Worked examples
The concept worked its metering and rating out on paper before any of it was built. Those examples are kept here as they were written, each one beside the golden case it seeded.
The expected numbers of a golden case are derived by hand from these examples and from the pricing model. They are never regenerated from what the engine produced, because a number the engine wrote says nothing about whether the engine is right (the golden harness). Turning the examples into that suite is WP 3.11 of the metering and rating roadmap.
Examples 2, 4 and 5 run through the engine today from seeded events, while no collector produces such events on any deployment (the providers that do not exist yet). Every example is rated with pricing/2026-03.yaml, and every usage record the engine writes also carries count: 1, which the examples omit.
Example 1: OpenStack instance resize mid-month
The golden case is instance_resize, which bills def-456 for 21600 and 23040 minutes.
VM def-456 is resized from m1.small to m1.large on March 16:
{
"billing_period": { "from": "2026-03-01T00:00:00Z", "to": "2026-04-01T00:00:00Z" },
"project_id": "proj-456",
"platform": "openstack",
"usage_records": [
{
"resource_type": "instance",
"resource_id": "def-456",
"state": "active",
"from": "2026-03-01T00:00:00Z",
"to": "2026-03-16T00:00:00Z",
"usage": {
"minutes": 21600,
"vcpus": 2, "ram_gb": 4, "disk_gb": 40, "flavor": "m1.small",
"egress_gb": 12.3, "ingress_gb": 5.1
}
},
{
"resource_type": "instance",
"resource_id": "def-456",
"state": "active",
"from": "2026-03-16T00:00:00Z",
"to": "2026-04-01T00:00:00Z",
"usage": {
"minutes": 23040,
"vcpus": 4, "ram_gb": 8, "disk_gb": 80, "flavor": "m1.large",
"egress_gb": 24.7, "ingress_gb": 10.2
}
}
]
}Example 2: Hetzner server upgrade mid-month
The golden case is hetzner_upgrade, which bills srv-001 for 20160 and 24480 minutes.
Server srv-001 is upgraded from CX21 to CX31 on March 15:
{
"billing_period": { "from": "2026-03-01T00:00:00Z", "to": "2026-04-01T00:00:00Z" },
"project_id": "hetzner-proj-42",
"platform": "hetzner",
"usage_records": [
{
"resource_type": "server",
"resource_id": "srv-001",
"state": "running",
"from": "2026-03-01T00:00:00Z",
"to": "2026-03-15T00:00:00Z",
"usage": {
"minutes": 20160,
"vcpus": 2, "ram_gb": 4, "disk_gb": 40, "server_type": "cx21"
}
},
{
"resource_type": "server",
"resource_id": "srv-001",
"state": "running",
"from": "2026-03-15T00:00:00Z",
"to": "2026-04-01T00:00:00Z",
"usage": {
"minutes": 24480,
"vcpus": 4, "ram_gb": 8, "disk_gb": 80, "server_type": "cx31"
}
}
]
}Example 3: OpenStack volume resize and retype
The golden case is volume_resize_retype, which bills vol-789 for 12960, 14400 and 17280 minutes.
Volume vol-789 is extended from 100 GB to 200 GB on March 10, then retyped from SSD to HDD on March 20:
{
"billing_period": { "from": "2026-03-01T00:00:00Z", "to": "2026-04-01T00:00:00Z" },
"project_id": "proj-456",
"platform": "openstack",
"usage_records": [
{
"resource_type": "volume",
"resource_id": "vol-789",
"state": "in-use",
"from": "2026-03-01T00:00:00Z",
"to": "2026-03-10T00:00:00Z",
"usage": { "minutes": 12960, "size_gb": 100, "type": "ssd" }
},
{
"resource_type": "volume",
"resource_id": "vol-789",
"state": "in-use",
"from": "2026-03-10T00:00:00Z",
"to": "2026-03-20T00:00:00Z",
"usage": { "minutes": 14400, "size_gb": 200, "type": "ssd" }
},
{
"resource_type": "volume",
"resource_id": "vol-789",
"state": "in-use",
"from": "2026-03-20T00:00:00Z",
"to": "2026-04-01T00:00:00Z",
"usage": { "minutes": 17280, "size_gb": 200, "type": "hdd" }
}
]
}Example 4: Gardener shoot worker scaling and hibernation
The golden case is shoot_scale_hibernate, which bills shoot-abc for 15840, 18720, 4320 and 5760 minutes.
