[Openstack] Auto Assigned Floating IPs take a long time to associate
Kevin Jackson
kevin at linuxservices.co.uk
Wed Mar 28 13:16:45 UTC 2012
It does appear that the database is updated (see a reply a few moments ago)
at the correct point... an explanation of what the tool is/isn't doing will
go a long way in helping me work out what I should be using the tools for /
configuration.
To an end user - it appears to take anywhere between a few minutes and 10
mins before an instance is accessible - but looking at what is happening
the instance is ready within seconds - so something is amiss with the
supplied tools.
Cheers,
Kev
On 28 March 2012 14:11, Kiall Mac Innes <kiall at managedit.ie> wrote:
> <stab in the dark>
> Have you kept an eye on the mysql table itself, rather than relying on the
> cli tools / dashboard that may very well cache the data?
> </stab in the dark>
>
> Thanks,
> Kiall
>
>
> On Wed, Mar 28, 2012 at 1:58 PM, Kevin Jackson <kevin at linuxservices.co.uk>wrote:
>
>> Cheers Phil,
>> It's not that I can't get to the instances - I'd assume it was an ARP
>> issue at that point - its the fact that Nova hasn't notified me that it has
>> assigned an IP address: see my additional note where I guessed an IP
>> address it would've assigned and I could access it... but management tools
>> were still blissfully unaware.
>> I used to have a working Diablo set up with pretty much this same set up
>> (this is under Essex RC1 / Ubuntu 12.04) and never had an issue.
>>
>> This just looks like it has assigned the IP to the instance, but hasn't
>> notified the management underbelly of MySQL so any client tools
>> interrogating the instance doesn't see that nova has done this work already.
>>
>> Kev
>>
>>
>> On 28 March 2012 13:04, Day, Phil <philip.day at hp.com> wrote:
>>
>>> Are you sure that its Nova that is taking the time to associate the IP,
>>> and not an ARP issue in your network ?****
>>>
>>> ** **
>>>
>>> I’ve seen this behaviour when quickly reusing floating IP addresses –
>>> Nova does the assignment and sends out an unsolicited ARP response
>>> (assuming you have the “send_arp_for_ha” flag set) – this is in
>>> network/linux_net.bind_floating_ip(). However sometimes an unsolicited
>>> APR response can get dropped in the network, ad so if the switch doesn’t
>>> see this message and it already has a previous ARP mapping in its cache
>>> then it will continue to try and send traffic to the previous user of that
>>> address until the cache times out. ****
>>>
>>> ** **
>>>
>>> Note that some network failover systems send multiple requests to get
>>> more certainty around this (for example I’ve seen a VPN solution use 6
>>> messages).****
>>>
>>> ** **
>>>
>>> There are a couple of things you could try:****
>>>
>>> ** **
>>>
>>> **- **Add a flag to be able to increase the number of
>>> arp_responses sent****
>>>
>>> **- **Change the allocation of floating_ips so that instead of
>>> picking the first free one in the DB you pick the one which has been unused
>>> for the longest time (reduces the risk of reusing an address before the
>>> switch times out the entry in its cache).****
>>>
>>> ** **
>>>
>>> Phil****
>>>
>>> ** **
>>>
>>> *From:* openstack-bounces+philip.day=hp.com at lists.launchpad.net [mailto:
>>> openstack-bounces+philip.day=hp.com at lists.launchpad.net] *On Behalf Of *Kevin
>>> Jackson
>>> *Sent:* 28 March 2012 12:49
>>> *To:* openstack at lists.launchpad.net
>>> *Subject:* [Openstack] Auto Assigned Floating IPs take a long time to
>>> associate****
>>>
>>> ** **
>>>
>>> Hi all,****
>>>
>>> I've got the following set in my nova.conf:****
>>>
>>> ** **
>>>
>>> --auto_assign_floating_ip****
>>>
>>> ** **
>>>
>>> and I fire up an instance.****
>>>
>>> Everything works, a private IP is assigned... the instance is running...
>>> but it can take an inordinate amount of time (anywhere upwards of 2 mins,
>>> sometimes a lot longer) to associate a floating IP automatically.****
>>>
>>> ** **
>>>
>>> Anybody else experienced this? Any clues on what I can do to
>>> troubleshoot this? What is the condition when a Floating IP is assigned?
>>> I've seen it assign Floating IPs very quickly when it is still Booting,
>>> not Active, say.****
>>>
>>> Is it dependent on anything within the Instance itself?****
>>>
>>> ** **
>>>
>>> Cheers,****
>>>
>>> ** **
>>>
>>> Kev****
>>>
>>> --
>>> Kevin Jackson
>>> @itarchitectkev****
>>>
>>
>>
>>
>> --
>> Kevin Jackson
>> @itarchitectkev
>>
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>>
>
--
Kevin Jackson
@itarchitectkev
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