A resource manager is a system in distributed computing that coordinates the allocation and management of computational resources like CPU, memory, and network bandwidth to fulfill the requirements of various applications or tasks.
A resource manager serves as a crucial mediator between the demand for computational resources and the physical or virtual infrastructure that supplies them. It is designed to oversee resource distribution by considering the needs, priorities, and limitations of different tasks, ensuring an efficient and equitable utilization of resources across the computing environment.
One of the key functions of a resource manager is to continuously monitor resource consumption and availability, allowing it to make informed decisions for resource reallocation and system optimization. This dynamic adjustment of resources is essential to handle fluctuating workloads and maintain optimal performance levels.
Resource managers also provide job scheduling, facilitating the orderly execution of tasks by deciding the timing and placement of jobs based on resource availability and predetermined policies. Moreover, they ensure fault tolerance and maintain system reliability by managing resource failures and disruptions through various mechanisms such as task migration and job retries.
In multi-tenant systems, resource isolation is a critical function to prevent conflicts and ensure security. Resource managers achieve this by enforcing quotas and controls, thereby safeguarding against unauthorized resource consumption or attacks.
They are integrated with the underlying infrastructure, such as compute clusters or cloud platforms, and interact through APIs or protocols to manage resources effectively. Examples of resource managers include Kubernetes for container orchestration, Apache YARN for job scheduling in Hadoop clusters, and cloud-based solutions like AWS Elastic Compute Cloud (EC2).