This was my first thought, too. We switched to mmap_index_only and didn't see any change in behavior. Looking at the smaps file attached to my original post, one can see that the mmapped index files take up only a minuscule part of RSS.
On Wed, May 4, 2011 at 11:37 PM, Oleg Anastasyev <olega...@gmail.com> wrote: > Probably this is because of mmapped io access mode, which is enabled by > default > in 64-bit VMs - RAM is occupied by data files. > If you have such a tight memory reqs, you can turn on standard access mode in > storage-conf.xml, but dont expect it to work fast then: > <!-- > > > ~ Access mode. mmapped i/o is substantially faster, but only practical on > > > ~ a 64bit machine (which notably does not include EC2 "small" instances) > > > ~ or relatively small datasets. "auto", the safe choice, will enable > > > ~ mmapping on a 64bit JVM. Other values are "mmap", "mmap_index_only" > > > ~ (which may allow you to get part of the benefits of mmap on a 32bit > > > ~ machine by mmapping only index files) and "standard". > > > ~ (The buffer size settings that follow only apply to standard, > > > ~ non-mmapped i/o.) > > > --> > > > <DiskAccessMode>standard</DiskAccessMode> > >
