[HADOOP-15245] S3AInputStream.skip() to use lazy seek

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.1.0
• Component/s: fs/s3
• Labels: pull-request-available
• Target Version/s: 3.5.0
• Assignee: Ahmar Suhail
• Reporter: Steve Loughran
• Created: 16/Feb/18 17:18
• Updated: 04/Jan/24 12:24

Description

the default skip() does a read and discard of all bytes, no matter how far ahead the skip is. This is very inefficient if the skip() is being done on S3A random IO, though exactly what to do when in sequential mode.

Proposed:

• add an optimized version of S3AInputStream.skip() which does a lazy seek, which itself will decided when to skip() vs issue a new GET.
• add some more instrumentation to measure how often this gets used

Issue Links

• links to: GitHub Pull Request #3927