[ovs-dev] [PATCH ovn] ovs: Bump submodule version to latest ovsdb-cs changes.

[Ben Pfaff]

On Thu, Mar 11, 2021 at 07:37:19PM +0100, Ilya Maximets wrote:
> Few bugfixes was accepted recently to OVS for ovsdb-cs code
> that are required for OVN build.
> e.g. ac09cbfcb70a ("ovsdb-cs: Fix use-after-free for the request id.")
> 
> This will also include all the changes necessary to build
> ddlog version of northd.
> 
> Signed-off-by: Ilya Maximets <i.maximets at ovn.org>
> ---
>  ovs | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/ovs b/ovs
> index 50e5523b9..ac09cbfcb 160000
> --- a/ovs
> +++ b/ovs
> @@ -1 +1 @@
> -Subproject commit 50e5523b9b2b154e5fafc5acdcdec85e9cc5a330
> +Subproject commit ac09cbfcb70ac6f443f039d5934448bd80f74493

You could consider bumping all the way to 39b937f06434 ("raft: Add
'stop-raft-rpc' failure test command."), which would add the commits
listed below.  But I support this either way.

Acked-by: Ben Pfaff <blp at ovn.org>

$ git log ac09cbfcb70ac6f443f039d5934448bd80f74493...39b937f064347884614002c9bdac79382a144fca
commit 39b937f064347884614002c9bdac79382a144fca
Author: Ilya Maximets <i.maximets at ovn.org>
Date:   Fri Feb 19 18:00:19 2021 +0100

    raft: Add 'stop-raft-rpc' failure test command.
    
    This command will stop sending and receiving any RAFT-related
    traffic or accepting new connections.  Useful to simulate
    network problems between cluster members.
    
    There is no unit test that uses it yet, but it's convenient for
    manual testing.
    
    Acked-by: Han Zhou <hzhou at ovn.org>
    Signed-off-by: Ilya Maximets <i.maximets at ovn.org>

commit 4c1d9ef14af3da3b904c1ceb4a6823bb3c5fd3e3
Author: Ilya Maximets <i.maximets at ovn.org>
Date:   Fri Feb 19 17:42:43 2021 +0100

    raft: Report disconnected in cluster/status if candidate retries election.
    
    If election times out for a server in 'candidate' role it sets
    'candidate_retrying' flag that notifies that storage is disconnected
    and client should re-connect.  However, cluster/status command
    reports 'Status: cluster member' and that is misleading.
    Reporting "disconnected from the cluster (election timeout)" instead.
    
    Reported-by: Carlos Goncalves <cgoncalves at redhat.com>
    Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1929690
    Fixes: 1b1d2e6daa56 ("ovsdb: Introduce experimental support for clustered databases.")
    Acked-by: Han Zhou <hzhou at ovn.org>
    Signed-off-by: Ilya Maximets <i.maximets at ovn.org>

commit 14b2b0aad7ae9254bad8b8c2cc9d5386065ab42f
Author: Ilya Maximets <i.maximets at ovn.org>
Date:   Wed Feb 17 16:44:57 2021 +0100

    raft: Reintroduce jsonrpc inactivity probes.
    
    It's not enough to just have heartbeats.
    
    RAFT heartbeats are unidirectional, i.e. leader sends them to followers
    but not the other way around.  Missing heartbeats provokes followers to
    start election, but if leader will not receive any replies it will not
    do anything while there is a quorum, i.e. there are enough other
    servers to make decisions.
    
    This leads to situation that while TCP connection is established,
    leader will continue to blindly send messages to it.  In our case this
    leads to growing send backlog.  Connection will be terminated
    eventually due to excessive send backlog, but this this might take a
    lot of time and wasted process memory.  At the same time 'candidate'
    will continue to send vote requests to the dead connection on its
    side.
    
    To fix that we need to reintroduce inactivity probes that will drop
    connection if there was no incoming traffic for a long time and remote
    server doesn't reply to the "echo" request.  Probe interval might be
    chosen based on an election timeout to avoid issues described in commit
    db5a066c17bd.
    
    Reported-by: Carlos Goncalves <cgoncalves at redhat.com>
    Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1929690
    Fixes: db5a066c17bd ("raft: Disable RAFT jsonrpc inactivity probe.")
    Acked-by: Han Zhou <hzhou at ovn.org>
    Signed-off-by: Ilya Maximets <i.maximets at ovn.org>