OK, so it sounds like I'm hearing that (a) Accessing index files over NFS from a "single" physical process on a single computer is safe and can be made to work.
(b) Accessing index files over NFS from "multiple" processes/machines might be problematic (c) In all cases, the performance would be lesser over NFS Thanks /Jong On Tue, Oct 2, 2012 at 9:36 AM, Tommaso Teofili <tommaso.teof...@gmail.com>wrote: > Ok, that saves you from concurrency issue, but in my experience is just > much slower than local file system, so still NFS can be used but with some > tradeoff on performance. > > My 2 cents, > Tommaso > > 2012/10/2 Jong Kim <jong.luc...@gmail.com> > > > The setup is I have a home-grown server process that has exclusive access > > to the index files. All reads and writes are done through this server. No > > other process is reading the same index files whether it's local or over > > NFS. > > /Jong > > On Tue, Oct 2, 2012 at 8:56 AM, Ian Lea <ian....@gmail.com> wrote: > > > > > I agree that reliability/corruption is not an issue. > > > > > > I would also put it that performance is likely to suffer, but that's > > > not certain. A fast disk mounted over NFS can be quicker than a slow > > > local disk. And how much do you care about performance? Maybe it > > > would be fast enough over NFS to make the ease of deployment balance > > > out lesser speed. > > > > > > What's the setup here? Will you be writing to an index on local disk > > > of server A and reading it, over NFS, from server B (and C and ...) or > > > what? > > > > > > -- > > > Ian. > > > > > > > > > On Tue, Oct 2, 2012 at 1:45 PM, Paul Libbrecht <p...@hoplahup.net> > > wrote: > > > > I doubt NFS is an unreliable file-system. > > > > Lucene uses normal random access to files and this has no reason to > be > > > unreliable unless bad things such as network drops happen (in which > case > > > you'd get direct failures or timeouts rather than corruption). I've > seen > > > fairly large infrastructures being based on NFS and corruption is > > something > > > I've never heard about. > > > > > > > > Note: no concurrent access to a lucene index, right? > > > > > > > > Paul > > > > > > > > > > > > Le 2 oct. 2012 à 14:01, Jong Kim a écrit : > > > > > > > >> Thank you all for reply. > > > >> > > > >> So it soudns like it is a known fact that the performance would > suffer > > > >> rather significantly when the index files are accessed over NFS. But > > how > > > >> about reliability and robustness (which seems even more important)? > > > Isn't > > > >> there any increased possibility for intermittent errors such as > index > > > file > > > >> corruption (due to cache inconsistency, difference in delete > > semantics, > > > >> etc.) when using NFS? Has anyone run into such trouble? Or is it > > > strictly > > > >> just a performance issue? > > > >> > > > >> /Jong > > > >> On Tue, Oct 2, 2012 at 5:17 AM, Paul Libbrecht <p...@hoplahup.net> > > > wrote: > > > >> > > > >>> My experience in the Lucene 1.x times were a factor of at least > four > > in > > > >>> writing to NFS and about two when reading from there. I'd > discourage > > > this > > > >>> as much as possible! > > > >>> > > > >>> (rsync is way more your friend for transporting and replication à > la > > > solr > > > >>> should also be considered) > > > >>> > > > >>> paul > > > >>> > > > >>> > > > >>> Le 2 oct. 2012 à 11:10, Ian Lea a écrit : > > > >>> > > > >>>> You'll certainly need to factor in the performance of NFS versus > > local > > > >>> disks. > > > >>>> > > > >>>> My experience is that smallish low activity indexes work just fine > > on > > > >>>> NFS, but large high activity indexes are not so good, particularly > > if > > > >>>> you have a lot of modifications to the index. > > > >>>> > > > >>>> You may want to install a custom IndexDeletionPolicy. See the > > > >>>> javadocs for details with specific reference to NFS. > > > >>>> > > > >>>> > > > >>>> -- > > > >>>> Ian. > > > >>>> > > > >>>> On Tue, Oct 2, 2012 at 3:21 AM, Vitaly Funstein < > > vfunst...@gmail.com> > > > >>> wrote: > > > >>>>> How tolerant is your project of decreased search and indexing > > > >>> performance? > > > >>>>> You could probably write a simple test that compares search and > > write > > > >>>>> speeds of local and NFS-mounted indexes and make the decision > based > > > on > > > >>> the > > > >>>>> results. > > > >>>>> > > > >>>>> On Mon, Oct 1, 2012 at 3:06 PM, Jong Kim <jong.luc...@gmail.com> > > > wrote: > > > >>>>> > > > >>>>>> Hi, > > > >>>>>> > > > >>>>>> According to the Lucene In Action (Second Edition), the section > > > 2.11.2 > > > >>>>>> "Accessing an index over a remote file system" explains that > there > > > are > > > >>>>>> issues related to accessing a Lucene index across remote file > > system > > > >>>>>> including NFS. > > > >>>>>> > > > >>>>>> I'm particuarly interested in NFS compatibility, and wondering > if > > > >>> there has > > > >>>>>> been any work done to solve or mitigate this problem. Has this > > issue > > > >>> been > > > >>>>>> addressed? If not, are there some reliable work-arounds that > make > > > this > > > >>>>>> possible at the expense of some sacrifice in other areas? > > > >>>>>> > > > >>>>>> Any information would be greatly appreciated, since my project > > > heavily > > > >>>>>> depends on the feasibility of this. > > > >>>>>> > > > >>>>>> Thanks > > > >>>>>> /Jong > > > >>>>>> > > > >>>> > > > >>>> > > --------------------------------------------------------------------- > > > >>>> To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > > >>>> For additional commands, e-mail: java-user-h...@lucene.apache.org > > > >>>> > > > >>> > > > >>> > > > >>> > --------------------------------------------------------------------- > > > >>> To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > > >>> For additional commands, e-mail: java-user-h...@lucene.apache.org > > > >>> > > > >>> > > > > > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > > > > > >
