You can use the Command-Line Interface (CLI) to create, modify, and list Cache Pools
and Cache Directives via the hdfs cacheadmin subcommand.
Cache Directives are identified by a unique, non-repeating, 64-bit integer ID. IDs will not be reused even if a Cache Directive is removed.
Cache Pools are identified by a unique string name.
You must first create a Cache Pool, and then add Cache Directives to the Cache Pool.
