Perhaps a clarification in the javadoc would be sufficient?
That would certainly help. See HADOOP-742.
On Apr 3, 2007, at 11:21 AM, Andrzej Bialecki (JIRA) wrote:
[ https://issues.apache.org/jira/browse/HADOOP-1197?
page=com.atlassian.jira.plugin.system.issuetabpanels:comment-
tabpanel#action_12486455 ]
Andrzej Bialecki commented on HADOOP-1197:
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These methods were added to support caching of transient Objects
created within the scope of a single task - especially Objects that
are costly to instantiate, and which follow a "singleton" pattern
within the scope of the current task. Examples: plugin registry,
which requires reading and parsing a lot of config files;
individual plugin instances; processing chains composed of several
plugins, etc.
These Objects are not Writable, nor does it make sense to make them
Writable - the only purpose of this pattern is to avoid repetitive
instantiation of Configurable objects with the same Configuration
instance.
If we remove this functionality from Hadoop, then a dozen Nutch
subsystems would break, since they rely on this feature. Nutch
could implement its own object cache, but then a lot of APIs would
have to be changed to take not only a Configuration instance but
also an object cache singleton ..
Perhaps a clarification in the javadoc would be sufficient?
The misleading Configuration.set(String, Object) should be removed
------------------------------------------------------------------
Key: HADOOP-1197
URL: https://issues.apache.org/jira/browse/
HADOOP-1197
Project: Hadoop
Issue Type: Bug
Components: conf
Affects Versions: 0.12.2
Reporter: Owen O'Malley
Assigned To: Owen O'Malley
Priority: Minor
Fix For: 0.13.0
I think that the confusing methods in Configuration:
set(String, Object)
getObject(String)
get(String, Object)
should be deprecated. Users expect them to work and in a
distributed environment, there is almost no way to make them work
correctly. If some user really needs the functionality, we should
implement it right and require that the objects be Writable and
serialize them into the Configuration.
Thoughts?
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