Index: src/docbkx/performance.xml =================================================================== --- src/docbkx/performance.xml (revision 1146162) +++ src/docbkx/performance.xml (working copy) @@ -199,7 +199,21 @@ } - +
+ + Table Creation: Deferred Log Flush + + +The default behavior for Puts using the Write Ahead Log (WAL) is that HLog edits will be written immediately. If deferred log flush is used, +WAL edits are kept in memory until the flush period. The benefit is aggregated and asynchronous HLog- writes, but the potential downside is that if + the RegionServer goes down the yet-to-be-flushed edits are lost. This is safer, however, than not using WAL at all with Puts. + + +Deferred log flush can be configured on tables via HTableDescriptor. The default value of hbase.regionserver.optionallogflushinterval is 1000ms. + +
+
HBase Client