1 //Here's the error log of it.
 2 2018-08-08T08:48:18.198487+01:00 0 [Note] WSREP: Initiating SST/IST transfer on DONOR side (wsrep_sst_xtrabackup-v2 --role 'donor' --address '192.168.1.102:4444/xtrabackup_sst//1' --socket '/tmp/mysql3308.sock' --datadir '/data/mysql/mysql3308/data/' --defaults-file '/data/mysql/mysql3308/my3308.cnf' --defaults-group-suffix ''  --binlog '/data/mysql/mysql3308/logs/mysql-bin' --gtid 'bd5525ab-9a15-11e8-aa0f-4b830c783fc7:21')
 3 2018-08-08T08:48:18.200272+01:00 2 [Note] WSREP: DONOR thread signaled with 0
 4 which: no socat in (/usr/sbin:/sbin:/opt/mysql/Percona-XtraDB-Cluster-5.7.22-rel22-29.26.1.Linux.x86_64.ssl102/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/mysql/bin:/usr/local/zabbix/bin:/usr/local/zabbix/sbin)
 5     2018-08-08T06:48:18.782344Z WSREP_SST: [ERROR] ******************* FATAL ERROR ********************** 
 6     2018-08-08T06:48:18.784043Z WSREP_SST: [ERROR] socat not found in path: /usr/sbin:/sbin:/opt/mysql/Percona-XtraDB-Cluster-5.7.22-rel22-29.26.1.Linux.x86_64.ssl102/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/mysql/bin:/usr/local/zabbix/bin:/usr/local/zabbix/sbin
 7     2018-08-08T06:48:18.785926Z WSREP_SST: [ERROR] ****************************************************** 
 8 2018-08-08T08:48:18.786496+01:00 0 [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup-v2 --role 'donor' --address '192.168.1.102:4444/xtrabackup_sst//1' --socket '/tmp/mysql3308.sock' --datadir '/data/mysql/mysql3308/data/' --defaults-file '/data/mysql/mysql3308/my3308.cnf' --defaults-group-suffix ''  --binlog '/data/mysql/mysql3308/logs/mysql-bin' --gtid 'bd5525ab-9a15-11e8-aa0f-4b830c783fc7:21': 2 (No such file or directory)
 9 2018-08-08T08:48:18.786587+01:00 0 [ERROR] WSREP: Command did not run: wsrep_sst_xtrabackup-v2 --role 'donor' --address '192.168.1.102:4444/xtrabackup_sst//1' --socket '/tmp/mysql3308.sock' --datadir '/data/mysql/mysql3308/data/' --defaults-file '/data/mysql/mysql3308/my3308.cnf' --defaults-group-suffix ''  --binlog '/data/mysql/mysql3308/logs/mysql-bin' --gtid 'bd5525ab-9a15-11e8-aa0f-4b830c783fc7:21'
10 2018-08-08T08:48:18.787610+01:00 0 [Warning] WSREP: 1.0 (zlm2): State transfer to 0.0 (zlm3) failed: -2 (No such file or directory)
11 
12 [root@zlm2 08:53:31 /data/mysql/mysql3308/data]
13 #rpm -qa|grep socat
14 
15 [root@zlm2 09:11:08 /data/mysql/mysql3308/data]
16 #yum install socat
17 ... //Omitted.
18 
19 Installed:
20   socat.x86_64 0:1.7.3.2-2.el7                                                                                                                       
21 
22 Complete!

Restart the PXC mysqld on zlm2.