Shoot shoot-abc scales from 3 to 5 workers on March 12, then hibernates on March 25 and wakes on March 28:
{
"billing_period": { "from": "2026-03-01T00:00:00Z", "to": "2026-04-01T00:00:00Z" },
"project_id": "team-alpha",
"platform": "gardener",
"usage_records": [
{
"resource_type": "shoot",
"resource_id": "shoot-abc",
"state": "active",
"from": "2026-03-01T00:00:00Z",
"to": "2026-03-12T00:00:00Z",
"usage": { "minutes": 15840, "worker_count": 3, "machine_type": "m1.xlarge" }
},
{
"resource_type": "shoot",
"resource_id": "shoot-abc",
"state": "active",
"from": "2026-03-12T00:00:00Z",
"to": "2026-03-25T00:00:00Z",
"usage": { "minutes": 18720, "worker_count": 5, "machine_type": "m1.xlarge" }
},
{
"resource_type": "shoot",
"resource_id": "shoot-abc",
"state": "hibernated",
"from": "2026-03-25T00:00:00Z",
"to": "2026-03-28T00:00:00Z",
"usage": { "minutes": 4320, "worker_count": 5, "machine_type": "m1.xlarge" }
},
{
"resource_type": "shoot",
"resource_id": "shoot-abc",
"state": "active",
"from": "2026-03-28T00:00:00Z",
"to": "2026-04-01T00:00:00Z",
"usage": { "minutes": 5760, "worker_count": 5, "machine_type": "m1.xlarge" }
}
]
}Example 5: Harbor repository with counters
The golden case is harbor_counters, which bills team-alpha/app for 24480 and 20160 minutes.
Repository team-alpha/app exists all month; storage grows from 10 GB to 15 GB on March 18:
{
"billing_period": { "from": "2026-03-01T00:00:00Z", "to": "2026-04-01T00:00:00Z" },
"project_id": "harbor-team-alpha",
"platform": "harbor",
"usage_records": [
{
"resource_type": "repository",
"resource_id": "team-alpha/app",
"state": "active",
"from": "2026-03-01T00:00:00Z",
"to": "2026-03-18T00:00:00Z",
"usage": {
"minutes": 24480,
"storage_gb": 10,
"pulls": 812,
"pushes": 47,
"egress_gb": 38.5
}
},
{
"resource_type": "repository",
"resource_id": "team-alpha/app",
"state": "active",
"from": "2026-03-18T00:00:00Z",
"to": "2026-04-01T00:00:00Z",
"usage": {
"minutes": 20160,
"storage_gb": 15,
"pulls": 711,
"pushes": 23,
"egress_gb": 31.2
}
}
]
}End to end: an OpenStack VM with state changes
The golden case is e2e_power_cycle, which bills abc-123 for 14400, 14400 and 15840 minutes.
A VM abc-123 (m1.large: 4 vCPUs, 8 GB RAM, 80 GB disk) runs the full month of March, but is powered off from March 11 to March 21 (10 days = 14400 minutes).
Step 1: metering
Metering produces three usage records, split at each state change:
{
"billing_period": { "from": "2026-03-01T00:00:00Z", "to": "2026-04-01T00:00:00Z" },
"project_id": "proj-456",
"platform": "openstack",
"usage_records": [
{
"resource_type": "instance",
"resource_id": "abc-123",
"state": "active",
"from": "2026-03-01T00:00:00Z",
"to": "2026-03-11T00:00:00Z",
"usage": { "minutes": 14400, "vcpus": 4, "ram_gb": 8, "disk_gb": 80, "egress_gb": 18.0 }
},
{
"resource_type": "instance",
"resource_id": "abc-123",
"state": "shutoff",
"from": "2026-03-11T00:00:00Z",
"to": "2026-03-21T00:00:00Z",
"usage": { "minutes": 14400, "vcpus": 4, "ram_gb": 8, "disk_gb": 80, "egress_gb": 0 }
},
{
"resource_type": "instance",
"resource_id": "abc-123",
"state": "active",
"from": "2026-03-21T00:00:00Z",
"to": "2026-04-01T00:00:00Z",
"usage": { "minutes": 15840, "vcpus": 4, "ram_gb": 8, "disk_gb": 80, "egress_gb": 22.5 }
}
]
}Step 2: rating
Rating applies the pricing model with state_modifiers (active = 1.0, shutoff = 0.5):
Record 1 (active, 10 days):
vcpus: (14400/60) × 4 × 0.02 × 1.0 = 19.20 EUR
ram_gb: (14400/60) × 8 × 0.005 × 1.0 = 9.60 EUR
disk_gb:(14400/60) × 80 × 0.001 × 1.0 = 19.20 EUR
egress: 18.0 × 0.09 = 1.62 EUR
→ subtotal: 49.62 EUR
