On Tue, Nov 29, 2011 at 9:56 AM, Nathan Halko <nat...@spotinfluence.com> wrote: > > The docs look great Dmitriy. Has anyone considered giving oversampling > ssvd over lanczos which is promising. Trying to scale out horizontally but > not seeing any difference between using one slave or many slaves. Any > ideas? (I won't go into detail about the setup here but if sounds familiar > I'd like to talk more).
What do you mean by a slave? a mapper? a machine? whether you increase input horizontally or vertically, you should see more mappers. If your cluster has enough capacity to scheudle all mappers right away, i beleive you will get almost the same time (i.e. almost linear scaling) for most of the jobs. > The basic problem with lanczos in the distributed > environment seems to be that a matrix-vector multiply is not enough work to > offset any setup costs, also there is not a distributed orthogonalization > with lanczos and I'm getting OOM's making it difficult to scale. I would > still like to contribute what results I have found but I'm short on time so > nothing besides work directly related to the completion of my thesis will > happen until that is done. > > On Fri, Nov 25, 2011 at 5:37 PM, Dmitriy Lyubimov <dlie...@gmail.com> wrote: > > > I attached the latex source as well (lyx, actually). I would've used > > Wiki if it supported mathjax. So anyone can modify the usage if need > > be. (Anyone who has lyx anyway). > > > > Dev docs were attached to several jira issues (and i had blog > > entries), if you want to move more recent copies of them moved over > > to wiki, i'd be happy to. Mainly, so far there are 2 working notes, > > one for original method, and another for power iterations, attached to > > corresponding jiras. > > > > > > On Fri, Nov 25, 2011 at 4:26 PM, Grant Ingersoll <gsing...@apache.org> > > wrote: > > > I hooked it into the Algorithms page. > > > > > > How do you intend to keep the PDF up to date? I like the focus more on > > the user, but it would also be good to have some dev docs. > > > > > > Also, with both Lanczos and this it would be good if we could hook them > > into some real examples. > > > > > > On Nov 25, 2011, at 5:42 PM, Dmitriy Lyubimov wrote: > > > > > >> Hi, > > >> > > >> I put a usage and overview doc for SSVD onto wiki. I'd appreciate if > > >> somebody else could look thru it, to scan for completeness and > > >> suggestions. > > >> > > >> I tried to approach it as a user-facing documentation, i.e. I tried to > > >> avoid discussing any implementation specifics . > > >> > > >> I had several users and Nathan Halko trying it out and actually > > >> favorably commenting on its scalability vs. Lanczos but i don't know > > >> first hand of any production use (even our own use is fairly limited > > >> (in terms of input volume we ever processed) and actually somewhat > > >> diverged from this Mahout implementation. Perhaps putting it more in > > >> front of users will help to receive more feedback. > > >> > > >> Thanks. > > >> -Dmitriy > > > > > > -------------------------------------------- > > > Grant Ingersoll > > > http://www.lucidimagination.com > > > > > > > > > > > > > >
