Analytics Query Service (AQS) is the software behind the `/metrics` family of endpoints in RESTBase. It is a read-only HTTP proxy to results served from Cassandra and Druid. It is currently based on a very fork of RESTBase, and has received little updates over the years.
As a part of the goal to sunset RESTBase, AQS needs to be migrated to a bespoke service exposed via the API Gateway.
### Overview
1. !!Implement a new, stand-alone AQS service!!
1. Deploy AQS 2.0 on k8s
1. Expose the `/metrics` hierarchy from the new service using the API Gateway
1. Switch RESTBase to proxying requests from the old AQS service, to the new k8s-based one
1. Deprecate the http://{project}/api/rest_v1/metrics resources
1. Eventually phase out the RESTBase `/metrics` hierarchy
Solving this will make us progress on multiple fronts: T198901 T262315
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NOTE: This will be picked up by Platform Engineering, with support from Analytics.
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**See also:**
https://wikitech.wikimedia.org/wiki/Analytics/Systems/AQS
https://github.com/wikimedia/analytics-aqs
https://github.com/wikimedia/restbase
https://wikimedia.org/api/rest_v1/
https://gitlab.wikimedia.org/eevans/aqs (work-in-progress AQS 2.0 code repository)