* ovn-controller
-** Flow table handling in ovn-controller.
-
- ovn-controller has to transform logical datapath flows from the
- database into OpenFlow flows.
-
-*** Definition (or choice) of data structure for flows and flow table.
-
- It would be natural enough to use "struct flow" and "struct
- classifier" for this. Maybe that is what we should do. However,
- "struct classifier" is optimized for searches based on packet
- headers, whereas all we care about here can be implemented with a
- hash table. Also, we may want to make it easy to add and remove
- support for fields without recompiling, which is not possible with
- "struct flow" or "struct classifier".
-
- On the other hand, we may find that it is difficult to decide that
- two OXM flow matches are identical (to normalize them) without a
- lot of domain-specific knowledge that is already embedded in struct
- flow. It's also going to be a pain to come up with a way to make
- anything other than "struct flow" work with the ofputil_*()
- functions for encoding and decoding OpenFlow.
-
- It's also possible we could use struct flow without struct
- classifier.
-
-*** Translating logical datapath actions into OpenFlow actions.
-
- Some of the logical datapath actions do not have natural
- representations as OpenFlow actions: they require
- packet-in/packet-out round trips through ovn-controller. The
- trickiest part of that is going to be making sure that the
- packet-out resumes the control flow that was broken off by the
- packet-in. That's tricky; we'll probably have to restrict control
- flow or add OVS features to make resuming in general possible. Not
- sure which is better at this point.
-
-*** OpenFlow flow table synchronization.
-
- The internal representation of the OpenFlow flow table has to be
- synced across the controller connection to OVS. This probably
- boils down to the "flow monitoring" feature of OF1.4 which was then
- made available as a "standard extension" to OF1.3. (OVS hasn't
- implemented this for OF1.4 yet, but the feature is based on a OVS
- extension to OF1.0, so it should be straightforward to add it.)
-
- We probably need some way to catch cases where OVS and OVN don't
- see eye-to-eye on what exactly constitutes a flow, so that OVN
- doesn't waste a lot of CPU time hammering at OVS trying to install
- something that it's not going to do.
-
-*** Logical/physical translation.
-
- When a packet comes into the integration bridge, the first stage of
- processing needs to translate it from a physical to a logical
- context. When a packet leaves the integration bridge, the final
- stage of processing needs to translate it back into a physical
- context. ovn-controller needs to populate the OpenFlow flows
- tables to do these translations.
-
*** Determine how to split logical pipeline across physical nodes.
From the original OVN architecture document:
The split pipeline processing split will influence how tunnel keys
are encoded.
-*** Monitor Pipeline table in OVN, trigger flow table recomputation on change.
-
** ovn-controller parameters and configuration.
*** SSL configuration.
Andy Zhou is looking at these issues.
-** Scaling number of connections.
-
- In typical use today a given ovsdb-server has only a single-digit
- number of simultaneous connections. The OVN Southbound database will
- have a connection from every hypervisor. This use case needs testing
- and probably coding work. Here are some possible improvements.
-
*** Reducing amount of data sent to clients.
Currently, whenever a row monitored by a client changes,
Epstein et al., "What's the Difference? Efficient Set
Reconciliation Without Prior Context". (I'm not yet aware of
previous non-academic use of this technique.)
-
-* Miscellaneous:
-
-** Init scripts for ovn-controller (on HVs), ovn-northd, OVN DB server.
-
-** Distribution packaging.
-
-* Not yet scoped:
-
-** Neutron plugin.
-
- This is being developed on OpenStack's development infrastructure
- to be along side most of the other Neutron plugins.
-
- http://git.openstack.org/cgit/openstack/networking-ovn
-
-** Gateways.
projects / cascardo / ovs.git / blobdiff