Remove the suggest metric from stats APIs (#29635)

This metric previously existed for backwards compatibility reasons
although the suggest stats were folded into search stats. This metric
was deprecated in 6.3.0 and this commit removes them for 7.0.0.

Author: jasontedor

docs/CHANGELOG.asciidoc

@@ -12,6 +12,8 @@
 <<write-thread-pool-fallback, Removed `thread_pool.bulk.*` settings and
 `es.thread_pool.write.use_bulk_as_display_name` system property>> ({pull}29609[#29609])
 
+<<remove-suggest-metric, Removed `suggest` metric on stats APIs>> ({pull}29635[#29635])
+
 === Breaking Java Changes
 
 === Deprecations

docs/reference/migration/migrate_7_0/api.asciidoc

@@ -22,7 +22,14 @@ The following parameters starting with underscore have been removed:
 Instead of these removed parameters, use their non camel case equivalents without
 starting underscore, e.g. use `version_type` instead of `_version_type` or `versionType`.
 
-
 ==== The parameter `fields` deprecated in 6.x has been removed from Bulk request 
 and Update request. The Update API returns `400 - Bad request` if request contains 
 unknown parameters (instead of ignored in the previous version).
+
+[[remove-suggest-metric]]
+==== Remove support for `suggest` metric/index metric in indices stats and nodes stats APIs
+
+Previously, `suggest` stats were folded into `search` stats. Support for the
+`suggest` metric on the indices stats and nodes stats APIs remained for
+backwards compatibility. Backwards support for the `suggest` metric was
+deprecated in 6.3.0 and now removed in 7.0.0.

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

@@ -152,9 +152,6 @@ public CommonStats(CommonStatsFlags flags) {
                 case Translog:
                     translog = new TranslogStats();
                     break;
-                case Suggest:
-                    // skip
-                    break;
                 case RequestCache:
                     requestCache = new RequestCacheStats();
                     break;
@@ -213,9 +210,6 @@ public CommonStats(IndicesQueryCache indicesQueryCache, IndexShard indexShard, C
                 case Translog:
                     translog = indexShard.translogStats();
                     break;
-                case Suggest:
-                    // skip
-                    break;
                 case RequestCache:
                     requestCache = indexShard.requestCache().stats();
                     break;

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

@@ -221,7 +221,7 @@ public enum Flag {
         Completion("completion", 11),
         Segments("segments", 12),
         Translog("translog", 13),
-        Suggest("suggest", 14), // unused
+        // 14 was previously used for Suggest
         RequestCache("request_cache", 15),
         Recovery("recovery", 16);
 

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

@@ -229,15 +229,6 @@ public boolean translog() {
         return flags.isSet(Flag.Translog);
     }
 
-    public IndicesStatsRequest suggest(boolean suggest) {
-        flags.set(Flag.Suggest, suggest);
-        return this;
-    }
-
-    public boolean suggest() {
-        return flags.isSet(Flag.Suggest);
-    }
-
     public IndicesStatsRequest requestCache(boolean requestCache) {
         flags.set(Flag.RequestCache, requestCache);
         return this;

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

@@ -148,9 +148,6 @@ protected ShardStats shardOperation(IndicesStatsRequest request, ShardRouting sh
         if (request.translog()) {
             flags.set(CommonStatsFlags.Flag.Translog);
         }
-        if (request.suggest()) {
-            flags.set(CommonStatsFlags.Flag.Suggest);
-        }
         if (request.requestCache()) {
             flags.set(CommonStatsFlags.Flag.RequestCache);
         }

server/src/main/java/org/elasticsearch/rest/action/admin/cluster/RestNodesStatsAction.java

@@ -146,10 +146,6 @@ public RestChannelConsumer prepareRequest(final RestRequest request, final NodeC
                     for (final String indexMetric : indexMetrics) {
                         final Consumer<CommonStatsFlags> handler = FLAGS.get(indexMetric);
                         if (handler != null) {
-                            if ("suggest".equals(indexMetric)) {
-                                deprecationLogger.deprecated(
-                                        "the suggest index metric is deprecated on the nodes stats API [" + request.uri() + "]");
-                            }
                             handler.accept(flags);
                         } else {
                             invalidIndexMetrics.add(indexMetric);

server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestIndicesStatsAction.java

