The Next Generation of Apache Hadoop MapReduce
I’m not sure how many companies have already hit this limit, but Yahoo! is showing again its Hadoop leadership:
The Apache Hadoop MapReduce framework has hit a scalability limit around 4,000 machines. We are developing the next generation of Apache Hadoop MapReduce that factors the framework into a generic resource scheduler and a per-job, user-defined component that manages the application execution. Since downtime is more expensive at scale high-availability is built-in from the beginning; as are security and multi-tenancy to support many users on the larger clusters. The new architecture will also increase innovation, agility and hardware utilization.

There are way too many interesting aspects covered in the post to spoil the pleasure of diving into them.
Original title and link: The Next Generation of Apache Hadoop MapReduce (NoSQL databases © myNoSQL)
via: http://developer.yahoo.com/blogs/hadoop/posts/2011/02/mapreduce-nextgen/