We recently built new linux server using CentOS Version 7.0. This release of CentOS comes with MariaDB and MySQL is not a standard offering.

When I tried installing MySQL, MySQL install failed with the following error:


--> Finished Dependency Resolution
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (@base/$releasever)
           Requires: libmysqlclient.so.18()(64bit)
           Removing: 1:mariadb-libs-5.5.50-1.el7_2.x86_64 (@updates)
               libmysqlclient.so.18()(64bit)
           Obsoleted By: mysql-community-libs-5.7.15-1.el6.x86_64 (mysql57-community)
              ~libmysqlclient.so.20()(64bit)
           Available: 1:mariadb-libs-5.5.44-2.el7.centos.x86_64 (base)
               libmysqlclient.so.18()(64bit)
           Available: 1:mariadb-libs-5.5.47-1.el7_2.x86_64 (updates)
               libmysqlclient.so.18()(64bit)
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (@base/$releasever)
           Requires: libmysqlclient.so.18(libmysqlclient_18)(64bit)
           Removing: 1:mariadb-libs-5.5.50-1.el7_2.x86_64 (@updates)
               libmysqlclient.so.18(libmysqlclient_18)(64bit)
           Obsoleted By: mysql-community-libs-5.7.15-1.el6.x86_64 (mysql57-community)
               Not found
           Available: 1:mariadb-libs-5.5.44-2.el7.centos.x86_64 (base)
               libmysqlclient.so.18(libmysqlclient_18)(64bit)
           Available: 1:mariadb-libs-5.5.47-1.el7_2.x86_64 (updates)
               libmysqlclient.so.18(libmysqlclient_18)(64bit)
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

With little digging, I found the Yum Package that has mariadb libraries:



yum list installed mariadb\*
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: mirror.es.its.nyu.edu
 * extras: mirrors.advancedhosters.com
 * updates: mirror.umd.edu
Installed Packages
mariadb-libs.x86_64                  1:5.5.50-1.el7_2                   @updates


Next step is to remove the mariadb libs:


yum remove mariadb-libs.x86_64
Loaded plugins: fastestmirror, langpacks
Resolving Dependencies
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.50-1.el7_2 will be erased
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Running transaction check
---> Package postfix.x86_64 2:2.10.1-6.el7 will be erased
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package          Arch       Version                Repository             Size
================================================================================
Removing:
 mariadb-libs     x86_64     1:5.5.50-1.el7_2       @updates              4.4 M
Removing for dependencies:
 postfix          x86_64     2:2.10.1-6.el7         @base/$releasever      12 M

Transaction Summary
================================================================================
Remove  1 Package (+1 Dependent package)

Installed size: 17 M
Is this ok [y/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Warning: RPMDB altered outside of yum.
  Erasing    : 2:postfix-2.10.1-6.el7.x86_64                                1/2
  Erasing    : 1:mariadb-libs-5.5.50-1.el7_2.x86_64                         2/2
  Verifying  : 1:mariadb-libs-5.5.50-1.el7_2.x86_64                         1/2
  Verifying  : 2:postfix-2.10.1-6.el7.x86_64                                2/2

Removed:
  mariadb-libs.x86_64 1:5.5.50-1.el7_2

Dependency Removed:
  postfix.x86_64 2:2.10.1-6.el7

Complete!

After removing the mariadb-libs, I was able to successfully install MySQL Database:



sudo yum install mysql-server
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: mirror.es.its.nyu.edu
 * extras: mirrors.advancedhosters.com
 * updates: mirror.umd.edu
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-server.x86_64 0:5.7.15-1.el6 will be installed
--> Processing Dependency: mysql-community-common(x86-64) = 5.7.15-1.el6 for package: mysql-community-server-5.7.15-1.el6.x86_64
--> Processing Dependency: mysql-community-client(x86-64) >= 5.7.9 for package: mysql-community-server-5.7.15-1.el6.x86_64
--> Running transaction check
---> Package mysql-community-client.x86_64 0:5.7.15-1.el6 will be installed
--> Processing Dependency: mysql-community-libs(x86-64) >= 5.7.9 for package: mysql-community-client-5.7.15-1.el6.x86_64
---> Package mysql-community-common.x86_64 0:5.7.15-1.el6 will be installed
--> Running transaction check
---> Package mysql-community-libs.x86_64 0:5.7.15-1.el6 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package                   Arch      Version         Repository            Size
================================================================================
Installing:
 mysql-community-server    x86_64    5.7.15-1.el6    mysql57-community    144 M
Installing for dependencies:
 mysql-community-client    x86_64    5.7.15-1.el6    mysql57-community     23 M
 mysql-community-common    x86_64    5.7.15-1.el6    mysql57-community    327 k
 mysql-community-libs      x86_64    5.7.15-1.el6    mysql57-community    2.1 M

Transaction Summary
================================================================================
Install  1 Package (+3 Dependent packages)

Total download size: 169 M
Installed size: 842 M
Is this ok [y/d/N]: y
Downloading packages:
warning: /var/cache/yum/x86_64/7/mysql57-community/packages/mysql-community-common-5.7.15-1.el6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Public key for mysql-community-common-5.7.15-1.el6.x86_64.rpm is not installed
(1/4): mysql-community-common-5.7.15-1.el6.x86_64.rpm      | 327 kB   00:00
(2/4): mysql-community-libs-5.7.15-1.el6.x86_64.rpm        | 2.1 MB   00:01
(3/4): mysql-community-client-5.7.15-1.el6.x86_64.rpm      |  23 MB   00:13
(4/4): mysql-community-server-5.7.15-1.el6.x86_64.rpm      | 144 MB   00:49
--------------------------------------------------------------------------------
Total                                              3.3 MB/s | 169 MB  00:51
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
Importing GPG key 0x5072E1F5:
 Userid     : "MySQL Release Engineering "
 Fingerprint: a4a9 4068 76fc bd3c 4567 70c8 8c71 8d3b 5072 e1f5
 Package    : mysql-community-release-el7-5.noarch (installed)
 From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
Is this ok [y/N]: y
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : mysql-community-common-5.7.15-1.el6.x86_64                   1/4
  Installing : mysql-community-libs-5.7.15-1.el6.x86_64                     2/4
  Installing : mysql-community-client-5.7.15-1.el6.x86_64                   3/4
  Installing : mysql-community-server-5.7.15-1.el6.x86_64                   4/4
  Verifying  : mysql-community-server-5.7.15-1.el6.x86_64                   1/4
  Verifying  : mysql-community-common-5.7.15-1.el6.x86_64                   2/4
  Verifying  : mysql-community-libs-5.7.15-1.el6.x86_64                     3/4
  Verifying  : mysql-community-client-5.7.15-1.el6.x86_64                   4/4

Installed:
  mysql-community-server.x86_64 0:5.7.15-1.el6

Dependency Installed:
  mysql-community-client.x86_64 0:5.7.15-1.el6
  mysql-community-common.x86_64 0:5.7.15-1.el6
  mysql-community-libs.x86_64 0:5.7.15-1.el6

Complete!

sudo service mysqld start
Starting mysqld (via systemctl):
                                                           [  OK  ]

Hope my findings will help others in resolving similar issue.