xtrabackup SST with different socket

Is there a way to specify a separate port/socket when using wsrep_sst_method=xtrabackup?

I am running 5.5.23-55 Percona XtraDB Cluster and wsrep_23.5.r333 as a separate MySQL instance on 2 test machines. These instances are running on a separate socket and port 3307 (both specified in the my.cnf on each machine). When using rsync, replication works correctly, but when using xtrabackup, I see the following in the innobackupex log on the donor (this is with the standard MySQL instance stopped):

120611 13:36:06 innobackupex: Starting mysql with options: --password=xxxxxxxx --user=‘root’ --unbuffered --120611 13:36:06 innobackupex: Connected to database with mysql child process (pid=11014)innobackupex: Error: mysql child process has died: ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/run/mysqld/mysqld.sock’ (2)

This is the socket for the other (non-Galera replicated MySQL instance). I want innobackupex to use /var/run/mysqld/mysqld2.sock instead. I’ve searched here, Google, and look at the Galera documentation so far and haven’t found a way to do so.

Thanks,
Brian

After more research/testing, it looks like what I really need to specify to innobackupex is the defaults-file parameter.

I’m still Googling and testing, but have not yet determined how to do this. Any ideas?

When innobackupex is launched it must be passed a path to the defaults file currently used by the server. So I suppose the use of the correct socket is a matter of proper configuration of that file, e.g. [mysql] section. Just a guess.