[
https://issues.apache.org/jira/browse/ACCUMULO-1787?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13800885#comment-13800885
]
Keith Turner commented on ACCUMULO-1787:
----------------------------------------
[~ecn] and I were discussing ACCUMULO-1451. The major compaction strategy
would not fully satisfy this use case because its not invoked for minor
compactions. However it still seems like it would be useful if the major
compaction strategy could optionally configure the rfile.
> support two tier compression codec configuration
> ------------------------------------------------
>
> Key: ACCUMULO-1787
> URL: https://issues.apache.org/jira/browse/ACCUMULO-1787
> Project: Accumulo
> Issue Type: Improvement
> Reporter: Adam Fuchs
> Attachments: ci_file_sizes.png
>
>
> Given our current configuration of one compression codec per table we have
> the option of leaning towards performance with something like snappy or
> leaning towards smaller footprint with something like gzip. With a change to
> the way we configure codecs we might be able to approach the best of both
> worlds. Consider the difference between files that have been written by major
> or minor compactions and files that exist at any given point in time. For
> better footprint on disk we care about the latter, but for total CPU usage
> over time we care about the former. The two distributions are distinct
> because Accumulo deletes files after major compactions. If we figure out
> whether a file is going to be long-lived at the time we write it then we can
> pick the compression codec that optimizes the relevant concern.
> One way to distinguish is by file size. Accumulo writes many small files and
> later major compacts those away, so the distribution of written files is
> skewed towards smaller files while the distribution of files existing at any
> point in time is skewed towards larger files. I recommend for each table we
> support a general compression codec and a second codec for files under a
> configurable size.
--
This message was sent by Atlassian JIRA
(v6.1#6144)
