Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
MapReduce, mail # user - How to change topology

Copy link to this message
Re: How to change topology
Ted Dunning 2012-10-09, 19:31
On Tue, Oct 9, 2012 at 12:17 PM, Steve Loughran <[EMAIL PROTECTED]>wrote:

> On 9 October 2012 16:51, Shinichi Yamashita <[EMAIL PROTECTED]> wrote:
>> Hi Steve,
>> Thank you for your reply.
>> > no, it's the Namenode and JobTracker that needs to be restarted;
>> > they are the bits that care where the boxes are.
>> I confirmed it in my cluster, and I understood it as follows.
>> First, the resolved node information is recorded in ConcurrentHashMap.
>> Next same node toplogy decision, HashMap data is given priority to over a
>> script.
>> The HashMap data become invalid by restart of NameNode and JobTracker.
> That's right. There's been lots of discussion on adding live topology
> resetting.

For what it's worth, there is at least one Hadoop derived distribution
which has live topology resetting already.

I can follow up offline with anyone who wants more information.