Inter-VM is our focus.
* [s] MOM — async
** FIX over RV in Lehman Eq
* [s] distributed cache — async?
Above mechanisms notify listeners. Note Listeners are usually async and multi-threaded.
* DB writes by one app, and periodic DB polling by receiving app
* [s] RMI
* [s] EJB? infrequent. I think this is less efficient than MOM
* [s] web service? not sure
* FTP? not real-time but at SOD (startOfDay) and EOD
* email? none
MOM is the clear favorite. Most efficient. Guaranteed
Within my front office app, RMI, MOM and cache are dominant. Within a related ticketing system (iticket), MOM and RMI are dominant.
DB is an extreme form of synchronous pub/sub.
[s=needs object serialization. cross-VM often requires serializable]