Now, even JOINER fails, and DONOR informed about it, I still see the processes running on DONOR.

DONOR log:
121108 18:53:02 [Note] WSREP: Running: 'wsrep_sst_xtrabackup --role 'donor' --address '10.4.101.225:4444/xtrabackup_sst' --auth '(null)' --socket '/tmp/mysql.sock' --datadir '/mnt/data/mysql/' --defaults-file '/etc/my.cnf' --gtid '9db8f201-2858-11e2-0800-0532898e059e:19606001''
121108 18:53:02 [Note] WSREP: sst_donor_thread signaled with 0
121108 18:54:05 [Note] WSREP: view(view_id(PRIM,7d0187d8-2a18-11e2-0800-3ad438ce660f,3) memb {
        7d0187d8-2a18-11e2-0800-3ad438ce660f,
} joined {
} left {
} partitioned {
        91dab590-2a18-11e2-0800-66ce82790edc,
})
121108 18:54:05 [Note] WSREP: forgetting 91dab590-2a18-11e2-0800-66ce82790edc (tcp://10.4.101.225:4567)
121108 18:54:05 [Note] WSREP: New COMPONENT: primary = yes, bootstrap = no, my_idx = 0, memb_num = 1
121108 18:54:05 [Note] WSREP: STATE_EXCHANGE: sent state UUID: b9cd2dba-2a18-11e2-0800-cc1626de4219
121108 18:54:05 [Note] WSREP: STATE EXCHANGE: sent state msg: b9cd2dba-2a18-11e2-0800-cc1626de4219
121108 18:54:05 [Note] WSREP: STATE EXCHANGE: got state msg: b9cd2dba-2a18-11e2-0800-cc1626de4219 from 0 (node1)
121108 18:54:05 [Note] WSREP: Quorum results:
        version    = 2,
        component  = PRIMARY,
        conf_id    = 2,
        members    = 1/1 (joined/total),
        act_id     = 19606001,
        last_appl. = 0,
        protocols  = 0/4/2 (gcs/repl/appl),
        group UUID = 9db8f201-2858-11e2-0800-0532898e059e
121108 18:54:05 [Note] WSREP: Flow-control interval: [16, 16]
121108 18:54:05 [Note] WSREP: New cluster view: global state: 9db8f201-2858-11e2-0800-0532898e059e:19606001, view# 3: Primary, number of nodes: 1, my index: 0, protocol version 2
121108 18:54:05 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
121108 18:54:05 [Note] WSREP: Assign initial position for certification: 19606001, protocol version: 2
121108 18:54:10 [Note] WSREP:  cleaning up 91dab590-2a18-11e2-0800-66ce82790edc (tcp://10.4.101.225:4567)

====

DONOR processes:
root      2771  0.0  0.0 106228  1416 pts/2    S    18:52   0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe
mysql     3121  0.5  5.5 12581992 918872 pts/2 Sl   18:52   0:01 /usr/local/Percona-XtraDB-Cluster-5.5.28-23.7.366.Linux.x86_64/bin/mysqld --basedir=/usr/local/Percona-XtraDB-Cluster-5.5.28-23.7.366.Linux.x86_64 --datadir=/mnt/data/mysql --plugin-dir=/usr/local/Percona-XtraDB-Cluster-5.5.28-23.7.366.Linux.x86_64/lib/mysql/plugin --user=mysql --log-error=/mnt/data/mysql/error.log --pid-file=/mnt/data/mysql/server-1352234832-az-1-region-a-geo-1.localdomain.pid
mysql     3160  0.0  0.0 106092  1324 pts/2    S    18:53   0:00 /bin/bash -ue /usr/local/Percona-XtraDB-Cluster-5.5.28-23.7.366.Linux.x86_64//bin/wsrep_sst_xtrabackup --role donor --address 10.4.101.225:4444/xtrabackup_sst --auth (null) --socket /tmp/mysql.sock --datadir /mnt/data/mysql/ --defaults-file /etc/my.cnf --gtid 9db8f201-2858-11e2-0800-0532898e059e:19606001
mysql     3172  0.1  0.0 143228 10824 pts/2    S    18:53   0:00 perl /usr/bin/innobackupex --galera-info --tmpdir=/tmp --stream=tar --defaults-file=/etc/my.cnf --socket=/tmp/mysql.sock /tmp
mysql     3174  0.0  0.0 106092  1160 pts/2    S    18:53   0:00 sh -c mysql  --defaults-file='/etc/my.cnf' --socket='/tmp/mysql.sock' --unbuffered -- >/tmp/wxtn5N8ejt 2>/tmp/gD1CmG_htH
mysql     3175  0.0  0.0 197916  1888 pts/2    S    18:53   0:00 mysql --defaults-file=/etc/my.cnf --socket=/tmp/mysql.sock --unbuffered --