Policy Administration Point (PAP) Architecture

The Policy Administration Point (PAP) keeps track of PDPs, supporting the deployment of PDP groups and the deployment of policies across those PDP groups. Policies are created using the Policy API, but are deployed via the PAP.

The PAP is stateless in a RESTful sense, using the database (persistent storage) to track PDPs and the deployment of policies to those PDPs. In short, policy management on PDPs is the responsibility of PAP; management of policies by any other manner is not permitted.

Because the PDP is the main unit of scalability in the Policy Framework, the framework is designed to allow PDPs in a PDP group to arbitrarily appear and disappear and for policy consistency across all PDPs in a PDP group to be easily maintained. The PAP is responsible for controlling the state across the PDPs in a PDP group. The PAP interacts with the policy database and transfers policies to PDPs.

The unit of execution and scaling in the Policy Framework is a PolicyImpl entity. A PolicyImpl entity runs on a PDP. As is explained above, a PolicyImpl entity is a PolicyTypeImpl implementation parameterized with a TOSCA Policy.

../_images/PolicyImplPDPSubGroup.svg

In order to achieve horizontal scalability, we group the PDPs running instances of a given PolicyImpl entity logically together into a PDPSubGroup. The number of PDPs in a PDPSubGroup can then be scaled up and down using Kubernetes. In other words, all PDPs in a subgroup run the same PolicyImpl, that is the same policy template implementation (in XACML, Drools, or APEX) with the same parameters.

The figure above shows the layout of PDPGroup and PDPSubGroup entities. The figure shows examples of PDP groups for Control Loop and Monitoring policies on the right.

The health of PDPs is monitored by the PAP in order to alert operations teams managing policies. The PAP manages the life cycle of policies running on PDPs.

The table below shows the deployment methods in which PolicyImpl entities can be deployed to PDP Subgroups.

Method Description Advantages Disadvantages
Cold

The PolicyImpl (PolicyTypeImpl and TOSCA Policy) are predeployed on the PDP. PDP is fully configured and ready to execute when started.

PDPs register with the PAP when they start, providing the pdpGroup they have been preconfigured with.

No run time configuration required and run time administration is simple. Very restrictive, no run time configuration of PDPs is possible.
Warm

The PolicyTypeImpl entity is predeployed on the PDP. A TOSCA Policy may be loaded at startup. The PDP may be configured or reconfigured with a new or updated TOSCA Policy at run time.

PDPs register with the PAP when they start, providing the pdpGroup they have been predeployed with if any. The PAP may update the TOSCA Policy on a PDP at any time after registration.

The configuration, parameters, and PDP group of PDPs may be changed at run time by loading or updating a TOSCA Policy into the PDP.

Support TOSCA Policy entity life cycle managgement is supported, allowing features such as PolicyImpl Safe Mode and PolicyImpl retirement.

Administration and management is required. The configuration and life cycle of the TOSCA policies can change at run time and must be administered and managed.
Hot

The PolicyImpl (PolicyTypeImpl and TOSCA Policy) are deployed at run time. The PolicyImpl (PolicyTypeImpl and TOSCA Policy) may be loaded at startup. The PDP may be configured or reconfigured with a new or updated PolicyTypeImpl and/or TOSCA Policy at run time.

PDPs register with the PAP when they start, providing the pdpGroup they have been preconfigured with if any. The PAP may update the TOSCA Policy and PolicyTypeImpl on a PDP at any time after registration

The policy logic, rules, configuration, parameters, and PDP group of PDPs may be changed at run time by loading or updating a TOSCA Policy and PolicyTypeImpl into the PDP.

Lifecycle management of TOSCA Policy entities and PolicyTypeImpl entites is supported, allowing features such as PolicyImpl Safe Mode and PolicyImpl retirement.

Administration and management is more complex. The PolicyImpl itself and its configuration and life cycle as well as the life cycle of the TOSCA policies can change at run time and must be administered and managed.

1 APIs

The APIs in the subchapters below are supported by the PAP.

1.1 REST API

The purpose of this API is to support CRUD of PDP groups and subgroups and to support the deployment and life cycles of policies on PDP sub groups and PDPs. This API is provided by the PolicyAdministration component (PAP) of the Policy Framework, see the ONAP Policy Framework Architecture page.

