收到报警，某个端口备份失败，查看备份日志如下，显示有DDL操作导致的备份中断，查看当时的二进制日志，当时执行了一条添加字段的sql语句。目前只能重新执行备份，并修改备份时间，避免再发生类似情况。

MySQL：5.7.11

xtrabackup：2.4.5

查找到官方修复bug的情况：

Running DDL statements on Percona Server 5.7 during the backup process could in some cases lead to failure while preparing the backup. Bug fixed #1555626.

MySQL 5.7 can sometimes skip redo logging when creating an index. If such ALTER TABLE is being issued during the backup, the backup would be inconsistent. xtrabackup will now abort with error message if such ALTER TABLEhas been done during the backup. Bug fixed #1582345.

所以说这种情况是正常的，应尽量避免在备份时执行这些sql

备份日志：

InnoDB: Last flushed lsn: 340748764928 load_index lsn 340748904772
# 一个DDL操作已经执行（未记录redo日志）。影响到的行可能未落地，PXB不能确保备份的一致性，请重试
[FATAL] InnoDB: An optimized(without redo logging) DDLoperation has been performed. All modified pages may not have been flushed to the disk yet.
    PXB will not be able take a consistent backup. Retry the backup operation
    # 断言失败
2017-06-01 08:43:19 0x7f396ee27700  InnoDB: Assertion failure in thread 139884650198784 in file ut0ut.cc line 916
# 故意生成一个内存陷阱，使备份中断
InnoDB: We intentionally generate a memory trap.
InnoDB: Submit a detailed bug report to http://bugs.mysql.com.
InnoDB: If you get repeated assertion failures or crashes, even
InnoDB: immediately after the mysqld startup, there may be
InnoDB: corruption in the InnoDB tablespace. Please refer to
InnoDB: http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html
InnoDB: about forcing recovery.
00:43:19 UTC - xtrabackup got signal 6 ;
This could be because you hit a bug or data is corrupted.
This error can also be caused by malfunctioning hardware.
Attempting to collect some information that could help diagnose the problem.
As this is a crash and something is definitely wrong, the information
collection process might fail.
Thread pointer: 0x0
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 0 thread_stack 0x10000
/usr/local/xtrabackup/bin/innobackupex(my_print_stacktrace+0x35)[0xd55c45]
/usr/local/xtrabackup/bin/innobackupex(handle_fatal_signal+0x273)[0xb0d5a3]
/lib64/libpthread.so.0[0x36ac20f710]
/lib64/libc.so.6(gsignal+0x35)[0x36abe32625]
/lib64/libc.so.6(abort+0x175)[0x36abe33e05]
/usr/local/xtrabackup/bin/innobackupex[0x7bfbe5]
/usr/local/xtrabackup/bin/innobackupex(_ZN2ib5fatalD1Ev+0xb3)[0x837743]
/usr/local/xtrabackup/bin/innobackupex[0x8af4a1]
/usr/local/xtrabackup/bin/innobackupex(_Z19recv_parse_log_recsm7store_tb+0x4df)[0x8b20ef]
/usr/local/xtrabackup/bin/innobackupex[0x763b60]
/usr/local/xtrabackup/bin/innobackupex[0x764176]
/usr/local/xtrabackup/bin/innobackupex[0x764523]
/lib64/libpthread.so.0[0x36ac2079d1]
/lib64/libc.so.6(clone+0x6d)[0x36abee88fd]
Please report a bug at https://bugs.launchpad.net/percona-xtrabackup

本文出自 “Amnesiasun” 博客，请务必保留此出处http://amnesiasun.blog.51cto.com/10965283/1931479

MySQL xtrabackup备份失败记录