Why Cassandra *and* Redis? What do you perceive as the strengths or weaknesses of the two?
On Mon, Jul 12, 2010 at 2:40 PM, Sandeep Kalidindi at PaGaLGuY.com <sandeep.kalidi...@pagalguy.com> wrote: > well we were going down constantly with VB running on 3-4 dedicated servers > due to huge traffic(couple of tens of millions of page views). We are also > planning on some new major features, hence the shift to cassandra with > future in mind. > Well roughly the architecture is like this(in order of how the request > proceeds) :- > 1) Varnish - php reads from cassandra and the performance isn't always > good(i am still yet to master it though. so probably my lack of expertise > here). So we use heavy use of varnish to cache as much as possible. VCL > means we can cache same page for different logged in users differently. ESI > means no need to worry about joins. Really varnish is quite a good companion > for NoSQL . > 2) Front end php servers - contains most of the template code - reads > directly from cassandra and Redis. > 3) Middleware(written in scala + python -- planning to move middleware to > scala completely to reduce no of langs in production) - all writes from php > directly go to the middleware - As cassandra is infact mostly a storage of > indices - which means you need to change your strategy from mysql(post > computation) to precomputing all the needed indices and storing them on > cassandra. so middleware takes care of computing the indices and storing > them in cassandra and redis accordingly. This way php will just submit the > write to middleware and the request can be completed while middleware might > take couple secs at most to compute the indices and finish the request > completely. > 4) Cassandra + redis clusters. > > So writes are taken care of by the middleware and hence writes complete uber > fast and reads are also quite fast courtesy of utilizing varnish where ever > it helps. > Still not in production though. Hope it helped. Would welcome anybody's > suggestions on the way i am using cassandra and if i can do anything better > Cheers, > Deepu. > > On Tue, Jul 13, 2010 at 2:48 AM, S Ahmed <sahmed1...@gmail.com> wrote: >> >> What sort of traffic levels made you port the application to Cassandra? >> Very interested in seeing this go live. >> What sort of server setup are you looking at using? >> >> On Mon, Jul 12, 2010 at 4:39 PM, Sandeep Kalidindi at PaGaLGuY.com >> <sandeep.kalidi...@pagalguy.com> wrote: >>> >>> No we re-coded from scratch with most of the needed functionality. >>> Cheers, >>> Deepu. >>> >>> On Mon, Jul 12, 2010 at 7:49 PM, S Ahmed <sahmed1...@gmail.com> wrote: >>>> >>>> Very interesting! >>>> What kind of integration do you have between vB and Cassandra? its not a >>>> port then? >>>> >>>> On Mon, Jul 12, 2010 at 3:34 AM, Sandeep Kalidindi at PaGaLGuY.com >>>> <sandeep.kalidi...@pagalguy.com> wrote: >>>>> >>>>> we were one of the vbulletin customers and our forums has been facing >>>>> some bad scaling issues. >>>>> we coded our forum software to work with cassandra. we are still >>>>> testing for bugs and might go live in couple of weeks. You can ask any >>>>> specific questions about vbulletin and cassandra and i will answer to the >>>>> best of my knowledge. >>>>> I our case a combination of cassandra and redis took care of most of >>>>> the functionality that vbulletin offers and much more. >>>>> Cheers, >>>>> Deepu. >>>>> >>>>> On Mon, Jul 12, 2010 at 9:58 AM, Paul Prescod <pres...@gmail.com> >>>>> wrote: >>>>>> >>>>>> On Sun, Jul 11, 2010 at 8:39 AM, S Ahmed <sahmed1...@gmail.com> wrote: >>>>>> > I want to build a vBulletin type application (forums, threads, >>>>>> > posts, user >>>>>> > management, etc). >>>>>> > Support multi-tenancy for a Saas type environment. >>>>>> > Would Cassandra be suitable for this type of application? >>>>>> > >>>>>> > >>>>>> > Thanks in advance. >>>>>> >>>>>> Most likely, it is technically a fine fit. But Cassandra is very early >>>>>> stage software, so you should expect that the documentation will not >>>>>> always be clear and things will change from version to version. If you >>>>>> are not extremely self-reliant, you may find it a frustrating >>>>>> experience. Unless you are confident you will have trouble scaling >>>>>> traditional technologies, it might not make business sense. >>>>>> >>>>>> Paul Prescod >>>>> >>>> >>> >> > >
