Today I spent a number of hours on the phone with remote hands on (something similar to webex) with a customer of mine working on the GetPackageInfo.aspx problem, that turns their NS environment into a no package delivery world from time to time...
This time around everything fell down when the nightly package refresh generated new snapshot for all 1,500+ packages on the NS. With 110+ package server (3 unconstrained, all other constrained) and ~7,000 clients in the middle of a software upgrade the package servers quickly reported all their packages not ready, whilst the clients added to the incoming load .
Cutting a long story short we looked at ways to speed-up the recovery of the Package Server agents on one of the uPS and found the CodebaseCache to be our worse enemy in that case!
Let's explain that. The cache is there to reduce workload on the database and store often used data (codebases, i.e. location where a package can be downloaded for given sites...