+                                        RequestOptions options) throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(
+            request,
+            CcrRequestConverters::getCcrStats,
+            options,
+            CcrStatsResponse::fromXContent,
+            Collections.emptySet()
+        );
+    }
+
+    /**
+     * Gets all CCR stats.
+     *
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ccr-get-stats.html">
+     * the docs</a> for more.
+     *
+     * @param request the request
+     * @param options the request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     */
+    public void getCcrStatsAsync(CcrStatsRequest request,
+                                 RequestOptions options,
+                                 ActionListener<CcrStatsResponse> listener) {
+        restHighLevelClient.performRequestAsyncAndParseEntity(
+            request,
+            CcrRequestConverters::getCcrStats,
+            options,
+            CcrStatsResponse::fromXContent,
+            listener,
+            Collections.emptySet()
+        );
+    }
+
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/CcrRequestConverters.java

@@ -23,6 +23,7 @@
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.client.methods.HttpPut;
+import org.elasticsearch.client.ccr.CcrStatsRequest;
 import org.elasticsearch.client.ccr.DeleteAutoFollowPatternRequest;
 import org.elasticsearch.client.ccr.GetAutoFollowPatternRequest;
 import org.elasticsearch.client.ccr.PauseFollowRequest;
@@ -100,4 +101,11 @@ static Request getAutoFollowPattern(GetAutoFollowPatternRequest getAutoFollowPat
         return new Request(HttpGet.METHOD_NAME, endpoint);
     }
 
+    static Request getCcrStats(CcrStatsRequest ccrStatsRequest) {
+        String endpoint = new RequestConverters.EndpointBuilder()
+            .addPathPartAsIs("_ccr", "stats")
+            .build();
+        return new Request(HttpGet.METHOD_NAME, endpoint);
+    }
+
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/ccr/AutoFollowStats.java

@@ -0,0 +1,105 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.client.ccr;
+
+import org.elasticsearch.ElasticsearchException;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+
+import java.util.AbstractMap;
+import java.util.List;
+import java.util.Map;
+import java.util.NavigableMap;
+import java.util.TreeMap;
+import java.util.stream.Collectors;
+
+public final class AutoFollowStats {
+
+    static final ParseField NUMBER_OF_SUCCESSFUL_INDICES_AUTO_FOLLOWED = new ParseField("number_of_successful_follow_indices");
+    static final ParseField NUMBER_OF_FAILED_INDICES_AUTO_FOLLOWED = new ParseField("number_of_failed_follow_indices");
+    static final ParseField NUMBER_OF_FAILED_REMOTE_CLUSTER_STATE_REQUESTS =
+        new ParseField("number_of_failed_remote_cluster_state_requests");
+    static final ParseField RECENT_AUTO_FOLLOW_ERRORS = new ParseField("recent_auto_follow_errors");
+    static final ParseField LEADER_INDEX = new ParseField("leader_index");
+    static final ParseField AUTO_FOLLOW_EXCEPTION = new ParseField("auto_follow_exception");
+
+    @SuppressWarnings("unchecked")
+    static final ConstructingObjectParser<AutoFollowStats, Void> STATS_PARSER = new ConstructingObjectParser<>("auto_follow_stats",
+        args -> new AutoFollowStats(
+            (Long) args[0],
+            (Long) args[1],
+            (Long) args[2],
+            new TreeMap<>(
+                ((List<Map.Entry<String, ElasticsearchException>>) args[3])
+                    .stream()
+                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)))
+        ));
+
+    private static final ConstructingObjectParser<Map.Entry<String, ElasticsearchException>, Void> AUTO_FOLLOW_EXCEPTIONS_PARSER =
+        new ConstructingObjectParser<>(
+            "auto_follow_stats_errors",
+            args -> new AbstractMap.SimpleEntry<>((String) args[0], (ElasticsearchException) args[1]));
+
+    static {
+        AUTO_FOLLOW_EXCEPTIONS_PARSER.declareString(ConstructingObjectParser.constructorArg(), LEADER_INDEX);
+        AUTO_FOLLOW_EXCEPTIONS_PARSER.declareObject(
+            ConstructingObjectParser.constructorArg(),
+            (p, c) -> ElasticsearchException.fromXContent(p),
+            AUTO_FOLLOW_EXCEPTION);
+
+        STATS_PARSER.declareLong(ConstructingObjectParser.constructorArg(), NUMBER_OF_FAILED_INDICES_AUTO_FOLLOWED);
+        STATS_PARSER.declareLong(ConstructingObjectParser.constructorArg(), NUMBER_OF_FAILED_REMOTE_CLUSTER_STATE_REQUESTS);
+        STATS_PARSER.declareLong(ConstructingObjectParser.constructorArg(), NUMBER_OF_SUCCESSFUL_INDICES_AUTO_FOLLOWED);
+        STATS_PARSER.declareObjectArray(ConstructingObjectParser.constructorArg(), AUTO_FOLLOW_EXCEPTIONS_PARSER,
+            RECENT_AUTO_FOLLOW_ERRORS);
+    }
+
+    private final long numberOfFailedFollowIndices;
+    private final long numberOfFailedRemoteClusterStateRequests;
+    private final long numberOfSuccessfulFollowIndices;
+    private final NavigableMap<String, ElasticsearchException> recentAutoFollowErrors;
+
+    AutoFollowStats(long numberOfFailedFollowIndices,
+                    long numberOfFailedRemoteClusterStateRequests,
+                    long numberOfSuccessfulFollowIndices,
+                    NavigableMap<String, ElasticsearchException> recentAutoFollowErrors) {
+        this.numberOfFailedFollowIndices = numberOfFailedFollowIndices;
+        this.numberOfFailedRemoteClusterStateRequests = numberOfFailedRemoteClusterStateRequests;
+        this.numberOfSuccessfulFollowIndices = numberOfSuccessfulFollowIndices;
+        this.recentAutoFollowErrors = recentAutoFollowErrors;
+    }
+
+    public long getNumberOfFailedFollowIndices() {
+        return numberOfFailedFollowIndices;
+    }
+
+    public long getNumberOfFailedRemoteClusterStateRequests() {
+        return numberOfFailedRemoteClusterStateRequests;
+    }
+
+    public long getNumberOfSuccessfulFollowIndices() {
+        return numberOfSuccessfulFollowIndices;
+    }
+
+    public NavigableMap<String, ElasticsearchException> getRecentAutoFollowErrors() {
+        return recentAutoFollowErrors;
+    }
+
+}

