Overview

Removes the level 2 overflow cache used when the level 1 cache is full, evicting entries from the level 1 instead. This resolves some of the thread safety issues of the level 2 cache. The level 2 cache required quiescence of RPCs to rebuild as it wasn’t thread safe to avoid locking the cache in the common read-only case, but this wasn’t well documented

Issue numbers for any defects discovered or addressed:

Documentation

Has in-repo user documentation been adjusted appropriately?

Not yet

Has in-repo design documentation been adjusted appropriately?

Not yet

Has the ChangeLog been updated with any user-facing improvements or breaking changes?

No

Expected performance impact

Once the commonly used segments stabilize into the cache, the performance should be improved over the level 2 overflow cache.

Status

Is this PR ready to review?

Code portion is ready. I’ll have the docs ready soon.