[ClusterLabs] corosync 2.4 CPG config change callback

[Jan Friesse]

Thomas Lamprecht napsal(a):
> Honza,
> 
> On 4/24/18 6:38 PM, Jan Friesse wrote:
>>> On 4/6/18 10:59 AM, Jan Friesse wrote:
>>>> Thomas Lamprecht napsal(a):
>>>>> Am 03/09/2018 um 05:26 PM schrieb Jan Friesse:
>>>>>> I've tested it too and yes, you are 100% right. Bug is there and it's
>>>>>> pretty easy to reproduce when node with lowest nodeid is paused. It's
>>>>>> slightly harder when node with higher nodeid is paused.
>>>>>>
>>>>>
>>>>> Do you were able to make some progress on this issue?
>>>>
>>>> Ya, kind of. Sadly I had to work on different problem, but I'm expecting to sent patch next week.
>>>>
>>>
>>> I guess the different problems where the ones related to the issued CVEs :)
>>
>> Yep.
>>
>> Also I've spent quite a lot of the time thinking about best possible solution. CPG is quite old, it was full of weird bugs and risk of breakage is very high.
>>
>> Anyway, I've decided to not to try hack what is apparently broken and just go for risky but proper solution (= needs a LOT more testing, but so far looks good).
>>
> 
> I did not looked deep into how your revert plays out with the
> mentioned commits of the heuristics approach, but this fix would
> mean to bring corosync back to a state it had already, and thus
> was already battle tested?

Yep, but not fully. Important change was to use joinlists as 
authoritative source of information about other node clients, so I 
believe that solved problems which should had been "solved" by downlist 
heuristics.


> 
> Patch and approach seems good to me, with my limited knowledge,
> when looking at the various "bandaid" fix commits you mentioned.
> 
>> Patch is in PR (needle): https://github.com/corosync/corosync/pull/347
>>
> 
> Much thanks! First tests work well here.
> I could not yet reproduce the problem with the patch applied in both,
> testcpg and our cluster configuration file system.

That's good to hear :)

> 
> I'll let it run

Perfect.

Regards,
   Honza

> 
> cheers,
> Thomas
>