TimeKeeper: a lightweight virtual time system for linux

We present TimeKeeper: a simple lightweight approach to embedding Linux containers (LXC) in virtual time. Each container can be directed to progress in virtual time either more rapidly or more slowly than the physical wall clock time. As a result, interactions between an LXC and physical devices can be artificially scaled, e.g., to make a network appear to be ten times faster with respect to the software within the LXC than it actually is. Our approach also supports synchronized (in virtual time) emulation, by grouping LXCs together into an experiment where the virtual times of containers are kept synchronized, even when they advance at different speeds. This has direct application to the integration of emulation and simulation within a common framework.