Reload PostgreSQL and Redis connection pools upon failure
Previously if the PostgreSQL or Redis connections were severed, GitLab Exporter would not be able to recover even if either database came back up since there was no reconnection mechanism. This change implements reconnection by shutting down each connection in the pool and reloading the pool.
Relates to https://gitlab.com/gitlab-com/enablement-sub-department/section-enable-request-for-help/-/issues/77
Edited by Stan Hu