[$] Containers, pseudo TTYs, and backward compatibility

There is no doubt that the addition of containertechnologies to Linux has created a lot of value,allowing workloads to be effectively and efficiently isolated from each other.Implementing these technologies presents a number of challenges,particularly as much of Linux and Unix was designed to use singletons:objects of which there could never ever be more than one, such ashost names, network routing tables, or process-ID namespaces.Containers require this design approach to be revised as they needmultiple instances of these objects. A singleton that has been causing problems recently is the set of pseudoterminals (TTYs).<p>Click below (subscribers only) for the full article from Neil Brown.