[HIVE-3707] Round map/reduce progress down when it is in the range [99.5, 100)

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.10.0
• Fix Version/s: 0.10.0
• Component/s: Logging, Query Processor
• Hadoop Flags: Reviewed
• Assignee: Kevin Wilfong
• Reporter: Kevin Wilfong
• Created: 13/Nov/12 20:00
• Updated: 10/Jan/13 19:53
• Resolved: 15/Nov/12 07:59

Description

In HadoopJobExecHelper the mapProgress and reduceProgress are the value of these counters taken from the running job rounded to an integer percentage. This means that e.g. if the mappers are 99.5% done this is stored as 100%.

One of the most common questions I see from new users is, the map and reduce both report being 100% done, why is the query still running?

By rounding down the value in this interval so it's only 100% when it's really 100% we could avoid that confusion.

Also, the way it appears the QueryPlan and MapRedTask determine if the map/reduce phases are done is by checking if this value == 100. I couldn't find anywhere where they're used for anything significant, but they're reporting early completion.