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Namespaces are one of the primary components of linux containers. Namespaces provide isolation of shared resources: they give each application its own unique view of the system. Because of namespaces, each docker container to appears to have its own filesystem and network. Linux added namespace support gradually over many releases. Due to this gradual change, each type of namespace offers its own unique challenges. Pid namespaces in particular require special handling, especially when multiple processes are involved.