diff --git src/main/docbkx/book.xml src/main/docbkx/book.xml index 3a4ff60..5343311 100644 --- src/main/docbkx/book.xml +++ src/main/docbkx/book.xml @@ -1040,6 +1040,32 @@ $ HADOOP_CLASSPATH=$(hbase mapredcp):/etc/hbase/conf hadoop jar MyApp +
+ MapReduce Scan Caching + TableMapReduceUtil now restores the option to set scanner caching (the number of rows + that is cached) on the Scan object that is passed in. This functionality was lost due to a + bug in HBase 0.95 (HBASE-11558), which is fixed for HBase 0.98.5 and 0.96.3. The priority order for + choosing the scanner caching is as follows: + + + Caching settings which are set on the scan object. + + + Caching settings which are specified via the configuration option + , which can either be set manually in + hbase-site.xml or via the helper method + TableMapReduceUtil.setScannerCaching(). + + + The default value HConstants.DEFAULT_HBASE_CLIENT_SCANNER_CACHING, which is set to + 100. + + + See the API documentation for Scan for more details. +
Bundled HBase MapReduce Jobs