Weiwei Yang created HDFS-12506:
----------------------------------

             Summary: Ozone: ListBucket is too slow
                 Key: HDFS-12506
                 URL: https://issues.apache.org/jira/browse/HDFS-12506
             Project: Hadoop HDFS
          Issue Type: Sub-task
          Components: ozone
            Reporter: Weiwei Yang
            Assignee: Weiwei Yang
            Priority: Blocker


Generated 3 million keys in ozone, and run {{listBucket}} command to get a list 
of buckets under a volume,

{code}
bin/hdfs oz -listBucket http://15oz1.fyre.ibm.com:9864/vol-0-15143 -user wwei
{code}

this call spent over *15 seconds* to finish. The problem was caused by the 
inflexible structure of KSM DB. Right now {{ksm.db}} stores keys like following

{code}
/v1/b1
/v1/b1/k1
/v1/b1/k2
/v1/b1/k3
/v1/b2
/v1/b2/k1
/v1/b2/k2
/v1/b2/k3
/v1/b3
/v1/b4
{code}

keys are sorted in nature order so when we do list buckets under a volume e.g 
/v1, we need to seek to /v1 point and start to iterate and filter keys, this 
ends up with scanning all keys under volume /v1. The problem with this design 
is we don't have an efficient approach to locate all buckets without scanning 
the keys.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-dev-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-dev-h...@hadoop.apache.org

Reply via email to