Introduction

TAD (Test And Diagnostic) monitors the amount of free memory available in the system at run time. It triggers the memory/Resource Reclamation (RR) process in TDM, when the amount of free memory drops below a configurable threshold. RR process can also be triggered by memory allocation failures which results in a notification being sent to TDM to try to reclaim memory.

Selfheal is a feature implemented in Test And Diagnostic Component.

Self-heal monitors:

• CPU usage
• Memory Usage
• RDK-B processes

Self-heal stores Reset count and Reboot Count.
Self-heal takes required action like: Reboot the device, Restart required process.
Self-heal does connectivity test.

Resource Monitoring and Process Monitoring

Resource Monitoring

Monitors the resources periodically (eg: 15 mins). If "Average Memory Used" reaches threshold value, reboot action will be executed. 

"resource_monitor.sh" script is used for monitoring Memory and CPU usage.
Located in the device path: "/fss/gw/usr/ccsp/tad/resource_monitor.sh".

Process Monitoring

Monitors the processes periodically (eg: 15 mins) based on it's process id (pid). Based on the process id availability, required action will be taken such as restarting the process, rebooting the device.

"task_health_monitor.sh" script is used for monitoring all RDK-B processes
Located in the device path: "/fss/gw/usr/ccsp/tad/task_health_monitor.sh"

Self-heal stores Reset Count and Reboot Count.

Connectivity Test

Self-heal does connectivity test. Ping test will be done through any server IP/URI, which need to be configured. If server IP/URI is not configured, Ping test won't be executed and no action will be taken. If server is configured and ping test fails, reboot action will be executed.

"self_heal_connectivity_test.sh" script is used for ping test

Action

Self-heal takes the required action through "corrective_action.sh" script. This script has implementation of the actions.

Some of the actions are:

rebootNeeded - Reboots the device
resetNeeded - Restarts the required process
storeInformation - Stores Memory and CPU usage

In Raspberry Pi the functionality of self-heal feature is provided by systemd.