PAM appliances show RAM usage at about 70% some time after reboot

Products

• CA Privileged Access Manager (PAM)

Issue/Introduction

After performing a reboot of a PAM appliance, RAM usage is low, but it starts increasing over time until reaching a percentage of circa 70% after some weeks

Once it is at that figure it does not decrease significantly, even if there is little activity in PAM

This article explains why this behaviour is observed

Environment

CA PAM 4.X releases

Cause

PAM tries to put unused memory to use.  Allocating more memory to MySQL is one of the most effective ways to improve DB performance. 

Therefore PAM monitors memory and adjusts MySQL memory, shooting for MySQL to use 60% of overall system memory...

• If overall memory usage is under 50%, MySQL memory usage is increased
• If overall memory usage is over 70%, MySQL memory is decreased

This is retested and adjusted if appropriate every 15 minutes via cron file monitor_and_adjust_system_resources.

Resolution

Unless memory usage keeps growing, this behaviour is working as designed. Memory usage should be stable around 67-70% after some time of operation due to the mechanism indicated above