I did change the JVM heap size from 16GB to 24GB. Will that make a difference?
Regards, Edwin On 28 January 2016 at 22:10, Alessandro Benedetti <abenede...@apache.org> wrote: > As already specified you need to distinguish between Solr Cache and OS > Memory mapped files. > What you should clearly notice in your situation is an increase of space > for the OS Memory mapped files. > Which means faster access to index segments ( almost all the different data > structures are memory mapped ). > > Related the internal Solr Cache, if you haven't changed the java memory > properties, I would expect not that much difference. > If you were on a virtual machine sharing physical memory with other virtual > instances, you could find benefits on the other hand. > > Cheers > > > On 28 January 2016 at 05:44, Zheng Lin Edwin Yeo <edwinye...@gmail.com> > wrote: > > > Thanks Erick and Shawn for your reply. > > > > We have recently upgraded the server RAM from 64MB to 192MB, and I > noticed > > that this caching occurs after we upgraded the RAM. Previously, the cache > > may not even be preserved in the same Solr session. > > So is it true that the upgrading of the server RAM creates enough spare > > memory for good caching? > > > > Regards, > > Edwin > > > > > > On 28 January 2016 at 12:27, Shawn Heisey <apa...@elyograg.org> wrote: > > > > > On 1/27/2016 8:11 PM, Zheng Lin Edwin Yeo wrote: > > > > I would like to find out, is the cache in the Solr cleared when I > shut > > > down > > > > the Solr instant and restart it? > > > > > > > > I am suspecting that the cache is not entirely cleared, because when > I > > > try > > > > to do a search on the same query as I did before the search, it still > > > has a > > > > return QTime that is much faster than the initial search. However, > > when I > > > > do a search on a new query, the return QTime is the original speed. > > > > > > > > I am using Solr 5.4.0, and this is my setting for the > queryResultCache. > > > > > > > > <queryResultCache class="solr.LRUCache" > > > > size="1024" > > > > initialSize="512" > > > > autowarmCount="0"/> > > > > > > The Solr caches are maintained in the Java heap, which is lost when > Java > > > stops. > > > > > > Although the Solr caches are not preserved across a restart, the > > > operating system does cache actual index data in main memory, so when > > > Solr asks for the same index data off of the disk again, it is pulled > > > directly from RAM, which is a LOT faster than the disk. In order to > > > deliver good performance, Solr is extremely reliant on this built-in > > > feature of all modern operating systems, so there must be enough spare > > > memory for good caching. > > > > > > Here are a couple of pages with some more detail: > > > > > > https://wiki.apache.org/solr/SolrPerformanceProblems > > > https://en.wikipedia.org/wiki/Page_cache > > > > > > Thanks, > > > Shawn > > > > > > > > > > > > -- > -------------------------- > > Benedetti Alessandro > Visiting card : http://about.me/alessandro_benedetti > > "Tyger, tyger burning bright > In the forests of the night, > What immortal hand or eye > Could frame thy fearful symmetry?" > > William Blake - Songs of Experience -1794 England >