Simplify indices stats API

Note: This breaks backward compatibility

* Removed clear/all parameters, now all stats are returned by default
* Made the metrics part of the URL
* Removed a lot of handlers
* Added shards/indices/cluster level paremeter to change response serialization
* Returning translog statistics in IndicesStats
* Added TranslogStats class
* Added IndexShard.translogStats() method to get the stats from concrete implementation
* Updated documentation

Closes #4054

docs/reference/indices/stats.asciidoc

@@ -20,8 +20,8 @@ Specific index stats can be retrieved using:
 curl localhost:9200/index1,index2/_stats
 --------------------------------------------------
 
-By default, `docs`, `store`, and `indexing`, `get`, and `search` stats
-are returned, other stats can be enabled as well:
+By default, all stats are returned, returning only specific stats can be
+specified as well in the URI. Those stats can be any of:
 
 [horizontal]
 `docs`:: 		The number of docs / deleted docs (docs not yet merged out).
@@ -45,7 +45,6 @@ are returned, other stats can be enabled as well:
 `flush`:: 		Flush statistics.
 `completion`:: 		Completion suggest statistics.
 `refresh`:: 	Refresh statistics.
-`clear`:: 		Clears all the flags (first).
 
 Some statistics allow per field granularity which accepts a list comma-separated list of included fields. By default all fields are included:
 
@@ -58,14 +57,12 @@ Here are some samples:
 
 [source,js]
 --------------------------------------------------
-# Get back stats for merge and refresh on top of the defaults
-curl 'localhost:9200/_stats?merge=true&refresh=true'
-# Get back stats just for flush
-curl 'localhost:9200/_stats?clear=true&flush=true'
+# Get back stats for merge and refresh only for all indices
+curl 'localhost:9200/_stats/merge,refresh'
 # Get back stats for type1 and type2 documents for the my_index index
-curl 'localhost:9200/my_index/_stats?clear=true&indexing=true&types=type1,type2
+curl 'localhost:9200/my_index/_stats/indexing?types=type1,type2
 # Get back just search stats for group1 and group2
-curl 'localhost:9200/_stats?clear=true&search=true&groups=group1,group2
+curl 'localhost:9200/_stats/search?groups=group1,group2
 --------------------------------------------------
 
 The stats returned are aggregated on the index level, with
@@ -77,22 +74,3 @@ they are created on other nodes. On the other hand, even though a shard
 "left" a node, that node will still retain the stats that shard
 contributed to.
 
-[float]
-=== Specific stats endpoints
-
-Instead of using flags to indicate which stats to return, specific REST
-endpoints can be used, for example:
-
-[source,js]
---------------------------------------------------
-# Merge stats across all indices
-curl localhost:9200/_stats/merge
-# Merge stats for the my_index index
-curl localhost:9200/my_index/_stats/merge
-# Indexing stats for my_index
-curl localhost:9200/my_index/_stats/indexing
-# Indexing stats for my_index for my_type1 and my_type2
-curl localhost:9200/my_index/_stats/indexing/my_type1,my_type2
-# Search stats for group1 and group2
-curl 'localhost:9200/_stats/search/group1,group2
---------------------------------------------------

src/main/java/org/elasticsearch/action/admin/indices/stats/CommonStats.java

@@ -40,6 +40,7 @@
 import org.elasticsearch.index.shard.DocsStats;
 import org.elasticsearch.index.shard.service.IndexShard;
 import org.elasticsearch.index.store.StoreStats;
+import org.elasticsearch.index.translog.TranslogStats;
 import org.elasticsearch.index.warmer.WarmerStats;
 import org.elasticsearch.search.suggest.completion.CompletionStats;
 
@@ -103,6 +104,9 @@ public CommonStats(CommonStatsFlags flags) {
                 case Percolate:
                     percolate = new PercolateStats();
                     break;
+                case Translog:
+                    translog = new TranslogStats();
+                    break;
                 default:
                     throw new IllegalStateException("Unknown Flag: " + flag);
             }
@@ -160,6 +164,9 @@ public CommonStats(IndexShard indexShard, CommonStatsFlags flags) {
                 case Percolate:
                     percolate = indexShard.shardPercolateService().stats();
                     break;
+                case Translog:
+                    translog = indexShard.translogStats();
+                    break;
                 default:
                     throw new IllegalStateException("Unknown Flag: " + flag);
             }
@@ -211,6 +218,9 @@ public CommonStats(IndexShard indexShard, CommonStatsFlags flags) {
     @Nullable
     public SegmentsStats segments;
 
