Enable the query cache in MySQL to improve performance

If you want to get optimized and speedy response from your MySQL server then you need to add following two configurations directive to your MySQL server:

query_cache_size=SIZE
The amount of memory (SIZE) allocated for caching query results. The default value is 0, which disables the query cache.

query_cache_type=OPTION
Set the query cache type. Possible options are as follows:
0 : Don’t cache results in or retrieve results from the query cache.
1 : Cache all query results except for those that begin with SELECT S_NO_CACHE.
2 : Cache results only for queries that begin with SELECT SQL_CACHE

Howto enable caching in MySQL

You can setup caching as follows:
$ mysql -u root –p
Output:

Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 16 to server version: 4.1.15-Debian_1-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql>

Now setup cache size 16Mb:

mysql> SET GLOBAL query_cache_size = 16777216;

Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE 'query_cache_size';

Output:

 +------------------+----------+
| Variable_name    | Value    |
+------------------+----------+
| query_cache_size | 16777216 |
+------------------+----------+

You can setup them in /etc/my.cnf (Red Hat) or /etc/mysql/my.cnf (Debian) file:
# vi /etc/my.cnf
Append config directives as follows:

query_cache_size = 268435456
query_cache_type=1
query_cache_limit=1048576

In above example the maximum size of individual query results that can be cached set to 1048576 using query_cache_limit system variable. Memory size in Kb.


Plesk12 what is the root password for MySQL?

Parallels Plesk Panel renames ‘root’ mysql account to ‘admin’ when the Panel is installed.
To get root privileges in mysql simply login with the ‘admin’ username instead. The password is the same as the admin password in Parallels Plesk Panel.

On server with Parallels Plesk Panel versions 8.x, 9.x and above admin password is stored in file /etc/psa/.psa.shadow. Use the following command to get the password:

~# cat /etc/psa/.psa.shadow

Since version 10 admin password stored in file /etc/psa/.psa.shadow is encrypted. Use the following command to get admin password in plain text:

~# /usr/local/psa/bin/admin –show-password

Despite version of Parallels Plesk Panel you may use the following command to login to mysql with root privileges:

~# mysql -uadmin -p`cat /etc/psa/.psa.shadow`


How-to enable gzip support on Nginx Plesk12

Create /etc/nginx/conf.d/gzip.conf with the following:

vim /etc/nginx/conf.d/gzip.conf

<code>gzip         on;
gzip_disable "MSIE [1-6]\.(?!.*SV1)";
gzip_proxied any;
gzip_types   text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript image/x-icon image/bmp image/svg+xml;
gzip_vary    on;


restart ngix service from Plesk or ssh</code>

gzip_types to compress other file types can be obtained from /etc/nginx/mime.types


Symantec BE: Backup Failed Access denied to directory

When backing up our linux server with RALUS having errors: Access denied to directory V-79-57344-33928 .

Perform the following at the remote Linux/UNIX computer:

1. Stop the RALUS by executing the command /etc/init.d/VRTSralus stop

2. The configuration file of the RALUS is the RALUS.cfg, located in the path /etc/VRTSralus on the remote UNIX/Linux server.

3. Open the RALUS.cfg in a text editor such as vi and locate the following line:

Software\VERITAS\Backup Exec\Engine\RALUS\Encoder=

4. Add the following to the above line: LATIN-1. The new line should like this:

Software\VERITAS\Backup Exec\Engine\RALUS\Encoder=LATIN-1

5. Execute the command /etc/init.d/VRTSralus start to start the RALUS on the remote Linux/UNIX server.

More Info at Symantec


Changing the domain in WordPress Multi Site.

If you have to or want to change the domain of your WordPress MU site. The domain name is actually stored in different places in the database, as well as online in wp-config.php. Every instance of these will need to be changed.

Before you do anything create a  backup. Go to phpMyAdmin, select your database, and choose Export. Save it to your computer. We’ll be making a copy of this and working on the copy. This way, if anything goes wrong, we still have our backup.

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