Hey folks,

One of the initiatives the CPE team has taken over this quarter is updating and improving the performances of datagrepper/datanomer.
That work is based upon the investigation done earlier in the year whose results can be found at: https://fedora-arc.readthedocs.io/en/latest/datanommer_datagrepper/index.html

One important item to note is that we will introduce a default value for the `delta` argument.
Currently, if you do not specify one, datagrepper will not limit its queries by time, which is very resource intensive and often so much so that you do not get any results back.
By setting a default `delta` argument we can ensure that just browsing the UI does not throw random time-out errors and increase the performance of some of the queries.

However, this is a **non-backward compatible change**!

If you have scripts relying on the fact that the messages returned can be of any date, they will break once the default delta is in place. You should thus adjust them to specify a delta (which will override the default one).

The default delta will likely be set to "one day" but that's not fixed yet. Once it has been fully confirmed we'll update again, so please treat this as an FYI, but also start looking at your scripts. Specifying the `delta` today won't break the current behavior and will ensure they keep working once the change has landed.

Secondly, the grouped feature [2] will be dropped as it's not supported in the new library. If you're using it, please reach out to us so we can figure out mitigation plans.

Enjoy Nest if you're attending and have a nice weekend!

Cheers,

Ant

[1] https://fedora-arc.readthedocs.io/en/latest/datanommer_datagrepper/index.html
[2] See the section "Formatting arguments" at: https://apps.fedoraproject.org/datagrepper/reference
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