2.1. Hyper-Distributed Application Graph
The HDAG is the top-most artifact used by the SMO in order to deploy an HDA as a combination of vertical apps, VOs and cVOs (as shown in the figure). It provides information about deployment which combines custom intent-orchestration mechanism with the configuration of the services for the specific deployment.
HDAG overview
The HDAG descriptor provides the key elements which contain the required information for the NEPHELE Platform to orchestrate an HDA, including intent, monitoring, artifact references and instantiation-time customizations.
2.1.1. Technologies
The HDAG is a simple descriptor which only requires the following background information:
JSONSChema Syntax (You can visualize it here )
2.1.2. Artifact Structure
Composed of a single artifact inside a parent folder.
HDAG artifact
2.1.3. Data Models
The descriptor contains a service chain with all the required information for the Nephele SMO Platform to orchestrate and manage it.
e.g.,
The HDAG descriptor is defined using a JSONSChema to ensure that the Nephele Platform works as expected.
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"hdaGraph": {
"type": "object",
"properties": {
"imVersion": {
"type": "string",
"enum": [
"0.4.0"
]
},
"id": {
"type": "string"
},
"version": {
"type": "string",
"pattern": "^(0|[1-9]\\d*)\\.(0|[1-9]\\d*)\\.(0|[1-9]\\d*)(?:-((?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\\.(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\\+([0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-]+)*))?$"
},
"designer": {
"type": "string"
},
"description": {
"type": "string"
},
"hdaGraphIntent":{
"type": "object",
"properties": {
"security": {
"type": "object",
"properties": {
"enabled": {
"type": "boolean",
"description": "Either colocation either VO-related security either app-graph deployed using the same Blueprint"
}
},
"required": ["enabled"],
"description": "Security settings related to colocation, VO-related security, or app-graph deployment"
},
"highAvailability": {
"type": "object",
"properties": {
"enabled": {
"type": "boolean",
"description": "Application graph is not considered for reconfigurations. Placement is final"
}
},
"required": ["enabled"],
"description": "High availability settings for the application graph"
},
"highPerformance": {
"type": "object",
"properties": {
"enabled": {
"type": "boolean",
"description": "Defined end-to-end for all services. If selected, overwrites the per service latency qos intent"
}
},
"required": ["enabled"],
"description": "High performance settings for all services, potentially overwriting service-specific latency QoS intent"
},
"energyEfficiency": {
"type": "object",
"properties": {
"enabled": {
"type": "boolean",
"description": "Cost reduction of cloud-deployed services"
}
},
"required": ["enabled"],
"description": "Energy efficiency settings for reducing the cost of cloud-deployed services"
}
},
"required": ["security", "highAvailability", "highPerformance", "energyEfficiency"],
"description": "Configuration object for various service settings related to security, availability, performance, and energy efficiency"
},
"services": {
"type": "array",
"minItems": 1,
"items": {
"type": "object",
"properties": {
"id": {
"type": "string"
},
"deployment": {
"type": "object",
"properties": {
"trigger": {
"type": "object",
"oneOf": [
{
"properties": {
"auto": {
"type": "object",
"properties": {
"dependencies": {
"type": "array",
"minItems": 0,
"items": {
"type": "object",
"properties": {
"serviceId": {
"type": "string"
}
},
"additionalProperties": false,
"required": [
"serviceId"
]
}
}
},
"additionalProperties": false
}
},
"additionalProperties": false
},
{
"properties": {
"event": {
"type": "object",
"properties": {
"condition": {
"type": "string"
},
"events": {
"type": "array",
"minItems": 1,
"items": {
"type": "object",
"properties": {
"id": {
"type": "string"
},
"source": {
"type": "array",
"minItems": 1,
"items": {
"type": "object",
"properties": {
"serviceId": {
"type": "string"
},
"metricId": {
"type": "string"
}
},
"additionalProperties": false,
"required": [
"serviceId",
"metricId"
]
}
},
"condition": {
"type": "object",
"properties": {
"promQuery": {
"type": "string"
},
"description": {
"type": "string"
},
"gracePeriod": {
"type": "string"
}
},
"required": [
"gracePeriod",
"promQuery",
"description"
]
}
},
