MySQL Bugs: #78926: MySQL-5.7.9 GA RHEL6 Source RPM breaks perl DBD::mysql installation

Bug #78926	MySQL-5.7.9 GA RHEL6 Source RPM breaks perl DBD::mysql installation
Submitted:	22 Oct 2015 16:06	Modified:	23 Oct 2015 14:43
Reporter:	Xiang Rao	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: C API (client library)	Severity:	S2 (Serious)
Version:	5.7.9	OS:	Red Hat (RHEL Server 6.5, Linux 2.6.32-431.23.3.el6.YAHOO.20140804.x86_64 x86_64, 64-bit)
Assigned to:	Bernt Marius Johnsen	CPU Architecture:	Any

Description:
While testing xtrabackup with customized build from mysql-community-5.7.9-1.el6.src.rpm, our old perl-DBD-mysql failed. So I followed the instruction from http://dev.mysql.com/doc/refman/5.7/en/perl-installation.html and tried to manually install DBD::mysql, which failed with error:
mysql.xs: In function ‘XS_DBD__mysql__GetInfo_dbd_mysql_get_info’:
mysql.xs:906: error: ‘net_buffer_length’ undeclared (first use in this function)
mysql.xs:906: error: (Each undeclared identifier is reported only once
mysql.xs:906: error: for each function it appears in.)
make: *** [mysql.o] Error 1
  CAPTTOFU/DBD-mysql-4.032.tar.gz
  /usr/bin/make -- NOT OK

I didn't find net_buffer_length from mysql.h, from our own build or https://github.com/mysql/mysql-server/blob/5.7/include/mysql.h. Looks like it was removed in 5.7.9 release: https://github.com/mysql/mysql-server/commit/57dab49ff348fa2e67e2ff32397adc97855b6c1e#diff...

How to repeat:
1. Build and install mysql-5.7.9 from mysql-community-5.7.9-1.el6.src.rpm.
2. sudo perl -MCPAN -e shell
3. cpan[1]> install DBD::mysql

We have a pull request with the perl DBD::mysql developers to fix this, you could perhaps apply that correction locally:

https://github.com/perl5-dbi/DBD-mysql/pull/42

Until the proposed patch is merged into DBD::MySQL, there are three possible workarounds:

1.  Install pre-compiled module instead of building locally.
2.  Apply patch (liked above) locally before building.
3.  Build locally using 5.7.8 or earlier MySQL Server.

The resulting modules will work against MySQL Server 5.7.9.

Thanks for the suggestions and will try them.

BTW, why  mysql-community-5.7.9-1.el6.src.rpm contains a tarball of mysql-5.1: mysql-5.1.72.tar.gz?

Thanks,

Xiang

We used the tarball of mysql-5.1: mysql-5.1.72.tar.gz to build the libs compat package.

DBD::mysql 4.033 released 2015-10-23 included a fix for this issue.

Installing DBD::mysql from CPAN with MySQL 5.7 installed should now work.

MySQL 5.7.9 included the following change, which caused the issue:

The mysql_options() C API function has two new options,
MYSQL_OPT_MAX_ALLOWED_PACKET and MYSQL_OPT_NET_BUFFER_LENGTH, that
set the max_allowed_packet and net_buffer_length system variables,
respectively. Each option name also now can be passed to the
mysql_get_option() C API function to retrieve its value. 

The (undocumented) mysql_get_parameters() function has been removed.
Applications that attempt to use it will get link errors and should
be modified to use mysql_options() and mysql_get_option() instead.

For DBD::mysql, resolve the issue as follows:

Upgrade to DBD::mysql 4.033 or higher, which includes a fix for
the C API change just described.