2.9.1. Doctor capabilities and usage

figure1 shows the currently implemented and tested architecture of Doctor. The implementation is based on OpenStack and related components. The Monitor can be realized by a sample Python-based implementation provided in the Doctor code repository. The Controller is realized by OpenStack Nova, Neutron and Cinder for compute, network and storage, respectively. The Inspector can be realized by OpenStack Congress, Vitrage or a sample Python-based implementation also available in the code repository of Doctor. The Notifier is realized by OpenStack Aodh.


Implemented and tested architecture Immediate Notification

Immediate notification can be used by creating ‘event’ type alarm via OpenStack Alarming (Aodh) API with relevant internal components support.

See: - Upstream spec document: https://specs.openstack.org/openstack/ceilometer-specs/specs/liberty/event-alarm-evaluator.html - Aodh official documentation: https://docs.openstack.org/aodh/latest

An example of a consumer of this notification can be found in the Doctor repository. It can be executed as follows:

git clone https://gerrit.opnfv.org/gerrit/doctor
cd doctor/doctor_tests/consumer
python sample.py "$CONSUMER_PORT" > consumer.log 2>&1 & Consistent resource state awareness

Resource state of compute host can be changed/updated according to a trigger from a monitor running outside of OpenStack Compute (Nova) by using force-down API.

See: * Upstream spec document: https://specs.openstack.org/openstack/nova-specs/specs/liberty/implemented/mark-host-down.html * Upstream Compute API reference document: https://developer.openstack.org/api-ref/compute * Doctor Mark Host Down Manual: https://git.opnfv.org/doctor/tree/docs/development/manuals/mark-host-down_manual.rst Valid compute host status given to VM owner

The resource state of a compute host can be retrieved by a user with the OpenStack Compute (Nova) servers API.

See: * Upstream spec document: https://specs.openstack.org/openstack/nova-specs/specs/mitaka/implemented/get-valid-server-state.html * Upstream Compute API reference document: https://developer.openstack.org/api-ref/compute * Doctor Get Valid Server State Manual: https://git.opnfv.org/doctor/tree/docs/development/manuals/get-valid-server-state.rst Port data plane status update

Port data plane status can be changed/updated in the case of issues in the underlying data plane affecting connectivity from/to Neutron ports.

See: * Upstream spec document: https://specs.openstack.org/openstack/neutron-specs/specs/pike/port-data-plane-status.html * Upstream Networking API reference document: https://developer.openstack.org/api-ref/network Doctor driver (Congress)

The Doctor driver can be notified about NFVI failures that have been detected by monitoring systems.

See: * Upstream spec document: https://specs.openstack.org/openstack/congress-specs/specs/mitaka/push-type-datasource-driver.html * Congress official documentation: https://docs.openstack.org/congress/latest Event API (Vitrage)

With this API, monitoring systems can push events to the Doctor datasource.

See: * Upstream spec document: https://specs.openstack.org/openstack/vitrage-specs/specs/ocata/event-api.html * Vitrage official documentation: https://docs.openstack.org/vitrage/latest Doctor datasource (Vitrage)

After receiving events from monitoring systems, the Doctor datasource identifies the affected resources based on the resource topology.

See: * Upstream spec document: https://specs.openstack.org/openstack/vitrage-specs/specs/ocata/doctor-datasource.html