Distributed clusters might encounter performance problems or unpredictable failures, especially when they are running in the cloud. Of all the kinds of failures, kernel failures may be the most difficult to analyze and simulate.
A practical solution is Berkeley Packet Filter (BPF), a highly flexible, efficient virtual machine that runs in the Linux kernel. It allows bytecode to be safely executed in various hooks, which exist in a variety of Linux kernel subsystems. BPF is mainly used for networking, tracing, and security.