[Feature Flag] Enable API last_activity_on logging

What

Remove the :api_activity_logging feature flag when we see no negative effects on database performance. The feature flag was introduced with !21725 (comment 277490451)

Owners

• Team: Ecosystem
• Most appropriate slack channel to reach out to: #g_ecosystem
• Best individual to reach out to: @Andysoiron

Expectations

The last_activity_on field gets updated once a day when the user made an API request. This could potentially lead to an increase of database transactions and transaction timing once a day at midnight UTC.

What can we monitor to detect problems with this?

https://dashboards.gitlab.net/d/000000126/grape-endpoints?orgId=1&var-action=Grape%23GET%20%2Fapi%2Fprojects&var-database=influxdb-01-inf-gprd

Roll Out

We will roll it out slowly by 10% every 4 days and monitor database transactions.

Update March 27th:

The feature flag is at 50% since March 23th and there seems to be no significant increase in database transactions or transaction timigs. This makes me confident that we can activate the feature flag globally.

Steps

• Enable on staging
• Test on staging
• Ensure that documentation has been updated
• Enable on GitLab.com for 10% and increase it every 4 days
• Coordinate a time to enable the flag with #production and #g_delivery on slack.
• Announce on the issue an estimated time this will be enabled on GitLab.com
• Enable on GitLab.com by running chatops command in #production
• Cross post chatops slack command to #support_gitlab-com and in your team channel
• Announce on the issue that the flag has been enabled
• Remove feature flag and add changelog entry
• After the flag removal is deployed, clean up the feature flag by running chatops command in #production channel

Rollout process

• Feb 25th: 10%
• Mar 9th: 20%
• Mar 13th: 30%
• Mar 17th: 40%
• Mar 23th: 50%
• Mar 27th: review the rollout process