On 9/27/06, Kevin Lewandowski <[EMAIL PROTECTED]> wrote:
On the performace wiki page it mentions a test box with 16GB ram. Did
anything special need to be done to use that much ram (with the OS or
java)? Would Solr on a system with Linux x86_64 and Tomcat be able to
use that much ram? (sorry, I don't know Java so I don't know if there
are any limitations there).
Yep, works fine.... We don't use the full 16GB for the java heap
though because:
- you want to leave RAM for the OS cache of the index files
- bigger heaps = longer gc pauses (at least with Java5).
Yes, we came to exactly the same conclusion.
You could try to use all of that RAM in the JVM, and load all of the
index with a RAMDirectory (or MMapDirectory), but both of those wound
up being slower than the configuration where we had a smaller JVM and
relied more on the OS-level cache to make index accesses really fast.
One trick I've heard is to do cat <path to Lucene index
directory>/_*.* > /dev/null to force all of the index data into the
OS cache.
-- Ken
--
Ken Krugler
Krugle, Inc.
+1 530-210-6378
"Find Code, Find Answers"
