From: Jarod Wilson <jarod@redhat.com>
To: Veaceslav Falico <vfalico@gmail.com>
Cc: linux-kernel@vger.kernel.org,
Uwe Koziolek <uwe.koziolek@redknee.com>,
Jay Vosburgh <j.vosburgh@gmail.com>,
Andy Gospodarek <gospo@cumulusnetworks.com>,
netdev@vger.kernel.org
Subject: Re: [PATCH] net/bonding: send arp in interval if no active slave
Date: Mon, 17 Aug 2015 13:12:23 -0400 [thread overview]
Message-ID: <55D215F7.3080905@redhat.com> (raw)
In-Reply-To: <20150817165500.GA21512@vps.falico.eu>
On 2015-08-17 12:55 PM, Veaceslav Falico wrote:
> On Mon, Aug 17, 2015 at 12:23:03PM -0400, Jarod Wilson wrote:
>> From: Uwe Koziolek <uwe.koziolek@redknee.com>
>>
>> With some very finicky switch hardware, active backup bonding can get
>> into
>> a situation where we play ping-pong between interfaces, trying to get one
>> to come up as the active slave. There seems to be an issue with the
>> switch's arp replies either taking too long, or simply getting lost,
>> so we
>> wind up unable to get any interface up and active. Sometimes, the issue
>> sorts itself out after a while, sometimes it doesn't.
>>
>> Testing with num_grat_arp has proven fruitless, but sending an additional
>> arp on curr_arp_slave if we're still in the arp_interval timeslice in
>> bond_ab_arp_probe(), has shown to produce 100% reliability in testing
>> with
>> this hardware combination.
>
> Sorry, I don't understand the logic of why it works, and what exactly are
> we fixiing here.
>
> It also breaks completely the logic for link state management in case of no
> current active slave for 2*arp_interval.
>
> Could you please elaborate what exactly is fixed here, and how it works? :)
I can either duplicate some information from the bug, or Uwe can, to
illustrate the exact nature of the problem.
> p.s. num_grat_arp maybe could help?
That was my thought as well, but as I understand it, that route was
explored, and it didn't help any. I don't actually have a reproducer
setup of my own, unfortunately, so I'm kind of caught in the middle here...
Uwe, can you perhaps further enlighten us as to what num_grat_arp
settings were tried that didn't help? I'm still of the mind that if
num_grat_arp *didn't* help, we probably need to do something keyed off
num_grat_arp.
>> [jarod: manufacturing of changelog]
>> CC: Jay Vosburgh <j.vosburgh@gmail.com>
>> CC: Veaceslav Falico <vfalico@gmail.com>
>> CC: Andy Gospodarek <gospo@cumulusnetworks.com>
>> CC: netdev@vger.kernel.org
>> Signed-off-by: Uwe Koziolek <uwe.koziolek@redknee.com>
>> Signed-off-by: Jarod Wilson <jarod@redhat.com>
>> ---
>> drivers/net/bonding/bond_main.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/net/bonding/bond_main.c
>> b/drivers/net/bonding/bond_main.c
>> index 0c627b4..60b9483 100644
>> --- a/drivers/net/bonding/bond_main.c
>> +++ b/drivers/net/bonding/bond_main.c
>> @@ -2794,6 +2794,11 @@ static bool bond_ab_arp_probe(struct bonding
>> *bond)
>> return should_notify_rtnl;
>> }
>>
>> + if (bond_time_in_interval(bond, curr_arp_slave->last_link_up, 2)) {
>> + bond_arp_send_all(bond, curr_arp_slave);
>> + return should_notify_rtnl;
>> + }
>> +
>> bond_set_slave_inactive_flags(curr_arp_slave,
>> BOND_SLAVE_NOTIFY_LATER);
>>
>> bond_for_each_slave_rcu(bond, slave, iter) {
>> --
>> 1.8.3.1
>>
--
Jarod Wilson
jarod@redhat.com
next prev parent reply other threads:[~2015-08-17 17:12 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-17 16:23 [PATCH] net/bonding: send arp in interval if no active slave Jarod Wilson
2015-08-17 16:55 ` Veaceslav Falico
2015-08-17 17:12 ` Jarod Wilson [this message]
2015-08-17 18:56 ` Uwe Koziolek
2015-08-17 19:14 ` Jay Vosburgh
2015-08-17 20:51 ` Uwe Koziolek
2015-08-31 22:21 ` Jarod Wilson
2015-09-01 23:15 ` Uwe Koziolek
2015-09-01 15:41 ` Andy Gospodarek
2015-09-01 23:10 ` Uwe Koziolek
2015-09-03 15:05 ` Jay Vosburgh
2015-09-04 11:04 ` Uwe Koziolek
2015-09-28 13:31 ` Jarod Wilson
2015-10-06 19:53 ` [PATCH v4] " Jarod Wilson
2015-10-06 19:58 ` Jarod Wilson
2015-10-07 12:03 ` Nikolay Aleksandrov
2015-10-07 13:29 ` Jarod Wilson
2015-10-09 14:36 ` Jarod Wilson
2015-10-09 15:25 ` Nikolay Aleksandrov
2015-10-09 15:31 ` Jay Vosburgh
2015-10-12 15:33 ` Jarod Wilson
2015-10-30 18:59 ` Uwe Koziolek
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