Hello Jae,
On Thu, Nov 29, 2012 at 8:53 PM, Jae metacret@gmail.com wrote:
- If Memory store type stores indexes in the main memory, does merging
happen in the memory?
Yes, as far as I know.
- I saw some postings saying local gateway with Memory store type does
not work.
Right. Local gateway assumes you have File System store with no memory
caching. For consistency.
If I want to close the index with Memory store type and flush to the disk,
which API can I call?
I don't think you can do that. But maybe someone else can confirm or show a
way to do it.
- Is there any performance data of Memory store type compared to MMap FS
and NIO FS?
I'm not aware of such benchmarks. But I assume results would depend heavily
on lots of variables, like how often you'd index and search, how big are
your documents and indices, how much RAM you have and how fast are the
disks, etc.
- I saw "outside of JVM heapspace". What does this exactly mean?
The in-memory index can be either stored in JVM's memory or outside of it.
The default is to store it outside, since that should put less stress on
the GC.
If I use Memory store type, what is recommended JVM heap space setting?
With FS store type, recommended setting is 50% to elasticsearch and 50% to
OS disk cache.
It depends on the size of your index and the size of your memory. If you
store it outside the JVM heap, you might do with less than 50%. If you
store it inside, you'll probably need more. Ultimately, I think the best
way to do is to run some performance tests while monitoring your cluster -
especially in terms of memory and GC.
Best regards,
Radu
http://sematext.com/ -- Elasticsearch -- Solr -- Lucene
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