pidstat command helps to find utilization of a pid. pidstat -u -p PID_NUMBER But I’ll explain the origins of this calculation at this post. Tools like pidstat or nmon which can display detailed CPU statistics by PID use /proc/PID/stat folders. If you run cat /proc/ANY_PID/stat you will see an output…

You may need forwarding a request to an another port at same machine or on a different machine. I assume that your preferred zone is enabled if not you can use command below(ethX is your network interface that takes requests to port); sudo firewall-cmd --permanent --zone=public --add-interface=ethX Than you should…

Puppet is an automation and configuration management tool. It is eligible for ensuring desired state configurations on servers. Here are some puppet terms. Manifests The various resources that you need to declare for a specific configuration are stored in files that are called manifests. Classes A class is a set…

Firewalld is a firewall management tool for Linux operating systems. It has same purpose(packet filtering) with iptables but it is an easier to use tool. Firewalld relies on a concept which is called “zones”. A network zone defines the level of trust for network connections. This is a one to…

Assume that you want to prevent access to custom files in a folder even a user has access rights to files. You should install SELinux tools to do steps completely. $ yum install policycoreutils-python policycoreutils-devel setools-console setroubleshoot setroubleshoot-server selinux-policy -y Firstly login to system as root, create a folder and…

This cluster is installed on Centos 7 operating systems. Nodes should be minimum 2GB memory, 2 CPUs. We’ll have one master node, two worker nodes at the end of the installation. Disable swap in all nodes swapoff -a Remove swap entry from /etc/fstab to disable after reboots. 2. Install docker…

This article is an introduction to SELinux in Red Hat or CentOS distributions. I will publish deeper articles about SELinux. SELinux is a security mechanism between subjects and objects. Subjects are users or processes, objects are files or ports. This mechanism provides a more granular access control than DAC. SELinux…

Jupyterhub is a multi-user version of Jupyter notebook. If you have an anaconda platform you can install it with this command; $ conda install -c conda-forge jupyterhub $ conda install notebook If you don’t you can go with pip but you should install nodejs/npm to install proxy module. $…

Prerequisites — Disable swap in all nodes swapoff -a Remove swap entry from /etc/fstab. Min: 2GB memory, 2 CPUs per node. Install docker on all nodes. yum -y install docker systemctl enable docker systemctl start docker All hosts file should be same and include all nodes hostnames. 192.168.1.60 kubemaster01 192.168.1.61 kubeworker01 192.168.1.62 kubeworker02…