MySQL Bugs: #69936: MySQL Cluster 7.3.x bundles memcached source twice -> please merge

Bug #69936	MySQL Cluster 7.3.x bundles memcached source twice -> please merge
Submitted:	6 Aug 2013 9:00	Modified:	26 Sep 2014 21:07
Reporter:	Hartmut Holzgraefe	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Cluster: Memcached	Severity:	S2 (Serious)
Version:	MySQL Cluster 7.3.1, 7.3.2, 7.4.1	OS:	Linux
Assigned to:		CPU Architecture:	Any

Description:
With Cluster 7.3 being based on MySQL 5.6 there are now two bundled versions of each memcached and libevent:

  mysql-cluster-gpl-7.3.1/plugin/innodb_memcached/daemon_memcached/
  mysql-cluster-gpl-7.3.1/storage/ndb/memcache/extra/memcached/

and

  mysql-cluster-gpl-7.3.1/libevent/
  mysql-cluster-gpl-7.3.1/storage/ndb/memcache/extra/libevent/

This looks like unnecessary duplication (copy&paste antipattern),
also the bundled versions don't seem to be the same, both differ
from original memcached 1.6beta1 code and from each other ...

How to repeat:
check source code

Suggested fix:
bundle only one version of memcached and libevent and use that version in both the innodb and ndb memcached protocol implementations ...

Even worse: when enabling WITH_INNODB_MEMCACHED in 7.3.1 CMake:

CMake Error at cmake/libutils.cmake:103 (ADD_LIBRARY):
  add_library cannot create target "event" because another target with the
  same name already exists.  The existing target is a static library created
  in source directory
  "/home/hartmut/projects/mysql/releases/mysql-cluster-gpl-7.3.1/libevent".
  See documentation for policy CMP0002 for more details.
Call Stack (most recent call first):
  storage/ndb/memcache/extra/libevent/CMakeLists.txt:75 (ADD_CONVENIENCE_LIBRARY)

Building NDB Memcache using /home/hartmut/projects/mysql/releases/mysql-cluster-gpl-7.3.1/storage/ndb/memcache/extra/memcached
Using gcc atomic builtins
CMake Error at plugin/innodb_memcached/daemon_memcached/CMakeLists.txt:47 (ADD_LIBRARY):
  add_library cannot create target "memcached_utilities" because another
  target with the same name already exists.  The existing target is a static
  library created in source directory
  "/home/hartmut/projects/mysql/releases/mysql-cluster-gpl-7.3.1/storage/ndb/memcache/extra/memcached".
  See documentation for policy CMP0002 for more details.

So raising this from "S4 Feature request" to "S2 Serious"

7.3.2 also affected

Hello Hartmut,

Thank you for the bug report. 
Verified as described on 7.3.2.

Thanks,
Umesh

How to repeat:

Download latest 7.3.2 source from bzr and then try to build as:

[ushastry@cluster-repo mysql-cluster-com-7.3.2]$ cmake -DCMAKE_INSTALL_PREFIX=/data/ushastry/cluster/mysql-cluster-7.3.2 -DWITH_BUNDLED_MEMCACHED=ON -DWITH_INNODB_MEMCACHED=ON

...
..
CMake Error at plugin/innodb_memcached/daemon_memcached/CMakeLists.txt:47 (ADD_LIBRARY):
  add_library cannot create target "memcached_utilities" because another
  target with the same name already exists.  The existing target is a static
  library created in source directory
  "/data/ushastry/setups/mysql-cluster-com-7.3.2/storage/ndb/memcache/extra/memcached".
  See documentation for policy CMP0002 for more details.

Still the case in MySQL Cluster 7.4.1