Configuring MySQL server enforced with TLS 1.2 or higher to connect to Hue

If your MySQL server is configured to use TLS version 1.2 or higher for an encrypted connection with Hue, then you may not be able to start the Hue server and the Kerberos ticket renewer. One solution to fix this problem is to upgrade the MySQL client to version 8.

One of the errors you may see while connecting to Hue if your MySQL server is configured with TLS 1.2 or higher is: “The health test result for HUE_SERVER_SCM_HEALTH has become bad: This role's process failed to start.” The error might be because the MySQL-Python module for Hue that is shipped with CDP uses an older libmysqlclient library which does not support TLS 1.2 and higher.

SSH into the Hue server host as a root user.
Change directory to /etc/cloudera-scm-agent/ and take a backup of the config.ini file.
Run the following command to get a list of all the installed MySQL packages:
```
rpm -qa | grep -i mysql*
```
Save the list of all the installed MySQL packages for future reference.
Remove all MySQL Community RPM packages and the Cloudera Manager agent:
```
yum erase mysql-community*|cloudera-manager-agent
```
Uninstalling the Cloudera Manager agent also uninstalls the MySQL-python library. Save the list of all the MySQL packages that are uninstalled for future reference.

Reinstall the Cloudera Manager agent as follows:

yum -y install cloudera-manager-agent

This installs all the required packages:

Package Arch Version Repository Size
===============================================================
Installing:
cloudera-manager-agent x86_64 7.2.4-7594142.el7 cloudera-manager 12 M
Installing for dependencies:
MySQL-python x86_64 1.2.5-1.el7 base 90 k
mysql-community-client-plugins x86_64 8.0.24-1.el7 mysql80-community 189 k
mysql-community-common x86_64 8.0.24-1.el7 mysql80-community 614 k
mysql-community-libs x86_64 8.0.24-1.el7 mysql80-community 4.0 M
mysql-community-libs-compat x86_64 8.0.24-1.el7 mysql80-community 1.2 M

Transaction Summary
===============================================================

Install the mysql-devel (the development header files and libraries for MySQL database client applications):

yum install mysql-devel

===============================================================
Package Arch Version Repository Size
===============================================================
Installing:
mysql-community-devel x86_64 8.0.24-1.el7 mysql80-community 6.5 M

Transaction Summary
===============================================================

Install the Python developer package:

yum install python-devel.x86_64 0:2.7.5-90.el7

===============================================================
Package Arch Version Repository Size
===============================================================
Removing:
python-devel x86_64 2.7.5-90.el7 @updates 1.0 M

Transaction Summary
===============================================================

Remove the existing _mysql.so file:

rm -rf /opt/cloudera/parcels/CDH-[***7.x-VERSION***]/lib/hue/build/env/lib/python3.11/site-packages/_mysql.so

Change directory to /usr/include/mysql and check whether the my_config.h file is present.
If the my_config.h file is present, then move to the next step.

If the my_config.h file is not present, then:
1. Go to https://dev.mysql.com/doc/dev/mysql-server/latest/my__config_8h_source.html and copy the contents of the my_config.h file.
2. Create a new my_config.h file using the following command:
```
vi /usr/include/mysql/my_config.h
```
3. Paste the content that you copied earlier in the /usr/include/mysql/my_config.h file and save it.

Install the MySQL Python library as follows:

/opt/cloudera/parcels/CDH/lib/hue/build/env/bin/pip install MySQL-python --force-reinstall --ignore-installed

Copy the _mysql.so (MySQL client library) to Cloudera’s local parcel directory:
1. Locate the _mysql.so file:
  locate _mysql.so
  
  Output: /usr/lib64/python3.11/site-packages/_mysql.so
2. Copy the _mysql.so file to Cloudera’s local parcel directory:
```
cp /opt/cloudera/parcels/CDH/lib/hue/build/env/lib/python3.11/site-packages/MySQLdb/_mysql.cpython-311-x86_64-linux-gnu.so /opt/cloudera/parcels/CDH/lib/hue/build/env/lib/python3.11/site-packages/_mysql.so
```
Log in to Cloudera Manager and restart the Hue service.