Query Cache: Add hit and miss count

closes #7355

src/main/java/org/elasticsearch/index/cache/query/QueryCacheStats.java

@@ -35,18 +35,24 @@ public class QueryCacheStats implements Streamable, ToXContent {
 
     long memorySize;
     long evictions;
+    long hitCount;
+    long missCount;
 
     public QueryCacheStats() {
     }
 
-    public QueryCacheStats(long memorySize, long evictions) {
+    public QueryCacheStats(long memorySize, long evictions, long hitCount, long missCount) {
         this.memorySize = memorySize;
         this.evictions = evictions;
+        this.hitCount = hitCount;
+        this.missCount = missCount;
     }
 
     public void add(QueryCacheStats stats) {
         this.memorySize += stats.memorySize;
         this.evictions += stats.evictions;
+        this.hitCount += stats.hitCount;
+        this.missCount += stats.missCount;
     }
 
     public long getMemorySizeInBytes() {
@@ -61,16 +67,28 @@ public class QueryCacheStats implements Streamable, ToXContent {
         return this.evictions;
     }
 
+    public long getHitCount() {
+        return this.hitCount;
+    }
+
+    public long getMissCount() {
+        return this.missCount;
+    }
+
     @Override
     public void readFrom(StreamInput in) throws IOException {
         memorySize = in.readVLong();
         evictions = in.readVLong();
+        hitCount = in.readVLong();
+        missCount = in.readVLong();
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(memorySize);
         out.writeVLong(evictions);
+        out.writeVLong(hitCount);
+        out.writeVLong(missCount);
     }
 
     @Override
@@ -78,6 +96,8 @@ public class QueryCacheStats implements Streamable, ToXContent {
         builder.startObject(Fields.QUERY_CACHE_STATS);
         builder.byteSizeField(Fields.MEMORY_SIZE_IN_BYTES, Fields.MEMORY_SIZE, memorySize);
         builder.field(Fields.EVICTIONS, getEvictions());
+        builder.field(Fields.HIT_COUNT, getHitCount());
+        builder.field(Fields.MISS_COUNT, getMissCount());
         builder.endObject();
         return builder;
     }
@@ -87,5 +107,7 @@ public class QueryCacheStats implements Streamable, ToXContent {
         static final XContentBuilderString MEMORY_SIZE = new XContentBuilderString("memory_size");
         static final XContentBuilderString MEMORY_SIZE_IN_BYTES = new XContentBuilderString("memory_size_in_bytes");
         static final XContentBuilderString EVICTIONS = new XContentBuilderString("evictions");
+        static final XContentBuilderString HIT_COUNT = new XContentBuilderString("hit_count");
+        static final XContentBuilderString MISS_COUNT = new XContentBuilderString("miss_count");
     }
 }

src/main/java/org/elasticsearch/index/cache/query/ShardQueryCache.java

@@ -40,6 +40,8 @@ public class ShardQueryCache extends AbstractIndexShardComponent implements Remo
 
     final CounterMetric evictionsMetric = new CounterMetric();
     final CounterMetric totalMetric = new CounterMetric();
+    final CounterMetric hitCount = new CounterMetric();
+    final CounterMetric missCount = new CounterMetric();
 
     @Inject
     public ShardQueryCache(ShardId shardId, @IndexSettings Settings indexSettings) {
@@ -47,7 +49,15 @@ public class ShardQueryCache extends AbstractIndexShardComponent implements Remo
     }
 
     public QueryCacheStats stats() {
-        return new QueryCacheStats(totalMetric.count(), evictionsMetric.count());
+        return new QueryCacheStats(totalMetric.count(), evictionsMetric.count(), hitCount.count(), missCount.count());
+    }
+
+    public void onHit() {
+        hitCount.inc();
+    }
+
+    public void onMiss() {
+        missCount.inc();
     }
 
     public void onCached(IndicesQueryCache.Key key, BytesReference value) {

src/main/java/org/elasticsearch/indices/cache/query/IndicesQueryCache.java

@@ -99,7 +99,6 @@ public class IndicesQueryCache extends AbstractComponent implements RemovalListe
     //TODO make these changes configurable on the cluster level
     private volatile String size;
     private volatile TimeValue expire;
-    //TODO expose this in our stats APIs
     private volatile Cache<Key, BytesReference> cache;
 
     @Inject
@@ -218,6 +217,7 @@ public class IndicesQueryCache extends AbstractComponent implements RemovalListe
         Loader loader = new Loader(queryPhase, context, key);
         BytesReference value = cache.get(key, loader);
         if (loader.isLoaded()) {
+            key.shard.queryCache().onMiss();
             // see if its the first time we see this reader, and make sure to register a cleanup key
             CleanupKey cleanupKey = new CleanupKey(context.indexShard(), ((DirectoryReader) context.searcher().getIndexReader()).getVersion());
             if (!registeredClosedListeners.containsKey(cleanupKey)) {
@@ -226,6 +226,8 @@ public class IndicesQueryCache extends AbstractComponent implements RemovalListe
                     context.searcher().getIndexReader().addReaderClosedListener(cleanupKey);
                 }
             }
+        } else {
+            key.shard.queryCache().onHit();
         }
 
