A Berkeley DB Replication Manager application can now designate one or more remote sites (called its "peers") to receive client-to-client requests.
In previous releases, there could be only one peer at a
time. If you called the
DB_ENV->repmgr_add_remote_site
method
specifying site "A" as a peer and you made another call
specifying site "B" as a peer, site "B" would become the only
peer, and site "A" would no longer be a peer.
Starting with Berkeley DB 11gR2, the same sequence of calls results in both site "A" and site "B" being possible peers. Replication Manager may select any of a site's possible peers to use for client-to-client requests. If the first peer that the Replication Manager selects cannot be used (for example, it is unavailable or it is the current master), Replication Manager attempts to use a different peer if there is more than one peer.
To get the pre-11gR2 peer behavior in this example, you
must make an additional call to the
DB_ENV->repmgr_add_remote_site
method,
specifying site "A" and a flag value that excludes the
DB_REPMGR_PEER
bit value to remove site
"A" as a possible peer.