 1 [root@zlm2 09:21:38 /data/mysql/mysql3308/data]
 2 #mysqladmin -P3308 shutdown
 3 
 4 [root@zlm2 09:22:10 /data/mysql/mysql3308/data]
 5 #ps aux|grep mysqld
 6 mysql     6295  0.1 22.4 1565212 227920 pts/0  Sl   08:47   0:02 mysqld --defaults-file=/data/mysql/mysql3308/my3308.cnf --wsrep-new-cluster
 7 root      6835  0.0  0.0 112640   956 pts/3    R+   09:22   0:00 grep --color=auto mysqld
 8 
 9 [root@zlm2 09:22:15 /data/mysql/mysql3308/data]
10 #ps aux|grep mysqld
11 root      6841  0.0  0.0 112640   960 pts/3    R+   09:22   0:00 grep --color=auto mysqld
12 
13 [root@zlm2 09:30:04 /data/mysql/mysql3308/data]
14 #mysqld --defaults-file=/data/mysql/mysql3308/my3308.cnf --wsrep-new-cluster &
15 [1] 7055
16 
17 [root@zlm2 09:30:20 /data/mysql/mysql3308/data]
18 #ps aux|grep mysqld
19 mysql     7055  0.4 22.1 1564952 224900 pts/3  Sl   09:30   0:02 mysqld --defaults-file=/data/mysql/mysql3308/my3308.cnf --wsrep-new-cluster
20 root      7583  0.0  0.0 112640   956 pts/3    R+   09:39   0:00 grep --color=auto mysqld

It still show the ERROR output when node zlm3 startup.

 1 2018-08-08T09:32:14.789691+01:00 0 [Note] WSREP: (e783b5a9, 'tcp://0.0.0.0:4567') connection established to 2bcb8dba tcp://192.168.1.102:4567
 2 2018-08-08T09:32:14.790669+01:00 0 [Note] WSREP: (e783b5a9, 'tcp://0.0.0.0:4567') turning message relay requesting on, nonlive peers: 
 3 2018-08-08T09:32:15.289238+01:00 0 [Note] WSREP: declaring 2bcb8dba at tcp://192.168.1.102:4567 stable
 4 2018-08-08T09:32:15.290161+01:00 0 [Note] WSREP: Node e783b5a9 state primary
 5 2018-08-08T09:32:15.291214+01:00 0 [Note] WSREP: Current view of cluster as seen by this node
 6 view (view_id(PRIM,2bcb8dba,2)
 7 memb {
 8     2bcb8dba,0
 9     e783b5a9,0
10     }
11 joined {
12     }
13 left {
14     }
15 partitioned {
16     }
17 )
18 2018-08-08T09:32:15.291254+01:00 0 [Note] WSREP: Save the discovered primary-component to disk
19 2018-08-08T09:32:15.291707+01:00 0 [Note] WSREP: New COMPONENT: primary = yes, bootstrap = no, my_idx = 1, memb_num = 2
20 2018-08-08T09:32:15.291726+01:00 0 [Note] WSREP: STATE EXCHANGE: Waiting for state UUID.
21 2018-08-08T09:32:15.791844+01:00 0 [Note] WSREP: STATE EXCHANGE: sent state msg: 2c64cc25-9add-11e8-bdeb-67bbb141911b
22 2018-08-08T09:32:15.793169+01:00 0 [Note] WSREP: STATE EXCHANGE: got state msg: 2c64cc25-9add-11e8-bdeb-67bbb141911b from 0 (zlm3)
23 2018-08-08T09:32:15.793198+01:00 0 [Note] WSREP: STATE EXCHANGE: got state msg: 2c64cc25-9add-11e8-bdeb-67bbb141911b from 1 (zlm2)
24 2018-08-08T09:32:15.793205+01:00 0 [Note] WSREP: Quorum results:
25     version    = 4,
26     component  = PRIMARY,
27     conf_id    = 1,
28     members    = 1/2 (primary/total),
29     act_id     = 21,
30     last_appl. = 0,
31     protocols  = 0/8/3 (gcs/repl/appl),
32     group UUID = bd5525ab-9a15-11e8-aa0f-4b830c783fc7
33 2018-08-08T09:32:15.793211+01:00 0 [Note] WSREP: Flow-control interval: [141, 141]
34 2018-08-08T09:32:15.793213+01:00 0 [Note] WSREP: Trying to continue unpaused monitor
35 2018-08-08T09:32:15.793314+01:00 2 [Note] WSREP: REPL Protocols: 8 (3, 2)
36 2018-08-08T09:32:15.793324+01:00 2 [Note] WSREP: New cluster view: global state: bd5525ab-9a15-11e8-aa0f-4b830c783fc7:21, view# 2: Primary, number of nodes: 2, my index: 1, protocol version 3
37 2018-08-08T09:32:15.793327+01:00 2 [Note] WSREP: Setting wsrep_ready to true
38 2018-08-08T09:32:15.793330+01:00 2 [Note] WSREP: Auto Increment Offset/Increment re-align with cluster membership change (Offset: 1 -> 2) (Increment: 1 -> 2)
39 2018-08-08T09:32:15.793332+01:00 2 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
40 2018-08-08T09:32:15.793337+01:00 2 [Note] WSREP: Assign initial position for certification: 21, protocol version: 3
41 2018-08-08T09:32:15.793351+01:00 0 [Note] WSREP: Service thread queue flushed.