+    @Nullable
+    public TranslogStats translog;
+
     public void add(CommonStats stats) {
         if (docs == null) {
             if (stats.getDocs() != null) {
@@ -334,6 +344,14 @@ public void add(CommonStats stats) {
         } else {
             segments.add(stats.getSegments());
         }
+        if (translog == null) {
+            if (stats.getTranslog() != null) {
+                translog = new TranslogStats();
+                translog.add(stats.getTranslog());
+            }
+        } else {
+            translog.add(stats.getTranslog());
+        }
     }
 
     @Nullable
@@ -411,6 +429,9 @@ public SegmentsStats getSegments() {
         return segments;
     }
 
+    @Nullable
+    public TranslogStats getTranslog() { return translog; }
+
     public static CommonStats readCommonStats(StreamInput in) throws IOException {
         CommonStats stats = new CommonStats();
         stats.readFrom(in);
@@ -468,6 +489,9 @@ public void readFrom(StreamInput in) throws IOException {
                 segments = SegmentsStats.readSegmentsStats(in);
             }
         }
+        if (in.getVersion().after(Version.V_1_0_0_Beta2)) {
+            translog = in.readOptionalStreamable(new TranslogStats());
+        }
     }
 
     @Override
@@ -566,6 +590,9 @@ public void writeTo(StreamOutput out) throws IOException {
                 segments.writeTo(out);
             }
         }
+        if (out.getVersion().after(Version.V_1_0_0_Beta2)) {
+            out.writeOptionalStreamable(translog);
+        }
     }
 
     // note, requires a wrapping object
@@ -616,6 +643,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         if (segments != null) {
             segments.toXContent(builder, params);
         }
+        if (translog != null) {
+            translog.toXContent(builder, params);
+        }
         return builder;
     }
 }

src/main/java/org/elasticsearch/action/admin/indices/stats/CommonStatsFlags.java

@@ -34,7 +34,7 @@ public class CommonStatsFlags implements Streamable, Cloneable {
     public final static CommonStatsFlags ALL = new CommonStatsFlags().all();
     public final static CommonStatsFlags NONE = new CommonStatsFlags().clear();
 
-    private EnumSet<Flag> flags = EnumSet.of(Flag.Docs, Flag.Store, Flag.Indexing, Flag.Get, Flag.Search, Flag.Percolate);
+    private EnumSet<Flag> flags = EnumSet.allOf(Flag.class);
     private String[] types = null;
     private String[] groups = null;
     private String[] fieldDataFields = null;
@@ -227,7 +227,8 @@ public static enum Flag {
         Warmer("warmer"),
         Percolate("percolate"),
         Completion("completion"),
-        Segments("segments");
+        Segments("segments"),
+        Translog("translog");
 
         private final String restName;
 

src/main/java/org/elasticsearch/action/admin/indices/stats/IndicesStatsRequest.java

@@ -29,8 +29,7 @@
 /**
  * A request to get indices level stats. Allow to enable different stats to be returned.
  * <p/>
- * <p>By default, the {@link #docs(boolean)}, {@link #store(boolean)}, {@link #indexing(boolean)}
- * are enabled. Other stats can be enabled as well.
+ * <p>By default, all statistics are enabled.
  * <p/>
  * <p>All the stats to be returned can be cleared using {@link #clear()}, at which point, specific
  * stats can be enabled.
@@ -239,6 +238,15 @@ public String[] completionFields() {
         return flags.completionDataFields();
     }
 
+    public IndicesStatsRequest translog(boolean translog) {
+        flags.set(Flag.Translog, translog);
+        return this;
+    }
+
+    public boolean translog() {
+        return flags.isSet(Flag.Translog);
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);

src/main/java/org/elasticsearch/action/admin/indices/stats/IndicesStatsRequestBuilder.java

@@ -154,6 +154,11 @@ public IndicesStatsRequestBuilder setCompletionFields(String... fields) {
         return this;
     }
 
+    public IndicesStatsRequestBuilder setTranslog(boolean translog) {
+        request.translog(translog);
+        return this;
+    }
+
     @Override
     protected void doExecute(ActionListener<IndicesStatsResponse> listener) {
         ((IndicesAdminClient) client).stats(request, listener);

src/main/java/org/elasticsearch/action/admin/indices/stats/IndicesStatsResponse.java

@@ -156,6 +156,12 @@ public void writeTo(StreamOutput out) throws IOException {
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        String level = params.param("level", "indices");
+        boolean isLevelValid = "indices".equalsIgnoreCase(level) || "shards".equalsIgnoreCase(level) || "cluster".equalsIgnoreCase(level);
+        if (!isLevelValid) {
+            return builder;
+        }
+
         builder.startObject("_all");
 
         builder.startObject("primaries");
@@ -168,35 +174,36 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
 
         builder.endObject();
 
