We're in a bit of a predicament, we have an e-music store currently built in PHP using codeigniter/mysql...
The current system has 100+K users and a decent song collection. Over the last few months I've been playing with
Cassandra... needless to say I'm impressed but I have a few questions.
Firstly, I want to avoid re-writing the entire site if possible so my instincts have made me inclined to replace the database layer
in code igniter... is this something anyone would recommend and are there any gotchas in doing that?
 
I can't say I've been terribly happy with PHP accessing cassandra, when sample data of the same size was put into mysql and in cassandra (of the same size/type)
The pages with php connecting to Cassandra took longer to load, (30K records in table).
I've thought maybe it was my setup that needed tweaking and I've played with as many a options as I could but the best I've gotten is matching query time.
Query speed test was simply getting time stamps right before and after query call returned...
 
Is this something anyone else has seen, any comments suggestions? I've tried using thrift, phpcassa and pandra with pretty similar numbers.
 
My other thought turned to maybe it was the way I designed my CFs, at first I used super columns to model user account CF based on a post I read
by Arin (WTF is a super column) but I later changed to using normal CFs.
 
I'm trying to make this work but I get the feeling my approach is somewhat...I don't mis-guided.
 
Here's a break down of the current model.
    CF:Users{
                uid
                fname
                lname
                username
                password
                street
                ....
            }
Some additional columns in place for a user but keeping it simple...
CF:Library{
                uid
                songid
                ...
                other info about user library
                }
 
CF:Songs{
                songid
                title
                artistid
                }
 
This all is still very relational like (considering I go on to have a CF for playlist and artists) and I'm not sure if this is a good design for the data but... when I looked into
combining some of the info and removing some CFs I run into the issue of replicating data all over the place. If for example I stored the artist name in the library for each record
then each then the artist would be replicated for every song they have for every user who has that song in their library....
 
Where do you sort of draw the line on deciding how much is okay to be replicated?
 
As much as I am not liking the idea of building the application from scratch, I'm considering the possibility of building from scratch in Java/JSP just to get the benefit of using
the hector client. (Efforts from the guys doing the PHP libs is much appreciated but PHP doesn't seem to go too well with Cas.)
 
In the process of making decisions because the upgrade/rebuild needs to have a fairly steady working version for October and I don't want to go wrong before even starting.
 
Recommendations. Suggestions, advice are all welcomed (Any experience with PHP and Cas. is also welcomed since all my fav. libs. are in PHP I'm reluctant to turn away)