RETIRED, Tricircle is to provide networking automation across Neutron.
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tricircle/doc/source/devspecs/quality-of-service.rst

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Tricircle Quality of Service

Background

QoS is defined as the ability to guarantee certain network requirements like bandwidth, latency, jitter and reliability in order to satisfy a Service Level Agreement (SLA) between an application provider and end tenants. In the Tricircle, each OpenStack instance runs its own Nova and Neutron services but shares the same Keystone service or uses federated KeyStones, which is a multi-region deployment mode. With networking automation, networks or ports created in different OpenStack cloud should be able to be associated with QoS policies.

Proposal

As networking automation across Neutron could be done through the Tricircle, the QoS automation should be able to work based on tenant's need too. When tenant wants to apply QoS to the network or port from the central Neutron, QoS can't be created in the local Neutron server in the bottom pod directly, since it's still unclear whether the network will be presented in this pod or not.

In order to achieve QoS automation operations, QoS can't be created in the local Neutron server directly until there are some existing networks/ports in bottom pod. The Tricircle central Neutron plugin(abbr: "central plugin") will operate QoS information in the local Neutron server, QoS service isn't like network/port that needs to be created during VM booting, in order to speed up the local VMs booting and reduce the delay that caused by synchronization between central Neutron and local Neutron, Tricircle central plugin should use an asynchronous method to associate QoS with the local network/port, or remove QoS association in each local Neutron if needed.

Implementation

Case 1, QoS policy creation

In this case, we only create QoS in the central Neutron.

Case 2, QoS policy association without local network/port in place

QoS has been created in the central Neutron but local network/port has not yet been created.

In this case, we just need to update network/port with QoS policy id in the central Neutron.

Case 3, QoS policy association with local network/port in place

After QoS has been created in the central Neutron and local network/port also has been created, associate QoS with network/port in the central Neutron.

In this case, network/port has been created in the local Neutron. After network/port is updated with the QoS policy id in the central Neutron, we also need to do some similar association in the local Neutron. Central Neutron uses "create_qos_policy" job to create the local QoS policy firstly, then update the network/port QoS association asynchronously in the local Neutron through the network/port routing information and add the QoS routing information in routing table. XJob will interact with local Neutron to update the QoS policy id for network/port in local Neutron.

Case 4, provision VM with QoS policy associated central port/network

QoS has been associated to central port/network first, local network/port is created later in VM provision.

In this case, QoS has been associated to the central network/port and at this point local network/port does not exist. Since QoS has not been created in the local Neutron but central Neutron has finished the association, local neutron needs to trigger central Neutron to finish the local network/port QoS association when VMs booting in the local. When VM booting in the bottom pod, local Neutron sends update port request with port information to central Neutron and if QoS id field exists in the network/port, the central Neutron will be triggered to use XJob to create an QoS policy creation job in the local Neutron (it also speeds up VM booting) and add the QoS routing information in routing table.

Case 5, QoS policy updating

In this case, if local network/port isn't associated with QoS, we only update QoS in the central Neutron.

If QoS policy has been associated with local network/port in place, after central Neutron updates QoS, central Neutron will use XJob to create a QoS asynchronous updating job through the network/port routing information. XJob will asynchronously update QoS in the local Neutron.

Case 6, QoS policy disassociation

For QoS policy disassociation, just need to change the parameters of "QoS_policy_id" to None when update network/port in the central Neutron and we can disassociate network/port.

In this case, if network/port in local Neutron isn't associated with QoS, we only disassociate network/port in the central Neutron.

If QoS policy has been associated with network/port in local Neutron, after central Neutron disassociates network, central Neutron will use XJob to create a network update job to disassociate the network with the QoS policy; for port, central Neutron will synchronously update the port to disassociate it with the QoS policy in the local Neutron.

Case 7, QoS policy deletion

QoS policy can only be deleted if there is no any association in central Neutron. In this case, if local network/port isn't associated with QoS, we only delete QoS in the central Neutron.

