Generating a 2048 bit RSA private key
writing new private key to '/etc/proftpd/ssl/proftpd.key.pem'
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
Country Name (2 letter code) [XX]:UA
State or Province Name (full name) :Kyivska
Locality Name (eg, city) [Default City]:Kyiv
Organization Name (eg, company) [Default Company Ltd]:Shkodenko V. Taras Ltd
Organizational Unit Name (eg, section) :IT
Common Name (eg, your name or your server's hostname) :shkodenko.com
Email Address :
First of all I would recommend you to make backups for all MySQL databases and configuration files you have.
The second recommendation is to use official Yum repositories located on http://dev.mysql.com/downloads/repo/yum/
It is the best possible option for CentOs and other Red Hat based Linux ditstibutions.
You should download repository depending on your distribution version.
For example on CentOs 6 you should use Red Hat Enterprise Linux 6 / Oracle Linux 6 (Architecture Independent), RPM Package – http://dev.mysql.com/downloads/file/?id=465605
If you have previously installed mysql from different repository run command:
# yum repolist all | grep mysql
to find out all Yum repositories list which contains mysql.
Example output of such command on my server:
# yum repolist all | grep mysql
mysql-connectors-community MySQL Connectors Community disabled
mysql-connectors-community-source MySQL Connectors Community – S disabled
mysql-tools-community MySQL Tools Community enabled: 40
mysql-tools-community-source MySQL Tools Community – Source disabled
mysql-tools-preview MySQL Tools Preview disabled
mysql-tools-preview-source MySQL Tools Preview – Source disabled
mysql55-community MySQL 5.5 Community Server disabled
mysql55-community-source MySQL 5.5 Community Server – S disabled
mysql56-community MySQL 5.6 Community Server disabled
mysql56-community-source MySQL 5.6 Community Server – S disabled
mysql57-community MySQL 5.7 Community Server enabled: 146
mysql57-community-source MySQL 5.7 Community Server – S disabled
To select disable version 5.6 and select version 5.7 you can use commands such commands:
Sometimes it is difficult to find best solution for some problem quickly.
For example, if you need to walk some nested array. You don’t know how deep it could be nested and extract values from it to make it flattern you can use amazing function array_walk_recursive together with anonymous function to solve such task like it is shown in example below:
This amazing example of magic is very simple: it calls our anonymous function for each $inputArray element, storing nested element values in $resultArray. Note, usage of & in use (&$resultArray) it tells we shoud pass variable by reference.
If you use such function like GROUP_CONCAT you should be aware of default result size is 1024 bytes. It could lead possible problems.
For example, check the SQL query below:
set @user_ids = (SELECT GROUP_CONCAT(user_id ORDER BY user_id SEPARATOR ',') FROM user WHERE enabled = 1);
If you expect result to be list of IDs separated by comma and you have data result bigger than 1024 characters it will be truncated to default length. If you use such result in another SQL queries such as:
SELECT some_stuff FROM user_stuff WHERE user_id IN (@user_ids);
It could lead to possible logical problems when some IDs will be cropped and wrong data will be used.
To solve such problem you can change session variable using SQL query:
SET SESSION group_concat_max_len = 1000000;
Where 1000000 is maximum possible GROUP_CONCAT result size.
Also, you can set this variable globally (it is preffered way if you work with big data in most cases. Then you should add such configuration to your /etc/my.cnf
group_concat_max_len = 1000000;
and restart MySQL server to apply new default configuration.