Index: src/docbkx/ops_mgt.xml =================================================================== --- src/docbkx/ops_mgt.xml (revision 1196716) +++ src/docbkx/ops_mgt.xml (working copy) @@ -417,6 +417,11 @@ +
Regions + Another common question for HBase administrators is determining the right number of regions per + RegionServer. This affects both storage and hardware planning. See . + +
Index: src/docbkx/performance.xml =================================================================== --- src/docbkx/performance.xml (revision 1196716) +++ src/docbkx/performance.xml (working copy) @@ -140,6 +140,11 @@ The number of regions for an HBase table is driven by the . Also, see the architecture section on + A lower number of regions is preferred, generally in the range of 20 to 200 + per RegionServer. Adjust the regionsize as appropriate to achieve this number. There + are some clusters that set the regionsize to 20Gb, for example, so you may need to + experiment with this setting based on your hardware configuration and application needs. +
Index: src/docbkx/book.xml =================================================================== --- src/docbkx/book.xml (revision 1196716) +++ src/docbkx/book.xml (working copy) @@ -565,6 +565,12 @@ second and third column family in the case where data access is usually column scoped; i.e. you query one column family or the other but usually not both at the one time. +
Cardinality of ColumnFamilies + Where multiple ColumnFamilies exist in a single table, be aware of the cardinality (i.e., number of rows). + If ColumnFamily-A has 1000,000 rows and ColumnFamily-B has 1 billion rows, ColumnFamily-A's data will likely be spread + across many, many regions (and RegionServers). This makes mass scans for ColumnFamily-A less efficient. + +
Rowkey Design
@@ -972,6 +978,11 @@
+
+ HBase MapReduce Read/Write Example With Multi-Table Output + TODO: example for MultiTableOutputFormat. + +
HBase MapReduce Summary Example The following example uses HBase as a MapReduce source and sink with a summarization step. This example will @@ -1575,7 +1586,6 @@ For more information, see the HFile source code.
-
HFile Tool @@ -1589,7 +1599,13 @@ usage for other things to do with the HFile tool.
+
+ StoreFile Directory Structure on HDFS + For more information of what StoreFiles look like on HDFS with respect to the directory structure, see . +
+
+
Blocks StoreFiles are composed of blocks. The blocksize is configured on a per-ColumnFamily basis.