PDP groups and subgroups may be prefedined in the system. Predefined groups and subgroups may be modified or deleted over this API. The policies running on predefined groups or subgroups as well as the instance counts and properties may also be modified.

A PDP may be preconfigured with its PDP group, PDP subgroup, and policies. The PDP sends this information to the PAP when it starts. If the PDP group, subgroup, or any policy is unknown to the PAP, the PAP locks the PDP in state PASSIVE.

PAP supports the operations listed in the following table, via its REST API:

Operation Description
Health check Queries the health of the PAP
Consolidated healthcheck Queries the health of all policy components
Statistics Queries various statistics
PDP state change Changes the state of all PDPs in a PDP Group
PDP Group create/update Creates/updates PDP Groups
PDP Group delete Deletes a PDP Group
PDP Group query Queries all PDP Groups
Deployment update Deploy/undeploy one or more policies in specified PdpGroups
Deploy policy Deploys one or more policies to the PDPs
Undeploy policy Undeploys a policy from the PDPs
Policy deployment status Queries the status of all deployed policies
PDP statistics Queries the statistics of PDPs

1.2 DMaaP API

PAP interacts with the PDPs via the DMaaP Message Router. The messages listed in the following table are transmitted via DMaaP:

Message Direction Description
PDP status Incoming Registers a PDP with PAP; also sent as a periodic heart beat; also sent in response to requests from the PAP
PDP update Outgoing Assigns a PDP to a PDP Group and Subgroup; also deploys or undeploys policies from the PDP
PDP state change Outgoing Changes the state of a PDP or all PDPs within a PDP Group or Subgroup

In addition, PAP generates notifications via the DMaaP Message Router when policies are successfully or unsuccessfully deployed (or undeployed) from all relevant PDPs.

Here is a sample notification:

{
    "deployed-policies": [
        {
            "policy-type": "onap.policies.monitoring.cdap.tca.hi.lo.app",
            "policy-type-version": "1.0.0",
            "policy-id": "onap.scaleout.tca",
            "policy-version": "2.0.0",
            "success-count": 3,
            "failure-count": 0
        }
    ],
    "undeployed-policies": [
        {
            "policy-type": "onap.policies.firewall",
            "policy-type-version": "1.0.0",
            "policy-id": "onap.firewall.tca",
            "policy-version": "6.0.0",
            "success-count": 3,
            "failure-count": 0
        }
    ]
}

2 PAP REST API Swagger

It is worth noting that we use basic authorization for access with user name and password set to healthcheck and zb!XztG34, respectively.

For every call, the client is encouraged to insert a uuid-type requestID as parameter. It is helpful for tracking each http transaction and facilitates debugging. More importantly, it complies with Logging requirements v1.2. If the client does not provide the requestID in a call, one will be randomly generated and attached to the response header, x-onap-requestid.

In accordance with ONAP API Common Versioning Strategy Guidelines, several custom headers are added in the response to each call:

Header Example value Description
x-latestversion 1.0.0 latest version of the API
x-minorversion 0 MINOR version of the API
x-patchversion 0 PATCH version of the API
x-onap-requestid e1763e61-9eef-4911-b952-1be1edd9812b described above; used for logging purposes

Download Health Check PAP API Swagger

This operation performs a health check on the PAP.

Here is a sample response:

{
    "code": 200,
    "healthy": true,
    "message": "alive",
    "name": "Policy PAP",
    "url": "self"
}

Download Consolidated Health Check PAP API Swagger

This operation performs a health check of all policy components. The response contains the health check result of each component. The consolidated health check is reported as healthy only if all the components are healthy, otherwise the “healthy” flag is marked as false.

Here is a sample response:

