Synced xtrabackup SST scripts from PXC source tree as of PXC 5.6.27-25.13
- PXC#480: xtrabackup-v2 SST fails with multiple log_bin directives in my.cn
- PXC#460: wsrep_sst_auth don't work in Percona-XtraDB-Cluster-56-5.6.25-25.
- PXC-416: Fix SST related issues.
- PXC-389: Merge remote-tracking branch 'wsrep/5.6' into 5.6-wsrep-pxc389
- Bug #1431101: SST does not clobber backup-my.cnf
1. Passes wsrep_sst_auth_value to SST scripts via WSREP_SST_OPT_AUTH envronmental variable, so it never appears on the command line
2. In mysqldump and xtrabackup* SST scripts which rely on MySQL authentication, instead of passing password on the command line, SST script sets MYSQL_PWD environment variable, so that password also never appears on the mysqldump/innobackupex command line.
- LP1380697: wsrep_sst_xtrabackup-v2 doesn't stop when mysql is SIGKILLed. (full fix for this (as engineeered by Percona) requires Linux-specific patch that we don't carry, but keep xtrabackup scripts as close as possible)
- LP1399134: Log the innobackupex/SST logs in SST to syslog if possible. (fixed)
- LP1405668: Race condition between donor and joiner in PXB SST. (fixed)
- LP1405985: Fail early if xtrabackup_checkkpoints is missing. (fixed)
- LP1407599: wsrep_sst_xtrabackup-v2 script causes innobackupex to print a false positive stack trace into the log. (fixed)
- LP1441762: IST Fails with SST script error. (fixed)
- LP1451670: Fail when move-back fails in xtrabackup SST. (fixed)
1. Passes wsrep_sst_auth_value to SST scripts via WSREP_SST_OPT_AUTH envronmental variable, so it never appears on the command line
2. In mysqldump and xtrabackup* SST scripts which rely on MySQL authentication, instead of passing password on the command line, SST script sets MYSQL_PWD environment variable, so that password also never appears on the mysqldump/innobackupex command line.
