Upax Mirror
A Upax mirror is an XLattice Node and so has a unique 20 or 32-byte nodeID; two RSA keys, one for encryption/decryption and one for digital signatures; some number of listening Acceptors, which accept connections; and may some local persistent storage - file space, the local file system.
A Upax mirror differs from a Upax server in that it only accepts requests for copies of data. It may not be used by a client to store data in the Upax cluster.
Also, while Upax servers use voting to maintain a consensus on what data is stored in the cluster, the mirror takes no part in these decisions: it simply records the final decision and and commits it to its log.
Although the mirror must maintain an accurate and up-to-date copy of the Upax commit log, the mirror may or may not maintain a complete copy of the data store. If a data file requested is not present in the mirror's store, it will fetch a copy from another mirror or a server and then return that copy to the client. The effect of this is that data files will tend to migrate to where they are used.