{
  "pdps": {
    "xacml": [
      {
        "instanceId": "dev-policy-xacml-pdp-5b6697c845-9j8lb",
        "pdpState": "ACTIVE",
        "healthy": "HEALTHY"
      }
    ],
    "drools": [
      {
        "instanceId": "dev-drools-0",
        "pdpState": "ACTIVE",
        "healthy": "HEALTHY"
      }
    ],
    "apex": [
      {
        "instanceId": "dev-policy-apex-pdp-0",
        "pdpState": "ACTIVE",
        "healthy": "HEALTHY",
        "message": "Pdp Heartbeat"
      }
    ]
  },
  "healthy": true,
  "api": {
    "name": "Policy API",
    "url": "https://dev-policy-api-7fb479754f-7nr5s:6969/policy/api/v1/healthcheck",
    "healthy": true,
    "code": 200,
    "message": "alive"
  },
  "distribution": {
    "name": "Policy SSD",
    "url": "https://dev-policy-distribution-84854cd6c7-zn8vh:6969/healthcheck",
    "healthy": true,
    "code": 200,
    "message": "alive"
  },
  "pap": {
    "name": "Policy PAP",
    "url": "https://dev-pap-79fd8f78d4-hwx7j:6969/policy/pap/v1/healthcheck",
    "healthy": true,
    "code": 200,
    "message": "alive"
  }
}

Download Statistics PAP API Swagger

This operation allows statistics for PDP groups, PDP subgroups, and individual PDPs to be retrieved.

Note

While this API is supported, most of the statistics are not currently updated; that work has been deferred to a later release.

Here is a sample response:

{
    "code": 200,
    "policyDeployFailureCount": 0,
    "policyDeploySuccessCount": 0,
    "policyDownloadFailureCount": 0,
    "policyDownloadSuccessCount": 0,
    "totalPdpCount": 0,
    "totalPdpGroupCount": 0,
    "totalPolicyDeployCount": 0,
    "totalPolicyDownloadCount": 0
}

Download State Change PAP Swagger

The state of PDP groups is managed by this operation. PDP groups can be in states PASSIVE, TEST, SAFE, or ACTIVE. For a full description of PDP group states, see the ONAP Policy Framework Architecture page.

Download Group Batch PAP API Swagger

This operation allows the PDP groups and subgroups to be created and updated. Many PDP groups can be created or updated in a single POST operation by specifying more than one PDP group in the POST operation body. This can be used to create the PDP group by providing all the details including the supported policy types for each subgroup. However, it cannot be used to update policies; that is done using one of the deployment requests. Consequently, the “policies” property of this request will be ignored. This can also be used to update a PDP Group, but supported policy types cannot be updated during the update operation. So, “policies” and “supportedPolicyTypes” properties in the request will be ignored if provided during the PDP Group update operation.

Note

If a subgroup is to be deleted from a PDP Group, then the policies must be removed from the subgroup first.

Note

Policies cannot be added/updated during PDP Group create/update operations. So, if provided, they are ignored. Supported policy types are defined during PDP Group creation. They cannot be updated once they are created. So, supportedPolicyTypes are expected during PDP Group create, but ignored if provided during PDP Group update.

Here is a sample request:

{
    "groups": [
        {
            "name": "SampleGroup",
            "pdpGroupState": "ACTIVE",
            "properties": {},
            "pdpSubgroups": [
                {
                    "pdpType": "apex",
                    "desiredInstanceCount": 2,
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.controlloop.operational.Apex",
                            "version": "1.0.0"
                        }
                    ],
                    "policies": []
                },
                {
                    "pdpType": "xacml",
                    "desiredInstanceCount": 1,
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.monitoring.cdap.tca.hi.lo.app",
                            "version": "1.0.0"
                        }
                    ],
                    "policies": []
                }
            ]
        }
    ]
}

Download Group Delete PAP API Swagger

The API also allows PDP groups to be deleted. DELETE operations are only permitted on PDP groups in PASSIVE state.

Download Group Query PAP API Swagger

This operation allows the PDP groups and subgroups to be listed as well as the policies that are deployed on each PDP group and subgroup.

Here is a sample response:

