service/ci.md

@@ -505,6 +505,20 @@ This will probably run into rate limiting, but should gently retry
 once it hits it to match the 100 queries / 6h (one query every 216
 seconds, technically) [rate limit](https://www.docker.com/increase-rate-limits/).
 
+### Distributed cache
+
+In order to increase the efficiency of the GitLab CI caching mechanism, job
+caches configured via the `cache:` key in `.gitlab-ci.yml` are uploaded to
+[object storage](service/object-storage) at the end of jobs. This means that it
+doesn't matter on which runner a job is run, it will always get the latest copy
+of its cache.
+
+This feature is enabled via the runner instance configuration located in
+`/etc/gitlab-runner/config.toml`, and is also configured on the OSUOSL-hosted
+runners.
+
+More details about caching in GitLab CI can be found here: https://docs.gitlab.com/ee/ci/caching/
+
 ## SLA
 
 The GitLab CI service is offered on a "best effort" basis and might