Vip QoS Policy Application

Problem description

For real cases, the bandwidth of vip should be limited, because the upstream network resource is provided by the ISP or other organizations. That means it is not free. The openstack provider or users should pay for the limited bandwidth, for example, users buy the 50M bandwidth from ISP for openstack environment to access Internet, also it will be used for the connection outside of openstack to access the servers in openstack. And the servers are behind LoadBalance VIP. We cannot offer the whole bandwidth to the servers, as maybe there also are the VMs want to access the external network. So we should take a bandwidth limitation towards vip port.

Also, if the upstream network resource had been used up mostly, we still want the backend servers behind loadbalancer are accessible and stable. The min bandwidth limitation is needed for this scenario.

For more QoS functions, in reality, we can’t limit our users or deployers to use loadbalance default drivers, such as haproxy driver and Octavia driver. They may be more concerned about the fields/functions related to QoS, like DSCP markings. They could integrate the third-party drivers which are concerned about these fields.

Proposed change

This spec introduces the Neutron QoS function to meet the requirements. Currently, there are 3 ports(at least) in the loadbalancer created by Octavia. One is from the lb-mgmt-net, the others are from the vip-subnet, called “loadbalancer-LOADBALANCER_ID” and “octavia-lb-vrrp-LOADBALNCER_ID”. The first one is vip port, the second one is for vrrp HA, and it will set “allowed_address_pairs” toward vip fixed_ip. The QoS policy should focus on the attached port “octavia-lb-vrrp-LOADBALNCER_ID”.

We could apply the Neutron QoS policy to the “octavia-lb-vrrp-LOADBALNCER_ID” ports, whether the topology is active-active or standalone.

There are the following changes:

• Extend a new column named “qos_policy_id” in vip table.
• Extend Octavia API, we need pass the vip-qos-policy-id which created in Neutron into LoadBalancer creation/update.
• Apply QoS policy on vip port in Loadbalancer working flow.

Alternatives

We accept the QoS parameters and implement the QoS function on our own.

Data model impact

In this spec, the QoS function will be provided by Neutron, so Octavia should know the relationship of QoS policies and the vip port of Loadbalancers. There will be some minor data model changes to Octavia in support of this change.

• vip table - qos_policy_id: associate QoS policy id with vip port.

REST API impact

Proposed attribute:

EXTEND_FIELDS = {
    'vip_qos_policy_id':{'allow_post': True, 'allow_put': True,
                        'validate': {'type:uuid': None},
                        'is_visible': True,
                        'default': None}
}

The definition in Octavia is like::

vip_qos_policy_id = wtypes.wsattr(wtypes.UuidType())

Some samples in Loadbalancer creation/update. Users allow pass “vip_qos_policy_id”.

Create/Update Loadbalancer Request:

POST/PUT /v2.0/lbaas/loadbalancers
{
    "loadbalancer": {
        "name": "loadbalancer1",
        "description": "simple lb",
        "project_id": "b7c1a69e88bf4b21a8148f787aef2081",
        "tenant_id": "b7c1a69e88bf4b21a8148f787aef2081",
        "vip_subnet_id": "013d3059-87a4-45a5-91e9-d721068ae0b2",
        "vip_address": "10.0.0.4",
        "admin_state_up": true,
        "flavor": "a7ae5d5a-d855-4f9a-b187-af66b53f4d04",
        "vip_qos_policy_id": "b61f8b45-e888-4056-94f0-e3d5af96211f"
    }
}

Response:
{
    "loadbalancer": {
        "admin_state_up": true,
        "description": "simple lb",
        "id": "a36c20d0-18e9-42ce-88fd-82a35977ee8c",
        "listeners": [],
        "name": "loadbalancer1",
        "operating_status": "ONLINE",
        "provisioning_status": "ACTIVE",
        "project_id": "b7c1a69e88bf4b21a8148f787aef2081",
        "tenant_id": "b7c1a69e88bf4b21a8148f787aef2081",
        "vip_address": "10.0.0.4",
        "vip_subnet_id": "013d3059-87a4-45a5-91e9-d721068ae0b2",
        "flavor": "a7ae5d5a-d855-4f9a-b187-af66b53f4d04",
        "provider": "sample_provider",
        "pools": [],
        "vip_qos_policy_id": "b61f8b45-e888-4056-94f0-e3d5af96211f"
    }
}

Security impact

None

Notifications impact

No expected change.

Other end user impact

Users will be able to specify qos_policy to create/update Loadbalancers.

Performance Impact

• It will be a very short time to cost in loadbalancer creation, as we need validate the input QoS policy.
• The QoS policy in Neutron side will affect the network performance based on the different types of QoS rules.

Other deployer impact

None

Developer impact

TBD.

Implementation

Assignee(s)

zhaobo reedip

Work Items

• Add the DB model and extend the table column.
• Extending Octavia V2 API to accept QoS policy.
• Add QoS application logic into Loadbalancer workflow.
• Add API validation code to validate access/existence of the qos_policy which created in Neutron.
• Add UTs to Octavia.
• Add API tests.
• Update CLI to accept QoS fields.
• Documentation work.

Dependencies

None

Testing

Unit tests, Functional tests, API tests and Scenario tests are necessary.

Documentation Impact

The Octavia API reference will need to be updated.

References