{
    "groups": [
        {
            "description": "This group should be used for managing all control loop related policies and pdps",
            "name": "controlloop",
            "pdpGroupState": "ACTIVE",
            "pdpSubgroups": [
                {
                    "currentInstanceCount": 0,
                    "desiredInstanceCount": 1,
                    "pdpInstances": [],
                    "pdpType": "apex",
                    "policies": [],
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.controlloop.Operational",
                            "version": "1.0.0"
                        }
                    ]
                },
                {
                    "currentInstanceCount": 0,
                    "desiredInstanceCount": 1,
                    "pdpInstances": [],
                    "pdpType": "drools",
                    "policies": [],
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.controlloop.Operational",
                            "version": "1.0.0"
                        }
                    ]
                },
                {
                    "currentInstanceCount": 0,
                    "desiredInstanceCount": 1,
                    "pdpInstances": [],
                    "pdpType": "xacml",
                    "policies": [],
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.controlloop.Guard",
                            "version": "1.0.0"
                        }
                    ]
                }
            ],
            "properties": {}
        },
        {
            "description": "This group should be used for managing all monitoring related policies and pdps",
            "name": "monitoring",
            "pdpGroupState": "ACTIVE",
            "pdpSubgroups": [
                {
                    "currentInstanceCount": 0,
                    "desiredInstanceCount": 1,
                    "pdpInstances": [],
                    "pdpType": "xacml",
                    "policies": [],
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.Monitoring",
                            "version": "1.0.0"
                        }
                    ]
                }
            ],
            "properties": {}
        },
        {
            "description": "The default group that registers all supported policy types and pdps.",
            "name": "defaultGroup",
            "pdpGroupState": "ACTIVE",
            "pdpSubgroups": [
                {
                    "currentInstanceCount": 0,
                    "desiredInstanceCount": 1,
                    "pdpInstances": [],
                    "pdpType": "apex",
                    "policies": [],
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.controlloop.operational.Apex",
                            "version": "1.0.0"
                        }
                    ]
                },
                {
                    "currentInstanceCount": 0,
                    "desiredInstanceCount": 1,
                    "pdpInstances": [],
                    "pdpType": "drools",
                    "policies": [],
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.controlloop.Operational",
                            "version": "1.0.0"
                        }
                    ]
                },
                {
                    "currentInstanceCount": 0,
                    "desiredInstanceCount": 1,
                    "pdpInstances": [],
                    "pdpType": "xacml",
                    "policies": [],
                    "properties": {},
                    "supportedPolicyTypes": [
                        {
                            "name": "onap.policies.controlloop.guard.FrequencyLimiter",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.controlloop.guard.MinMax",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.controlloop.guard.Blacklist",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.controlloop.guard.coordination.FirstBlocksSecond",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.Monitoring",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.monitoring.*",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.AffinityPolicy",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.DistancePolicy",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.HpaPolicy",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.OptimizationPolicy",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.PciPolicy",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.QueryPolicy",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.SubscriberPolicy",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.Vim_fit",
                            "version": "1.0.0"
                        },
                        {
                            "name": "onap.policies.optimization.VnfPolicy",
                            "version": "1.0.0"
                        }
                    ]
                }
            ],
            "properties": {}
        }
    ]
}

Download Deployments Batch PAP API Swagger

This operation allows policies to be deployed on specific PDP groups. Each subgroup includes an “action” property, which is used to indicate that the policies are being added (POST) to the subgroup, deleted (DELETE) from the subgroup, or that the subgroup’s entire set of policies is being replaced (PATCH) by a new set of policies. As such, a subgroup may appear more than once in a single request, one time to delete some policies and another time to add new policies to the same subgroup.

Here is a sample request:

{
    "groups": [
        {
            "name": "SampleGroup",
            "deploymentSubgroups": [
                {
                    "pdpType": "apex",
                    "action": "POST",
                    "policies": [
                        {
                            "name": "onap.controllloop.operational.apex.bbs.EastRegion",
                            "version": "1.0.0"
                        }
                    ]
                }
            ]
        }
    ]
}

Download Deploy PAP API Swagger

This operation allows policies to be deployed across all relevant PDP groups. PAP will deploy the specified policies to all relevant subgroups. Only the policies supported by a given subgroup will be deployed to that subgroup.

Note

The policy version is optional. If left unspecified, then the latest version of the policy is deployed. On the other hand, if it is specified, it may be an integer, or it may be a fully qualified version (e.g., “3.0.2”). In addition, a subgroup to which a policy is being deployed must have at least one PDP instance, otherwise the request will be rejected.

Here is a sample request:

{
  "policies": [
    {
      "policy-id": "onap.scaleout.tca",
      "policy-version": 1
    },
    {
      "policy-id": "ControlLoop-vDNS-6f37f56d-a87d-4b85-b6a9-cc953cf779b3"
    },
    {
      "policy-id": "guard.frequency.ControlLoop-vDNS-6f37f56d-a87d-4b85-b6a9-cc953cf779b3"
    },
    {
      "policy-id": "guard.minmax.ControlLoop-vDNS-6f37f56d-a87d-4b85-b6a9-cc953cf779b3"
    }
  ]
}

Download Undeploy PAP API Swagger

This operation allows policies to be undeployed from PDP groups.

