[ 
https://issues.apache.org/jira/browse/KUDU-1952?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Todd Lipcon updated KUDU-1952:
------------------------------
    Component/s: perf

> round-robin block allocation can place all blocks for a given column on one 
> disk
> --------------------------------------------------------------------------------
>
>                 Key: KUDU-1952
>                 URL: https://issues.apache.org/jira/browse/KUDU-1952
>             Project: Kudu
>          Issue Type: Bug
>          Components: fs, perf
>    Affects Versions: 1.3.0
>            Reporter: Todd Lipcon
>
> Currently the LBM allocates across disks in round-robin order. I ran a test 
> using 4 data disks and a table with 12 columns. This caused very uneven 
> allocation across disks, since all data for column N ended up on disk N%4. 
> This also makes single-column scans slow since they read from only a single 
> disk.
> In a more mixed workload this is likely to be less problematic, but still it 
> seems like we should take available space into consideration for allocation, 
> and/or add more randomness.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to