You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@hbase.apache.org by st...@apache.org on 2014/04/29 21:37:04 UTC

svn commit: r1591067 - in /hbase/trunk: hbase-common/src/main/resources/hbase-default.xml src/main/docbkx/performance.xml

Author: stack
Date: Tue Apr 29 19:37:04 2014
New Revision: 1591067

URL: http://svn.apache.org/r1591067
Log:
Improve text and description around hbase checksumming

Modified:
    hbase/trunk/hbase-common/src/main/resources/hbase-default.xml
    hbase/trunk/src/main/docbkx/performance.xml

Modified: hbase/trunk/hbase-common/src/main/resources/hbase-default.xml
URL: http://svn.apache.org/viewvc/hbase/trunk/hbase-common/src/main/resources/hbase-default.xml?rev=1591067&r1=1591066&r2=1591067&view=diff
==============================================================================
--- hbase/trunk/hbase-common/src/main/resources/hbase-default.xml (original)
+++ hbase/trunk/hbase-common/src/main/resources/hbase-default.xml Tue Apr 29 19:37:04 2014
@@ -1027,10 +1027,16 @@ possible configurations would overwhelm 
     <name>hbase.regionserver.checksum.verify</name>
     <value>true</value>
     <description>
-        If set to true, HBase will read data and then verify checksums for
-        hfile blocks. Checksum verification inside HDFS will be switched off.
-        If the hbase-checksum verification fails, then it will switch back to
-        using HDFS checksums.
+        If set to true, HBase will verify checksums for hfile blocks. HBase
+        writes checksums inline with the data when it writes out hfiles. HDFS
+        writes checksums to a separate file from data necessitating extra seeks.
+        Setting this flag should save some on i/o.  Checksum verification by
+        HDFS will be internally disabled on hfile streams when this flag is set.
+        If the hbase-checksum verification fails, we will switch back to using
+        HDFS checksums (so do not disable HDFS checksums!  And besides this
+        feature applies to hfiles only, not to WALs).  If this parameter is set
+        to false, then hbase will not verify any checksums, instead it will
+        depend on checksum verification being done in the HDFS client.  
     </description>
   </property>
   <property>

Modified: hbase/trunk/src/main/docbkx/performance.xml
URL: http://svn.apache.org/viewvc/hbase/trunk/src/main/docbkx/performance.xml?rev=1591067&r1=1591066&r2=1591067&view=diff
==============================================================================
Binary files - no diff available.