sapcc-autoscaling

SAP CC Autoscaling (Castellum)

Inspect Castellum autoscaling state: view resource configurations, check pending resize operations, diagnose failed scaling actions.

MCP Tools

Note: Castellum MCP tools are planned but not yet implemented in the MCP server. The skill documents the service for reference. When tools become available, they will follow the castellum_ prefix pattern.

Expected Tools (NOT YET AVAILABLE)

Tool	Purpose	Expected Parameters
castellum_list_resources	List autoscaling-managed resources	project_id
castellum_get_resource	Get autoscaling config for a resource	asset_type, asset_id
castellum_list_operations	List scaling operations history	asset_type, state

Interim Workaround

Until Castellum MCP tools are available:

• Use maia_query with PromQL to check Castellum metrics: castellum_resource_*
• Use hermes_list_events(target_type=autoscaling/resource) for scaling audit trail

Gotchas

1. project_id must be a valid UUID. The tool validates UUID format and rejects anything else. You cannot pass a project name — resolve it to UUID first via Keystone if needed.

2. asset_type uses a colon-separated hierarchy. Format is project-quota:<service>:<resource>, e.g., project-quota:compute:cores or project-quota:network:floating_ips. Getting this format wrong returns empty results without an error.

3. Castellum watches Limes, does not replace it. Castellum monitors usage via Limes and triggers resize operations. The actual quota values live in Limes. To see current quota/usage, use limes_get_project_quota. Castellum shows the autoscaling configuration and pending/failed operations.

4. Pending does not mean stuck. Pending operations are queued resizes that have not yet been executed. Castellum processes these asynchronously. Only flag operations that have been pending for an unusually long time (hours).

5. Failed operations include the failure reason. The recently-failed endpoint shows why a resize failed (e.g., parent quota exhausted, constraint violation). This is the primary diagnostic tool for scaling failures.

6. Not all resources are auto-scalable. Only resources that have Castellum configuration will appear. If get_project_resources returns empty or missing resources, those resources are not configured for autoscaling.

7. Thresholds define when scaling triggers. Each configured resource has usage thresholds (high/low) that trigger upscale/downscale. The get_project_resources response shows these thresholds alongside current usage.

Common Workflows

Check Autoscaling Configuration for a Project

1. castellum_get_project_resources with project_id=<uuid> — see all configured resources and their thresholds.
2. For each resource, note the high/low thresholds and current usage percentage.
3. Cross-reference with limes_get_project_quota to see actual quota values.

Diagnose Why a Resource Did Not Autoscale

1. castellum_list_recently_failed_operations with project_id=<uuid> — check for failures.
2. If failures exist, read the error reason (typically quota exhaustion at parent level).
3. If no failures and no pending ops, castellum_get_project_resources — check if thresholds are configured and if usage is actually above the high threshold.

Monitor Pending Resize Operations

1. castellum_list_pending_operations — see all queued resizes (optionally filter by project or asset_type).
2. Check timestamps — operations pending for over an hour may indicate a processing backlog.
3. If a specific resource is pending, verify the parent quota has headroom via Limes.

Cross-Service References

Need	Service	Tool
Current quota and usage values	Limes	limes_get_project_quota
Project UUID from name	Keystone	keystone_list_projects
Audit trail of resize actions	Hermes	hermes_list_events(initiator_name=castellum)
Compute resource details	Nova	nova_list_servers