.. contents::
:depth: 3
-The PAP keeps track of PDPs, supporting the deployment of PDP groups and the deployment of a *policy set* across those
-PDP groups. Policies are created using the Policy API, but are deployed via the PAP.
+.. toctree::
+ InternalPapPdp.rst
-A 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 PAPs; management of policy sets or
-policies by any other manner is not permitted.
+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 policy sets to PDPs.
-
-There are a number of rules for PDP group and PDP state management:
-
-1. Only one version of a PDP group may be ACTIVE at any time
-
-2. If a PDP group with a certain version is ACTIVE and a later version of the same PDP group is activated, then the
- system upgrades the PDP group
-
-3. If a PDP group with a certain version is ACTIVE and an earlier version of the same PDP group is activated, then the
- system downgrades the PDP group
-
-4. There is no restriction on the number of PASSIVE versions of a PDP group that can exist in the system
+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*.
+
+.. image:: 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 No run time configuration Very restrictive, no run time
+ TOSCA *Policy*) are predeployed on the PDP. required and run time configuration of PDPs is possible.
+ PDP is fully configured and ready to administration is simple.
+ execute when started.
+
+ PDPs register with the PAP when they
+ start, providing the *pdpGroup* they
+ have been preconfigured with.
+
+Warm The *PolicyTypeImpl* entity is predeployed The configuration, parameters, Administration and management is
+ on the PDP. A TOSCA *Policy* may be loaded and PDP group of PDPs may be required. The configuration and
+ at startup. The PDP may be configured or changed at run time by loading life cycle of the TOSCA policies
+ reconfigured with a new or updated TOSCA or updating a TOSCA *Policy* can change at run time and must be
+ *Policy* at run time. into the PDP. administered and managed.
+
+ PDPs register with the PAP when they start, Support TOSCA *Policy* entity
+ providing the *pdpGroup* they have been life cycle managgement is
+ predeployed with if any. The PAP may update supported, allowing features
+ the TOSCA *Policy* on a PDP at any time such as *PolicyImpl* Safe Mode
+ after registration. and *PolicyImpl* retirement.
+
+Hot The *PolicyImpl* (*PolicyTypeImpl* and The policy logic, rules, Administration and management is
+ TOSCA *Policy*) are deployed at run time. configuration, parameters, and more complex. The *PolicyImpl*
+ The *PolicyImpl* (*PolicyTypeImpl* and PDP group of PDPs may be itself and its configuration and
+ TOSCA *Policy*) may be loaded at startup. changed at run time by loading life cycle as well as the life
+ The PDP may be configured or reconfigured or updating a TOSCA *Policy* cycle of the TOSCA policies can
+ with a new or updated *PolicyTypeImpl* and *PolicyTypeImpl* into the change at run time and must be
+ and/or TOSCA *Policy* at run time. PDP. administered and managed.
+
+ PDPs register with the PAP when they Lifecycle management of TOSCA
+ start, providing the *pdpGroup* they have *Policy* entities and
+ been preconfigured with if any. The PAP may *PolicyTypeImpl* entites is
+ update the TOSCA *Policy* and supported, allowing features
+ *PolicyTypeImpl* on a PDP at any time after such as *PolicyImpl* Safe Mode
+ registration and *PolicyImpl* retirement.
+========== =========================================== ============================== ==================================
1 APIs
:widths: 25,70
"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
-------------
.. literalinclude:: response/health-check-pap-resp.json
:language: json
+.. swaggerv2doc:: swagger/consolidated-healthcheck-pap.json
+
+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:
+
+.. literalinclude:: response/consolidated-healthcheck-pap-resp.json
+ :language: json
+
.. swaggerv2doc:: swagger/statistics-pap.json
This operation allows statistics for PDP groups, PDP subgroups, and individual PDPs to be retrieved.
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 update the policy types supported by various subgroups.
+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 "policy" property of this
+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::
- Due to current limitations, if a subgroup is to be deleted from a PDP Group, then the policies must be removed from
+ 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:
.. literalinclude:: request/groups-batch-pap-req.json
.. note::
Due to current limitations, a fully qualified policy version must always be specified.
-
-3 Future Features
-=================
-3.1 Order Health Check on PDPs
-==============================
+.. swaggerv2doc:: swagger/deployed-policy-pap.json
+
+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:
+
+.. literalinclude:: response/deployed-policy-pap-resp.json
+ :language: json
+
+.. swaggerv2doc:: swagger/pdp-statistics-pap.json
-This operation will allow a PDP group health check to be ordered on PDP groups and on individual PDPs. The operation
-will return a HTTP status code of *202: Accepted* if the health check request has been accepted by the PAP. The PAP will
-then order execution of the health check on the PDPs.
+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:
+
+.. literalinclude:: response/pdp-statistics-pap-resp.json
+ :language: json
+
+
+3 Future Features
+=================
-As health checks may be long lived operations, Health checks will be scheduled for execution by this operation. Users
-will check the result of a health check test by issuing a PDP Group Query operation and checking the *healthy* field of
-PDPs.
+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