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

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

@@ -358,6 +358,13 @@ public class RegionLoad implements RegionMetrics {
     return metrics.getLastMajorCompactionTimestamp();
   }
 
+  /**
+   * @return the reference count for the stores of this region
+   */
+  public int getStoreRefCount() {
+    return metrics.getStoreRefCount();
+  }
+
   /**
    * @see java.lang.Object#toString()
    */
@@ -366,6 +373,7 @@ public class RegionLoad implements RegionMetrics {
     StringBuilder sb = Strings.appendKeyValue(new StringBuilder(), "numberOfStores",
         this.getStores());
     Strings.appendKeyValue(sb, "numberOfStorefiles", this.getStorefiles());
+    Strings.appendKeyValue(sb, "storeRefCount", this.getStoreRefCount());
     Strings.appendKeyValue(sb, "storefileUncompressedSizeMB",
         this.getStoreUncompressedSizeMB());
     Strings.appendKeyValue(sb, "lastMajorCompactionTimestamp",

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

@@ -144,4 +144,8 @@ public interface RegionMetrics {
    */
   long getLastMajorCompactionTimestamp();
 
+  /**
+   * @return the reference count for the stores of this region
+   */
+  int getStoreRefCount();
 }

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

@@ -64,6 +64,7 @@ public final class RegionMetricsBuilder {
           Size.Unit.KILOBYTE))
         .setStoreCount(regionLoadPB.getStores())
         .setStoreFileCount(regionLoadPB.getStorefiles())
+        .setStoreRefCount(regionLoadPB.getStoreRefCount())
         .setStoreFileSize(new Size(regionLoadPB.getStorefileSizeMB(), Size.Unit.MEGABYTE))
         .setStoreSequenceIds(regionLoadPB.getStoreCompleteSequenceIdList().stream()
           .collect(Collectors.toMap(
@@ -109,6 +110,7 @@ public final class RegionMetricsBuilder {
           .get(Size.Unit.KILOBYTE))
         .setStores(regionMetrics.getStoreCount())
         .setStorefiles(regionMetrics.getStoreCount())
+        .setStoreRefCount(regionMetrics.getStoreRefCount())
         .setStorefileSizeMB((int) regionMetrics.getStoreFileSize().get(Size.Unit.MEGABYTE))
         .addAllStoreCompleteSequenceId(toStoreSequenceId(regionMetrics.getStoreSequenceId()))
         .setStoreUncompressedSizeMB(
@@ -123,6 +125,7 @@ public final class RegionMetricsBuilder {
   private final byte[] name;
   private int storeCount;
   private int storeFileCount;
+  private int storeRefCount;
   private long compactingCellCount;
   private long compactedCellCount;
   private Size storeFileSize = Size.ZERO;
@@ -151,6 +154,10 @@ public final class RegionMetricsBuilder {
     this.storeFileCount = value;
     return this;
   }
+  public RegionMetricsBuilder setStoreRefCount(int value) {
+    this.storeRefCount = value;
+    return this;
+  }
   public RegionMetricsBuilder setCompactingCellCount(long value) {
     this.compactingCellCount = value;
     return this;
@@ -220,6 +227,7 @@ public final class RegionMetricsBuilder {
     return new RegionMetricsImpl(name,
         storeCount,
         storeFileCount,
+        storeRefCount,
         compactingCellCount,
         compactedCellCount,
         storeFileSize,
@@ -242,6 +250,7 @@ public final class RegionMetricsBuilder {
     private final byte[] name;
     private final int storeCount;
     private final int storeFileCount;
+    private final int storeRefCount;
     private final long compactingCellCount;
     private final long compactedCellCount;
     private final Size storeFileSize;
@@ -261,6 +270,7 @@ public final class RegionMetricsBuilder {
     RegionMetricsImpl(byte[] name,
         int storeCount,
         int storeFileCount,
+        int storeRefCount,
         final long compactingCellCount,
         long compactedCellCount,
         Size storeFileSize,
@@ -280,6 +290,7 @@ public final class RegionMetricsBuilder {
       this.name = Preconditions.checkNotNull(name);
       this.storeCount = storeCount;
       this.storeFileCount = storeFileCount;
+      this.storeRefCount = storeRefCount;
       this.compactingCellCount = compactingCellCount;
       this.compactedCellCount = compactedCellCount;
       this.storeFileSize = Preconditions.checkNotNull(storeFileSize);
@@ -313,6 +324,11 @@ public final class RegionMetricsBuilder {
       return storeFileCount;
     }
 
