I am using Fedora workstation as my main OS on my laptop for many years, but usually I face a problem with my wifi device when I try to update my OS or change it. So, here is a solution to fix the problem: First, you have to determine your wifi device model by this […]
There are some known security issues that can make an Apache Web Server insecure. If using Apache as a web service is your approach, then you should scan your web server in first step. There are many tools to scan a web server. here we will use NIKTO. Nikto is a free tool which is […]
If you scan your WordPress site with wpscan tool, you would see a message like this: It means that a hacker can generate a DDOS attack on your host using this URL, cause this URL return a blank page and a 200 HTML Response Code. Also, this script will use a considerable amount of RAM […]
To encrypt connections between client and database server you have to set some parameters in sqlnet.ora file ($ORACLE_HOME/network/admin/sqlnet.ora) of server and client (you have to install oracle client on the client): server side: client side: the ENCRYPTION_CLIENT parameter can have one of these values: ACCEPTED : The client or server will allow both encrypted and […]
You have many options to install and configure a loadbalancer in RedHat 7. One of the best options is HAPorxy. To setup HAProxy, you have to download related RPM file and then install it: Then, you have to make changes in config file (/etc/haproxy/haproxy.conf): in this sample we have 4 servers as below: APP1: 192.168.1.2 […]
If you add a new disk to your OS, you won’t find this device in the device list (fdisk -l command). So you have two options to make it available: Reboot your machine Make the OS rescan all connected devices In operational environments, the first option is not considerable. So we have to choose the […]
To change the Character Set and Collation of a field of a table you have to use this query: if the table contains data, you have to update that data as follow:
If you want to REBUILD and REORGANIZE all your indexes in a database, you have to use this query: Rebuild: Reorganize:
To see the progress of Backup or Restore process you can use this query:
If you see Fatal NI connect error 12547 error in alert log file of a Database in the middle of startup, and the database process couldn’t find DB PARAMETER FILE and CONTROL FILE, you have to check permissions,owner and group of these files: The permission of these files have to be 6751. The group of […]