Expose global_search_indexing_apdex as a prometheus metric
We want to expose global_search_indexing_apdex
to Prometheus, so that we can use GitLab runbooks to read it and use it in the error budget framework.
We can use GitLab Application Service Level Indicators (SLIs) to implement custom SLIs for indexing, and then every time we index a model, we can increment the SLI. We should do this at both locations where we index, ElasticCommitIndexerWorker
and ProcessBookkeepingService
Edited by Roy Zwambag