[PATCH nvme-cli rfc 0/6] Support discovery log change events

[james.smart@broadcom.com (James Smart)]

On 3/14/2019 1:43 PM, James Smart wrote:
>
>
> On 3/13/2019 5:00 PM, Sagi Grimberg wrote:
>>
>>>>> Hmm.
>>>>>
>>>>> Last time I've posted the autoconnect scripts you said you'd 
>>>>> rather have them updated to be useful for generic discovery events.
>>>>> So what happened to that?
>>>>
>>>> I would like to have a single event, but the one difference is that
>>>> the discovery log page events come on a discovery controller and in
>>>> the fc case we don't have such a controller (the NVME_INSTANCE env).
>>>>
>>>> If we can resolve this difference we can unite and have a single udev
>>>> handler for both...
>>>
>>> We shouldn't unite them. They are very different things.? One is an 
>>> event that says I found a discovery controller go probe it, while 
>>> the other is a discovery controller saying I have a discovery log 
>>> entry go connect to it.?? My position is we should have both.
>>
>> Well I agree with you, but these the question is would userspace do
>> something different for each? As of now it doesn't.
>
> I would think it would do something different. What we don't do well 
> currently is specify per-connection parameters - when automated. 
> That's where I see the difference.
>
> I would think parameters for the discovery controller should be 
> separate from parameters for? storage controllers. So the scripts 
> could use two different config files to look up defaults or 
> per-connect values.
>
> For example, the discovery controller probe request can look at a 
> discovery_connect.cfg, obtain defaults or a tr-addr-based match for 
> say ctrl-loss-timeout, whether to be long-lived, and if long-lived 
> what the keep-alive-tmo should be.
>
> While the connect request can look at storage_connect.cfg, use the 
> tr-addr-values and nqn to determine if it should not be connected to 
> (default is yes), and if connecting, defaults or any tuning based on 
> nqn or tr-addr-values to use for the connect.
>

These are still very similar - but I guess what separated things for me 
was the defaults for discovery vs storage would be different.

-- james