[ovs-dev] [PATCH v3 2/5] ovn: Add generic HA chassis group
Numan Siddique
nusiddiq at redhat.com
Thu Mar 7 16:37:11 UTC 2019
On Tue, Mar 5, 2019 at 11:34 PM Han Zhou <zhouhan at gmail.com> wrote:
> > > +
> > > +static void
> > > +add_to_ha_ref_chassis_info(struct ha_ref_chassis_info *ref_ch_info,
> > > + const struct sbrec_chassis *chassis)
> > > +{
> > > + for (size_t j = 0; j < ref_ch_info->n_ref_chassis; j++) {
> > > + if (ref_ch_info->ref_chassis[j] == chassis) {
> > > + return;
> > > + }
> > > + }
> > > +
> > > + ref_ch_info->ref_chassis = xrealloc(ref_ch_info->ref_chassis,
> > > + sizeof
> *ref_ch_info->ref_chassis *
> > > +
> (++ref_ch_info->n_ref_chassis));
> >
> > This may be inefficient, considering the amount of ref chassises to be
> > added for each HA group. It is better to xrealloc for original_size *
> > 2 every time and expand only when more space is needed.
> >
> > > + ref_ch_info->ref_chassis[ref_ch_info->n_ref_chassis - 1] =
> > > + CONST_CAST(struct sbrec_chassis *, chassis);
> > > +}
> > > +
> > > +static void
> > > +update_sb_ha_group_ref_chassis(struct shash *ha_ref_chassis_map)
> > > +{
> > > + struct shash_node *node, *next;
> > > + SHASH_FOR_EACH_SAFE (node, next, ha_ref_chassis_map) {
> > > + struct ha_ref_chassis_info *ha_ref_info = node->data;
> > > +
> sbrec_ha_chassis_group_set_ref_chassis(ha_ref_info->ha_chassis_group,
> > > +
> ha_ref_info->ref_chassis,
> > > +
> ha_ref_info->n_ref_chassis);
> > > + free(ha_ref_info->ref_chassis);
> > > + free(ha_ref_info);
> > > + shash_delete(ha_ref_chassis_map, node);
> > > + }
> > > +}
> > > +
> > > +/* This function returns logical router datapath (with a distributed
> > > + * gateway port) to which 'od' is connected to - either directly
> > > + * or indirectly (via transit logical switches).
> > > + * Returns NULL if no logical router with gw port found.
> > > + */
> > > +static struct ovn_datapath *
> > > +get_router_dp_with_gw_port(struct hmap *ports,
> > > + struct ovn_datapath *od,
> > > + struct ovn_datapath *peer_od)
> > > +{
> > > + if (!od) {
> > > + return NULL;
> > > + }
> > > +
> > > + if (od->nbs) {
> > > + /* It's a logical switch datapath. */
> > > + if (peer_od) {
> > > + /* If peer datapath is not logical router, then
> > > + * something is wrong. */
> > > + ovs_assert(peer_od->nbr);
> > > + }
> > > +
> > > + for (size_t i = 0; i < od->n_router_ports; i++) {
> > > + if (!od->router_ports[i]->peer) {
> > > + /* If there is no peer port connecting to the
> > > + * router datapath, ignore it. */
> > > + continue;
> > > + }
> > > +
> > > + struct ovn_datapath *router_dp =
> od->router_ports[i]->peer->od;
> > > + if (router_dp->l3dgw_port && router_dp->l3dgw_port->nbrp)
> {
> > > + /* Router datapath has a distributed gateway router
> port. */
> > > + return router_dp;
> >
> > I think we can't return when just one router_dp is found. There can be
> > more than one connected router that has gateway router ports. So the
> > return value of this function should be a set.