+    @Override
+    public int getStoreRefCount() {
+      return storeRefCount;
+    }
+
     @Override
     public Size getStoreFileSize() {
       return storeFileSize;
@@ -399,6 +415,8 @@ public final class RegionMetricsBuilder {
           this.getStoreCount());
       Strings.appendKeyValue(sb, "storeFileCount",
           this.getStoreFileCount());
+      Strings.appendKeyValue(sb, "storeRefCount",
+        this.getStoreRefCount());
       Strings.appendKeyValue(sb, "uncompressedStoreFileSize",
           this.getUncompressedStoreFileSize());
       Strings.appendKeyValue(sb, "lastMajorCompactionTimestamp",

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

@@ -231,6 +231,8 @@ 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

@@ -152,4 +152,9 @@ 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 @@ public class MetricsRegionSourceImpl implements MetricsRegionSource {
               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

@@ -94,6 +94,11 @@ public class TestMetricsRegionSourceImpl {
       return 0;
     }
 
+    @Override
+    public long getStoreRefCount() {
+      return 0;
+    }
+
     @Override
     public long getMemStoreSize() {
       return 0;

hbase-protocol-shaded/src/main/protobuf/ClusterStatus.proto

@@ -143,6 +143,12 @@ message RegionLoad {
 
   /** the current total filtered read requests made to region */
   optional uint64 filtered_read_requests_count = 19;
+
+  /** 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 */

hbase-protocol/src/main/protobuf/ClusterStatus.proto

@@ -139,6 +139,12 @@ message RegionLoad {
 
   /** the current total filtered read requests made to region */
   optional uint64 filtered_read_requests_count = 19;
+
+  /** 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 */

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStore.java

@@ -2668,4 +2668,10 @@ public class HStore implements Store, HeapSize, StoreConfigInformation, Propagat
   public int getCurrentParallelPutCount() {
     return currentParallelPutCount.get();
   }
+
+  public int getStoreRefCount() {
+    return this.storeEngine.getStoreFileManager().getStorefiles().stream()
+      .filter(sf -> sf.getReader() != null).filter(HStoreFile::isHFile)
+      .mapToInt(HStoreFile::getRefCount).sum();
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MetricsRegionWrapperImpl.java

@@ -48,6 +48,7 @@ public class MetricsRegionWrapperImpl implements MetricsRegionWrapper, Closeable
   private ScheduledExecutorService executor;
   private Runnable runnable;
   private long numStoreFiles;
+  private long storeRefCount;
   private long memstoreSize;
   private long storeFileSize;
   private long maxStoreFileAge;
@@ -119,6 +120,11 @@ public class MetricsRegionWrapperImpl implements MetricsRegionWrapper, Closeable
     return storeFileSize;
   }
 
+  @Override
+  public long getStoreRefCount() {
+    return storeRefCount;
+  }
+
   @Override
   public long getReadRequestCount() {
     return this.region.getReadRequestsCount();
@@ -221,6 +227,7 @@ public class MetricsRegionWrapperImpl implements MetricsRegionWrapper, Closeable
     @Override
     public void run() {
       long tempNumStoreFiles = 0;
+      int tempStoreRefCount = 0;
       long tempMemstoreSize = 0;
       long tempStoreFileSize = 0;
       long tempMaxStoreFileAge = 0;
@@ -232,8 +239,9 @@ public class MetricsRegionWrapperImpl implements MetricsRegionWrapper, Closeable
       long avgAgeNumerator = 0;
       long numHFiles = 0;
       if (region.stores != null) {
-        for (Store store : region.stores.values()) {
+        for (HStore store : region.stores.values()) {
           tempNumStoreFiles += store.getStorefilesCount();
+          tempStoreRefCount += store.getStoreRefCount();
           tempMemstoreSize += store.getMemStoreSize().getDataSize();
           tempStoreFileSize += store.getStorefilesSize();
           OptionalLong storeMaxStoreFileAge = store.getMaxStoreFileAge();
@@ -260,6 +268,7 @@ public class MetricsRegionWrapperImpl implements MetricsRegionWrapper, Closeable
       }
 
       numStoreFiles = tempNumStoreFiles;
+      storeRefCount = tempStoreRefCount;
       memstoreSize = tempMemstoreSize;
       storeFileSize = tempStoreFileSize;
       maxStoreFileAge = tempMaxStoreFileAge;

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/MetricsRegionWrapperStub.java

@@ -60,6 +60,11 @@ public class MetricsRegionWrapperStub implements MetricsRegionWrapper {
     return 102;
   }
 
+  @Override
+  public long getStoreRefCount() {
+    return 0;
+  }
+
   @Override
   public long getMemStoreSize() {
     return 103;