Sunday, 1 December 2024

pg_wal folder bloat problem on Standby nodes

›
Problem/Case When using typical physical streaming, pg_wal size grows very fast and unexpectedly on DR (Disaster)/Backup/Standby node Solut...
Tuesday, 7 November 2023

psql cli tricks

›
-- show the connection info # \ conninfo -- show IP address connected by the postgres client # select inet_server_addr (); -- enable timing ...
Wednesday, 13 July 2022

How to add a user into "wheel" group?

›
For example, you have only a root user for the super-user activities, but you wanted to use a custom user for some specific purposes. To mak...
Tuesday, 24 May 2022

'ansible.utils.unsafe_proxy.AnsibleUnsafeText object' has no attribute 'stdout'

›
Action $  ansible-playbook -i /etc/ansible/hosts /etc/ansible/example.yml -v Error 'ansible.utils.unsafe_proxy.AnsibleUnsafeText object...
Friday, 20 August 2021

"Attempting to decrypt but no vault secrets found" issue solution

›
Action $  ansible-playbook -i /etc/ansible/hosts /etc/ansible/example.yml -v Error Attempting to decrypt but no vault secrets found Solution...
Monday, 14 June 2021

el vs rhel

›
el (enterprise linux) e.g. centos, rocky linux, alma linux rhel (red hat enterprise linux) The main difference is that Red Hat provides tech...
Sunday, 13 September 2020

A basic git exercise

›
e.g. an example with basic git commands  source: develop  branch  target: private  branch  (not exist on the git local/remote repository at ...
Monday, 15 June 2020

How to resolve "[Errno 13] Permission denied"?

›
Action $  ansible-playbook -i /etc/ansible/hosts /etc/ansible/example.yml -v Error ERROR! Unexpected Exception, this is probably a bug: [Err...
Monday, 16 December 2019

unzip vs gunzip

›
e.g. using unzip and gunzip tools for extracting the zip files * example.txt file compressed into example.zip file -> Listing content...
Wednesday, 20 November 2019

How to reset mariadb root password on using Galera Cluster system?

›
e.g. reset root password two machines in a cluster 1st step: -> Activate " safe_to_bootstrap " parameter  on first machine ...
Friday, 18 October 2019

e.g. preparing multiple virtual machines in local network

›
Hostnames: VM node-A, VM node-B, VM node-C Adapter 1: Host-only Adapter (VirtualBox-Host-Only Ethernet Adapter) Type -> Paravirtualiz...
Monday, 30 September 2019

How to solve git merge conflict?

›
e.g. git merge conflict issue source: private branch target: develop branch 1st step: $ git clone http://blabla --branch private 2nd...
Tuesday, 27 August 2019

Ansible Commands Book

›
-> valid syntax of the playbook $ ansible-playbook -i myhosts example.yml -v  -- syntax-check -> show elapsed time of the playbook $ ...

How to drop database/user on logical replicated database?

›
1st step on 2nd node: $ echo "DROP SUBSCRIPTION exampledb_node_2" | psql on 1st node: $ echo "DROP PUBLICATION exampledb...
Saturday, 29 June 2019

Kubernetes label usage

›
e.g. namespace; kube-system -> List labels # kubectl get pods --all-namespaces --show-labels # kubectl get pods -n kube-system -...
Sunday, 19 May 2019

Examples of "escape sequences" usage on echo command

›
To use interpretation of backslash escapes, just need to put " -e " parameters afterward echo command. Info: " -e " me...
Friday, 22 February 2019

Linux Terminal Commands Book

›
*  chage (manage user password settings) *  hostnamectl   (show hostname settings) *  date  (manage system date and time) * rpm   (means ...
Thursday, 3 January 2019

How to fix "connection refused" error?

›
Error e.g. The connection to the server 10.10.10.10:6443 was refused - did you specify the right host or port? Solution On kubernetes ...
Wednesday, 19 December 2018

What are the differences of su/ su -/ sudo / sudo su in linux system?

›
Info:  su means, switch user or substitute user sudo means, super user do to use sudo command, related user must be defined in sudoers fi...
Thursday, 1 November 2018

How to change timezone?

›
-> Determine your timezone # cd /usr/share/zoneinfo # tzselect e.g. Europe/Istanbul -> Remove current localtime soft link # rm ...