With MySQL 5.6, innobackex isn't detecting xtrabackup properly

[Cormac]

O/S: Scientific Linux release 6.1 (Carbon)

MySQL Details:
MySQL-devel-5.6.4_m7-1.el6.x86_64
MySQL-shared-compat-5.6.4_m7-1.el6.x86_64
MySQL-server-5.6.4_m7-1.el6.x86_64
MySQL-client-5.6.4_m7-1.el6.x86_64
MySQL-shared-5.6.4_m7-1.el6.x86_64

XtraBackup Version:
xtrabackup-1.6.5-328.rhel6.x86_64

This is the problem we hit:
# /usr/bin/innobackupex-1.5.1 --defaults-file=/etc/mysql/mysql.cnf /backup

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012. All Rights Reserved.

This software is published under
the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.

120329 17:22:57 innobackupex-1.5.1: Starting mysql with options: --defaults-file='/etc/mysql/mysql.cnf' --unbuffered --
120329 17:22:57 innobackupex-1.5.1: Connected to database with mysql child process (pid=1131)
120329 17:23:03 innobackupex-1.5.1: Connection to database server closed
IMPORTANT: Please check that the backup run completes successfully.
           At the end of a successful backup run innobackupex-1.5.1
           prints "completed OK!".

innobackupex-1.5.1: Using mysql Ver 14.14 Distrib 5.6.4-m7, for Linux (x86_64) using readline 5.1
innobackupex-1.5.1: Using mysql server version Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

sh: --: invalid option
Usage: sh [GNU long option] [option] ...
 sh [GNU long option] [option] script-file ...
GNU long options:
 --debug
 --debugger
 --dump-po-strings
 --dump-strings
 --help
 --init-file
 --login
 --noediting
 --noprofile
 --norc
 --posix
 --protected
 --rcfile
 --rpm-requires
 --restricted
 --verbose
 --version
Shell options:
 -irsD or -c command or -O shopt_option (invocation only)
 -abefhkmnptuvxBCHP or -o option
innobackupex-1.5.1: fatal error: no 'mysqld' group in MySQL options
innobackupex-1.5.1: fatal error: OR no 'datadir' option in group 'mysqld' in MySQL options

This is the contents of mysql.cnf:

# cat /etc/mysql/mysql.cnf
[client]
user = username
password = xxxxxxxxxx
socket = /var/lib/mysql/mysql.sock
host = localhost
##datadir=/srv/data/mysql

[mysqld]
user=mysql
port=3306
basedir=/usr
datadir=/srv/data/mysql
tmpdir=/dev/shm
pid-file=/var/run/mysql/mysqld.pid
socket=/var/lib/mysql/mysql.sock
character-set-server=utf8

# This must match your current log file size if these logs
# already exist.
innodb_log_file_size=1900M
innodb_log_buffer_size=8M
innodb_flush_log_at_trx_commit=2

I re-ran the backup and traced what perl was doing, using this line:

env PERLDB_OPTS="NonStop=1 AutoTrace=1 frame=2" perl -dS /usr/bin/innobackupex-1.5.1 --defaults-file=/etc/mysql/mysql.cnf /backup

(several hundred lines snipped):

2174: if ($option_defaults_file) {
2175: $options = $options . " --defaults-file=\"$option_defaults_file\" ";
2178: $options = $options . "--print-param";
2183: $cmdline = "$option_ibbackup_binary $options";
2184: @lines = `$cmdline`;
sh: --: invalid option
Usage: sh [GNU long option] [option] ...
sh [GNU long option] [option] script-file ...
GNU long options:
--debug
--debugger
--dump-po-strings
--dump-strings
--help
--init-file
--login
--noediting
--noprofile
--norc
--posix
--protected
--rcfile
--rpm-requires
--restricted
--verbose
--version
Shell options:
-irsD or -c command or -O shopt_option (invocation only)
-abefhkmnptuvxBCHP or -o option

The cause seems to be in "sub read_config_file" where it goes:
$cmdline = "$option_ibbackup_binary $options";

@lines = `$cmdline`;

Without specifying the --ibbinary $cmdline shows:
--defaults-file="/etc/mysql/mysql.cnf" --print-param

So its trying to exec "--defaults-file="/etc/mysql/mysql.cnf" --print-param" and throwing a sh error as a result.

When you add the --ibbackup=xtrabackup the backup then proceeds as normal.

[Alexey Kopytov (akopytov)]

Thank you for the bug report.

I see the problem now -- XtraBackup does not support MySQL 5.6 yet. Fixing version detection is of course easy -- but there may be other compatibility issues, so we have a number of things to do, including testing, before we can support 5.6.