Erick, Thanks for clarification. I was under impression that
MMapDirectory is being used for both read/write operations. Now, I see
how it is being used. Essentially, it only reads from MMapDirectory and
writes directly to disk. So, the updated file(s) on the disk
automatically read into memory as they are Memory mapped?
On 10/26/15 8:43 PM, Erick Erickson wrote:
You're really looking at this backwards. The MMapDirectory stuff is
for Solr (Lucene, really) _reading_ data from closed segment files.
When indexing, there are internal memory structures that are flushed
to disk on commit, but these have nothing to do with MMapDirectory.
So the question is really moot ;)
Best,
Erick
On Mon, Oct 26, 2015 at 5:47 PM, Rallavagu <rallav...@gmail.com> wrote:
All,
Are memory mapped files (mmap) flushed to disk during "hard commit"? If yes,
should we disable OS level (Linux for example) memory mapped flush?
I am referring to following for mmap files for Lucene/Solr
http://blog.thetaphi.de/2012/07/use-lucenes-mmapdirectory-on-64bit.html
Linux level flush
http://www.cyberciti.biz/faq/linux-stop-flushing-of-mmaped-pages-to-disk/
Solr's hard and soft commit
https://lucidworks.com/blog/2013/08/23/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
Thanks in advance.
