HBASE-11307 Deprecate SlabCache

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/CacheConfig.java

@@ -515,6 +515,7 @@ public class CacheConfig {
         GLOBAL_BLOCK_CACHE_INSTANCE = lruCache;
       }
     } else {
+      LOG.warn("SlabCache is deprecated. Consider BucketCache as a replacement.");
       GLOBAL_BLOCK_CACHE_INSTANCE = new DoubleBlockCache(
           lruCacheSize, slabCacheOffHeapCacheSize, blockSize, blockSize, conf);
     }

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/DoubleBlockCache.java

@@ -35,8 +35,10 @@ import org.apache.hadoop.util.StringUtils;
  * cache before looking for the block in the off heap cache. Metrics are the
  * combined size and hits and misses of both caches.
  *
- **/
+ * @deprecated As of 1.0, replaced by {@link org.apache.hadoop.hbase.io.hfile.bucket.BucketCache}.
+ */
 @InterfaceAudience.Private
+@Deprecated
 public class DoubleBlockCache implements ResizableBlockCache, HeapSize {
 
   static final Log LOG = LogFactory.getLog(DoubleBlockCache.class.getName());

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SingleSizeCache.java

@@ -51,8 +51,10 @@ import com.google.common.cache.RemovalNotification;
  * Eviction and LRUness is taken care of by Guava's MapMaker, which creates a
  * ConcurrentLinkedHashMap.
  *
+ * @deprecated As of 1.0, replaced by {@link org.apache.hadoop.hbase.io.hfile.bucket.BucketCache}.
  **/
 @InterfaceAudience.Private
+@Deprecated
 public class SingleSizeCache implements BlockCache, HeapSize {
   private final Slab backingStore;
   private final ConcurrentMap<BlockCacheKey, CacheablePair> backingMap;

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/slab/Slab.java

@@ -33,9 +33,11 @@ import com.google.common.base.Preconditions;
  * Slab is a class which is designed to allocate blocks of a certain size.
  * Constructor creates a number of DirectByteBuffers and slices them into the
  * requisite size, then puts them all in a buffer.
- **/
-
+ *
+ * @deprecated As of 1.0, replaced by {@link org.apache.hadoop.hbase.io.hfile.bucket.BucketCache}.
+ */
 @InterfaceAudience.Private
+@Deprecated
 class Slab implements org.apache.hadoop.hbase.io.HeapSize {
   static final Log LOG = LogFactory.getLog(Slab.class);
 

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabCache.java

@@ -57,8 +57,10 @@ import com.google.common.util.concurrent.ThreadFactoryBuilder;
  * 
  * <p>It is configured with a call to {@link #addSlab(int, int)}
  *
- **/
+ * @deprecated As of 1.0, replaced by {@link org.apache.hadoop.hbase.io.hfile.bucket.BucketCache}.
+ */
 @InterfaceAudience.Private
+@Deprecated
 public class SlabCache implements SlabItemActionWatcher, BlockCache, HeapSize {
   private final ConcurrentHashMap<BlockCacheKey, SingleSizeCache> backingStore;
   private final TreeMap<Integer, SingleSizeCache> slabs;

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/slab/SlabItemActionWatcher.java

@@ -24,8 +24,11 @@ import org.apache.hadoop.hbase.io.hfile.BlockCacheKey;
 
 /**
  * Interface for objects that want to know when actions occur in a SingleSizeCache.
- * */
+ *
+ * @deprecated As of 1.0, replaced by {@link org.apache.hadoop.hbase.io.hfile.bucket.BucketCache}.
+ */
 @InterfaceAudience.Private
+@Deprecated
 interface SlabItemActionWatcher {
 
   /**

src/main/docbkx/book.xml

@@ -1953,7 +1953,8 @@ rs.close();
           <para>LruBlockCache is the original implementation, and is entirely within the Java heap.
             SlabCache and BucketCache are mainly intended for keeping blockcache data offheap,
             although BucketCache can also keep data onheap and in files.</para>
-          <para> BucketCache has seen more production deploys and has more deploy options. Fetching
+          <para><emphasis>SlabCache is deprecated and will be removed in 1.0!</emphasis></para>
+          <para>BucketCache has seen more production deploys and has more deploy options. Fetching
             will always be slower when fetching from BucketCache or SlabCache, as compared with the
             native onheap LruBlockCache. However, latencies tend to be less erratic over time,
             because there is less garbage collection.</para>
@@ -2112,6 +2113,7 @@ rs.close();
           <title>Offheap Block Cache</title>
           <section>
             <title>Enable SlabCache</title>
+            <para><emphasis>SlabCache is deprecated and will be removed in 1.0!</emphasis></para>
             <para> SlabCache is originally described in <link
                 xlink:href="http://blog.cloudera.com/blog/2012/01/caching-in-hbase-slabcache/">Caching
                 in Apache HBase: SlabCache</link>. Quoting from the API documentation for <link