[gfarm-discuss:08381] Re: SQLite Database in gfarm

[Osamu Tatebe <tatebe@xxxxxxxxxxxxxxxx>]

Hi Sven,
(B
(BIn the sense that a busy server is not selected by a client,
(Bwe support the hotspot detection and load balancing.  For
(Bdetails of the scheduling policy, refer to a comment in
(Blib/libgfarm/gfarm/schedule.c.  On the other hand, automatic
(Breplication of a hot file is not implemented (or not included
(Bin the software distribution), although there are some research
(Bstaffs.
(B
(BThanks,
(BOsamu
(B
(BOn Tue, 17 Apr 2007 08:31:57 +0200
(BSven Dzepina <sd@xxxxxxxxxxxxxxxxxx> wrote:
(B
(B> Hi Osamu,
(B> 
(B> thank you for your help. This is exactly that, what I thought.
(B> 
(B> Another question:
(B> Does Gfarm support Hotspot-Detection? If a file is highly demanded, the system 
(B> automatically replicates it on other machines and the metadata server routes 
(B> to different machines for load balancing purposes.
(B> 
(B> Greetings,
(B> Sven
(B> 
(B> Am Dienstag, 17. April 2007 05:04 schrieb Osamu Tatebe:
(B> > Hi Sven,
(B> >
(B> > I probably misunderstand your question.  Do you mean you would like
(B> > to store sqlite database in Gfarm file system?  Though we do not
(B> > try this, it may be stored in Gfarm file system at least when you
(B> > use GfarmFS-FUSE.  Possible issue would be how to lock files in
(B> > sqlite.  Regarding the system call hook, we need to check whether
(B> > it works or not.
(B> >
(B> > Regarding the high reliability, it depends how the database file is
(B> > managed by sqlite.  When you use -N option in gfarmfs, the specified
(B> > number of file replicas will be automatically created in the
(B> > background after the close operation if the file is updated.  If
(B> > this helps, Gfarm would support some reliability.
(B> >
(B> > Thanks,
(B> > Osamu
(B> >
(B> > On Tue, 17 Apr 2007 09:07:09 +0900
(B> >
(B> > Osamu Tatebe <tatebe@xxxxxxxxxxxxxxxx> wrote:
(B> > > Hi Sven,
(B> > >
(B> > > sqlite interface is not implemented.  To incorporate the interface,
(B> > > metadb_sqlite.c is required after the model of metadb_pgsql.c in
(B> > > lib/libgfarm/gfarm directory.  Also, it is necessary to add this
(B> > > entry in metadb_sw.[ch] and config.c.
(B> > >
(B> > > I guess you probably concern about the performance of PostgreSQL.
(B> > > In this case, 'localfs' metadata backend is worth being considered.
(B> > > Although config-gfarm does not support this backend, specify a
(B> > > directory for this backend by localfs_datadir in gfarm.conf
(B> > > like
(B> > >
(B> > > localfs_datadir /some/where
(B> > >
(B> > > Note that neither postgresql_* nor ldap_* directive should be
(B> > > specified.  Moreover, when you use 'localfs' (or 'sqlite' if
(B> > > someone contribute a code) metadata backend, gfarm_agent is
(B> > > indispensable to share the metadata by several client nodes.
(B> > >
(B> > > Thanks,
(B> > > Osamu
(B> > >
(B> > > On Mon, 16 Apr 2007 17:23:00 +0200
(B> > >
(B> > > Sven Dzepina <sd@xxxxxxxxxxxxxxxxxx> wrote:
(B> > > > Hello,
(B> > > >
(B> > > > is it possible to use a sqlite database in /gfarm ?
(B> > > > Does this function without any problems and high reliability?
(B> > > >
(B> > > > Greetings,
(B> > > > Sven
(B> 
(B> -- 
(B> 
(B> Mit freundlichen Grüßen
(B> Sven Dzepina
(B> _____________________________________________________
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