Mailing-List: contact hadoop-dev-help@lucene.apache.org; run by ezmlm
Precedence: bulk
Reply-To: hadoop-dev@lucene.apache.org
Message-ID: <10074588.1186155113298.JavaMail.jira@brutus>
Date: Fri, 3 Aug 2007 08:31:53 -0700 (PDT)
From: "Arun C Murthy (JIRA)" <jira@apache.org>
To: hadoop-dev@lucene.apache.org
Subject: [jira] Issue Comment Edited: (HADOOP-785) Divide the server and
 client configurations
In-Reply-To: <4048066.1165393281134.JavaMail.jira@brutus>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/HADOOP-785?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12517561 ] 

Arun C Murthy edited comment on HADOOP-785 at 8/3/07 8:31 AM:
--------------------------------------------------------------

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...


 was:
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.