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==============
OVN To-do List
==============

* Refactor ovn-northd code to have separate functions to add logical flows
  for gateway logical routers and logical routers with distributed gateway
  port.

* VLAN trunk ports.

  Russell Bryant: "Today that would require creating 4096 ports for the VM and
  attach to 4096 OVN networks, so doable, but not quite ideal."

* Service function chaining.

* Hitless upgrade, especially for data plane.

* Dynamic IP to MAC binding enhancements.

  OVN has basic support for establishing IP to MAC bindings dynamically, using
  ARP.

  * Table size limiting.

    The table of MAC bindings must not be allowed to grow unreasonably large.

* MTU handling (fragmentation on output)

* Support multiple tunnel encapsulations in Chassis.

  So far, both ovn-controller and ovn-controller-vtep only allow chassis to
  have one tunnel encapsulation entry.  We should extend the implementation
  to support multiple tunnel encapsulations.

* Update learned MAC addresses from VTEP to OVN

  The VTEP gateway stores all MAC addresses learned from its physical
  interfaces in the 'Ucast_Macs_Local' and the 'Mcast_Macs_Local' tables.
  ovn-controller-vtep should be able to update that information back to
  ovn-sb database, so that other chassis know where to send packets destined
  to the extended external network instead of broadcasting.

* Translate ovn-sb Multicast_Group table into VTEP config

  The ovn-controller-vtep daemon should be able to translate the
  Multicast_Group table entry in ovn-sb database into Mcast_Macs_Remote table
  configuration in VTEP database.

* OVN OCF pacemaker script to support Active / Passive HA for OVN dbs provides
  the option to configure the inactivity_probe value. The default 5 seconds
  inactivity_probe value is not sufficient and ovsdb-server drops the client
  IDL connections for openstack deployments when the neutron server is heavily
  loaded.

  We need to find a proper solution to solve this issue instead of increasing
  the inactivity_probe value.

* ACL

  * Support FTP ALGs.

* OVN Interconnection

  * Packaging for Debian.

* IP Multicast Relay

  * When connecting bridged logical switches (localnet) to logical routers
    with IP Multicast Relay enabled packets might get duplicated. We need
    to find a way of determining if routing has already been executed (on a
    different hypervisor) for the IP multicast packet being processed locally
    in the router pipeline.

* ovn-controller Incremental processing

  * Implement I-P for datapath groups.
  * Implement I-P for route exchange relevant ports.

* ovn-northd parallel logical flow processing

  * Multi-threaded logical flow computation was optimized for the case
    when datapath groups are disabled.  Datpath groups are always enabled
    now so northd parallel processing should be revisited.

* ovn-controller daemon module

  * Dumitru Ceara: Add a new module e.g. ovn/lib/daemon-ovn.c that wraps
    OVS' daemonize_start() call and initializes the additional things, like
    the unixctl commands. Or, we should move the APIs such as
    daemon_started_recently() to OVS's lib/daemon.

* Chassis_Template_Var

  * Support template variables when tracing packets with ovn-trace.

* Load Balancer templates

  * Support combining the VIP IP and port into a single template variable.

* ovn-controller conditional monitoring

  * Improve sub-ports (with parent_port set) conditional monitoring; these
    are currently unconditionally monitored, even if ovn-monitor-all is
    set to false.

* ovn-northd parallel build

  * Move the lflow build parallel processing from northd.c to lflow-mgr.c
    This would also ensure that the variables declared in northd.c
    (eg. thread_lflow_counter) are not externed in lflow-mgr.c.

* Remove flows with `check_pkt_larger` when userspace datapath can handle
  PMTUD. (https://issues.redhat.com/browse/FDP-256)

* Remove ssl_ciphersuites workaround for clustered databases from ovn-ctl
  after 26.03 release, assuming it will be an LTS release.

* Dynamic Routing

  * Add incremental processing of en_dynamic_routes for stateful configuration
    changes.

  * The ovn-controller currently loads all Advertised_Route entries on startup.
    This is to prevent deleting our routes on restart. If we defer updating
    routes until we are sure to have loaded all necessary Advertised_Routes
    this could be changed.

  * Improve handling of the Learned_Route table in ovn-controller conditional
    monitoring; once a new local datapath is added we need to wait for
    monitoring conditions to update before we actually try to learn routes.
    Otherwise we could try to add duplicated Learned_Routes and the ovnsb
    commit would fail.

  * Allow ovn-evpn-local-ip to accept list of
    $VNI1:$LOCAL_IP1,$VNI2:$LOCAL_IP2 combinations which will be properly
    reflected in physical flows for given LS with VNI.

  * Learn FDBs dynamically from the incoming traffic for EVPN. The same way
    we do for other traffic passing through LS.

  * Add support for EVPN L3, that involves MAC Binding learning and
    advertisement.

* Datapath sync nodes

  * Migrate data stored in the ovn\_datapath structure to
    ovn\_synced\_logical_router and ovn\_synced\_logical\_switch. This will
    allow for the eventual removal of the ovn\_datapath structure from the
    codebase.

* CI

  * ovn-kubernetes: Only a subset of the ovn-kubernetes features is currently
    tested in GitHub CI.  We should extend our testing to support
    OVN_ENABLE_INTERCONNECT=true and potentially more of the CI lanes
    ovn-kubernetes/ovn-kubernetes defines in its GitHub project.
