What happens I forget to enable syslog agent prior to upgrading to Tanzu Application Service (TAS) for VMs 2.8?

Products

• VMware Tanzu Application Service for VMs

Issue/Introduction

You already upgraded to Tanzu Application Service (TAS) for VMs 2.8 and you realized you forgot to enable syslog agents as prescribed in the upgrade doc which can be found here: Operations Manager v2.8 Release Notes.

What is the implication of upgrading to version TAS for VMs 2.8 without enabling syslog agents? How can I enable syslog agents?

Environment

Product Version: 2.8

Resolution

TAS for VMs 2.8 only has syslog agents. There is no longer an option to use syslog adapters in the new versions of TAS for VMs. When you upgrade to TAS for VMs 2.8, syslog adapters would have been removed and replaced with syslog agents.

This change was done for reasons of scaling and complexity. The previous architecture required a set of dedicated VMs and ran into scaling issues. The adapters also depended on the Loggregator firehose, which has inherent scaling limitations as throughput increases. The new syslog agents live directly alongside the apps whose logs they drain, allowing higher throughput and more app drains.

If you already upgraded to TAS for VMs 2.8, there is nothing else to do to enable syslog agent. This is enabled by default.

Our recommended procedure is to upgrade the syslog agents and redeploy on TAS for VMs 2.7, which switches from adapters to agents with very little loss of logs being sent through app drains. However, if you have already upgraded from TAS for VMs 2.7 to TAS for VMs 2.8 without having enabled syslog agents while still on TAS for VMs 2.7, then the logs being sent over app drains may not be sent for the entirety of the upgrade. Logs generated during upgrade will be lost.