Functionality of the Garden healthcheck process

Products

• VMware Tanzu Application Service for VMs

Issue/Introduction

Garden Health Checker Functionality

The Garden Health Checker (garden-healthchecker) process was introduced (In garden-runc-release v1.22.6) to enhance platform reliability by monitoring and performing HTTP-based Health Checks on the Garden process.
This functionality was designed to ensure that the critical process was always up and running.

Health Check Failures

It is important to be aware that, in certain scenarios, the Garden Health Checker might encounter failures, resulting in the Garden process restart.
The failures can occur in environments deployed on resource limited or constrained Infrastructure, especially during times of increased resource utilization.
Various factors, such as Network issues, Disk problems, CPU and Memory constraints, can cause Health Check failures.

Consequences of Health Check Failures

When Health Check failures occur, it causes the restart of the Garden process.
The restart has a significant impact on application instances running on the affected Diego_Cell VM.
The application instances on the VM experience a disruption as they are terminated and recreated on other Diego_Cell VMs.

Prevention of Health Check Failures

In the cases of Health Check failures, it's important to investigate and address the underlying issues to minimize disruptions to your application instances.
Monitoring of infrastructure resource utilization and appropriate resource allocation will prevent these failures.

 

Removal of Garden Health Checker Functionality

The Garden Health Checker process was found to be too aggressive when evaluating and acting upon failed health checks.
The Garden Health Checker has been removed in favor of Rep processes Health Check capabilities.
The Rep process has a more dynamic Health Check to test and better determine the health of the VM.  

Introduction of the garden-healthchecker Process

• First introduced garden-runc-release 1.22.6  (Healthcheck added)
• Removed for improvements garden-runc-release 1.29.0 (Healthcheck removed)
• Reintroduced garden-runc-release 1.37.0 (Healthcheck re-added)
• Removed garden-runc-release 1.43.0 (Healthcheck removed)

 

 

TAS Versions that have garden-healthchecker

TAS 5.0.X Versions with garden-healthchecker
TAS - 5.0.1 garden-runc v1.41.0
TAS - 5.0.0 garden-runc v1.37.0


TAS 4.0.X Versions with garden-healthchecker
TAS - 4.0.11 garden-runc v1.41.0
TAS - 4.0.10 garden-runc v1.37.0
TAS - 4.0.9 garden-runc v1.37.0
TAS - 4.0.8 garden-runc v1.37.0
TAS - 4.0.7 garden-runc v1.37.0
TAS - 4.0.0 garden-runc v1.25.0


TAS 3.0.X Versions with garden-healthchecker
TAS - 3.0.19 garden-runc v1.41.0
TAS - 3.0.18 garden-runc v1.37.0
TAS - 3.0.17 garden-runc v1.37.0
TAS - 3.0.16 garden-runc v1.37.0
TAS - 3.0.9 garden-runc v1.26.0
TAS - 3.0.8 garden-runc v1.25.0
TAS - 3.0.7 garden-runc v1.23.0
TAS - 3.0.6 garden-runc v1.22.9
TAS - 3.0.5 garden-runc v1.22.9
TAS - 3.0.4 garden-runc v1.22.7


TAS 2.13.X Versions with garden-healthchecker
TAS - 2.13.26 garden-runc v1.41.0
TAS - 2.13.25 garden-runc v1.37.0
TAS - 2.13.24 garden-runc v1.37.0
TAS - 2.13.23 garden-runc v1.37.0
TAS - 2.13.11 garden-runc v1.22.7


TAS 2.12.X Versions with garden-healthchecker
TAS - 2.12.20 garden-runc v1.25.0
TAS - 2.12.19 garden-runc v1.23.0
TAS - 2.12.18 garden-runc v1.22.9
TAS - 2.12.17 garden-runc v1.22.9
TAS - 2.12.16 garden-runc v1.22.7


TAS 2.11.X Versions with garden-healthchecker
TAS - 2.11.40 garden-runc v1.41.0
TAS - 2.11.39 garden-runc v1.37.0
TAS - 2.11.38 garden-runc v1.37.0
TAS - 2.11.37 garden-runc v1.37.0
TAS - 2.11.30 garden-runc v1.26.0
TAS - 2.11.29 garden-runc v1.25.0
TAS - 2.11.28 garden-runc v1.23.0
TAS - 2.11.27 garden-runc v1.22.9
TAS - 2.11.26 garden-runc v1.22.9
TAS - 2.11.25 garden-runc v1.22.7