MYSQL service is automatically shutting down

Steps: 

• check for corrupted tables
  • the service automatically shuts down if the system tries to access a table that is already corrupted
  • corrupted tables can be a result of hardware deterioration or if the unit is always shut down improperly
  • possible solutions:
    • try and recover all tables using innodb_force_recovery
    • check if the unit needs to be replaced/upgraded 
    • we need to inform the user to shut the unit down properly
• check for hardware
  • check hard drive health
    • from experience, IBdata and the database tables have a high chance to get corrupted if the hard drive has very low health (<85%) which is why the drive health should be kept at >90%
    • if the harddrive health is too low, suggest to HD that the harddrive be replaced and the POS to be re-setup
  • check RAM usage
    • Client could have many open browser tabs or they're using another software eating up the RAM.
    • check for viruses or malware which can eat up the unit's resources
    • MySQL shuts down automatically if the available RAM is below a certain level. 
    • Inform client to avoid using the unit for other purposes than for the POS especially for the older units. 
  • check system files
    • check system files by running  'sfc /scannow' to check system files integrity.
• check for system events 
  • forced shutdown - user should shut exit the pos and shut the unit down properly. If not, this can easily cause data base corruption and affect hard drive health too
  • system error - solution can be case to case 

After troubleshooting

• remind user to backup data consistently for all terminals even if there're no errors encountered especially if drive health is less than recommended value

Sample Mantis issues: 

1.  Unhandled exception has occurred in your application