"Tables to cache" Title Not Display At "MySQL Server Configuration" Page

[Francewhoa]

Steps to Reproduce

1. Using Debian 10 Buster, install a fresh Webmin 1.941 & Virtualmin 6.08
2. Navigate to "Webmin" ---> "Servers" ---> "MySQL Database Server" ---> "MySQL Server Configuration"
3. Below "Network buffer size" field, notice that the next field below is not display. This is the challenge. The number 1 in this screenshot shows the location of this challenge.
   
4. Expected result is the field titled Tables to cache needs to be display. So that end-users know what this configuration is for.

Using

• Debian 10 Buster
• MariaDB 10.3.18
• Webmin 1.941
• Virtualmin 6.08
• Authentic theme version 19.46

Cause

This is a speculation about what might cause this challenge:

1. Back in 2005, starting with MySQL 5.1.3 table_cache was depreciated and renamed to table_open_cache(1). In other words, it's the same variable. Just a new & clearer name.
2. On Debian 10 Buster, the default database server is MariaDB 10.3.18. Maybe somehow Webmin searches the default mariadb.conf.d configuration file at /etc/mysql/mariadb.conf.d for table_cache variable. But found none. Because this variable name was depreciated. It is now call table_open_cache.
3. In turn, somehow Webmin display no field title for table_open_cache. But does display its value if any are set.

(1)Sources about back in 2005, starting with MySQL 5.1.3 table_cache was depreciated and renamed to table_open_cache:

   * https://mariadb.com/kb/en/where-is-the-table_cache-in-mariadb/ or https://archive.md/TnZJb
   * https://bugs.mysql.com/bug.php?id=51599
   * https://bugs.mysql.com/bug.php?id=68315

For those not familiar with Tables to cache, with Debian 10 Buster with its default MariaDB 10.3.18 in the back end, Tables to cache is called the table_open_cache variable

If the end-user manually edit this configuration file at /etc/mysql/mariadb.conf.d then set table_open_cache = 163840. Then navigate to "Webmin" ---> "Servers" ---> "MySQL Database Server" ---> "MySQL Server Configuration" the value 163840 is display. But somehow the field title is still not display Table to cache. The number 2 in this screenshot shows this challenge.

Note

• On Debian 10 Buster
  • The default database server is MariaDB. Which uses the variable table_open_cache
  • The configuration file is located at /etc/mysql/mariadb.conf.d
• On Debian 7 Wheezy
  • The default database server is MySQL. Which uses the variable table_cachea
• @Francewhoa :) Note to myself. UB IT's Unique ID: 20200506.1229

[Francewhoa]

Screenshot

This screenshot show another fresh Webmin 1.941 installation we did today. Notice that the table_open_cache variable default value 512 is display. But somehow the field title Table to cache is not. The number 1 in this screenshot below shows the location of this challenge.

mariadb.conf.d

This mariadb.conf.d file is located at /etc/mysql/mariadb.conf.d. Its content is copied as is below. Notice the table_open_cache = 512 line below.

[server]


[mysqld]




user                    = mysql
pid-file                = /run/mysqld/mysqld.pid
socket                  = /run/mysqld/mysqld.sock

basedir                 = /usr
datadir                 = /var/lib/mysql
tmpdir                  = /tmp
lc-messages-dir         = /usr/share/mysql




bind-address            = 127.0.0.1



















query_cache_size = 32M












log_error = /var/log/mysql/error.log













expire_logs_days        = 10




























character-set-server  = utf8mb4
collation-server      = utf8mb4_general_ci
innodb_file_per_table = 1
thread_cache_size = 8
myisam_sort_buffer_size = 64M
read_rnd_buffer_size = 8M
read_buffer_size = 2M
sort_buffer_size = 2M
table_open_cache = 512
max_allowed_packet = 1M
key_buffer_size = 384M

















[embedded]




[mariadb]




[mariadb-10.3]

[iliaross]

Francois, thanks for detailed and clear issue report. Pleasure to take a look. Appreciate this!!

Next Webmin version will have it fixed.

[Francewhoa]

Thanks @iliaross :) For both the fix and your quick reply