Linux High Availability

We supply Linux high availability clustering solutions. The aim is to use a set of building blocks to provide highly available and reliable mission critical applications.

We use a variety of technologies including disk replication, cluster resource management software and storage cluster technologies. These include a combination of Ceph, GlusterFS, Haproxy, DRBD, Corosync, Pacemaker , Keepalived and more.

Using Linux High availability and Disaster Recovery technologies in conjunction with KVM virtualization.

The diagram below shows how you can use disk replication to create a Linux Disaster Recovery virtualization solution that replicates virtual machines in real time so that if a failure occurs, the synchronized virtual machine can just be booted off the second KVM hypervisor.

HAProxy Load Balancing

  • Layer 4 (TCP) and Layer 7 (HTTP) load balancing
  • Advanced health checking with customizable checks
  • Support for sticky ses sions and persistence
  • Detailed real-time monitoring and statistics
  • SSL/TLS termination and offloading
  • Dynamic configuration through runtime API

HAProxy can be deployed in various configurations: 

  1. Active-Passive Setup 
    • Two HAProxy instances where one is active and the other is standby ○ Failover managed through Keepalived using VRRP protocol
    • Ensures zero downtime during maintenance or failures 
  1. Active-Active Setup 
    • Multiple active HAProxy instances sharing the load
    • DNS round-robin or additional load balancer distributing traffic
    • Maximum resource utilization and scalability 
  1. Multi-tier Architecture 
    • Layer 7 proxying for web applications
    • Layer 4 proxying for database and application servers
    • Separate management of external and internal traffic 

Traefik Modern Proxy

Traefik is a modern HTTP reverse proxy and load balancer designed for microservices and container environments. Its key features include: 

  • Automatic service discovery and configuration 
  • Native integration with Docker, Kubernetes, and other platforms 
  • Real-time configuration updates without restarts 
  • Let’s Encrypt integration for automatic SSL/TLS
  • Advanced routing and middleware capabilities 
  • Modern dashboard with real-time metrics 

Traefik deployment patterns: 

  1. Container Orchestration 
    • Automatic discovery of Docker containers
    • Dynamic routing based on container labels
    • Seamless scaling and updates 
  1. Kubernetes Integration 
    • Native Kubernetes Ingress controller
    • Custom Resource Definitions (CRDs) support
    • Automatic pod discovery and routing 
  1. High Availability Setup 
    • Multiple Traefik instances for redundancy
    • Shared configuration through key-value stores
    • Integration with cluster management tools 

Both HAProxy and Traefik can be integrated with our existing high availability stack: 

  • Corosync/Pacemaker for cluster management 
  • Keepalived for floating IP management 
  • DRBD for configuration replication 
  • Monitoring through Prometheus and Grafana 

 

These proxies provide critical load balancing and routing capabilities essential for building robust, highly available infrastructure.