[LUCENE-2500] A Linux-specific Directory impl that bypasses the buffer cache

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1, 4.0-ALPHA
• Component/s: modules/other
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Michael McCandless
• Created: 15/Jun/10 13:14
• Updated: 28/Aug/22 12:27
• Resolved: 24/Jun/10 12:18

Description

I've been testing how we could prevent Lucene's merges from evicting
pages from the OS's buffer cache. I tried fadvise/madvise (via JNI)
but (frustratingly), I could not get them to work (details at
http://chbits.blogspot.com/2010/06/lucene-and-fadvisemadvise.html).

The only thing that worked was to use Linux's O_DIRECT flag, which
forces all IO to bypass the buffer cache entirely... so I created a
Linux-specific Directory impl to do this.