since ignition can constantly retry though (after reboots), I guess it 
depends on how long the apps running are it are allowed to not have the 
node available.

On Friday, June 9, 2017 at 12:23:36 PM UTC-7, Charles Allen wrote:
>
> Thank you, Alex!
>
> It is worth noting that AWS's S3 has 99.9% monthly uptime SLAs as of the 
> time of this writing (as per https://aws.amazon.com/s3/sla/ ).
> For 5 minutes to be enough for ignition to expect recovery, that means the 
> underlying service should have 99.99% monthly uptime SLA. 
>
> So it is not immediately clear that pulling from S3 is a suitable target 
> for ignition as it is currently configured.
>
> Thoughts?
>  
> On Thursday, June 8, 2017 at 2:19:15 PM UTC-7, Alex Crawford wrote:
>>
>> On 06/07, Charles Allen wrote: 
>> > Is the retry behavior of ignition fetches documented anywhere? 
>>
>> It is not, but it really should be. Ignition will retry fetches until 
>> they succeed (there are other mechanisms in the OS which will cut the 
>> entire boot process short though). Fetches are considered complete if 
>> they return HTTP codes less than 500. So, for example, if you fetch a 
>> config which results in a 404, Ignition will immediately fail. If it 
>> returns a 500, Ignition will keep trying. 
>>
>> > I would be very concerned if a simple 5XX response from an S3 endpoint 
>> > could prevent an instance from booting without warning. 
>>
>> Agreed. On top of the above behavior, if Ignition fails to complete and 
>> it gets stuck in the initramfs, the machine will begin a five-minute 
>> countdown. If there is no user input within that time, the machine will 
>> reboot and start the whole process again. The effect is that your 
>> machine will continually attempt to boot and run Ignition until it is 
>> sucessful. 
>>
>> -Alex 
>>
>

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