Todd Lipcon created KUDU-1952:
---------------------------------
Summary: 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
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)