42 2018-08-08T09:32:16.392574+01:00 0 [Note] WSREP: Member 0.0 (zlm3) requested state transfer from '*any*'. Selected 1.0 (zlm2)(SYNCED) as donor.
43 2018-08-08T09:32:16.392599+01:00 0 [Note] WSREP: Shifting SYNCED -> DONOR/DESYNCED (TO: 21)
44 2018-08-08T09:32:16.392659+01:00 2 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
45 2018-08-08T09:32:16.392879+01:00 0 [Note] WSREP: Initiating SST/IST transfer on DONOR side (wsrep_sst_xtrabackup-v2 --role 'donor' --address '192.168.1.102:4444/xtrabackup_sst//1' --socket '/tmp/mysql3308.sock' --datadir '/data/mysql/mysql3308/data/' --defaults-file '/data/mysql/mysql3308/my3308.cnf' --defaults-group-suffix ''  --binlog '/data/mysql/mysql3308/logs/mysql-bin' --gtid 'bd5525ab-9a15-11e8-aa0f-4b830c783fc7:21')
46 2018-08-08T09:32:16.396838+01:00 2 [Note] WSREP: DONOR thread signaled with 0
47 2018-08-08T09:32:17.917352+01:00 0 [Note] WSREP: (e783b5a9, 'tcp://0.0.0.0:4567') turning message relay requesting off
48     2018-08-08T07:32:27.003790Z WSREP_SST: [INFO] Streaming the backup to joiner at 192.168.1.102 4444
49 2018-08-08T09:32:27.124206+01:00 4 [Note] Access denied for user 'sst'@'192.168.1.101' (using password: YES)
50 2018-08-08T09:32:27.138281+01:00 5 [Note] Aborted connection 5 to db: 'unconnected' user: 'sst' host: 'localhost' (Got an error reading communication packets)
51     2018-08-08T07:32:27.139336Z WSREP_SST: [ERROR] ******************* FATAL ERROR ********************** 
52     2018-08-08T07:32:27.140923Z WSREP_SST: [ERROR] xtrabackup finished with error: 1.  Check /data/mysql/mysql3308/data//innobackup.backup.log
53 --------------- innobackup.backup.log (START) --------------------
54 xtrabackup: recognized server arguments: --datadir=/data/mysql/mysql3308/data --server-id=1013308 --open_files_limit=65536 --log_bin=/data/mysql/mysql3308/logs/mysql-bin --innodb_data_file_path=ibdata1:100M:autoextend --innodb_buffer_pool_filename=ib_buffer_pool --innodb_log_group_home_dir=./ --innodb_log_files_in_group=3 --innodb_log_file_size=100M --innodb_file_per_table=1 --innodb_open_files=65535 --innodb_page_size=16k --innodb_read_io_threads=4 --innodb_write_io_threads=4 --innodb_io_capacity=200 --innodb_doublewrite=1 --innodb_log_buffer_size=128M --innodb_flush_log_at_trx_commit=1 --innodb_buffer_pool_size=100M --innodb_flush_method=O_DIRECT --defaults_group=mysqld --parallel=4 
