diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
index b51e8010513..ac9db75c022 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
@@ -4217,8 +4217,8 @@ public class HBaseAdmin implements Admin {
     HTableDescriptor htd = getTableDescriptor(tableName);
     HColumnDescriptor family = htd.getFamily(columnFamily);
     if (family == null || !family.isMobEnabled()) {
-      throw new IllegalArgumentException("Column family " + columnFamily
-              + " is not a mob column family");
+      throw new IllegalArgumentException("Column family " + Bytes.toString(columnFamily)
+        + " is not a mob column family");
     }
   }
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java
index 0de276296a0..5bded37db92 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java
@@ -3013,9 +3013,7 @@ public final class ProtobufUtil {
     // This used to be builder.mergeDelimitedFrom(in);
     // but is replaced to allow us to bump the protobuf size limit.
     final int firstByte = in.read();
-    if (firstByte == -1) {
-      // bail out. (was return false;)
-    } else {
+    if (firstByte != -1) {
       final int size = CodedInputStream.readRawVarint32(firstByte, in);
       final InputStream limitedInput = new LimitInputStream(in, size);
       final CodedInputStream codedInput = CodedInputStream.newInstance(limitedInput);
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ExpiredMobFileCleanerChore.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ExpiredMobFileCleanerChore.java
index 8c9bc2bd518..72ac7922fe6 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ExpiredMobFileCleanerChore.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ExpiredMobFileCleanerChore.java
@@ -35,6 +35,8 @@ import org.apache.hadoop.hbase.mob.ExpiredMobFileCleaner;
 import org.apache.hadoop.hbase.mob.MobConstants;
 import org.apache.hadoop.hbase.mob.MobUtils;
 
+import com.google.protobuf.ServiceException;
+
 /**
  * The Class ExpiredMobFileCleanerChore for running cleaner regularly to remove the expired
  * mob files.
@@ -81,8 +83,12 @@ public class ExpiredMobFileCleanerChore extends ScheduledChore {
               cleaner.cleanExpiredMobFiles(htd.getTableName().getNameAsString(), hcd);
             } catch (LockTimeoutException e) {
               LOG.info("Fail to acquire the lock because of timeout, maybe a"
-                + " MobFileCompactor is running", e);
-            } catch (Exception e) {
+                + " MobCompactor is running", e);
+            } catch (ServiceException e) {
+              LOG.error(
+                "Fail to clean the expired mob files for the column " + hcd.getNameAsString()
+                  + " in the table " + htd.getNameAsString(), e);
+            } catch (IOException e) {
               LOG.error(
                 "Fail to clean the expired mob files for the column " + hcd.getNameAsString()
                   + " in the table " + htd.getNameAsString(), e);
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/mob/mapreduce/SweepJob.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/mob/mapreduce/SweepJob.java
index 3a06ad8c07c..b0c39566b07 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/mob/mapreduce/SweepJob.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/mob/mapreduce/SweepJob.java
@@ -96,7 +96,7 @@ public class SweepJob {
   public static final String WORKING_FILES_DIR_KEY = "mob.sweep.job.files.dir";
   //the MOB_SWEEP_JOB_DELAY is ONE_DAY by default. Its value is only changed when testing.
   public static final String MOB_SWEEP_JOB_DELAY = "hbase.mob.sweep.job.delay";
-  protected static long ONE_DAY = 24 * 60 * 60 * 1000;
+  protected static final long ONE_DAY = 24 * 60 * 60 * 1000;
   private long compactionStartTime = EnvironmentEdgeManager.currentTime();
   public final static String CREDENTIALS_LOCATION = "credentials_location";
   private CacheConfig cacheConfig;
@@ -461,7 +461,7 @@ public class SweepJob {
   /**
    * A result with index.
    */
-  private class IndexedResult implements Comparable<IndexedResult> {
+  private static class IndexedResult implements Comparable<IndexedResult> {
     private int index;
     private String value;
 
@@ -516,7 +516,7 @@ public class SweepJob {
    * It merges and sort the readers in different sequence files as one where
    * the results are read in order.
    */
-  private class MergeSortReader {
+  private static class MergeSortReader {
 
     private List<SequenceFile.Reader> readers = new ArrayList<SequenceFile.Reader>();
     private PriorityQueue<IndexedResult> results = new PriorityQueue<IndexedResult>();
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HMobStore.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HMobStore.java
index ad0c4d79854..faf6d813b09 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HMobStore.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HMobStore.java
@@ -543,6 +543,7 @@ public class HMobStore extends HStore {
     return cellsSizeCompactedFromMob;
   }
 
+  @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "VO_VOLATILE_INCREMENT")
   public void updateMobFlushCount() {
     mobFlushCount++;
   }