Record 2 (shutoff, 10 days – 50% modifier on time_gauge, no egress):
vcpus: (14400/60) × 4 × 0.02 × 0.5 = 9.60 EUR
ram_gb: (14400/60) × 8 × 0.005 × 0.5 = 4.80 EUR
disk_gb:(14400/60) × 80 × 0.001 × 0.5 = 9.60 EUR
egress: 0 × 0.09 = 0.00 EUR
→ subtotal: 24.00 EUR
Record 3 (active, 11 days):
vcpus: (15840/60) × 4 × 0.02 × 1.0 = 21.12 EUR
ram_gb: (15840/60) × 8 × 0.005 × 1.0 = 10.56 EUR
disk_gb:(15840/60) × 80 × 0.001 × 1.0 = 21.12 EUR
egress: 22.5 × 0.09 = 2.03 EUR
→ subtotal: 54.83 EURStep 3: rating output
The rating output aggregates per resource and shows the state breakdown:
{
"billing_period": {
"from": "2026-03-01T00:00:00Z",
"to": "2026-04-01T00:00:00Z"
},
"project_id": "proj-456",
"platform": "openstack",
"line_items": [
{
"resource_type": "instance",
"resource_id": "abc-123",
"platform": "openstack",
"description": "m1.large instance",
"periods": [
{
"state": "active",
"hours": 240,
"usage": { "vcpus": 4, "ram_gb": 8, "disk_gb": 80, "egress_gb": 18.0 },
"cost": { "vcpus": 19.20, "ram_gb": 9.60, "disk_gb": 19.20, "egress_gb": 1.62, "total": 49.62 },
"state_modifier": 1.0
},
{
"state": "shutoff",
"hours": 240,
"usage": { "vcpus": 4, "ram_gb": 8, "disk_gb": 80, "egress_gb": 0 },
"cost": { "vcpus": 9.60, "ram_gb": 4.80, "disk_gb": 9.60, "egress_gb": 0, "total": 24.00 },
"state_modifier": 0.5
},
{
"state": "active",
"hours": 264,
"usage": { "vcpus": 4, "ram_gb": 8, "disk_gb": 80, "egress_gb": 22.5 },
"cost": { "vcpus": 21.12, "ram_gb": 10.56, "disk_gb": 21.12, "egress_gb": 2.03, "total": 54.83 },
"state_modifier": 1.0
}
],
"total": 128.45
}
],
"related_costs": [],
"total": 128.45,
"currency": "EUR"
}A VM that runs the entire month of March (744 hours) at full price costs 148.80 EUR plus egress. With ten days powered off at the 50% modifier, the total drops to 128.45 EUR. A shelved VM (state_modifier: 0.0) costs 0 EUR for the shelved period.
The credit that follows from the same power cycle is the golden case correction_credit. It bills the month as one active interval, finalizes it, and then corrects it with the power cycle arriving late. The three deltas add up to a credit of 24.00 EUR. That case carries no expected.json: its expectations live in the golden integration test.
Related costs: Gardener and OpenStack
A Gardener shoot is billed to its project as a management fee, and the worker VM it runs on is billed as a related cost of that project rather than hidden in the shoot price (see project registry, relations and exclusive attribution). The golden case is related_costs, which bills shoot-abc and worker-1 for 44640 minutes each.
{
"billing_period": {
"from": "2026-03-01T00:00:00Z",
"to": "2026-04-01T00:00:00Z"
},
"project_id": "team-alpha",
"platform": "gardener",
"line_items": [
{
"resource_type": "shoot",
"resource_id": "shoot-abc",
"platform": "gardener",
"description": "Shoot cluster shoot-abc (management fee)",
"periods": [
{ "state": "active", "hours": 744, "usage": { "worker_count": 3 },
"cost": { "worker_count": 223.20, "total": 223.20 }, "state_modifier": 1.0 }
],
"total": 223.20
}
],
"related_costs": [
{
"relation_type": "infrastructure_tenant",
"project_id": "shoot-abc-os-tenant",
"platform": "openstack",
"line_items": [
{
"resource_type": "instance",
"resource_id": "worker-1",
"platform": "openstack",
"description": "m1.xlarge worker node",
"periods": [
{ "state": "active", "hours": 744,
"usage": { "vcpus": 8, "ram_gb": 16, "disk_gb": 160 },
"cost": { "vcpus": 119.04, "ram_gb": 59.52, "disk_gb": 119.04, "total": 297.60 },
"state_modifier": 1.0 }
],
"total": 297.60
}
],
"total": 297.60
}
],
"total": 520.80,
"currency": "EUR"
}