Shenshengli hbase-25450 The parameter "hbase.bucketcache.size" is misdescribed (#2821)

Signed-off-by: Anoop Sam John <anoopsamjohn@apache.org>
Signed-off-by: stack <stack@apache.org>

hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java

@@ -1400,9 +1400,7 @@ public final class HConstants {
   public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
 
   /**
-   * When using bucket cache, this is a float that EITHER represents a percentage of total heap
-   * memory size to give to the cache (if < 1.0) OR, it is the capacity in
-   * megabytes of the cache.
+   * When using bucket cache, it is the capacity in megabytes of the cache.
    */
   public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
 

hbase-common/src/main/resources/hbase-default.xml

@@ -1033,9 +1033,7 @@ possible configurations would overwhelm and obscure the important.
   <property>
     <name>hbase.bucketcache.size</name>
     <value></value>
-    <description>A float that EITHER represents a percentage of total heap memory
-    size to give to the cache (if &lt; 1.0) OR, it is the total capacity in
-    megabytes of BucketCache. Default: 0.0</description>
+    <description>It is the total capacity in megabytes of BucketCache. Default: 0.0</description>
   </property>
   <property>
     <name>hbase.bucketcache.bucket.sizes</name>

hbase-server/src/main/java/org/apache/hadoop/hbase/io/util/MemorySizeUtil.java

@@ -234,7 +234,7 @@ public class MemorySizeUtil {
   }
 
   /**
-   * @param conf used to read config for bucket cache size. (< 1 is treated as % and > is treated as MiB)
+   * @param conf used to read config for bucket cache size. 
    * @return the number of bytes to use for bucket cache, negative if disabled.
    */
   public static long getBucketCacheSize(final Configuration conf) {

src/main/asciidoc/_chapters/hbase-default.adoc

@@ -1242,6 +1242,7 @@ Whether or not the bucketcache is used in league with the LRU
 .Description
 Used along with bucket cache, this is a float that EITHER represents a percentage of total heap
    memory size to give to the cache (if < 1.0) OR, it is the capacity in megabytes of the cache.
+   (After HBase-2.0, "hbase.bucketcache.size" cannot be between 0-1)
 +
 .Default
 `0` when specified as a float