cassandra@cqlsh> select * from "local_group_default_T_unique_devices".data where timestamp = '20180201' and project='es.wikipedia' and granularity='monthly' and "_domain"='analytics.wikimedia.org' and "access-site"='all-sites' limit 1 ;

_domain | project | access-site | granularity | timestamp | _tid | _del | devices
-------------------------+--------------+-------------+-------------+-----------+--------------------------------------+------+-----------
analytics.wikimedia.org | es.wikipedia | all-sites | monthly | 20180201 | 13814000-1dd2-11b2-8080-808080808080 | null | 151476294

(1 rows)
cassandra@cqlsh> select * from "local_group_default_T_unique_devices".data where timestamp = '20180101' and project='es.wikipedia' and granularity='monthly' and "_domain"='analytics.wikimedia.org' and "access-site"='all-sites' limit 1 ;

_domain | project | access-site | granularity | timestamp | _tid | _del | devices
---------+---------+-------------+-------------+-----------+------+------+---------

(0 rows)

I double checked data:

• Monthly uniques are missing for 2018-01
• Daily uniques are not missing

Here is what happened:

• At the beginning of February I restarted he Cassandra bundle to pick a conf change pushed in January (https://tools.wmflabs.org/sal/log/AWFRTM-ekkJ8OkTwh7DO).
• I made a mistake in not being careful enough checking for jobs completion: the monthly uniques job was not finished and actually failed (https://tools.wmflabs.org/sal/log/AWFV8nwFL7tQ11ghvJH4)
• Since I restarted the loading beginning in Feb, the monthly loading for January didn't happen.

I start a dedicated coordinator for that specific month now.

Solved - Data is in cassandra (we need to wait for cache updates before seeing the data in AQS).

Change 419692 had a related patch set uploaded (by Joal; owner: Joal):
[analytics/refinery@master] Correct cassandra loading monthly jobs

https://gerrit.wikimedia.org/r/419692

Change 419692 merged by Joal:
[analytics/refinery@master] Correct cassandra loading monthly jobs

https://gerrit.wikimedia.org/r/419692