client/rest-high-level/src/main/java/org/elasticsearch/client/ccr/CcrStatsRequest.java

@@ -0,0 +1,25 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.client.ccr;
+
+import org.elasticsearch.client.Validatable;
+
+public final class CcrStatsRequest implements Validatable {
+}

client/rest-high-level/src/main/java/org/elasticsearch/client/ccr/CcrStatsResponse.java

@@ -0,0 +1,62 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.client.ccr;
+
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.XContentParser;
+
+public final class CcrStatsResponse {
+
+    static final ParseField AUTO_FOLLOW_STATS_FIELD = new ParseField("auto_follow_stats");
+    static final ParseField FOLLOW_STATS_FIELD = new ParseField("follow_stats");
+
+    private static final ConstructingObjectParser<CcrStatsResponse, Void> PARSER = new ConstructingObjectParser<>("indices",
+        args -> {
+            AutoFollowStats autoFollowStats = (AutoFollowStats) args[0];
+            IndicesFollowStats indicesFollowStats = (IndicesFollowStats) args[1];
+            return new CcrStatsResponse(autoFollowStats, indicesFollowStats);
+        });
+
+    static {
+        PARSER.declareObject(ConstructingObjectParser.constructorArg(), AutoFollowStats.STATS_PARSER, AUTO_FOLLOW_STATS_FIELD);
+        PARSER.declareObject(ConstructingObjectParser.constructorArg(), IndicesFollowStats.PARSER, FOLLOW_STATS_FIELD);
+    }
+
+    public static CcrStatsResponse fromXContent(XContentParser parser) {
+        return PARSER.apply(parser, null);
+    }
+
+    private final AutoFollowStats autoFollowStats;
+    private final IndicesFollowStats indicesFollowStats;
+
+    public CcrStatsResponse(AutoFollowStats autoFollowStats, IndicesFollowStats indicesFollowStats) {
+        this.autoFollowStats = autoFollowStats;
+        this.indicesFollowStats = indicesFollowStats;
+    }
+
+    public AutoFollowStats getAutoFollowStats() {
+        return autoFollowStats;
+    }
+
+    public IndicesFollowStats getIndicesFollowStats() {
+        return indicesFollowStats;
+    }
+}