acassen/keepalived
Keepalived
Keepalived is a high availability manager and virtual IP failover tool that ensures continuous service availability. It coordinates the migration of floating IP addresses between master and backup nodes using the Virtual Router Redundancy Protocol to manage router redundancy and seamless failover.
The project distinguishes itself by integrating with the Linux kernel IPVS module to function as a transport-layer load balancer. It distributes network traffic across backend servers using various scheduling algorithms and forwarding methods such as NAT, direct routing, or tunneling.
The system includes network health monitoring capabilities using TCP, HTTP, and the Bidirectional Forwarding Detection protocol to identify failures in milliseconds. It further supports automated failover orchestration through the execution of custom scripts, SMTP administrative alerts, and the synchronization of routing paths across multiple instances.
The software provides a configuration surface that supports templatization, network namespace isolation, and the export of system metrics via SNMP.
Features
- High Availability Services - Coordinates virtual IP addresses and failover between nodes using the VRRP protocol to ensure continuous service availability.
- High Availability Networking - Ensures continuous service by automatically migrating virtual IP addresses between master and backup nodes using the VRRP protocol.
- IPVS Interface Mapping - Translates user-space configuration into Linux kernel IP Virtual Server rules for high-performance transport-layer load balancing.
- Protocol Failover High Availability - Identifies link and peer failures in milliseconds using the BFD protocol to trigger rapid failover transitions.
- Automated Master Failovers - Coordinates virtual IP addresses across nodes using an election process to ensure backup takeover when a master fails.
- Virtual IP Failovers - Transitions virtual IP addresses between master and backup nodes based on priority and health states.
- Round-Robin Load Balancings - Implements Round Robin and Weighted Least Connection algorithms to distribute requests across real servers via NAT.
- Gratuitous ARP Broadcasting - Sends unsolicited ARP updates to notify network switches of virtual IP migrations during master-to-backup transitions.
- Bidirectional Forwarding Detection - Uses the BFD protocol to provide fast bidirectional forwarding detection for instance tracking and server monitoring.
- Floating IP Management - Assigns a virtual IP address to a group of nodes and migrates it to a backup if the primary fails.
- High Availability Routing - Maintains consistent routing paths for IPv4 and IPv6 using a virtual router protocol to provide failover.
- IPVS Load Balancers - Interfaces with the Linux kernel IPVS module to balance network traffic across backend servers.
- Load Balancers - Distributes network traffic across multiple backend servers using the Linux kernel IPVS module for high performance scaling.
- Load Balancing - Distributes network traffic across multiple backend servers using various scheduling algorithms via a kernel module.
- Network Routing and Traffic Management - Routes incoming requests to backend servers using NAT, IP tunneling, or direct routing to balance load.
- Virtual IP Failover Systems - Creates floating IP addresses that migrate between master and backup nodes to ensure continuous service availability.
- Service Instance IP Failovers - Provides virtual IP failover mechanisms to redirect requests to backup nodes when a master router becomes unavailable.
- Router State Synchronization - Groups multiple instances together to maintain consistent states and routing paths during a protocol takeover.
- Traffic Distribution - Balances network traffic using IPVS forwarding methods including NAT, Direct Routing, and Tunneling.
- Virtual Router Redundancy Management - Coordinates virtual router instances to provide seamless failover and maintain consistent routing paths across a network cluster.
- VRRP Coordination - Coordinates high availability across network interfaces using the VRRP protocol to ensure seamless failover.
- VRRP Management Tools - Manages virtual IP addresses and failover between nodes using the Virtual Router Redundancy Protocol.
- VRRP State Coordination - Coordinates virtual IP ownership between nodes using a priority-based election and heartbeat mechanism for seamless failover.
- Network Service Health Monitors - Detects server or link failures via TCP, HTTP, or BFD to trigger automatic failover and remove unhealthy nodes.
- Upstream Health Monitoring - Monitors the availability and status of backend servers via TCP, HTTP, and other protocols to manage the load balancing pool.
- Network Health Monitors - Uses TCP, HTTP, and custom scripts to detect service failures and trigger failover transitions.
- Polling-Based Health Monitors - Regularly probes backend servers using various network protocols to dynamically update the active routing pool.
- Server Health Monitoring - Detects server failures through health checks to remove unhealthy nodes from the active traffic pool.
- Service Health Monitoring - Executes backend service health checks to detect failures and ensure traffic is only routed to healthy nodes.
- Hash-Based Session Affinity - Assigns connections to specific servers using source or destination IP hashing to ensure session persistence.
- Remediation Script Execution - Executes corrective scripts automatically when system health checks fail to trigger recovery actions.
- Connection State Synchronization - Binds a daemon to a network interface to keep connection states consistent across different nodes.
- Kernel IPVS Interfaces - Translates internal configuration into Linux kernel IPVS rules for high-performance transport-layer load balancing.
- Network Routing Rules - Sets up static IP addresses and routing rules that persist independently of failover state transitions.
- Network Session Persistence - Tracks network connections using the kernel firewall to ensure client requests consistently reach the same backend server.
- Weighted Route Failovers - Directs all traffic to the available server with the highest weight to provide a backup mechanism.
- Protocol Instance Synchronizations - Groups multiple virtual router instances to ensure they fail over as a single unit and maintain consistent routing paths.
- Routing Path Synchronization - Groups multiple virtual router instances to fail over as a single unit and maintain consistent routing.
- Destination-Based Routing - Directs packets to servers based on the destination IP address with options for locality-based overrides.
- Macvlan Virtual Network Creation - Creates virtual network interfaces with unique MAC addresses to reduce the impact of router takeovers on upstream hardware.
- Event-Driven Notification Triggers - Triggers external scripts or SMTP alerts immediately in response to real-time system events and state changes.
- Virtual MAC Mapping - Creates macvlan interfaces to provide virtual MAC addresses and reduce the impact of router takeovers.
- System Health Monitoring - Tracks network interfaces, processes, and BFD sessions to trigger priority adjustments or failover states.
- Event-Triggered Scripts - Executes external scripts triggered by state transitions or health check failures to automate system recovery.
Star history
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