[TAJO-223] Maximize disk read bandwidth utilization of StorageManagerV2 by moving Tuple creation role to next()

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.2-incubating
• Component/s: Storage
• Labels: performance
• Assignee: Keuntae Park
• Reporter: Keuntae Park
• Created: 02/Oct/13 06:51
• Updated: 04/Oct/13 09:59
• Resolved: 04/Oct/13 09:53

Description

Currently, Tuple creation mechanism of StorageManagerV2 is as follows:
1) At file scan, scheduled scanner reads data from disk, makes a Tuple, and insert it to the Tuple pool
2) next() of the scanner just pulls an already created Tuple from the Tuple pool asynchronously

Because of Tuple creation time, scanner cannot fully use its time to read disk, which results in less disk read bandwidth utilization

So, if Tuple creation role is moved to next() and scanners spend their whole time to read file at file scan,
we can fully utilize disk read bandwidth