Wan traffic?

Hi, firstly thanks to everyone for a truely awesome program. I was just wondering if anyone would reccomend rsync_wan or xtrabackup as sst method for wan replication. Our sites are separated T1 lines, but it is crusial, that all data be kept up to date.

xtrabackup is always recommended - it’s not blocking for the most part of transfer unlike the rsync. Moreover, with xbstream option, compact and compressed methods are available, which can matter specially on WAN links. More info here: http://www.percona.com/doc/percona-x…_transfer.html
However note that SST is needed only on node joining or sync after some failures, and not used for keeping the node up to date during normal operation, where wsrep replication handles this.