[ovs-git] [openvswitch/ovs] 04f888: ovsdb-idl: Fix the database update signaling if it...
Ilya Maximets
noreply at github.com
Fri Jun 11 05:07:23 UTC 2021
Branch: refs/heads/master
Home: https://github.com/openvswitch/ovs
Commit: 04f8881f5795483968987d6d7e8b522c11f2d06e
https://github.com/openvswitch/ovs/commit/04f8881f5795483968987d6d7e8b522c11f2d06e
Author: Ilya Maximets <i.maximets at ovn.org>
Date: 2021-06-11 (Fri, 11 Jun 2021)
Changed paths:
M lib/ovsdb-idl.c
Log Message:
-----------
ovsdb-idl: Fix the database update signaling if it has never been connected.
The symptom of this issue is that OVS bridge looses its IP address on
restart.
Simple reproducer:
0. start ovsdb-server and ovs-vswitchd
1. ovs-vsctl add-br br0
2. ifconfig br0 10.0.0.1 up
3. ovs-appctl -t ovs-vswitchd exit
4. start ovs-vswitchd back.
After step #3 ovs-vswitchd is down, but br0 interface exists and
has configured IP address. After step #4 there is no IP address
on the port br0.
What happened:
1. ovsdb-cs connects to the database via ovsdb-idl and requests
database lock.
--> get_schema for _Server database
--> lock request
2. ovsdb-cs receives schema for the _Server database. And sends
monitor request.
<-- schema for _Server
--> monitor_cond for _Server
3. ovsdb-cs receives lock reply.
<-- locked
At this point ovsdb-cs generates OVSDB_CS_EVENT_TYPE_LOCKED
event and passes it to ovsdb-idl. ovsdb-idl increases change_seqno.
4. ovsdb_idl_has_ever_connected() is 'true' now, because change_seqno
is not zero.
5. ovs-vswitchd decides that it has connection with database and
all the initial data, therefore initiates configuration of bridges.
bridge_run():ovsdb_idl_has_ever_connected() --> true
6. Since monitor request for the Open_vSwitch database is not even
sent yet, the database is empty. This leads to removal of all the
ports and all other resources.
7. When data finally received, ovs-vswitchd re-creates bridges and
ports, but IP addresses can not be restored.
While splitting out ovsdb-cs from ovsdb-idl one part of the logic
was lost. Particularly, before the split, ovsdb-idl updated
change_seqno only in MONITORING state.
Restoring the logic by updating the change_seqno only if may send
transaction, i.e. lock is ours and ovsdb-cs is in the MONITORING
state. This matches with the main purpose of increasing change_seqno
at this point, i.e. to force the client to re-try the transaction.
With this change ovsdb_idl_has_ever_connected() remains 'false'
until the first monitor reply with the actual data received.
This issue was reported several times during the last couple of weeks.
Reported-at: https://bugzilla.redhat.com/1968445
Reported-at: https://mail.openvswitch.org/pipermail/ovs-dev/2021-June/383512.html
Reported-at: https://mail.openvswitch.org/pipermail/ovs-discuss/2021-June/051222.html
Fixes: 1c337c43ac1c ("ovsdb-idl: Break into two layers.")
Signed-off-by: Ilya Maximets <i.maximets at ovn.org>
Acked-by: Dumitru Ceara <dceara at redhat.com>
Commit: c5a58ec155d89addeaff73cef95dc5f0dce2ef97
https://github.com/openvswitch/ovs/commit/c5a58ec155d89addeaff73cef95dc5f0dce2ef97
Author: Ilya Maximets <i.maximets at ovn.org>
Date: 2021-06-11 (Fri, 11 Jun 2021)
Changed paths:
M python/ovs/db/idl.py
M tests/ovsdb-cluster.at
M tests/test-ovsdb.py
Log Message:
-----------
python: idl: Allow retry even when using a single remote.
As described in commit [1], it's possible that remote IP is backed by
a load-balancer and re-connection to this same IP will lead to
connection to a different server. This case is supported for C version
of IDL and should be supported in a same way for python implementation.
[1] ca367fa5f8bb ("ovsdb-idl.c: Allows retry even when using a single remote.")
Signed-off-by: Ilya Maximets <i.maximets at ovn.org>
Acked-by: Dumitru Ceara <dceara at redhat.com>
Compare: https://github.com/openvswitch/ovs/compare/91cb55bc8aad...c5a58ec155d8
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