From a98f2d30ef662f8827bd75aec378315e7978e754 Mon Sep 17 00:00:00 2001 From: Misty Stanley-Jones Date: Mon, 17 Nov 2014 13:56:51 +1000 Subject: [PATCH] HBASE-11939 Document Compressed Blockcache --- src/main/docbkx/book.xml | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/src/main/docbkx/book.xml b/src/main/docbkx/book.xml index 706936c8ca1..dd777fd81f2 100644 --- a/src/main/docbkx/book.xml +++ b/src/main/docbkx/book.xml @@ -2516,6 +2516,25 @@ rs.close(); +
+ Comprewssed Blockcache + HBASE-11331 introduced lazy blockcache decompression, more simply referred to + as compressed blockcache. When compressed blockcache is enabled. data and encoded data + blocks are cached in the blockcache in their on-disk format, rather than being + decompressed and decrypted before caching. + For a RegionServer + hosting more data than can fit into cache, enabling this feature with SNAPPY compression + has been shown to result in 50% increase in throughput and 30% improvement in mean + latency while, increasing garbage collection by 80% and increasing overall CPU load by + 2%. See HBASE-11331 for more details about how performance was measured and achieved. + For a RegionServer hosting data that can comfortably fit into cache, or if your workload + is sensitive to extra CPU or garbage-collection load, you may receive less + benefit. + Compressed blockcache is disabled by default. To enable it, set + hbase.block.data.cachecompressed to true in + hbase-site.xml on all RegionServers. +