My bad about the attachment, there you go: http://i.imgur.com/XKtw32K.png Thanks for the details answer and that helps alot.
Thank, -Utkarsh On Tue, Apr 16, 2013 at 9:48 PM, Shawn Heisey <s...@elyograg.org> wrote: > On 4/16/2013 10:01 PM, Otis Gospodnetic wrote: > > Not sure if it's just me, but I'm not seeing your inlined image. > > It's not just you. > > > On Tue, Apr 16, 2013 at 7:52 PM, Utkarsh Sengar <utkarsh2...@gmail.com > >wrote: > >> So I have 2 questions: > >> 1. What is the recommended memory for those 2 nodes? > >> 2. I am not sure what does Physical memory mean in context to solr. My > >> understanding of the physical memory is the actual RAM in my machine and > >> 'top' says that I have used just 4.6GB or 23.7GB. Why is Solr admin > >> reporting that I have used 22.84GB out of 23.7GB? > > Attachments don't work well on mailing lists. We can't see your image. > Best to put the file on the Internet somewhere (like dropbox or another > file sharing site) and include the public link. After you get an answer > to your question, you can remove the file. > > Answers to your two questions: > > 1) A good rule of thumb is that you want to have enough RAM to equal or > exceed the sum of two things: The amount of memory that your programs > take (including the max heap setting you give to Solr), and the size of > your Solr index(es) stored on that server. You may be able to get away > with less memory than this, but you do want to have enough memory for a > sizable chunk of your on-disk index. Example: If Solr is the only major > program running on the machine, you give Solr a 4GB heap, and your index > is 20GB, an ideal setup would have at least 24GB of RAM. > > 2) You are seeing the result of the way that all modern operating > systems work. The extra memory that is not being currently used by > programs is borrowed by the operating system to cache data from your > disk into RAM, so that frequently accessed data will not have be read > from the disk. Reading from main memory is many orders of magnitude > faster than reading from disk. The memory that is being used for the > disk cache (on top it shows up as 'cached') is instantly made available > to programs that request it. > > http://blog.thetaphi.de/2012/07/use-lucenes-mmapdirectory-on-64bit.html > > 2a) Operating systems like Linux tell you the truth about the OS using > excess memory for the disk cache. With the most basic information > tools, Windows tells you a semi-lie and will report that memory as free. > The newest versions of Windows seem to have gotten the hint and do > include tools that will give you the true picture. > > 2b) For good performance, Solr is extremely reliant on having a big > enough disk cache so that reads from disk are rare. This is the case > for most other programs too, actually. > > Thanks, > Shawn > > -- Thanks, -Utkarsh
