[ https://issues.apache.org/jira/browse/HDFS-4184?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Todd Lipcon resolved HDFS-4184. ------------------------------- Resolution: Duplicate > Add the ability for Client to provide more hint information for DataNode to > manage the OS buffer cache more accurate > -------------------------------------------------------------------------------------------------------------------- > > Key: HDFS-4184 > URL: https://issues.apache.org/jira/browse/HDFS-4184 > Project: Hadoop HDFS > Issue Type: New Feature > Reporter: binlijin > > HDFS now has the ability to use posix_fadvise and sync_data_range syscalls to > manage the OS buffer cache. > {code} > When hbase read hlog the data we can set dfs.datanode.drop.cache.behind.reads > to true to drop data out of the buffer cache when performing sequential reads. > When hbase write hlog we can set dfs.datanode.drop.cache.behind.writes to > true to drop data out of the buffer cache after writing > When hbase read hfile during compaction we can set > dfs.datanode.readahead.bytes to a non-zero value to trigger readahead for > sequential reads, and also set dfs.datanode.drop.cache.behind.reads to true > to drop data out of the buffer cache when performing sequential reads. > and so on... > {code} > Current we can only set these feature global in datanode,we should set these > feature per session. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira