NPE in IdxRegion.IdxRegionScanner/KeyProvider with HBase 0.20.5

[jbaldassari]

Between HBase-0.20.4 and HBase-0.20.5 the method HRegion.RegionScanner.initHeap() was removed, and the code that was previously in that method was moved into the HRegion.RegionScanner constructor. As a result of this change, IdxRegion.IdxRegionScanner fails to initialize properly.

The problem is that lines 318-321 in IdxRegion check if storeHeap == null, and the KeyProvider instance is only initialized if that condition is true. But storeHeap is never null because it is initialized in the HRegion.RegionScanner constructor, so the KeyProvider never gets initialized, and any methods called on it throw NPE because memstoreHeap is null.

The fix is simple, and I have a patch that I'll attach shortly.

[jbaldassari]

Hmm, not sure how to attach a file here (I guess I'm supposed to fork the project or something?), but the patch is so trivial that I'll just paste it here, and hopefully it'll show up ok:

/src/main/java/org/apache/hadoop/hbase/regionserver/IdxRegion.java index 8ce32ab..8e1eade 100644 --- a/src/main/java/org/apache/hadoop/hbase/regionserver/IdxRegion.java +++ b/src/main/java/org/apache/hadoop/hbase/regionserver/IdxRegion.java @@ -309,16 +309,13 @@ public class IdxRegion extends HRegion {

         numberOfOngoingIndexedScans.incrementAndGet();
         keyProvider = new KeyProvider(idxSearchContext, matchedExpression, scan);

•        keyProvider.init();
   }
  
  
   @Override
   public boolean next(List<KeyValue> outResults) throws IOException {
       ReadWriteConsistencyControl.resetThreadReadPoint(rwcc);
  

•        if (storeHeap == null) {
  

•            keyProvider.init();
  

•            initHeap();
  

•        }
       //DebugPrint.println("IdxScanner.next");
       // Seek to the next key value
       seekNext();
  

[jbaldassari]

/src/main/java/org/apache/hadoop/hbase/regionserver/IdxRegion.java
index 8ce32ab..8e1eade 100644
--- a/src/main/java/org/apache/hadoop/hbase/regionserver/IdxRegion.java
+++ b/src/main/java/org/apache/hadoop/hbase/regionserver/IdxRegion.java
@@ -309,16 +309,13 @@ public class IdxRegion extends HRegion {
 
             numberOfOngoingIndexedScans.incrementAndGet();
             keyProvider = new KeyProvider(idxSearchContext, matchedExpression, scan);
+            keyProvider.init();
         }
 
 
         @Override
         public boolean next(List outResults) throws IOException {
             ReadWriteConsistencyControl.resetThreadReadPoint(rwcc);
-            if (storeHeap == null) {
-                keyProvider.init();
-                initHeap();
-            }
             //DebugPrint.println("IdxScanner.next");
             // Seek to the next key value
             seekNext();

[jbaldassari]

OK, that looks better. Let me know if there is a better way to submit the patch.