Hi Yang, You may also want to have a look at this presentation by Ben Reed : http://vimeo.com/13282102
It's a great overview of Hedwig and it could help you understand it better. Actually, it should probably be referenced from the bookkeeper wiki! Matthieu On Sep 15, 2011, at 10:12 AM, Flavio Junqueira wrote: Hi Yang, Hubs use BookKeeper to persist messages, but they are different components in the system. BookKeeper does not implement Zab, ZooKeeper does. Replication in BookKeeper uses a simple quorum protocol. -Flavio On Sep 15, 2011, at 9:15 AM, Yang wrote: I'm trying to understand how Hedwig works and its guarantees. from my understanding of the wiki, I guess that a hub is composed of all the servers of a bookkeeper cluster, right? then the BookKeeperPersistenceManager uses a bookkeeper client to write to the Ledger, which is replicated using ZAB protocol onto all the servers in the hub; and subscribers would call the persistence manager to read from the ledger ?? Thanks Yang flavio junqueira research scientist [email protected]<mailto:[email protected]> direct +34 93-183-8828 avinguda diagonal 177, 8th floor, barcelona, 08018, es phone (408) 349 3300 fax (408) 349 3301