-        builder.startObject(Fields.INDICES);
-        for (IndexStats indexStats : getIndices().values()) {
-            builder.startObject(indexStats.getIndex(), XContentBuilder.FieldCaseConversion.NONE);
+        if ("indices".equalsIgnoreCase(level) || "shards".equalsIgnoreCase(level)) {
+            builder.startObject(Fields.INDICES);
+            for (IndexStats indexStats : getIndices().values()) {
+                builder.startObject(indexStats.getIndex(), XContentBuilder.FieldCaseConversion.NONE);
 
-            builder.startObject("primaries");
-            indexStats.getPrimaries().toXContent(builder, params);
-            builder.endObject();
+                builder.startObject("primaries");
+                indexStats.getPrimaries().toXContent(builder, params);
+                builder.endObject();
 
-            builder.startObject("total");
-            indexStats.getTotal().toXContent(builder, params);
-            builder.endObject();
+                builder.startObject("total");
+                indexStats.getTotal().toXContent(builder, params);
+                builder.endObject();
 
-            if ("shards".equalsIgnoreCase(params.param("level", null))) {
-                builder.startObject(Fields.SHARDS);
-                for (IndexShardStats indexShardStats : indexStats) {
-                    builder.startArray(Integer.toString(indexShardStats.getShardId().id()));
-                    for (ShardStats shardStats : indexShardStats) {
-                        builder.startObject();
-                        shardStats.toXContent(builder, params);
-                        builder.endObject();
+                if ("shards".equalsIgnoreCase(level)) {
+                    builder.startObject(Fields.SHARDS);
+                    for (IndexShardStats indexShardStats : indexStats) {
+                        builder.startArray(Integer.toString(indexShardStats.getShardId().id()));
+                        for (ShardStats shardStats : indexShardStats) {
+                            builder.startObject();
+                            shardStats.toXContent(builder, params);
+                            builder.endObject();
+                        }
+                        builder.endArray();
                     }
-                    builder.endArray();
+                    builder.endObject();
                 }
                 builder.endObject();
             }
-
             builder.endObject();
         }
-        builder.endObject();
 
         return builder;
     }

src/main/java/org/elasticsearch/action/admin/indices/stats/TransportIndicesStatsAction.java

@@ -190,6 +190,9 @@ protected ShardStats shardOperation(IndexShardStatsRequest request) throws Elast
             flags.set(CommonStatsFlags.Flag.Completion);
             flags.completionDataFields(request.request.completionFields());
         }
+        if (request.request.translog()) {
+            flags.set(CommonStatsFlags.Flag.Translog);
+        }
 
         return new ShardStats(indexShard, flags);
     }

src/main/java/org/elasticsearch/index/shard/service/IndexShard.java

@@ -20,6 +20,7 @@
 package org.elasticsearch.index.shard.service;
 
 import org.elasticsearch.ElasticSearchException;
+import org.elasticsearch.index.translog.TranslogStats;
 import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.bytes.BytesReference;
@@ -108,6 +109,8 @@ public interface IndexShard extends IndexShardComponent {
 
     CompletionStats completionStats(String... fields);
 
+    TranslogStats translogStats();
+
     PercolatorQueriesRegistry percolateRegistry();
 
     ShardPercolateService shardPercolateService();

src/main/java/org/elasticsearch/index/shard/service/InternalIndexShard.java

@@ -28,6 +28,7 @@
 import org.elasticsearch.ElasticSearchException;
 import org.elasticsearch.ElasticSearchIllegalArgumentException;
 import org.elasticsearch.ElasticSearchIllegalStateException;
+import org.elasticsearch.index.translog.TranslogStats;
 import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.cluster.routing.ShardRoutingState;
 import org.elasticsearch.common.Booleans;
@@ -561,6 +562,11 @@ public IdCacheStats idCacheStats() {
         return shardIdCache.stats();
     }
 
+    @Override
+    public TranslogStats translogStats() {
+        return translog.stats();
+    }
+
     @Override
     public CompletionStats completionStats(String... fields) {
         CompletionStats completionStats = new CompletionStats();

src/main/java/org/elasticsearch/index/translog/Translog.java

@@ -130,6 +130,11 @@ public interface Translog extends IndexShardComponent, CloseableIndexComponent {
 
     void syncOnEachOperation(boolean syncOnEachOperation);
 
+    /**
+     * return stats
+     */
+    TranslogStats stats();
+
     static class Location {
         public final long translogId;
         public final long translogLocation;