"additionalProperties": false,
"required": [
"id",
"source",
"condition"
]
}
}
},
"required": [
"condition",
"events"
],
"additionalProperties": false
}
},
"required": [
"event"
],
"additionalProperties": false
}
]
},
"intent": {
"type": "object",
"properties": {
"network": {
"type": "object",
"properties": {
"deviceProximity": {
"type": "object",
"properties": {
"enabled": {
"type": "boolean",
"description": "If true, enable TSN. Only relevant for the VO"
}
},
"required": ["enabled"],
"description": "Device proximity settings for VO"
},
"latencies": {
"type": "array",
"items": {
"type": "object",
"properties": {
"connectionPoint": {
"type": "string",
"description": "Relevant for the next service in the application graph"
},
"qos": {
"type": "string",
"enum": ["ultralow", "low", "best-effort"],
"description": "\"ultralow\" - under 10ms, \"low\" - 1hop maximum, \"best-effort\" - default value"
}
},
"required": ["connectionPoint", "qos"],
"description": "Latency settings for the connection point in the application graph"
},
"description": "Latency settings related to connection and QoS for the application graph"
}
},
"required": ["deviceProximity", "latencies"],
"description": "Network configurations for services, including device proximity and latency settings"
},
"compute": {
"type": "object",
"properties": {
"cpu": {
"type": "string",
"enum": ["light", "small", "medium", "large"],
"description": "\"light\" - 0.5 vCPU, \"small\" - 1 vCPU, \"medium\" - 4 vCPU, \"large\" - 8 vCPU"
},
"ram": {
"type": "string",
"enum": ["light", "small", "medium", "large"],
"description": "\"light\" - 500MB RAM, \"small\" - 1 GB RAM, \"medium\" - 2 GB RAM, \"large\" - 8 GB RAM"
},
"storage": {
"type": "string",
"enum": ["small", "medium", "large"],
"description": "\"small\" - 10GB, \"medium\" - 20GB, \"large\" - 40GB"
},
"gpu": {
"type": "object",
"properties": {
"enabled": {
"type": "boolean",
"description": "If true, GPU is enabled"
}
},
"required": ["enabled"],
"description": "GPU settings for compute resources"
}
},
"required": ["cpu", "ram", "storage", "gpu"],
"description": "Compute resource settings, including CPU, RAM, storage, and GPU configurations"
},
"connectionPoints": {
"type": "array",
"minItems": 0,
"items": {
"type": "string"
}
},
"coLocation": {
"type": "array",
"minItems": 0,
"items": {
"type": "object"
},
"properties": {
"id": {
"type": "string"
},
"groundedGraphId": {
"type": "string"
}
},
"required": [
"id"
],
"additionalProperties": false
},
"metrics": {
"type": "array",
"items": {
"type": "object",
"properties": {
"id": {
"type": "string",
"description": "Identifier used for events"
},
"metricName": {
"type": "string",
"description": "Name of metric exposed to Prometheus"
},
"selector": {
"type": "object",
"description": "The target service (label). Cannot be to a pod directly, has to point to the service",
"additionalProperties": {
"type": "string"
}
},
"endpoint": {
"type": "object",
"description": "Information about the endpoint",
"properties": {
"port": {
"type": "string",
"description": "Name of exposed port"
},
"interval": {
"type": "string",
"description": "Scraping period of Prometheus"
}
},
"required": [
"port",
"interval"
],
"additionalProperties": false
}
},
"required": [
"id",
"metricName",
"selector",
"endpoint"
],
"additionalProperties": false
}
}
},
"required": [
"compute",
"network",
"coLocation",
"connectionPoints"
],
"additionalProperties": false
}
},
"required": [
"trigger",
"intent"
],
"additionalProperties": true
},
"artifact": {
"type": "object",
"properties": {
"ociImage": {
"type": "string"
},
"ociConfig": {
"type": "object",
"properties": {
"type": {
"type": "string"
},
"implementer": {
"type": "string"
}
},
"required": [
"type",
"implementer"
],
"additionalProperties": false
},
"ociRun": {
"type": "object",
"properties": {
"name": {
"type": "string"
},
"version": {
"type": "string"
}
},
"required": [
"name",
"version"
],
"additionalProperties": false
}
},
"required": [
"ociImage",
"ociConfig",
"ociRun"
],
"additionalProperties": true
}
},
"required": [
"id",
"deployment",
"artifact"
]
}
}
},
"additionalProperties": false,
"required": [
"imVersion",
"designer",
"version",
"hdaGraphIntent",
"description",
"services"
]
}
},
"additionalProperties": false,
"required": [
"hdaGraph"
]
}
2.1.4. OCI manifests
2.1.4.1. Image manifest
It follows the standard container manifest structure.