Note

If the policy version is specified, then it may be an integer, or it may be a fully qualified version (e.g., “3.0.2”). On the other hand, if left unspecified, then the latest deployed version will be undeployed.

Note

Due to current limitations, a fully qualified policy version must always be specified.

Download Deployed Policy PAP API Swagger

This operation allows the deployed policies to be listed together with their respective deployment status. The result can be filtered based on policy name & version.

Here is a sample response:

[
  {
    "policy-type": "onap.policies.monitoring.cdap.tca.hi.lo.app",
    "policy-type-version": "1.0.0",
    "policy-id": "MICROSERVICE_vFW_CDS_Service_v2_0_app_1_0_0_I95",
    "policy-version": "1.0.0",
    "success-count": 1,
    "failure-count": 0,
    "incomplete-count": 0
  },
  {
    "policy-type": "onap.policies.controlloop.Operational",
    "policy-type-version": "1.0.0",
    "policy-id": "OPERATIONAL_vFW_CDS_Service_v2_0_OperationalPolicyLegacy_1_0_0_Ly6",
    "policy-version": "1.0.0",
    "success-count": 1,
    "failure-count": 0,
    "incomplete-count": 0
  },
  {
    "policy-type": "onap.policies.monitoring.cdap.tca.hi.lo.app",
    "policy-type-version": "1.0.0",
    "policy-id": "MICROSERVICE_vFW_CDS_Service_v2_0_app_1_0_0_WNX",
    "policy-version": "1.0.0",
    "success-count": 1,
    "failure-count": 0,
    "incomplete-count": 0
  },
  {
    "policy-type": "onap.policies.controlloop.operational.common.Drools",
    "policy-type-version": "1.0.0",
    "policy-id": "OPERATIONAL_vFW_CDS_Service_v2_0_Drools_1_0_0_6SN",
    "policy-version": "1.0.0",
    "success-count": 1,
    "failure-count": 0,
    "incomplete-count": 0
  }
]

Download PDP Statistics PAP API Swagger

This operation allows the PDP statistics to be retrieved for all registered PDPs. The result can be filtered based on PDP group, PDP subgroup & PDP instance.

Here is a sample response:

{
  "defaultGroup": {
    "apex": [
      {
        "pdpInstanceId": "dev-policy-apex-pdp-0",
        "timeStamp": "Apr 29, 2020, 6:15:29 PM",
        "pdpGroupName": "defaultGroup",
        "pdpSubGroupName": "apex",
        "policyDeployCount": 0,
        "policyDeploySuccessCount": 0,
        "policyDeployFailCount": 0,
        "policyExecutedCount": 0,
        "policyExecutedSuccessCount": 0,
        "policyExecutedFailCount": 0,
        "engineStats": []
      },
      {
        "pdpInstanceId": "dev-policy-apex-pdp-0",
        "timeStamp": "Apr 29, 2020, 6:17:29 PM",
        "pdpGroupName": "defaultGroup",
        "pdpSubGroupName": "apex",
        "policyDeployCount": 0,
        "policyDeploySuccessCount": 0,
        "policyDeployFailCount": 0,
        "policyExecutedCount": 0,
        "policyExecutedSuccessCount": 0,
        "policyExecutedFailCount": 0,
        "engineStats": []
      },
      {
        "pdpInstanceId": "dev-policy-apex-pdp-0",
        "timeStamp": "Apr 29, 2020, 6:19:29 PM",
        "pdpGroupName": "defaultGroup",
        "pdpSubGroupName": "apex",
        "policyDeployCount": 0,
        "policyDeploySuccessCount": 0,
        "policyDeployFailCount": 0,
        "policyExecutedCount": 0,
        "policyExecutedSuccessCount": 0,
        "policyExecutedFailCount": 0,
        "engineStats": []
      }
    ]
  }
}

3.1 Disable policies in PDP

This operation will allow disabling individual policies running in PDP engine. It is mainly beneficial in scenarios where network operators/administrators want to disable a particular policy in PDP engine for a period of time due to a failure in the system or for scheduled maintenance.

End of Document