[
https://issues.apache.org/jira/browse/HADOOP-785?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12517561
]
Arun C Murthy commented on HADOOP-785:
--------------------------------------
bq. To summarize, we might end up having a couple of duplicate config items,
potentially having different values. Does this seem like a problem?
Sorry if I wasn't clear before, but this proposal is _explicitly designed_
keeping in mind tricky knobs such as {ipc.client.connection.maxidletime} and
this is how it would work:
One can, and should, specify different values for
{ipc.client.connection.maxidletime} in hadoop-server.xml and hadoop-client.xml.
Now, the values seen by ServerConfiguration (reads hadoop-default.xml and
hadoop-server.xml) viz. used by the {{TaskTracker}} is clearly different from
that seen by the child-vm which uses {{ClientConfiguration}}.
So, yes, in summary this proposal encourages and facilitates the *same* config
knobs being setup separately for use in different contexts...
> Divide the server and client configurations
> -------------------------------------------
>
> Key: HADOOP-785
> URL: https://issues.apache.org/jira/browse/HADOOP-785
> Project: Hadoop
> Issue Type: Improvement
> Components: conf
> Affects Versions: 0.9.0
> Reporter: Owen O'Malley
> Assignee: Arun C Murthy
> Fix For: 0.15.0
>
>
> The configuration system is easy to misconfigure and I think we need to
> strongly divide the server from client configs.
> An example of the problem was a configuration where the task tracker has a
> hadoop-site.xml that set mapred.reduce.tasks to 1. Therefore, the job tracker
> had the right number of reduces, but the map task thought there was a single
> reduce. This lead to a hard to find diagnose failure.
> Therefore, I propose separating out the configuration types as:
> class Configuration;
> // reads site-default.xml, hadoop-default.xml
> class ServerConf extends Configuration;
> // reads hadoop-server.xml, $super
> class DfsServerConf extends ServerConf;
> // reads dfs-server.xml, $super
> class MapRedServerConf extends ServerConf;
> // reads mapred-server.xml, $super
> class ClientConf extends Configuration;
> // reads hadoop-client.xml, $super
> class JobConf extends ClientConf;
> // reads job.xml, $super
> Note in particular, that nothing corresponds to hadoop-site.xml, which
> overrides both client and server configs. Furthermore, the properties from
> the *-default.xml files should never be saved into the job.xml.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
