👉 Overview
👀 What ?
The Linux CGroup Namespace is a feature that isolates and limits resource usage for a collection of processes in Linux operating system. It is a part of the Linux kernel's containerization technologies and is used to manage and restrict resource allocation to groups of processes.
🧐 Why ?
The use of CGroup Namespace is crucial in modern computing environments as it allows for better resource management, process isolation and containerization. This feature is particularly important in cloud computing and in environments where multiple applications or services are running concurrently on the same system. It helps to ensure that each process or group of processes has a fair share of the system resources, and prevents any single process from consuming all the resources and causing system instability.
⛏️ How ?
CGroup Namespace can be used by creating hierarchies of control groups, which can then be assigned specific limits on resources like CPU time, system memory, network bandwidth, or combinations of these. These resource limits can be dynamically adjusted as per the needs of the system. To implement CGroup Namespace, one needs to have a Linux kernel with CGroup Namespace support, and utilities like 'cgcreate', 'cgexec' and 'cgclassify' for managing control groups.
⏳ When ?
CGroup Namespace has been a part of the Linux kernel since version 2.6.24, which was released in 2008. Its use has become more widespread with the rise of containerization and cloud computing.
⚙️ Technical Explanations
In Linux, a CGroup (control group) is a collection of processes that are bound by the same criteria and are treated as a single entity from the perspective of resource allocation. CGroup Namespace provides a way to partition these groups of processes into isolated environments, each with their own view of the system resources. This is done using a hierarchical structure, where each CGroup can have multiple child CGroups, each with their own resource limits. The resource limits are enforced by the Linux kernel, which ensures that each CGroup only uses the resources it is allocated. This allows for more fine-grained control over the system resources, and helps to improve system stability and performance.