SA Bagus

https://www.techtarget.com/whatis/definition/troubleshooting   1. Contact the team, because the point of view from another peer is helpful. 2. Contact the vendor, if we have support, use it very well. 3. Contact the service owner, they know their features well. 4. Use Statistics from the monitoring tool very well, it is helpful as data for troubleshooting. 5. Back to basic knowledge sometimes is a good practice. 

As an IT man who considers himself as a problem solver, this flowchart diagram will be important to troubleshoot the problem. https://www.learncisco.net/courses/icomm-ccna-voice/cisco-uc-solution-maintenance/general-troubleshooting.html

Iinvestigation: Check nodes total, be familiar with the environment (connection flow, device/software naming). Check resources via monitoring command and monitoring graph. Check network & port connection, check the firewall. Check variable, naming, username, hostname, domain name. Check Linux processes. Check installation guideline/steps, operation procedures. Check speed (network, disk i/o, CPU, memory). Check log messages. Check software dependency (library). Check software environment (Linux environment)/virtual environment. Check user, file & directory permission. Check, coordinate and communicate with colleagues, supervisor, and 3rd party. Check user and vendor. Check notes. Check history. Check and crosscheck with other information. Check browser inspection. Check limitation(DB connection, java max connection, kernel max connection, etc). Check and run the app in debug mode. Check and compare with another environment, another end client. Check