Index: conf/hbase-env.sh
===================================================================
--- conf/hbase-env.sh (revision 1240895)
+++ conf/hbase-env.sh (working copy)
@@ -45,7 +45,7 @@
# Uncomment below if you intend to use the EXPERIMENTAL off heap cache.
# export HBASE_OPTS="$HBASE_OPTS -XX:MaxDirectMemorySize="
-# Set hbase.offheapcachesize in hbase-site.xml
+# Set hbase.offheapcache.percentage in hbase-site.xml to a nonzero value.
# Uncomment and adjust to enable JMX exporting
Index: src/main/java/org/apache/hadoop/hbase/io/hfile/CacheConfig.java
===================================================================
--- src/main/java/org/apache/hadoop/hbase/io/hfile/CacheConfig.java (revision 1240895)
+++ src/main/java/org/apache/hadoop/hbase/io/hfile/CacheConfig.java (working copy)
@@ -329,7 +329,7 @@
}
if (cachePercentage > 1.0) {
throw new IllegalArgumentException(HConstants.HFILE_BLOCK_CACHE_SIZE_KEY +
- " must be between 0.0 and 1.0, not > 1.0");
+ " must be between 0.0 and 1.0, and not > 1.0");
}
// Calculate the amount of heap to give the heap.
@@ -338,7 +338,7 @@
int blockSize = conf.getInt("hbase.offheapcache.minblocksize",
HFile.DEFAULT_BLOCKSIZE);
long offHeapCacheSize =
- (long) (conf.getFloat("hbase.offheapcache.percentage", (float) 0.95) *
+ (long) (conf.getFloat("hbase.offheapcache.percentage", (float) 0) *
DirectMemoryUtils.getDirectMemorySize());
LOG.info("Allocating LruBlockCache with maximum size " +
StringUtils.humanReadableInt(cacheSize));
Index: src/main/resources/hbase-default.xml
===================================================================
--- src/main/resources/hbase-default.xml (revision 1240895)
+++ src/main/resources/hbase-default.xml (working copy)
@@ -851,4 +851,13 @@
hbase.thrift.maxQueuedRequests threads.
+
+ hbase.offheapcache.percentage
+ 0
+
+ The amount of off heap space to be allocated towards the experimental
+ off heap cache. If you desire the cache to be disabled, simply set this
+ value to 0.
+
+
Index: src/docbkx/upgrading.xml
===================================================================
--- src/docbkx/upgrading.xml (revision 1240895)
+++ src/docbkx/upgrading.xml (working copy)
@@ -171,7 +171,7 @@
A new cache was contributed to 0.92.0 to act as a solution between using the “on-heap” cache which is the current LRU cache the region servers have and the operating system cache which is out of our control.
-To enable, set “-XX:MaxDirectMemorySize” in hbase-env.sh to the value that you want to dedicate to that cache. This should only be set for servers and not for clients; in fact, if you already had to add that configuration on for any reason and still use it today it’s going to enable this feature. Use at your own risk.
+To enable, set “-XX:MaxDirectMemorySize” in hbase-env.sh to the value for maximum direct memory size and specify hbase.offheapcache.percentage in hbase-site.xml with the percentage that you want to dedicate to off-heap cache. This should only be set for servers and not for clients. Use at your own risk.
See this blog post for additional information on this new experimental feature: http://www.cloudera.com/blog/2012/01/caching-in-hbase-slabcache/