[ACCUMULO-3297] FileManager semaphore acquisition may block Root and Metadata scans

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.6.1
• Fix Version/s: 1.6.2, 1.7.0
• Component/s: tserver

Environment

Tserver

• Assignee: Eric C. Newton
• Reporter: Marc Parisi
• Created: 04/Nov/14 20:10
• Updated: 06/Nov/14 18:58
• Resolved: 06/Nov/14 18:53

Description

FileManager.java contains a semaphore to limit the max open files when calling acquireUninterruptibly( # permits ) when opening the readers. If scans against all tables causes the number of max open permits to exceed the configured system property, scans against the metadata and root extents will block until other readers are released.

This should be changed so that scans against the root and metadata extents proceed, despite exceeding the number of max open files. This likely means bypassing the semaphore acquisition for these tablets.

Issue Links

• duplicates: ACCUMULO-97 !METADATA scans could be delayed by regular scans
• is duplicated by: ACCUMULO-97 !METADATA scans could be delayed by regular scans