E.g.
{ "schemaVersion": 2, "mediaType": "application/vnd.oci.image.manifest.v1+json", "config": { "mediaType": "application/vnd.nephele.hdag.config.v1+json", "digest": "sha256:8bcbbfb98ab93d80fb25343aabf46efe595fb05b21ad97d1e394ee5e08b30ae0", "size": 421 }, "layers": [ { "mediaType": "application/tar+gzip", "digest": "sha256:06698addaa5d783bacfb18c2ecddf09bb3b7c2c846fbe09a4db003f4ecaad352", "size": 1117, "annotations": { "org.opencontainers.image.title": "myfirsthdag-0.1.0.tar.gz" } } ], "annotations": { "org.opencontainers.image.authors": "NEPHELE", "org.opencontainers.image.created": "2024-09-23T15:01:20Z", "org.opencontainers.image.description": "This is my first artifact", "org.opencontainers.image.title": "myfirsthdag", "org.opencontainers.image.version": "0.1.0" } }
2.1.4.2. Config manifest
The Config OCI manifest is what Nephele uses to characterize the HDAG without the need of extracting all the contents from the artifact. HDAGs have the application/vnd.nephele.hdag.config.v1+json mediaType.
- E.g.,
This json follows a standard structure defined by the following jsonschema
{ "$schema": "http://json-schema.org/draft-07/schema#", "title": "HDAG Configuration Schema", "type": "object", "properties": { "schemaVersion": { "type": "string", "enum": ["0.4.0"], "description": "Schema version" }, "configMediaType": { "type": "string", "enum": ["application/vnd.nephele.hdag.config.v1+json"], "description": "Media type for the HDAG configuration." }, "artifactType": { "type": "string", "enum": ["HDAG"], "description": "Type of the artifact, must be 'HDAG'." }, "dataModelSpec": { "type": "string", "pattern": "^[0-9]+\\.[0-9]+\\.[0-9]+$", "description": "Data model specification version in semantic version format." }, "descriptor": { "type": "object", "properties": { "name": { "type": "string", "description": "Path to the descriptor file." }, "id": { "type": "string", "description": "ID of the descriptor." }, "version": { "type": "string", "pattern": "^[0-9]+\\.[0-9]+\\.[0-9]+$", "description": "Version of the descriptor in semantic version format." } }, "required": ["name", "id", "version"] }, "dependencies": { "type": "array", "items": { "type": "object", "properties": { "artifactType": { "type": "string", "enum": ["VO"], "description": "Artifact type, must be 'VO'." }, "ref": { "type": "string", "format": "uri", "description": "Reference URL for the dependency." }, "location": { "type": "string", "enum": ["external", "internal"], "description": "Location of the dependency." }, "mode": { "type": "string", "enum": ["hard", "soft"], "description": "Mode of the dependency." } }, "required": ["artifactType", "ref", "location", "mode"] } } }, "required": [ "schemaVersion", "configMediaType", "artifactType", "dataModelSpec", "descriptor", "dependencies" ] }
2.1.5. How to create one
The creation of an HDAG can be done in two ways:
The create command of the hdarctl tool offers the options shown in the figure below to obtain a baseline descriptor, which only requires a few additional configurations to be pushed to the HDAR.
The Dashboard offers a UI which presents a user-friendly and intuitive form to generate the baseline HDAG in an analogous way as what the hdarctl does. Then, the user can configure the remaining details via the UI, allowing the Dashboard to interact with the HDAR and automatically push the configurations.
hdarctl create comand