55 xtrabackup: recognized client arguments: --datadir=/data/mysql/mysql3308/data --server-id=1013308 --open_files_limit=65536 --log_bin=/data/mysql/mysql3308/logs/mysql-bin --innodb_data_file_path=ibdata1:100M:autoextend --innodb_buffer_pool_filename=ib_buffer_pool --innodb_log_group_home_dir=./ --innodb_log_files_in_group=3 --innodb_log_file_size=100M --innodb_file_per_table=1 --innodb_open_files=65535 --innodb_page_size=16k --innodb_read_io_threads=4 --innodb_write_io_threads=4 --innodb_io_capacity=200 --innodb_doublewrite=1 --innodb_log_buffer_size=128M --innodb_flush_log_at_trx_commit=1 --innodb_buffer_pool_size=100M --innodb_flush_method=O_DIRECT --defaults_group=mysqld --parallel=4 --port=3308 --user=sst --password=* --socket=/tmp/mysql3308.sock --lock-ddl=1 --backup=1 --galera-info=1 --binlog-info=ON --stream=xbstream --target-dir=/tmp/pxc_sst_sn2p/donor_xb_qh5x 
56 180808 09:32:27  version_check Connecting to MySQL server with DSN 'dbi:mysql:;mysql_read_default_group=xtrabackup;port=3308;mysql_socket=/tmp/mysql3308.sock' as 'sst'  (using password: YES).
57 Failed to connect to MySQL server: DBI connect(';mysql_read_default_group=xtrabackup;port=3308;mysql_socket=/tmp/mysql3308.sock','sst',...) failed: Access denied for user 'sst'@'192.168.1.101' (using password: YES) at - line 1314.
58 180808 09:32:27 Connecting to MySQL server host: localhost, user: sst, password: set, port: 3308, socket: /tmp/mysql3308.sock
59 Using server version 5.7.22-22-29.26-log
60 180808 09:32:27 Executing LOCK TABLES FOR BACKUP...
61 Error: failed to execute query SHOW ENGINE INNODB STATUS: Access denied; you need (at least one of) the PROCESS privilege(s) for this operation
62 --------------- innobackup.backup.log (END) ----------------------
63     2018-08-08T07:32:27.143691Z WSREP_SST: [ERROR] ****************************************************** 
64     2018-08-08T07:32:27.145779Z WSREP_SST: [ERROR] Cleanup after exit with status:22
65 2018-08-08T09:32:27.158932+01:00 0 [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup-v2 --role 'donor' --address '192.168.1.102:4444/xtrabackup_sst//1' --socket '/tmp/mysql3308.sock' --datadir '/data/mysql/mysql3308/data/' --defaults-file '/data/mysql/mysql3308/my3308.cnf' --defaults-group-suffix ''  --binlog '/data/mysql/mysql3308/logs/mysql-bin' --gtid 'bd5525ab-9a15-11e8-aa0f-4b830c783fc7:21': 22 (Invalid argument)
66 2018-08-08T09:32:27.159041+01:00 0 [ERROR] WSREP: Command did not run: wsrep_sst_xtrabackup-v2 --role 'donor' --address '192.168.1.102:4444/xtrabackup_sst//1' --socket '/tmp/mysql3308.sock' --datadir '/data/mysql/mysql3308/data/' --defaults-file '/data/mysql/mysql3308/my3308.cnf' --defaults-group-suffix ''  --binlog '/data/mysql/mysql3308/logs/mysql-bin' --gtid 'bd5525ab-9a15-11e8-aa0f-4b830c783fc7:21'
67 2018-08-08T09:32:27.160430+01:00 0 [Warning] WSREP: 1.0 (zlm2): State transfer to 0.0 (zlm3) failed: -22 (Invalid argument)
68 
69