Managing large Debian repositories with Pulp (and less than 50GiB of RAM)

Pulp is a platform for software repository management.
The pulp_deb plugin adds Apt-repository support for Debian packages.
Until recently, the pulp_deb implementation did not scale well for large repositories.
Synchronizing a full Debian or Ubuntu release (typically containing around 50,000 Packages) would routinely take hours before falling victim to the OOM-killer.
This talk discusses the changes we employed to fix this lamentable state of affairs.
It concludes with lessons learned for the development of pulp_deb 3.