> >
> > > + }
> > > + }
> > > +
> > > + /* The logical switch datapath is not connected to any
> > > + * logical router with a distributed gateway port. Check if it
> > > + * is indirectly connected to a logical router with a gw
> port. */
> > > + for (size_t i = 0; i < od->n_router_ports; i++) {
> > > + if (!od->router_ports[i]->peer) {
> > > + continue;
> > > + }
> > > +
> > > + struct ovn_datapath *router_dp =
> > > + od->router_ports[i]->peer->od;
> > > +
> > > + /* If we don't check this, we will be in an infinite
> loop. */
> > > + if (router_dp != peer_od) {
> >
> > peer_od should also be a set, it should skip checking any datapath
> > that has already been checked. Consider the case LR1 is connected with
> > LS1, LS2 and LS3.
> >
> > > + router_dp = get_router_dp_with_gw_port(ports,
> router_dp,
> > > + od);
> > > + if (router_dp) {
> > > + /* Found a logical router with gw port indirectly
> connected
> > > + * to 'od'. */
> > > + return router_dp;
> > > + }
> > > + }
> > > + }
> > > + } else if (od->nbr) {
> > > + /* It's a logical router datapath. */
> > > + if (peer_od) {
> > > + /* If peer datapath is not logical switch, then
> > > + * something is wrong. */
> > > + ovs_assert(peer_od->nbs);
> >
> > A router port can be peered with another router port directly, so this
> > assert is not true.
> >
> > > + }
> > > +
> > > + /* Check if this logical router datapath is indirectly
> connected
> > > + * to another logical router via a transit logical
> switch(es). */
> > > + for (size_t i = 0; i < od->nbr->n_ports; i++) {
> > > + struct ovn_port *router_port =
> > > + ovn_port_find(ports, od->nbr->ports[i]->name);
> > > +
> > > + if (!router_port || !router_port->peer) {
> > > + continue;
> > > + }
> > > + /* If we don't check this, we will be in an infinite
> loop. */
> > > + if (router_port->peer->od != peer_od) {
> > > + struct ovn_datapath *router_dp;
> > > + /* router_port->peer->od points a logical switch
> datapath. */
> > > + router_dp = get_router_dp_with_gw_port(ports,
> > > +
> router_port->peer->od,
> > > + od);
> > > + if (router_dp) {
> > > + /* Found a logical router with gw port indirectly
> connected
> > > + * to 'od'. */
> > > + return router_dp;
> > > + }
> > > + }
> > > + }
> > > + }
> > > +
> > > + return NULL;
> > > +}
> >
> > In general, it may refer to the flood-fill approach implemented in
> > ovn-controller for populating local datapaths in binding.c, which is
> > similar to the purpose here. However, we should consider an
> > optimization here since the flood-fill cost would apply for every
> > port-binding. It can be optimized with a cache, which maps between
> > each datapath and its related router_dps with gw ports, to avoid
> > repeated traversing. (In ovn-controller it can be optimized, too, but
> > the gain is not as big as here since only local port-bindings are
> > checked in ovn-controller.)
> >
>
Thanks for the comments Han. I will work on them.
I haven't thought of an optimization yet. I will try to explore based
on your suggestions. At the same time, I personally think the code
shouldn't get complicated because of the optimization. (I feel the present
code in ovn-controller [1] is a bit complicated -
[1] -
https://github.com/openvswitch/ovs/blob/master/ovn/controller/bfd.c#L98
)
I think it is uncommon to have indirect logical router connections which
eventually
connect to a router with a gateway router port.
May be I am wrong. Do you think it's common to have such setups ?
I forgot to mention, this implementation is for finding out the
> required BFD sessions, however, it can be reused for a more generic
> purpose - to figure out whether a tunnel is needed between each pair
> of chassises. There happens to be a related discussion ongoing here:
> https://mail.openvswitch.org/pipermail/ovs-discuss/2019-March/048281.html
>
>
I have seen thread. I will try to make it generic.
If not I think we can revisit the code later and make it generic and more
optimized.
As a first step I think it should be reasonable to aim to have the solution
for the HA_Chassis_Group's ref_chassis calculation.
Does this sound good ?
Thanks
Numan
Thanks,
> Han
>
More information about the dev
mailing list