[CASSANDRA-10222] Periodically attempt to delete failed snapshot deletions on Windows

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 2.2.2
• Component/s: Legacy/Local Write-Read Paths
• Labels: Windows
• Assignee: Joshua McKenzie
• Reporter: Joshua McKenzie

Authors

Joshua McKenzie

Reviewers

Stefania Alborghetti

• Created: 28/Aug/15 15:24
• Updated: 16/Apr/19 09:30
• Resolved: 08/Sep/15 16:23

Description

The changes in CASSANDRA-9658 leave us in a position where a node on Windows will have to be restarted to clear out snapshots that cannot be deleted at request time due to sstables still being mapped, thus preventing deletions of hard links. A simple periodic task to categorize failed snapshot deletions and retry them would help prevent node disk utilization from growing unbounded by snapshots as compaction will eventually make these snapshot files deletable.

Given that hard links to files in NTFS don't take up any extra space on disk so long as the original file still exists, the only limitation for users from this approach will be the inability to 'move' a snapshot file to another drive share. They will be copyable, however, so it's a minor platform difference.

This goes directly against the goals of CASSANDRA-8271 and will likely be built on top of that code. Until such time as we get buffered performance in-line with memory-mapped, this is an interim necessity for production roll-outs.

Issue Links

• links to: 2.2 branch
• links to: 3.0 branch