Simplify and enhance the management of DRBD resources
What is DRBD Reactor?
DRBD® Reactor is an event-based management framework for DRBD® resources. It monitors the state of DRBD devices and takes predefined actions in response to state changes. It is designed to replace or complement traditional resource management tools like Pacemaker in certain scenarios, especially when a lighter, more focused tool is sufficient or preferred.
Logical Structure
DRBD Reactor is hierarchically structured in two parts: a core and plug-ins. The core listens for certain conditions, whereas plug-ins perform operations when specified conditions are met.
Relevant Plug-ins
Promoter
Manages HA services, automates failover and resource promotion in a DRBD cluster.
Prometheus
Prometheus is an open source monitoring and alert tool exposing 26 DRBD metrics.
User Mode Helper (UMH)
Executes user-defined scripts or actions when specific events occur, e.g. send a Slack message when a DRBD resource loses a connection.
“DRBD itself knows best where it has ‘good data’ and which node to promote. [DRBD Reactor] shifts all the complexity to other existing components, like DRBD quorum and systemd for service starting.”
Roland Kammerer
DRBD Engineer
Key Features
Simplified Resource Management
It provides an alternative to traditional cluster management solutions like Pacemaker, offering simpler configuration and operation for setups focused on DRBD.
Lightweight and Efficient
Unlike full-fledged cluster management systems, DRBD Reactor is lightweight and designed specifically for DRBD.
Event-Driven Automation
DRBD Reactor responds to events like resource promotion, demotion, connection establishment, or disconnection, and triggers predefined actions.
Integration with systemd
DRBD Reactor is tightly integrated with systemd, making it easy to use on modern Linux distributions.
Customizable Actions
Users can define custom handlers or scripts for specific events, enabling fine-grained control over how the system reacts to changes.
Resource Health Monitoring
DRBD Reactor continuously monitors the health of DRBD resources and ensures they are in the desired state.
