[ACCUMULO-97] !METADATA scans could be delayed by regular scans

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Component/s: tserver
• Assignee: Unassigned
• Reporter: Keith Turner
• Created: 28/Oct/11 19:32
• Updated: 21/Nov/14 17:56
• Resolved: 06/Nov/14 18:58

Description

The tablet server only allows scans to open a max number of files. Once the max is reached, scans wait. Its possible that a !METADATA scan could get stuck waiting for a long running non !METADATA scan to release files. This could slow down the whole system. !METADATA scans wold not starve because a fair semaphore is used. However with client timeouts, starvation may be possible.

Issue Links

• duplicates: ACCUMULO-3297 FileManager semaphore acquisition may block Root and Metadata scans
• is duplicated by: ACCUMULO-959 compactions starving METADATA table scans
• is duplicated by: ACCUMULO-3297 FileManager semaphore acquisition may block Root and Metadata scans
• is duplicated by: ACCUMULO-3359 FileManager.reserverReaders provides no pooling for meta table files
• is superceded by: ACCUMULO-416 reevaluate limiting the number of open files given HDFS improvements