HBASE-1009 Master stuck in loop wanting to assign but regions are closing

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@719155 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -79,6 +79,7 @@ Release 0.19.0 - Unreleased
    HBASE-1005  Regex and string comparison operators for ColumnValueFilter
    HBASE-910   Scanner misses columns / rows when the scanner is obtained
                durring a memcache flush
+   HBASE-1009  Master stuck in loop wanting to assign but regions are closing
       
   IMPROVEMENTS
    HBASE-901   Add a limit to key length, check key and value length on client side

src/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -110,6 +110,11 @@ public class HRegion implements HConstants {
   static final Random rand = new Random();
   static final Log LOG = LogFactory.getLog(HRegion.class);
   final AtomicBoolean closed = new AtomicBoolean(false);
+  /* Closing can take some time; use the closing flag if there is stuff we don't want
+   * to do while in closing state; e.g. like offer this region up to the master as a region
+   * to close if the carrying regionserver is overloaded.  Once set, it is never cleared.
+   */
+  private final AtomicBoolean closing = new AtomicBoolean(false);
   private final RegionHistorian historian;
 
   //////////////////////////////////////////////////////////////////////////////
@@ -329,6 +334,13 @@ public class HRegion implements HConstants {
     return this.closed.get();
   }
   
+  /**
+   * @return True if closing process has started.
+   */
+  public boolean isClosing() {
+    return this.closing.get();
+  }
+  
   /**
    * Close down this HRegion.  Flush the cache, shut down each HStore, don't 
    * service any more calls.
@@ -365,6 +377,7 @@ public class HRegion implements HConstants {
       LOG.warn("region " + this + " already closed");
       return null;
     }
+    this.closing.set(true);
     synchronized (splitLock) {
       synchronized (writestate) {
         // Disable compacting and flushing by background threads for this
@@ -419,7 +432,6 @@ public class HRegion implements HConstants {
             result.addAll(store.close());
           }
           this.closed.set(true);
-          
           LOG.info("Closed " + this);
           return result;
         } finally {

src/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -1762,6 +1762,9 @@ public class HRegionServer implements HConstants, HRegionInterface, Runnable {
     ArrayList<HRegionInfo> regions = new ArrayList<HRegionInfo>();
     synchronized (onlineRegions) {
       for (HRegion r : onlineRegions.values()) {
+        if (r.isClosed() || r.isClosing()) {
+          continue;
+        }
         if (regions.size() < numRegionsToReport) {
           regions.add(r.getRegionInfo());
         } else {