         // try and be smart, and reuse an already loaded and constructed QueryResult of in VM execution

src/main/java/org/elasticsearch/rest/action/cat/RestIndicesAction.java

@@ -129,6 +129,12 @@ public class RestIndicesAction extends AbstractCatAction {
         table.addCell("query_cache.evictions", "sibling:pri;alias:qce,queryCacheEvictions;default:false;text-align:right;desc:query cache evictions");
         table.addCell("pri.query_cache.evictions", "default:false;text-align:right;desc:query cache evictions");
 
+        table.addCell("query_cache.hit_count", "sibling:pri;alias:qchc,queryCacheHitCount;default:false;text-align:right;desc:query cache hit count");
+        table.addCell("pri.query_cache.hit_count", "default:false;text-align:right;desc:query cache hit count");
+
+        table.addCell("query_cache.miss_count", "sibling:pri;alias:qcmc,queryCacheMissCount;default:false;text-align:right;desc:query cache miss count");
+        table.addCell("pri.query_cache.miss_count", "default:false;text-align:right;desc:query cache miss count");
+
         table.addCell("flush.total", "sibling:pri;alias:ft,flushTotal;default:false;text-align:right;desc:number of flushes");
         table.addCell("pri.flush.total", "default:false;text-align:right;desc:number of flushes");
 
@@ -314,6 +320,12 @@ public class RestIndicesAction extends AbstractCatAction {
             table.addCell(indexStats == null ? null : indexStats.getTotal().getQueryCache().getEvictions());
             table.addCell(indexStats == null ? null : indexStats.getPrimaries().getQueryCache().getEvictions());
 
+            table.addCell(indexStats == null ? null : indexStats.getTotal().getQueryCache().getHitCount());
+            table.addCell(indexStats == null ? null : indexStats.getPrimaries().getQueryCache().getHitCount());
+
+            table.addCell(indexStats == null ? null : indexStats.getTotal().getQueryCache().getMissCount());
+            table.addCell(indexStats == null ? null : indexStats.getPrimaries().getQueryCache().getMissCount());
+
             table.addCell(indexStats == null ? null : indexStats.getTotal().getFlush().getTotal());
             table.addCell(indexStats == null ? null : indexStats.getPrimaries().getFlush().getTotal());
 

src/main/java/org/elasticsearch/rest/action/cat/RestNodesAction.java

@@ -124,6 +124,8 @@ public class RestNodesAction extends AbstractCatAction {
 
         table.addCell("query_cache.memory_size", "alias:qcm,queryCacheMemory;default:false;text-align:right;desc:used query cache");
         table.addCell("query_cache.evictions", "alias:qce,queryCacheEvictions;default:false;text-align:right;desc:query cache evictions");
+        table.addCell("query_cache.hit_count", "alias:qchc,queryCacheHitCount;default:false;text-align:right;desc:query cache hit counts");
+        table.addCell("query_cache.miss_count", "alias:qcmc,queryCacheMissCount;default:false;text-align:right;desc:query cache miss counts");
 
         table.addCell("flush.total", "alias:ft,flushTotal;default:false;text-align:right;desc:number of flushes");
         table.addCell("flush.total_time", "alias:ftt,flushTotalTime;default:false;text-align:right;desc:time spent in flush");
@@ -231,6 +233,8 @@ public class RestNodesAction extends AbstractCatAction {
 
             table.addCell(stats == null ? null : stats.getIndices().getQueryCache().getMemorySize());
             table.addCell(stats == null ? null : stats.getIndices().getQueryCache().getEvictions());
+            table.addCell(stats == null ? null : stats.getIndices().getQueryCache().getHitCount());
+            table.addCell(stats == null ? null : stats.getIndices().getQueryCache().getMissCount());
 
             table.addCell(stats == null ? null : stats.getIndices().getFlush().getTotal());
             table.addCell(stats == null ? null : stats.getIndices().getFlush().getTotalTime());

src/test/java/org/elasticsearch/indices/stats/IndexStatsTests.java

@@ -27,6 +27,7 @@ import org.elasticsearch.action.get.GetResponse;
 import org.elasticsearch.action.index.IndexRequestBuilder;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.action.search.SearchType;
+import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.stream.BytesStreamInput;
 import org.elasticsearch.common.io.stream.BytesStreamOutput;
@@ -225,10 +226,14 @@ public class IndexStatsTests extends ElasticsearchIntegrationTest {
         }
 
         assertThat(client().admin().indices().prepareStats("idx").setQueryCache(true).get().getTotal().getQueryCache().getMemorySizeInBytes(), equalTo(0l));
+        assertThat(client().admin().indices().prepareStats("idx").setQueryCache(true).get().getTotal().getQueryCache().getHitCount(), equalTo(0l));
+        assertThat(client().admin().indices().prepareStats("idx").setQueryCache(true).get().getTotal().getQueryCache().getMissCount(), equalTo(0l));
         for (int i = 0; i < 10; i++) {
             assertThat(client().prepareSearch("idx").setSearchType(SearchType.COUNT).get().getHits().getTotalHits(), equalTo((long) numDocs));
             assertThat(client().admin().indices().prepareStats("idx").setQueryCache(true).get().getTotal().getQueryCache().getMemorySizeInBytes(), greaterThan(0l));
         }
+        assertThat(client().admin().indices().prepareStats("idx").setQueryCache(true).get().getTotal().getQueryCache().getHitCount(), greaterThan(0l));
+        assertThat(client().admin().indices().prepareStats("idx").setQueryCache(true).get().getTotal().getQueryCache().getMissCount(), greaterThan(0l));
 
         // index the data again...
         IndexRequestBuilder[] builders = new IndexRequestBuilder[numDocs];