I haven't started using Seqouia/C-jdbc but I am probing the ability to
do something like this:

Controller CW has 2 controllers under it - C1 & C2.
C1 is local and has a host HA with X.db's tables t1 & t2.
C2 is remote and has a host HB also with X.db's tables t1 & t2.

Controller CR has 2 controllers under it - C3 & C4.
C3 is local and has a host HC with X.db's tables t1 & t2.
C4 is remote and has a host HD also with X.db's tables t1 & t2.

X.db is MySql type, from experience I've found that MySQL is better off
doing either only writes or only reads. So I want to segregate my read
and write stores. Hence, HA & HB are meant for writing into, while HC &
HD are meant for reading.

Now writes coming to CW should be treated like transactions which land
up on local and remote X.db. These are my WRITE-ONLY-DBs.

Likewise I want reads to goto CR for load balancing with higher
priority to read from HC than HD.


Questions:
(a) Can c-jdbc help in replication of data between HA-HC and HB-HD ?
Which component would help to set this up ? Or do I need to go for
out-of-band MySQL replication ?

(b) Is this configuration optimal for high scalability or availability
? Should I have added contollers horizontally instead of vertically ?

(c) Also, looks like I'd have to write an app to direct writes to CW
and read to CR. Or is there a way to obviate that with the controller
settings itself ?

Please advise.