Affects Version/s: None
Fix Version/s: None
Currently each Hadoop job uploads the required resources (jars/files/archives) to a new location in HDFS. Map-reduce nodes involved in executing this job would then download these resources into local disk.
In an environment where most of the users are using a standard set of jars and files (because they are using a framework like Hive/Pig) - the same jars keep getting uploaded and downloaded repeatedly. The overhead of this protocol (primarily in terms of end-user latency) is significant when:
- the jobs are small (and conversantly - large in number)
- Namenode is under load (meaning hdfs latencies are high and made worse, in part, by this protocol)
Hadoop should provide a way for jobs in a cooperative environment to not submit the same files over and again. Identifying and caching execution resources by a content signature (md5/sha) would be a good alternative to have available.
|Transition||Time In Source Status||Execution Times||Last Executer||Last Execution Date|
|1961d 23h 35m||1||Vinod Kumar Vavilapalli||13/Nov/15 18:57|
|Status||Open [ 1 ]||Resolved [ 5 ]|
|Resolution||Duplicate [ 3 ]|