HBASE-15181 Addendum fixes findbugs warning (Clara Xiong)

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

@@ -135,6 +135,13 @@ public class DateTieredCompactionPolicy extends RatioBasedCompactionPolicy {
         partitionFilesToBuckets(candidatesInWindow, comConf.getBaseWindowMillis(),
           comConf.getWindowsPerTier(), now);
     LOG.debug("Compaction buckets are: " + buckets);
+    if (buckets.size() >= storeConfigInfo.getBlockingFileCount()) {
+      LOG.warn("Number of compaction buckets:" +  buckets.size()
+        + ", exceeds blocking file count setting: "
+        + storeConfigInfo.getBlockingFileCount()
+        + ", either increase hbase.hstore.blockingStoreFiles or "
+        + "reduce the number of tiered compaction windows");
+    }
 
     return newestBucket(buckets, comConf.getIncomingWindowMin(), now,
       comConf.getBaseWindowMillis(), mayUseOffPeak);
@@ -234,7 +241,7 @@ public class DateTieredCompactionPolicy extends RatioBasedCompactionPolicy {
       public boolean apply(StoreFile storeFile) {
         // Known findbugs issue to guava. SuppressWarning or Nonnull annotation don't work.
         if (storeFile == null) {
-          throw new NullPointerException();
+          return false;
         }
         return storeFile.getMaximumTimestamp() >= cutoff;
       }

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

@@ -50,13 +50,13 @@ import org.junit.experimental.categories.Category;
 
 @Category(SmallTests.class)
 public class TestCompactionPolicy {
-  private final static Log LOG = LogFactory.getLog(TestDefaultCompactSelection.class);
+  private final static Log LOG = LogFactory.getLog(TestCompactionPolicy.class);
   protected final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
 
   protected Configuration conf;
   protected HStore store;
   private static final String DIR = TEST_UTIL.getDataTestDir(
-    TestDefaultCompactSelection.class.getSimpleName()).toString();
+    TestCompactionPolicy.class.getSimpleName()).toString();
   protected static Path TEST_FILE;
   protected static final int minFiles = 3;
   protected static final int maxFiles = 5;