Appdiscovery Diagnostics

Application Discovery Service Diagnostics

When to use

Any AWS Application Discovery Service investigation — agent deployment, agentless discovery, data collection, export, dependency mapping, or Athena integration.

Investigation workflow

Step 1 — Collect and triage

aws discovery describe-agents --max-results 20
aws discovery describe-continuous-exports --max-results 10
aws discovery list-configurations --configuration-type SERVER --max-results 20

Step 2 — Domain deep dive

aws discovery describe-agents --filters name=agentIds,values=<agent-id>,condition=EQUALS
aws discovery describe-export-tasks --max-results 10
aws discovery get-discovery-summary

Step 3 — Detailed investigation

aws discovery start-data-collection-by-agent-ids --agent-ids <id1> <id2>
aws discovery describe-tags --filters name=configurationId,values=<server-id>
aws cloudtrail lookup-events --lookup-attributes AttributeKey=EventSource,AttributeValue=discovery.amazonaws.com --max-results 10

Read references/guardrails.md before concluding on any Application Discovery Service issue.

Gotchas: Application Discovery Service

• Two discovery methods: agent-based (installed on servers) and agentless (VMware vCenter).
• Agents collect detailed data including network connections for dependency mapping.
• Agentless collector discovers VMware VMs via vCenter API — no agent installation needed.
• Data is stored in Migration Hub home region.
• Continuous export to S3 enables Athena queries on discovery data.
• Agent requires outbound HTTPS to discovery service endpoint.

Anti-hallucination rules

1. Agent-based and agentless discovery collect different data — agents provide more detail.
2. Discovery data is stored in the Migration Hub home region, not the agent's region.
3. Continuous export must be enabled separately — it's not automatic.
4. Athena integration requires continuous export to be active.
5. Agentless collector requires VMware vCenter access — it doesn't work with other hypervisors.
6. Spend no more than 2 minutes on any single hypothesis. Pivot if inconclusive.

12 runbooks