Index: src/docbkx/book.xml
===================================================================
--- src/docbkx/book.xml (revision 1324714)
+++ src/docbkx/book.xml (working copy)
@@ -1253,6 +1253,8 @@
map-tasks which will double-write your data to HBase; this is probably
not what you want.
+ See for more information.
+
Index: src/docbkx/configuration.xml
===================================================================
--- src/docbkx/configuration.xml (revision 1324714)
+++ src/docbkx/configuration.xml (working copy)
@@ -1585,6 +1585,13 @@
For more information about compactions and the compaction file selection process, see
+ Speculative Execution
+ Speculative Execution of MapReduce tasks is on by default, and for HBase clusters it is generally advised to turn off
+ Speculative Execution at a system-level unless you need it for a specific case, where it can be configured per-job.
+ Set the properties mapred.map.tasks.speculative.execution and
+ mapred.reduce.tasks.speculative.execution to false.
+
+
Other Configurations
@@ -1602,6 +1609,7 @@
on the size you need by surveying regionserver UIs; you'll see index block size accounted near the
top of the webpage).
+