On 11/10/20 1:26 AM, Ben Pfaff wrote: > On Mon, Nov 09, 2020 at 02:44:27PM +0100, Dumitru Ceara wrote: >> On 11/6/20 4:36 AM, Ben Pfaff wrote: >>> Many of these could be replaced by "ovn-nbctl sync". Some weren't >>> really needed at all because they were adjacent to something that itself >>> called sync or otherwise used --wait. Some were more appropriately >>> done with explicit waits for what was really needed. >>> >>> I left some "sleep"s. Some were because they were "negative" sleeps: >>> they were giving time for something to happen that should *not* happen >>> (in other words, if you wait for it to happen, you'll wait forever, >>> unless there's a bug). Some were because I didn't know how to properly >>> wait for what they were waiting for, or because I didn't understand >>> the circumstances deeply enough. >>> >>> Signed-off-by: Ben Pfaff <[email protected]> >>> --- >>> tests/ovn-northd.at | 7 ++ >>> tests/ovn.at | 167 ++++++++++++-------------------------------- >>> 2 files changed, 52 insertions(+), 122 deletions(-) >>> >>> diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at >>> index 949a8eee054e..5d670233561e 100644 >>> --- a/tests/ovn-northd.at >>> +++ b/tests/ovn-northd.at >>> @@ -1120,6 +1120,7 @@ ovn-nbctl --wait=sb -- --id=@hc create \ >>> Load_Balancer_Health_Check vip="10.0.0.10\:80" -- add Load_Balancer . \ >>> health_check @hc >>> wait_row_count Service_Monitor 2 >>> +check ovn-nbctl --wait=hv sync >> >> This should be "--wait=sb". ovn-controller is not started for tests in >> ovn-northd.at and "--wait=hv" would return immediately. This applies to >> all "ovn-nbctl --wait=hv sync" in ovn-northd.at. > > I see what you mean. > > This is surprising to me. When I defined this stuff years ago, my > intent was that --wait=hv would be stronger than --wait=sb. That is, > --wait=sb would cause ovn-nbctl to wait for the southbound database to > catch up with the northbound changes, and --wait=hb would cause it to > wait for the southbound database AND the hypervisors to catch up. > > That's even how it's documented for ovn-nbctl: > > <p> > With <code>--wait=sb</code>, before <code>ovn-nbctl</code> exits, it > waits for <code>ovn-northd</code> to bring the southbound database > up-to-date with the northbound database updates. > </p> > > <p> > With <code>--wait=hv</code>, before <code>ovn-nbctl</code> exits, it > additionally waits for all OVN chassis (hypervisors and gateways) to > become up-to-date with the northbound database updates. (This can > become an indefinite wait if any chassis is malfunctioning.) > </p> > > That's not what actually happens, though. As you point out, if there > are no hypervisors, then the hypervisors are always up-to-date, even if > the database is not. > > I think this is a bug in ovn-nbctl. Arguably, it's a bug in the > database definition (perhaps hv_cfg shouldn't even be filled in but left > empty if there are no chassis) but I think it is too late to fix it > there. It is, however, easy enough to fix it in ovn-nbctl. > > (And at the same time, I'll change these in ovn-northd to just say > --wait=sb. You have a point.) > > How about this as an additional patch? > > -8<--------------------------cut here-------------------------->8-- > > From 7b373c22dbda2f808f3d5f3b8ae6eb67612dbe87 Mon Sep 17 00:00:00 2001 > From: Ben Pfaff <[email protected]> > Date: Mon, 9 Nov 2020 16:12:50 -0800 > Subject: [PATCH ovn] ovn-nbctl: Make --wait=hv wait for southbound database in > corner case. > > In the corner case where there are no chassis, --wait=hv didn't wait at > all, instead of waiting for the southbound database. > > Reported-by: Dumitru Ceara <[email protected]> > Signed-off-by: Ben Pfaff <[email protected]> > --- > ovn-nb.xml | 27 ++++++++++++++++++++------- > utilities/ovn-nbctl.c | 2 +- > 2 files changed, 21 insertions(+), 8 deletions(-) > > diff --git a/ovn-nb.xml b/ovn-nb.xml > index 51b186b84419..d3e51f3e5e87 100644 > --- a/ovn-nb.xml > +++ b/ovn-nb.xml > @@ -84,13 +84,26 @@ > </column> > > <column name="hv_cfg"> > - Sequence number that <code>ovn-northd</code> sets to the smallest > - sequence number of all the chassis in the system, as reported in the > - <code>Chassis_Private</code> table in the southbound database. Thus, > - <ref column="hv_cfg"/> equals <ref column="nb_cfg"/> if all chassis > are > - caught up with the northbound configuration (which may never happen, > if > - any chassis is down). This value can regress, if a chassis was > removed > - from the system and rejoins before catching up. > + <p> > + Sequence number that <code>ovn-northd</code> sets to the smallest > + sequence number of all the chassis in the system, as reported in > the > + <code>Chassis_Private</code> table in the southbound database. > Thus, > + <ref column="hv_cfg"/> equals <ref column="nb_cfg"/> if all > chassis are > + caught up with the northbound configuration (which may never > happen, if > + any chassis is down). This value can regress, if a chassis was > removed > + from the system and rejoins before catching up. > + </p> > + > + <p> > + If there are no chassis, then <code>ovn-northd</code> copies > + <code>nb_cfg</code> to <ref column="hv_cfg"/>. Thus, in this case, > + the (nonexistent) hypervisors are always considered to be caught > up. > + This means that hypervisors can be "caught up" even in cases where > + <ref column="sb_cfg"/> would show that the southbound database is > + not. To detect when both the hypervisors and the southbound > database > + are caught up, a client should take the smaller of <ref > + column="sb_cfg"/> and <ref column="hv_cfg"/>. > + </p> > </column> > > <column name="hv_cfg_timestamp"> > diff --git a/utilities/ovn-nbctl.c b/utilities/ovn-nbctl.c > index 4f28edc808ec..ee9849de53a9 100644 > --- a/utilities/ovn-nbctl.c > +++ b/utilities/ovn-nbctl.c > @@ -6357,7 +6357,7 @@ do_nbctl(const char *args, struct ctl_command > *commands, size_t n_commands, > NBREC_NB_GLOBAL_FOR_EACH (nb, idl) { > int64_t cur_cfg = (wait_type == NBCTL_WAIT_SB > ? nb->sb_cfg > - : nb->hv_cfg); > + : MIN(nb->sb_cfg, nb->hv_cfg)); > if (cur_cfg >= next_cfg) { > if (print_wait_time) { > printf("Time spent on processing nb_cfg > %"PRId64":\n", >
Looks good to me, thanks! _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
