Resource Request

• Request resources of each container.
  • CPU
  • Memory
• Locality constraints for the constainers.
  • According to Network topology
  • Allow application to specify locality.
• Generally, a container processes an HDFS block.
• Request resources at any time.
  • All requests at beginning.
    • Spark in this way.
  • Or requests resources dynamically to meet the changing needs.
• In MapReduce,
  • Map tasks request containers up front,
  • Reduce tasks containers are not started until later.
  • If any tasks fail, additional container would be requested.

TODO

1. How to know the hosts of all containers.