@@ -62,7 +62,6 @@ public String getName() {
         metrics.put("store", r -> r.store(true));
         metrics.put("indexing", r -> r.indexing(true));
         metrics.put("search", r -> r.search(true));
-        metrics.put("suggest", r -> r.search(true));
         metrics.put("get", r -> r.get(true));
         metrics.put("merge", r -> r.merge(true));
         metrics.put("refresh", r -> r.refresh(true));
@@ -102,9 +101,6 @@ public RestChannelConsumer prepareRequest(final RestRequest request, final NodeC
             for (final String metric : metrics) {
                 final Consumer<IndicesStatsRequest> consumer = METRICS.get(metric);
                 if (consumer != null) {
-                    if ("suggest".equals(metric)) {
-                        deprecationLogger.deprecated("the suggest metric is deprecated on the indices stats API [" + request.uri() + "]");
-                    }
                     consumer.accept(indicesStatsRequest);
                 } else {
                     invalidMetrics.add(metric);

server/src/test/java/org/elasticsearch/indices/stats/IndexStatsIT.java

@@ -589,10 +589,6 @@ public void testAllFlags() throws Exception {
 
         IndicesStatsResponse stats = builder.execute().actionGet();
         for (Flag flag : values) {
-            if (flag == Flag.Suggest) {
-                // suggest flag is unused
-                continue;
-            }
             assertThat(isSet(flag, stats.getPrimaries()), equalTo(false));
             assertThat(isSet(flag, stats.getTotal()), equalTo(false));
         }
@@ -628,10 +624,6 @@ public void testAllFlags() throws Exception {
         }
 
         for (Flag flag : EnumSet.complementOf(flags)) { // check the complement
-            if (flag == Flag.Suggest) {
-                // suggest flag is unused
-                continue;
-            }
             assertThat(isSet(flag, stats.getPrimaries()), equalTo(false));
             assertThat(isSet(flag, stats.getTotal()), equalTo(false));
         }
@@ -684,7 +676,7 @@ public void testEncodeDecodeCommonStats() throws IOException {
     public void testFlagOrdinalOrder() {
         Flag[] flags = new Flag[]{Flag.Store, Flag.Indexing, Flag.Get, Flag.Search, Flag.Merge, Flag.Flush, Flag.Refresh,
                 Flag.QueryCache, Flag.FieldData, Flag.Docs, Flag.Warmer, Flag.Completion, Flag.Segments,
-                Flag.Translog, Flag.Suggest, Flag.RequestCache, Flag.Recovery};
+                Flag.Translog, Flag.RequestCache, Flag.Recovery};
 
         assertThat(flags.length, equalTo(Flag.values().length));
         for (int i = 0; i < flags.length; i++) {
@@ -935,8 +927,6 @@ private static void set(Flag flag, IndicesStatsRequestBuilder builder, boolean s
             case Translog:
                 builder.setTranslog(set);
                 break;
-            case Suggest: // unused
-                break;
             case RequestCache:
                 builder.setRequestCache(set);
                 break;
@@ -979,8 +969,6 @@ private static boolean isSet(Flag flag, CommonStats response) {
                 return response.getSegments() != null;
             case Translog:
                 return response.getTranslog() != null;
-            case Suggest: // unused
-                return true;
             case RequestCache:
                 return response.getRequestCache() != null;
             case Recovery:

server/src/test/java/org/elasticsearch/rest/action/admin/cluster/RestNodesStatsActionTests.java

@@ -148,14 +148,4 @@ public void testIndexMetricsRequestOnAllRequest() throws IOException {
                 containsString("request [/_nodes/stats] contains index metrics [" + indexMetric + "] but all stats requested")));
     }
 
-    public void testSuggestIsDeprecated() throws IOException {
-        final Map<String, String> params =
-                Stream.of(Tuple.tuple("metric", "indices"), Tuple.tuple("index_metric", "suggest"))
-                        .collect(Collectors.toMap(Tuple::v1, Tuple::v2));
-        final RestRequest request =
-                new FakeRestRequest.Builder(xContentRegistry()).withPath("/_nodes/stats").withParams(params).build();
-        action.prepareRequest(request, mock(NodeClient.class));
-        assertWarnings("the suggest index metric is deprecated on the nodes stats API [/_nodes/stats]" );
-    }
-
 }