CRaC (Coordinated Restore at Checkpoint) is an OpenJDK project for the coordination of Java applications at checkpoints which leverages the CRIU (Checkpoint/Restore In Userspace) library for process snapshotting. This talk will briefly introduce Firecracker, an open source virtualization technology based on KVM, explain how CRaC can be used with it and compare it with CRIU.

The second part of the talk will introduce some new tools based on Userfaultfd and DAMON which allow fine grained analysis of of the JVM's memory access patterns during restore and end with a discussion on how the JVM could be optimized to improve them.