I should add, Nate, that the intention is to do a read before write validation and have that occur as close to the data as possible.
if there is a better hook to implement it on I'd love a pointer to it. JK On Fri, Jul 8, 2011 at 12:21 PM, Nate McCall <n...@datastax.com> wrote: > Validation occurs at the API level, returning an > InvalidRequestException to the caller of the API (a thrift client in > this case). Specifically, a mutation will not be scheduled for the > storage until it has been validated at the API level. > > If the intention is to do a read-before-write validation as an > AbstractType extension, then yes, the underlying value could indeed > change between validation and storage. If this were the goal, you need > to implement locking externally (via zookeper or similar as previously > mentioned). > > On Fri, Jul 8, 2011 at 10:21 AM, William Oberman > <ober...@civicscience.com> wrote: > > I haven't ever written my own > org.apache.cassandra.db.marshal.AbstractType > > (which is I think what your talking about), so I have no idea. > > > > Looking up the JavaDoc for that class, validate says "validate that the > byte > > array is a valid sequence for the type we are supposed to be comparing", > > which sounds like a local operation to me (e.g. it shouldn't fetch remote > > data, it's just saying "yep, this is a valid member of type T"). > > > > will > > > > On Fri, Jul 8, 2011 at 11:17 AM, Jeffrey Kesselman <jef...@gmail.com> > wrote: > >> > >> Alright, > >> So are you saying the column validator, as specified > >> by conf/storage-conf.xml is checked in the client interface library and > not > >> on the server side? That seems odd to me on a number of levels, not the > >> least being I cant see how thrift could autogenerate that > >> for different languages or how those other languages would use a Java > class. > >> > >> On Fri, Jul 8, 2011 at 11:13 AM, William Oberman > >> <ober...@civicscience.com> wrote: > >>> > >>> I use a language specific wrapper around thrift as my "client", but > yes, > >>> I guess I fundamentally mean thrift == client, and the cassandra server > == > >>> server. > >>> > >>> will > >>> > >>> On Fri, Jul 8, 2011 at 11:08 AM, Jeffrey Kesselman <jef...@gmail.com> > >>> wrote: > >>>> > >>>> I am confused by what you mean by "Cassandra client code." Is this > part > >>>> of the Cassnadra server? > >>>> My architecture is my "user" talks thrift to Cassandra. > >>>> > >>> > >> > >> > >> > >> -- > >> It's always darkest just before you are eaten by a grue. > > > > > > > -- It's always darkest just before you are eaten by a grue.
