HADOOP-9773. TestLightWeightCache should not set size limit to zero when testing it.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1507165 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4979. Implement retry cache on Namenode. Contributed by Suresh Srinivas.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1507170 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HADOOP-9204-trunk-gd