octavia/doc/source/admin/sr-iov.rst

Using SR-IOV Ports with Octavia

Single Root I/O Virtualization (SR-IOV) can significantly reduce the latency through an Octavia Amphora based load balancer while maximizing bandwith and request rates. With Octavia Amphora load balancers, you can attach SR-IOV Virtual Functions (VF) as the VIP port and/or backend member ports.

Enabling SR-IOV on Your Compute Hosts

To allow Octavia load balancers to use SR-IOV, you must configure nova and neutron to make SR-IOV available on at least one compute host. Please follow the Networking Guide to setup your compute hosts for SR-IOV.

Configuring Host Aggregates, Compute and Octavia Flavors

Octavia hot-plugs the network ports into the Amphora as the load balancer is being provisioned. This means we need to use host aggregates and compute flavor properties to make sure the Amphora are created on SR-IOV enable compute hosts with the correct networks.

Host Aggregates

This configuration can be as simple or complex as you need it to be. A simple approach would be to add one property for the SR-IOV host aggregate, such as:

$ openstack aggregate create sriov_aggregate
$ openstack aggregate add host sriov_aggregate sriov-host.example.org
$ openstack aggregate set --property sriov-nic=true sriov_aggregate

A more advanced configuration may list out the specific networks that are available via the SR-IOV VFs:

$ openstack aggregate create sriov_aggregate
$ openstack aggregate add host sriov_aggregate sriov-host.example.org
$ openstack aggregate set --property public-sriov=true --property members-sriov=true sriov_aggregate

Compute Flavors

Next we need to create a compute flavor that includes the required properties to match the host aggregate. Here is an example for a basic Octavia Amphora compute flavor using the advanced host aggregate discussed in the previous section:

$ openstack flavor create --id amphora-sriov-flavor --ram 1024 --disk 3 --vcpus 1 --private sriov.amphora --property hw_rng:allowed=True --property public-sriov=true --property members-sriov=true

Note

This flavor is marked "private" so must be created inside the Octavia service account project.

Octavia Flavors

Now that we have the compute service setup to properly place our Amphora instances on hosts with SR-IOV NICs on the right networks, we can create an Octavia flavor that will use the compute flavor.

$ openstack loadbalancer flavorprofile create --name amphora-sriov-profile --provider amphora --flavor-data '{"compute_flavor": "amphora-sriov-flavor", "sriov_vip": true}'
$ openstack loadbalancer flavor create --name SRIOV-public-members --flavorprofile amphora-sriov-profile --description "A load balancer that uses SR-IOV for the 'public' network and 'members' network." --enable

Building the Amphora Image

Neutron does not support security groups on SR-IOV ports, so Octavia will use nftables inside the Amphroa to provide network security. The amphora image must be built with nftables enabled for SR-IOV enabled load balancers. Images with nftables enabled can be used for both SR-IOV enabled load balancers as well as load balancers that are not using SR-IOV ports. When the SR-IOV for load balancer VIP ports feature was added to Octavia, the default setting for using nftables has been changed to True. Prior to this it needed to be enabled by setting an environment variable before building the Amphora image:

$ export DIB_OCTAVIA_AMP_USE_NFTABLES=True
$ ./diskimage-create.sh