Chad wrote: > Please forgive my ignorance, but I am not sure I understand about the > client vs server side replication. > > Could someone throw out a quick paragraph describing the 2 and/or a > pro/con list? > If I do client side replication, how to I access the files on the servers? > Am I relying on the clients to sync the data between the servers? Client-side replication is exactly what it sounds like. :) When a write operation is initiated on a given client, the client is responsible for communicating that operation to all of the servers. Likewise, server-side replication is also exactly what it sounds like. In this model, a given client communicates with only one server, and the server is responsible for communicating any changes to the other servers in the pool. Logically speaking it's a straightforward shift of responsibility, but it has a non-trivial impact in one key area : availability. In the server-side setup, a given client is technically only aware of one server at any given moment. If that server becomes inaccessible (for whatever reason), there must be a mechanism for the client to ? become aware ? of another server. In the client-side setup, each client is aware of all of the servers (by design), and thus if a server becomes inaccessible, the client (indeed, all of the clients) can continue to interact with the remaining servers in the pool. > There are times when no clients are up and the servers are "doing > things" to the file system. There's nothing stopping you from changing your logical architecture to a client-side replication setup, then having your servers (read : data storage units) run a client process as well, thus making said machines both ? servers ? and ? clients ? from a Gluster perspective. -- Daniel Maher <dma+gluster AT witbe DOT net>
