[CASSANDRA-4050] Rewrite RandomAccessReader to use FileChannel / nio to address Windows file access violations

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.2.0 beta 1
• Component/s: Local Write-Read Paths
• Labels: Windows

Environment

Windows 7

• Assignee: Joshua McKenzie
• Reporter: Jim Newsham
• Reviewer: Benedict
• Created: 14/Mar/12 20:22
• Updated: 08/Dec/15 16:32
• Resolved: 07/Apr/14 20:52

Description

On Windows w/older java I/O libraries the files are not opened with FILE_SHARE_DELETE. This causes problems as hard-links cannot be deleted while the original file is opened - our snapshots are a big problem in particular. The nio library and FileChannels open with FILE_SHARE_DELETE which should help remedy this problem.

Original text:
I'm using Cassandra 1.0.8, on Windows 7. When I take a snapshot of the database, I find that I am unable to delete the snapshot directory (i.e., dir named "

{datadir}

{keyspacename}\snapshots{snapshottag}") while Cassandra is running: "The action can't be completed because the folder or a file in it is open in another program. Close the folder or file and try again" [in Windows Explorer]. If I terminate Cassandra, then I can delete the directory with no problem.

I expect to be able to move or delete the snapshotted files while Cassandra is running, as this should not affect the runtime operation of Cassandra.

Issue Links

• is duplicated by: CASSANDRA-8390 The process cannot access the file because it is being used by another process
• relates to: CASSANDRA-6283 Windows 7 data files kept open / can't be deleted after compaction.