hadoop-common-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Steve Loughran <ste...@apache.org>
Subject Re: How to HA the NameNode?
Date Thu, 30 Jul 2009 12:27:45 GMT
imcaptor wrote:
> Dear All:
>   The NameNode is the Single Point of hadoop,

It's *one* SPOF - unless your datacentre has multiple gigabit backbones 
on separate switches and more than electricity supply from different 
power supply grids, you have others out there. Then there's the issue of 
which fault lines your facility is close to, whether it is built on the 
mud flows of previous eruptions (Enumclaw, WA spring to mind), etc.

> I want to know how to HA the NameNode.

This is a major engineering project that has been discussed on the 
lists. If you want to get involved in it, and have the skills -and the 
testing facilities- you would be welcome. Testing HA/failover is tricky 
because of the many ways things can fail.

Otherwise, focus on making sure your namenode data is streamed off onto 
different disks, you have a secondary NN, and you  have a good recovery 
process that includes the failure of the NN hardware

View raw message