HBASE-7121 Fix TestHFileOutputFormat after moving RS to metrics2

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1407216 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -25,6 +25,7 @@ import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
 import org.apache.hadoop.hbase.HDFSBlocksDistribution;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.io.hfile.BlockCache;
+import org.apache.hadoop.hbase.io.hfile.CacheConfig;
 import org.apache.hadoop.hbase.io.hfile.CacheStats;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
@@ -46,7 +47,8 @@ class MetricsRegionServerWrapperImpl
   public static final int PERIOD = 15;
 
   private final HRegionServer regionServer;
-  private final BlockCache blockCache;
+
+  private BlockCache blockCache;
 
   private volatile long numStores = 0;
   private volatile long numStoreFiles = 0;
@@ -70,13 +72,29 @@ class MetricsRegionServerWrapperImpl
 
   public MetricsRegionServerWrapperImpl(final HRegionServer regionServer) {
     this.regionServer = regionServer;
-    this.blockCache = this.regionServer.cacheConfig.getBlockCache();
-    this.cacheStats = blockCache.getStats();
+    initBlockCache();
+
     this.executor = CompatibilitySingletonFactory.getInstance(MetricsExecutor.class).getExecutor();
     this.runnable = new RegionServerMetricsWrapperRunnable();
     this.executor.scheduleWithFixedDelay(this.runnable, PERIOD, PERIOD, TimeUnit.SECONDS);
   }
 
+  /**
+   * It's possible that due to threading the block cache could not be initialized
+   * yet (testing multiple region servers in one jvm).  So we need to try and initialize
+   * the blockCache and cacheStats reference multiple times until we succeed.
+   */
+  private synchronized  void initBlockCache() {
+    CacheConfig cacheConfig = this.regionServer.cacheConfig;
+    if (cacheConfig != null && this.blockCache == null) {
+      this.blockCache = cacheConfig.getBlockCache();
+    }
+
+    if (this.blockCache != null && this.cacheStats == null) {
+      this.cacheStats = blockCache.getStats();
+    }
+  }
+
   @Override
   public String getClusterId() {
     return regionServer.getClusterId();
@@ -309,7 +327,7 @@ class MetricsRegionServerWrapperImpl
 
     @Override
     synchronized public void run() {
-
+      initBlockCache();
       cacheStats = blockCache.getStats();
 
       HDFSBlocksDistribution hdfsBlocksDistribution =

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

@@ -19,8 +19,11 @@
 package org.apache.hadoop.hbase.regionserver;
 
 import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.metrics2.MetricsExecutor;
 
+import java.util.Map;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
@@ -44,17 +47,29 @@ public class MetricsRegionWrapperImpl implements MetricsRegionWrapper {
 
   @Override
   public String getTableName() {
-    return this.region.getTableDesc().getNameAsString();
+    HTableDescriptor tableDesc = this.region.getTableDesc();
+    if (tableDesc == null) {
+      return "";
+    }
+    return tableDesc.getNameAsString();
   }
 
   @Override
   public String getRegionName() {
-    return this.region.getRegionInfo().getEncodedName();
+    HRegionInfo regionInfo = this.region.getRegionInfo();
+    if (regionInfo == null) {
+      return "";
+    }
+    return regionInfo.getEncodedName();
   }
 
   @Override
   public long getNumStores() {
-    return this.region.stores.size();
+    Map<byte[],Store> stores = this.region.stores;
+    if (stores == null) {
+      return 0;
+    }
+    return stores.size();
   }
 
   @Override
@@ -90,11 +105,13 @@ public class MetricsRegionWrapperImpl implements MetricsRegionWrapper {
       long tempMemstoreSize = 0;
       long tempStoreFileSize = 0;
 
+      if (region.stores != null) {
         for (Store store : region.stores.values()) {
           tempNumStoreFiles += store.getStorefilesCount();
           tempMemstoreSize += store.getMemStoreSize();
           tempStoreFileSize += store.getStorefilesSize();
         }
+      }
 
       numStoreFiles = tempNumStoreFiles;
       memstoreSize = tempMemstoreSize;