Resource Scheduler on

Overview

Mon, 01 Jan 0001 00:00:00 +0000

The OpenNebula resource scheduler framework is a modular system that applies different scheduling algorithms to allocate three types of resources:

Hosts – Determines the Hosts where VMs will run.
System Datastores – Selects the storage location for VM virtual disk images.
Virtual Networks – Assigns Virtual Networks for VM interfaces when set to auto mode.

This scheduling mechanism is used for the following cloud operations:

Scheduler Configuration

Mon, 01 Jan 0001 00:00:00 +0000

The OpenNebula scheduler is a configurable component that determines how Virtual Machines (VMs) are allocated and migrated across the infrastructure. This section describes the relevant configuration parameters found in oned.conf that control the scheduler’s behavior.

Scheduler Driver Configuration

The SCHED_MAD parameter specifies the scheduler driver responsible for managing scheduling operations. The configuration includes:

EXECUTABLE: The path to the scheduler driver executable. This can be either an absolute path or a path relative to /usr/lib/one/mads/.
ARGUMENTS: A set of arguments passed to the scheduler driver:
- -t: Number of threads, i.e. the number of concurrent scheduling operations.
- -p: Scheduler used for initial VM placement:
  - rank: The default OpenNebula matchmaking algorithm.
  - one_drs: Optimizes VM placement and balances cluster load.
- -o: Scheduler used for cluster-wide VM optimization:
  - one_drs: Optimizes VM placement and balances cluster load.

Example configuration:

Rank Scheduler

Mon, 01 Jan 0001 00:00:00 +0000

The OpenNebula Rank Scheduler is responsible for allocating pending Virtual Machines to available hypervisor nodes. It’s a dedicated daemon installed alongside the OpenNebula Daemon (oned), but can be deployed independently on a different machine. The Scheduler is distributed as part of the operating system package opennebula with the system service opennebula-scheduler.

Overview

The Rank Scheduler implements a match-making algorithm for VM allocation. The goal of this policy is to prioritize the resources that are more suitable for the VM.

Distributed Resource Scheduler

Mon, 01 Jan 0001 00:00:00 +0000

The OpenNebula Distributed Resource Scheduler (DRS) optimizes resource allocation and prevents resource contention within a single OpenNebula cluster. It integrates with OpenNebula’s built-in monitoring and forecasting systems, considering real-time Virtual Machine (VM) and Host usage metrics as well as predictions of future resource consumption.

OpenNebula DRS offers flexible automation levels, allowing recommendations to be generated and applied either automatically or manually. Administrators can review and execute migration suggestions through the OpenNebula Sunstone GUI.