From 05e0f7478e7b289e7b903f748861d330cc301c8c Mon Sep 17 00:00:00 2001 From: Nick Dimiduk Date: Wed, 20 Aug 2014 12:54:56 -0700 Subject: [PATCH] Revert "Document blockcache prefetch option (Misty Stanley-Jones)" This reverts commit 7f567830032f6dac027a6e0075987400c93c58f3. --- src/main/docbkx/book.xml | 14 ++++++-------- src/main/docbkx/performance.xml | 31 ------------------------------- 2 files changed, 6 insertions(+), 39 deletions(-) diff --git a/src/main/docbkx/book.xml b/src/main/docbkx/book.xml index be0a65b6044..3a4ff604b7b 100644 --- a/src/main/docbkx/book.xml +++ b/src/main/docbkx/book.xml @@ -2139,14 +2139,12 @@ rs.close();
General Cache Configurations - Apart from the cache implementaiton itself, you can set some general configuration - options to control how the cache performs. See . After setting any of these options, restart or rolling restart your cluster for the - configuration to take effect. Check logs for errors or unexpected behavior. - See also , which discusses a new option - introduced in HBASE-9857. + Apart from the cache implementaiton itself, you can set some general + configuration options to control how the cache performs. + See . + After setting any of these options, restart or rolling restart your cluster for the + configuration to take effect. Check logs for errors or unexpected behavior.
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- Prefetch Option for Blockcache - HBASE-9857 - adds a new option to prefetch HFile contents when opening the blockcache, if a columnfamily - or regionserver property is set. This option is available for HBase 0.98.3 and later. The - purpose is to warm the blockcache as rapidly as possible after the cache is opened, using - in-memory table data, and not counting the prefetching as cache misses. This is great for - fast reads, but is not a good idea if the data to be preloaded will not fit into the - blockcache. It is useful for tuning the IO impact of prefetching versus the time before all - data blocks are in cache. - To enable prefetching on a given column family, you can use HBase Shell or use the - API. - - Enable Prefetch Using HBase Shell - hbase> create 'MyTable', { NAME => 'myCF', PREFETCH_BLOCKS_ON_OPEN => 'true' } - - - Enable Prefetch Using the API - -// ... -HTableDescriptor tableDesc = new HTableDescriptor("myTable"); -HColumnDescriptor cfDesc = new HColumnDescriptor("myCF"); -cfDesc.setPrefetchBlocksOnOpen(true); -tableDesc.addFamily(cfDesc); -// ... - - - See the API documentation for CacheConfig. -
<varname>hbase.regionserver.global.memstore.size</varname> See .