[HADOOP-15944] S3AInputStream logging to make it easier to debug file leakage

• Type: Sub-task
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 3.1.1
• Component/s: fs/s3
• Assignee: Unassigned
• Reporter: Steve Loughran
• Created: 19/Nov/18 13:11
• Updated: 04/Oct/22 16:23

Description

Problem: if an app opens too many input streams, then all the http connections in the S3A pool can be used up; all attempts to do other FS operations fail timing out for http pool access

Proposed simple solution: log better what's going on with input stream lifecyce, specifically

1. include URL of file in open, reopen & close events
2. maybe: Separate logger for these events, though S3A Input stream should be enough as it doesn't do much else.
3. maybe: have some prefix in the events like "Lifecycle", so that you could use the existing log @ debug, grep for that phrase and look at the printed URLs to identify what's going on
4. stream metrics: expose some of the state of the http connection pool and/or active input and output streams

Idle output streams don't use up http connections, as they only connect during block upload.

Issue Links

• relates to: HADOOP-17338 Intermittent S3AInputStream failures: Premature end of Content-Length delimited message body etc