Cgroups, short for "control groups", are a Linux kernel feature that provides a way to limit, manage and isolate resource usage of a set of processes. Cgroups allow system administrators to allocate resources such as CPU, memory, network bandwidth, and I/O bandwidth to a set of processes.
Cgroups are typically used for resource management in multi-tenant environments, where multiple applications or users share a single physical system. By using cgroups, system administrators can ensure that each application or user gets a fair share of the available resources, and can prevent one application or user from monopolizing resources and affecting the performance of other applications or users.
Here are some examples of how cgroups can be used for resource management:
CPU management: Cgroups can be used to limit the CPU usage of a set of processes. For example, a cgroup can be created to limit the CPU usage of a group of processes running a batch job, to ensure that the job doesn’t consume all available CPU resources and affect the performance of other applications running on the system.
Memory management: Cgroups can be used to limit the amount of memory that a set of processes can use. For example, a cgroup can be created to limit the memory usage of a group of processes running a database server, to ensure that the database server doesn’t consume all available memory and affect the performance of other applications running on the system.
Network management: Cgroups can be used to limit the network bandwidth that a set of processes can use. For example, a cgroup can be created to limit the network bandwidth of a group of processes running a web server, to ensure that the web server doesn’t consume all available network bandwidth and affect the performance of other applications running on the system.
I/O management: Cgroups can be used to limit the I/O bandwidth that a set of processes can use. For example, a cgroup can be created to limit the I/O bandwidth of a group of processes running a file server, to ensure that the file server doesn’t consume all available I/O bandwidth and affect the performance of other applications running on the system.
In summary, cgroups are a powerful Linux kernel feature that can be used to manage and isolate resource usage of a set of processes. Cgroups can be used to allocate and limit resources such as CPU, memory, network bandwidth, and I/O bandwidth to a set of processes. Cgroups are useful for resource management in multi-tenant environments, where multiple applications or users share a single physical system.