[atlas] ripe-atlas Digest, Vol 137, Issue 8

Hello,

On 2023-01-09 22:59, Geert Jan de Groot wrote:
> One question perhaps is if a probe running very obsoleted probe code, is 
> useful or perhaps at some time probes older than version 1234 should not 
> be used for pool measurements?
> 
> For instance, release 2345 enables measurements on 240/12 while older 
> releases, including release 2344, 240/12 is broken.
> Then, having probes with software 2344 or lower will give bias on 
> measurements for 240/12.

Let me offer some background information here.

For the most part, newer firmware versions provide bugfixes and/or new 
functionality. If a particular feature already exists in version 
$OLD_VERSION which is running on some probes, there's no reason to 
exclude probes from measurements that need this feature just because 
it's not the $NEWEST_VERSION.

On the flip side, the measurement scheduler is _mostly_ aware of new 
features in the firmware, in particular new measurement types and 
options and such. The we-no-longer-exclude-240/4 change is not one where 
we added this logic; mostly because it would be an exceptional case for 
a transitional period, ie. until probes upgrade to the version that has 
this change.

The exception here is the v1/v2 probes; these are not useful for these 
measurements. Because of this I'd recommend excluding these, either in 
the measurement specification, or while processing the results.

> And for that reason I wonder if it makes sense to have a policy to 
> "phase out" probes that are running obsoleted code, however well intended?

Indeed, that is a direction we are / will be headed. We plan to add 
notifications for software probe hosts if their probe firmware is not 
up-to-date. In addition, eventually we'll "phase out" (as you say) 
probes that have too old firmware - where the definition of "too old" 
can change over time.

Cheers,
Robert

> Geert Jan