If there is QoS policy routing info, after central Neutron deletes QoS, central Neutron will use XJob to create a QoS asynchronous deletion job through the network/port routing information. XJob will asynchronously delete QoS in the local Neutron.

Case 8, QoS rule creation

In this case, if local network/port isn't associated with QoS, we only create QoS rule in the central Neutron.

If QoS policy has been associated with local network/port in place, after central Neutron creates QoS rules, central Neutron will use XJob to create a QoS rules syncing job through the network/port routing information, then asynchronously creates QoS rules in the local Neutron.

Case 9, QoS rule updating

In this case, if local network/port isn't associated with QoS, we only update QoS rule in the central Neutron. If QoS policy has been associated with local network/port in place, after central Neutron updates QoS rule, central Neutron will trigger XJob to create a QoS rules syncing job in the local Neutron through the network/port routing information. XJob will asynchronously update QoS rule in the local Neutron.

Case 10, QoS rule deletion

In this case, if local network/port isn't associated with QoS, we only delete QoS rule in the central Neutron.

If QoS policy has been associated with local network/port in place, after central Neutron deletes QoS rule, central Neutron will use XJob to create a QoS rules syncing job through the network/port routing information. XJob will asynchronously delete QoS rule in the local Neutron.

QoS XJob jobs list

  • 1: create_qos_policy(self, ctxt, policy_id, pod_id, res_type, res_id=None)

Asynchronously creating QoS policy for the corresponding pod which id equals "pod_id", specify network or port in through the parameter res_type and res_id. If res_type is RT_NETWORK, then res_id is network's uuid, if res_type is RT_PORT, then res_id is port's uuid

Triggering condition:

When associating network/port in the central Neutron, if this network/port exists in the local Neutron, triggering this asynchronous job to complete the local association.

When central plugin processing a port update request sent by local plugin and finding the port is associated with QoS.

If pod_id is POD_NOT_SPECIFIED then the async job will process all related pods, so the create_qos_policy(self, ctxt, policy_id, pod_id) job will deal with not only single pod's QoS association.

If the res_type is RT_NETWORK/RT_PORT, after creating the qos policy on pod, the async job will bind the qos policy that just created to the network/port specified by the parameter of res_id.

  • 2: update_qos_policy(self, ctxt, policy_id, pod_id)

Asynchronously updating QoS policy for the corresponding pod which id equals "pod_id".

Triggering condition:

When updating QoS policy in the central Neutron, if it also exists in the local Neutron, triggering this asynchronous job to complete the local QoS updating.

If pod_id is POD_NOT_SPECIFIED then the async job will process all related pods, so the update_qos_policy(self,ctxt,policy_id,pod_id) job will deal with not only single pod's QoS association.

  • 3: delete_qos_policy(self, ctxt, policy_id, pod_id)

Asynchronously deleting QoS policy for the corresponding pod which id equals "pod_id".

Triggering condition:

When deleting QoS policy in the central Neutron, if this QoS policy exists in the local Neutron, triggering this asynchronous job to complete the local QoS deletion. (Warning: the deleted QoS policy must be disassociated first.)

If pod_id is POD_NOT_SPECIFIED then the async job will process all related pods, so the delete_qos_policy(self,ctxt,policy_id,pod_id) job will deal with not only single pod's QoS association.

  • 4: sync_qos_policy_rules(self, ctxt, policy_id)

Asynchronous operation for rules of one QoS policy for specified project. There are two trigger conditions. The one is that central Neutron creates/updates/deletes QoS rules after QoS policy has been associated with local network/port. The other is that central plugin processes a port update request sent by local plugin and finds the port is associated with QoS policy.

If the rule both exists in the central Neutron and local Neutron, but with inconsistent content, just asynchronously updating this QoS rule in the local Neutron.

If the rule exits in the central Neutron, but it does not exist in the local Neutron, just asynchronously creating this QoS rule in the local Neutron.

If the rule exits in the local Neutron, but it does not exist in the central Neutron, just asynchronously deleting this QoS rule in the local Neutron.

Data Model Impact

None

Dependencies

None

Documentation Impact

Release notes