HBASE-22459 Expose store reader reference count (#248)

Author: apurtell

hbase-client/src/main/java/org/apache/hadoop/hbase/RegionLoad.java

@@ -187,6 +187,13 @@ public long getLastMajorCompactionTs() {
     return regionLoadPB.getLastMajorCompactionTs();
   }
 
+  /**
+   * @return the reference count for the stores of this region
+   */
+  public int getStoreRefCount() {
+    return regionLoadPB.getStoreRefCount();
+  }
+
   /**
    * @see java.lang.Object#toString()
    */
@@ -196,6 +203,7 @@ public String toString() {
         this.getStores());
     sb = Strings.appendKeyValue(sb, "numberOfStorefiles",
         this.getStorefiles());
+    sb = Strings.appendKeyValue(sb, "storeRefCount", this.getStoreRefCount());
     sb = Strings.appendKeyValue(sb, "storefileUncompressedSizeMB",
       this.getStoreUncompressedSizeMB());
     sb = Strings.appendKeyValue(sb, "lastMajorCompactionTimestamp",

hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/MetricsRegionServerSource.java

@@ -229,6 +229,8 @@ public interface MetricsRegionServerSource extends BaseSource, JvmPauseMonitorSo
   String WALFILE_SIZE_DESC = "Size of all WAL Files";
   String STOREFILE_COUNT = "storeFileCount";
   String STOREFILE_COUNT_DESC = "Number of Store Files";
+  String STORE_REF_COUNT = "storeRefCount";
+  String STORE_REF_COUNT_DESC = "Store reference count";
   String MEMSTORE_SIZE = "memStoreSize";
   String MEMSTORE_SIZE_DESC = "Size of the memstore";
   String STOREFILE_SIZE = "storeFileSize";

hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/MetricsRegionWrapper.java

@@ -142,4 +142,9 @@ public interface MetricsRegionWrapper {
    * Get the replica id of this region.
    */
   int getReplicaId();
+
+  /**
+   * @return the number of references active on the store
+   */
+  long getStoreRefCount();
 }

hbase-hadoop2-compat/src/main/java/org/apache/hadoop/hbase/regionserver/MetricsRegionSourceImpl.java

@@ -213,6 +213,10 @@ void snapshot(MetricsRecordBuilder mrb, boolean ignored) {
               regionNamePrefix + MetricsRegionServerSource.STOREFILE_COUNT,
               MetricsRegionServerSource.STOREFILE_COUNT_DESC),
           this.regionWrapper.getNumStoreFiles());
+      mrb.addGauge(Interns.info(
+              regionNamePrefix + MetricsRegionServerSource.STORE_REF_COUNT,
+              MetricsRegionServerSource.STORE_REF_COUNT),
+          this.regionWrapper.getStoreRefCount());
       mrb.addGauge(Interns.info(
               regionNamePrefix + MetricsRegionServerSource.MEMSTORE_SIZE,
               MetricsRegionServerSource.MEMSTORE_SIZE_DESC),

hbase-hadoop2-compat/src/test/java/org/apache/hadoop/hbase/regionserver/TestMetricsRegionSourceImpl.java

@@ -22,9 +22,6 @@
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
 
-import java.util.Map;
-
-import org.apache.commons.math.stat.descriptive.DescriptiveStatistics;
 import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
 import org.apache.hadoop.hbase.testclassification.SmallTests;
 import org.apache.hadoop.hbase.testclassification.MetricsTests;
@@ -94,6 +91,11 @@ public long getNumStoreFiles() {
       return 0;
     }
 
+    @Override
+    public long getStoreRefCount() {
+      return 0;
+    }
+
     @Override
     public long getMemstoreSize() {
       return 0;

hbase-protocol/src/main/java/org/apache/hadoop/hbase/protobuf/generated/ClusterStatusProtos.java

@@ -136,6 +136,15 @@ message RegionLoad {
 
   /** the most recent sequence Id of store from cache flush */
   repeated StoreSequenceId store_complete_sequence_id = 18;
+
+  /** branch-2 defines filtered_read_requests_count = 19, the current total
+      filtered read requests made to region */
+
+  /** master defines cp_requests_count = 20, the current total coprocessor
+      requests made to region */
+
+  /** the number of references active on the store */
+  optional int32 store_ref_count = 21 [ default = 0 ];
 }
 
 /* Server-level protobufs */