[PIG-1492] DefaultTuple and DefaultMemory understimate their memory footprint

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.0
• Fix Version/s: 0.8.0
• Assignee: Thejas Nair
• Reporter: Thejas Nair
• Created: 10/Jul/10 01:39
• Updated: 17/Dec/10 22:44
• Resolved: 21/Jul/10 18:30

Description

There are several places where we highly underestimate the memory footprint . For example, for map datatypes, we don't account for the per entry cost for the map container data structures. The estimated size of a tuple having map with 100 integer key-value entries , as per current version of code is 3260 bytes, while what is observed is around 6775 bytes . To verify the memory footprint, i checked free memory before and after creating multiple instances of the object , using code on the lines of http://www.javaspecialists.eu/archive/Issue029.html .

In PIG-1443 similar change was done to fix this for CHARARRAY .