define alert rule for missing GDC metadata archive

[tomkralidis]

In cases where a GDC does not produce a metadata archive zipfile on a daily basis (noting the 24 hour retention time for GC), there exists a risk / gap in not being able to cold start a GDC from a known archive. Consider raising an alert in this case.

[kaiwirt]

What are suitable solutions for this?

GC providing a metric with the time stamp of the last time it received the archive?

Consider how the GDC can ensure that the archive is complete and unzipable before sending it

[kaiwirt]

I was wondering if this is a duplicate of #16 ?

Do we need two metrics, one for metadata and one for the archive? See also the comment from @aschremm in #16
I only recall that we wanted to have an alert when the archive is not received by the GC for more than 24 hours....

@tomkralidis

[tomkralidis]

@kaiwirt we have wmo_wis2_gc_last_metadata_timestamp_seconds as part of GC metrics. Can we define a rule to trigger an alert when the timestamp is older than 24 hours?

[kaiwirt]

This could be added to https://github.com/wmo-im/wis2-metric-hierarchy/blob/main/alerts/gc.yml

[antje-s]

Currently we do not use the metric wmo_wis2_gc_last_metadata_timestamp_seconds for the zip-archive but set the timestamp for the last download of a metadata record per centre_id

[kaiwirt]

@antje-s : Would it be possible to add the zip-archive as a metadata record from the GDC in that sense?

[kaiwirt]

@el4ren Is it possible to make the suggested change such that the linked pull request can go in?