I realize that the value will come from hadoop-default.xml when it's not
defined elsewhere. I guess I was just suggesting that it makes the code
less-clear to have an explicit default in cases where the value *would* be
provided from a -default file, or the equivalent.

Having spent enough time reading others' code over the years, figuring out
*why* a value gets set, especially with a fancy configuration environment
(yes, hadoop's configuration is definitely in the "fancy" realm) by walking
the code is a tricky operation. My comment was merely that we might want to
have a better way of being explicit when things are really "system
defaults". The idiom used makes plenty of sense for user-created or
rarely-set values which have no specific defaults. Just my $0.02, though,
perhaps no one else agrees.

On 4/9/06, Doug Cutting (JIRA) <[EMAIL PROTECTED]> wrote:
>
>     [
> http://issues.apache.org/jira/browse/HADOOP-51?page=comments#action_12373803]
>
> Doug Cutting commented on HADOOP-51:
> ------------------------------------
>
> > the idiom of conf.getType("config.value",defaultValue) is good for
> user-defined values, but shouldn't the default be skipped for things that
> are defined in hadoop-default.xml, in general?
>
> The value from hadoop-default.xml is used in preference to the
> defaultValue paramter.  The paramter is only used as a last resort when no
> value is found in hadoop-default.xml or any other config file.
>
> > per-file replication counts
> > ---------------------------
> >
> >          Key: HADOOP-51
> >          URL: http://issues.apache.org/jira/browse/HADOOP-51
> >      Project: Hadoop
> >         Type: New Feature
>
> >   Components: dfs
> >     Versions: 0.2
> >     Reporter: Doug Cutting
> >     Assignee: Konstantin Shvachko
> >      Fix For: 0.2
> >  Attachments: Replication.patch
> >
> > It should be possible to specify different replication counts for
> different files.  Perhaps an option when creating a new file should be the
> desired replication count.  MapReduce should take advantage of this feature
> so that job.xml and job.jar files, which are frequently accessed by lots
> of machines, are more highly replicated than large data files.
>
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--
Bryan A. Pendleton
Ph: (877) geek-1-bp

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