Hi David, > I'm not sure exactly what the requirements here are but a couple of existing > projects that might provide a usable journal/log: > > objectweb howl is a transaction log, basically its designed to write > "prepare" entries that have some data and "commit" entries that say the data > is no longer relevant. I imagine you could write the ldif entry as the > "prepare" record and some indication of all replicas being up-to-date as the > "commit" entry.
That's something we might check, as it may alleviate the burden of writing our own wheel... > activemq has quite a few journal/log schemes. I think that they are mostly > using kaha. I'm don't understand all the features but think that it would > do everything you need. IIUC typically the messages themselves are written > to one "database" and for each subscription an index entry is written to a > related reference database. As the acks come in for the subscriptions the > index entries are removed and after all deliveries have happened the main > entry is removed. Another project to look at. > I imagine you could implement the whole replication scheme using activemq > embedded brokers on each server but this might not be the most performant > implementation. Regarding activeMQ, atm, nothing has been decided. We thought about using a JMS system to manage replication, as it offrs a reliable asynchronous system to communicate between servers. We have to go a bit further in the requirements, nothing is really stabilized atm. -- Regards, Cordialement, Emmanuel Lécharny www.iktek.com
