SST does not clobber backup-my.cnf

[Jervin R]

Xtrabackup-v2 SST fails because backup-my.cnf exists:

2015-03-12 01:06:37 17347 [Note] WSREP: Requesting state transfer: success, donor: 1
WSREP_SST: [INFO] WARNING: Stale temporary SST directory: /var/lib/mysql//.sst from previous state transfer (20150312 01:06:37.785)
WSREP_SST: [INFO] Proceeding with SST (20150312 01:06:37.793)
WSREP_SST: [INFO] Evaluating socat -u TCP-LISTEN:4444,reuseaddr stdio | xbstream -x; RC=( ${PIPESTATUS[@]} ) (20150312 01:06:37.794)
WSREP_SST: [INFO] Cleaning the existing datadir and innodb-data/log directories (20150312 01:06:37.796)
removed `/var/lib/mysql/mysqld.sock'
removed `/var/lib/mysql/mysql-bin.index'
removed `/var/lib/mysql/mysql-bin.000001'
removed `/var/lib/mysql/ibdata1'
removed `/var/lib/mysql/ib_logfile0'
removed `/var/lib/mysql/ib_logfile1'
removed `/var/lib/mysql/auto.cnf'
WSREP_SST: [INFO] Waiting for SST streaming to complete! (20150312 01:06:37.834)
2015-03-12 01:06:39 17347 [Note] WSREP: (07d9cf83, 'tcp://0.0.0.0:4567') turning message relay requesting off
xbstream: Can't create/write to file '././backup-my.cnf' (Errcode: 17 - File exists)
xbstream: failed to create file.
2015/03/12 01:06:48 socat[17603] E write(1, 0x1060400, 8192): Broken pipe
WSREP_SST: [ERROR] Error while getting data from donor node: exit codes: 1 1 (20150312 01:06:48.105)
WSREP_SST: [ERROR] Cleanup after exit with status:32 (20150312 01:06:48.108)
2015-03-12 01:06:48 17347 [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup-v2 --role 'joiner' --address '192.168.90.3' --auth '' --datadir '/var/lib/mysql/' --defaults-file '/etc/my.cnf' --parent '17347' '' : 32 (Broken pipe)
2015-03-12 01:06:48 17347 [ERROR] WSREP: Failed to read uuid:seqno from joiner script.
2015-03-12 01:06:48 17347 [ERROR] WSREP: SST failed: 32 (Broken pipe)
2015-03-12 01:06:48 17347 [ERROR] Aborting

mysql> show global variables like '%version%';
+-------------------------+---------------------------------------------------------------------------------------------------+
| Variable_name | Value |
+-------------------------+---------------------------------------------------------------------------------------------------+
| innodb_version | 5.6.22-72.0 |
| protocol_version | 10 |
| slave_type_conversions | |
| version | 5.6.22-72.0-56-log |
| version_comment | Percona XtraDB Cluster (GPL), Release rel72.0, Revision 978, WSREP version 25.8, wsrep_25.8.r4150 |
| version_compile_machine | x86_64 |
| version_compile_os | Linux |
+-------------------------+---------------------------------------------------------------------------------------------------+
7 rows in set (0.00 sec)

mysql> show global status like '%version%';
+------------------------+---------------+
| Variable_name | Value |
+------------------------+---------------+
| Ssl_version | |
| wsrep_protocol_version | 7 |
| wsrep_provider_version | 3.9(r93aca2d) |
+------------------------+---------------+
3 rows in set (0.00 sec)

[Jervin R (revin)]

The backup-my.cnf is on /var/lib/mysql/.sst/backup.my.cnf on the joiner.

[Raghavendra D Prabhu (raghavendra-prabhu)]

@Jervin,

Yes, with a $DATADIR/.sst/backup.my.cnf, this can occur.

The .sst directory can only exist if a previous SST failed, and it is not removed as follows:

        wsrep_log_info "Moving the backup to ${TDATA}"
        timeit "Xtrabackup move stage" "$INNOMOVE"
        if [[ $? -eq 0 ]];then
            wsrep_log_info "Move successful, removing ${DATA}"
            rm -rf $DATA
            DATA=${TDATA}
        else
            wsrep_log_error "Move failed, keeping ${DATA} for further diagnosis"
            wsrep_log_error "Check ${DATA}/innobackup.move.log for details"
        fi

[Alexey Kopytov (akopytov)]

https://github.com/percona/percona-xtradb-cluster/pull/28
https://github.com/percona/percona-xtradb-cluster/pull/29

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXC-1120