"Jeffrey W. Baker" wrote:
>
> On Fri, 28 Apr 2000, Adi wrote:
>
> > "Jeffrey W. Baker" wrote:
> > >
> > > On Fri, 28 Apr 2000, Dan McCormick wrote:
> > >
> > > > "Jeffrey W. Baker" wrote:
> > > > >
> > > > > On my sites I use a central database for storing the session objects, and
> > > > > all of the https servers access this central resource. Obviously if it
> > > > > goes down, everything is toast, but the same can be said of the database
> > > > > that stores all of the customer information, etc.
> > > > >
> > > > > -jwb
> > > >
> > > > Are you using Apache::ASP to generate sessions?
> > > >
> > > > Has anyone tried using Tie::DBI to store Apache::ASP sessions in a db?
> > > > That might solve problems with NFS sharing issues, though it might also
> > > > bog things down.
> > >
> > > No, I use Apache::Session - jwb
> >
> > Dan,
> >
> > I suggest you switch to Apache::Session. If you've got a site that gets
> > heavy traffic (which sounds like is the case if you're thinking about load
> > balancing), you definitely want a true DBMS handling your session data, not
> > just a Berkeley DB_File.
>
> I wouldn't buy that one on its own merits. I think that each site should
> evaluate their performance situation and see what backing store works for
> them. Sleepycat DB (nee Berkeley DB) 3.x, using balanced tree storage, is
> a damn fast storage mechanism. If you only have a single web server, dbm
> files are often the fastest blob storage mechanism. With that said,
> remote DBMS storage scales best with more than a single web server. Much
> better than NFS.
>
Good point, I didn't think of blob data. Storable is relatively slow
compared to dbm? How hard do you think it would be to take DBM code and
write it into simply a data serializer (like Storable's nfreeze)? That
would be the best of both worlds, eh?
I was under the impression that Sleepycat is a much better solution for
embedding into an application, where all data is kept in memory. I wouldn't
think .db files could come close to a caching DBMS like MySQL, unless the
.db file is on a caching filesystem.
Another plus for using MySQL to store sessions is that version 3.23 (alpha)
has entirely in-memory heap tables. This is a perfect fit for session data,
since sessions typically last a very short time, and one can assume the
database restart to session turnover ratio is very low.
-Adi
