HBASE-14838 Add clarification docs to SimpleRegionNormalizer. Signed-off-by: Sean Busbey <bus...@cloudera.com>
Project: http://git-wip-us.apache.org/repos/asf/hbase/repo Commit: http://git-wip-us.apache.org/repos/asf/hbase/commit/ca7a82fb Tree: http://git-wip-us.apache.org/repos/asf/hbase/tree/ca7a82fb Diff: http://git-wip-us.apache.org/repos/asf/hbase/diff/ca7a82fb Branch: refs/heads/hbase-12439 Commit: ca7a82fb5704af27459557168afc96e1193ac7cb Parents: 60d33ce Author: Josh Elser <els...@apache.org> Authored: Mon Dec 7 12:51:44 2015 -0500 Committer: Sean Busbey <bus...@cloudera.com> Committed: Wed Dec 16 08:58:48 2015 -0600 ---------------------------------------------------------------------- .../hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java | 4 ++++ 1 file changed, 4 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/hbase/blob/ca7a82fb/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java ---------------------------------------------------------------------- diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java index d843bd1..659b3dc 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java @@ -45,6 +45,10 @@ import java.util.List; * to merge, if R1 + R1 < S, and normalization stops * <li> Otherwise, no action is performed * </ol> + * <p> + * Region sizes are coarse and approximate on the order of megabytes. Additionally, + * "empty" regions (less than 1MB, with the previous note) are not merged away. This + * is by design to prevent normalization from undoing the pre-splitting of a table. */ @InterfaceAudience.Private public class SimpleRegionNormalizer implements RegionNormalizer {