The trouble is the aggregate query to return the big blue numbers on the dashboard and /notifications/{notification_type} page is taking too long to return.
I have some ideas on how to improve the query, but should take some time to do some more research and test. In the meantime, let's just ignore "todays" total numbers for the high volume services. There are only two services that this will affect.
We no longer will send them any stats so therefore don't need the code
- the code to work out the nightly stats
- the performance platform client
- any configuration for the client
- any nightly tasks that kick off the sending off the stats
We will require a change in cronitor as we no longer will have this task
run meaning we need to delete the cronitor check.
The '/service/monthly-data-by-service` endpoint which is used for the
'Monthly notification statuses for live services' Platform Admin report
did not including `pending` notifications. This updates the DAO function
that the endpoint calls to group `pending` and `sending` notifications together.
the nightly task won't be affected, it'll just trigger three times more
sub-tasks.
this doesn't need to be a two-part deploy because we only trigger this
overnight, so as long as the deploy completes in daytime we don't need
to worry about celery task signatures
previously we checked notifications table, and if the results were
zero, checked the notification history table to see if there's data
in there. When we know that data isn't in notifications, we're still
checking. These queries take half a second per service, and we're
doing at least ten for each of the five thousand services we have in
notify. Most of these services have no data in either table for any
given day, and we can reduce the amount of queries we do by only
checking one table.
Check the data retention for a service, and then if the date is older
than the retention, get from history table.
NOTE: This requires that the delete tasks haven't run yet for the day!
If your retention is three days, this will look in the Notification
table for data from three days ago - expecting that shortly after the
task finishes, we'll delete that data.
This PR updates those queries to look in either Notification or NotificationHistory. Since the data does not exist in both tables at the same time we can do with and not worry about the data retention.
The query will iterate over each service, then each notification type and query the data if no results then try the history table.
the create_nightly_notification_status task runs at 00:30am UK time,
however this means that in summer datetime.today() will return the
wrong date as the server (which runs on UTC) will run the task at
23:30 (populating the wrong row in the table).
fix this to use nice tz aware functions
The previous query was including all notifications regardless of notification_status. I don't think that's right, it shouldn't include things like technical-failure or validation-failed. Thoughts?
I also need to remove the query that's no longer being used.
Currently, admin app requests service statistics (with notification
counts grouped by status) and template statistics (with counts by
template) in order to display the service dashboard.
Service statistics are gathered from FactNotificationStatus table
(counts for the last 7 days) combined with Notification (counts for
today).
Template statistics are currently gathered from redis cache, which
contains a separate counter per template per day. It's hard for us
to maintain consistency between redis and DB counts. Currently it
doesn't update the count for cancelled letters, counter resets in
the middle of the day might produce a wrong result for the rest of
the week and cleared redis cache can't be repopulated for services
with low data retention periods).
Since FactNotificationStatus already contains separate counts for
each template_id we can use the existing logic with some additional
filters to get separate counts for each template and status combination,
which would allow us to populate the service dashboard page from one
query response.
The query follows the same pattern as the other queries, getting the statistics from the fact_notification_status table for dates older than today and union that with today.
Tests required.
we previously always read from NotificationHistory to get the
notification status stats for a job. Now, if the job is more than three
days old read from ft_notification_status table, otherwise read from
the notifications table (to keep live updates).
