Monitoring Agent Migration at Scale

Context

A fleet of production Linux servers was running a monitoring agent version approaching end of support. The migration covered messaging, DRM, licensing and backend services.

Problem

A manual replacement could leave hosts unregistered, attached to the wrong metadata or without monitoring visibility during the change window.

My role

Designed and executed the migration runbook, including pre-change validation, automation, rollout and post-change verification.

Technical actions

1. [01] Backed up the existing agent configuration before each host change.
2. [02] Inventoried groups, templates and metadata before touching the agent.
3. [03] Built a Bash helper to calculate the expected host name from the infrastructure convention.
4. [04] Replaced the agent package and reconfigured the monitoring proxies.
5. [05] Validated autoregistration, group/template assignment and agent logs after migration.
6. [06] Documented rollback steps even though no rollback was required.

Operational impact

Approximately 50 hosts were migrated by Lautaro. No rollback was required, and no host lost monitoring visibility for more than approximately two minutes.

Evidence

• [✓] Controlled rollout across multiple change windows.
• [✓] Repeatable checklist and validation path.

What this demonstrates

• Infrastructure migration at operational scale.
• Automation that reduces host-by-host error risk.
• Change management with rollback thinking.