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SafeKit: Microsoft Azure Load Balancing & Application High Availability Farm Cluster

Enhance the Cloud Load Balancer with Application-Level Monitoring and Self-Healing

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A SafeKit Farm Cluster for Azure is a software-defined high availability solution optimized for Cloud environments. By providing Deep Monitoring & Self-Healing directly on application nodes, it ensures that software failures are detected and resolved locally before they impact availability. It integrates seamlessly with Azure Load Balancers, using intelligent health checks to route traffic only to fully operational nodes.

What are the advantages of a SafeKit Farm Cluster for Azure applications?

  • Azure Load Balancer Integration: Automatically provides precise health checks to Azure Load Balancers, ensuring traffic is routed based on the actual state of the Azure application rather than just server pings.
  • Deep Monitoring & Self-Healing: Detects "zombie" states where a Cloud instance is "Running" but the application has crashed. SafeKit triggers an automatic service restart locally before notifying the Cloud Load Balancer to failover.
  • Hybrid Farm & Mirror Capability: Uniquely allows mixing a Farm cluster (for scaling front-ends via Cloud LB) with a Mirror cluster (for synchronous data replication of back-ends), solving the persistent storage challenge in Azure.
  • Kubernetes Alternative: SafeKit provides high availability for both legacy and containerized applications (not designed for Kubernetes) without the operational overhead and complexity of Kubernetes orchestration.
  • Uniform Deployment (On-Prem or Cloud): Aside from configuring the Virtual IP within a Cloud Load Balancer, the SafeKit deployment process remains identical across on-premises and cloud environments.
SafeKit High Availability Azure Cluster Architecture providing Virtual IP, Automatic Failover, Automatic Failback, and Network Load Balancing
SafeKit Farm NLB Cluster for Azure

How the SafeKit software simply implements a Azure Network Load Balancing (NLB) cluster?

What is the SafeKit Farm NLB solution for Azure?

SafeKit provides network load balancing and high availability for Azure across two or more nodes.

This article explains how to quickly implement a Azure cluster without requiring specialized High Availability (HA) expertise.

The solution works by integrating SafeKit's application health checks with a virtual IP defined at the Azure load balancer level. By configuring specific application service names and application checkers, SafeKit ensures the load balancer only directs traffic to healthy, operational applications.

SafeKit enables network load balancing and automatic failover, delivering seamless scalability and continuous service availability for your mission-critical applications.

How does SafeKit application monitoring differ from standard NLB health checks?

Unlike standard NLB hardware that rely on simple pings and port checks, SafeKit features integrated application-level checkers. While a traditional balancer only confirms if a server is "alive," SafeKit monitors the actual health of specific Azure applications.

This deep monitoring allows the system to detect "zombie" states—where the server is up but the software has crashed—triggering automatic service restarts or traffic redirection that standard NLB solutions cannot perform.

How does SafeKit handle Uniform Deployment and the Cloud Virtual IP?

SafeKit is a cloud-agnostic solution, ensuring that the deployment process and architecture remain consistent across on-premises servers and all major cloud providers. The primary architectural difference lies in how the Virtual IP (VIP) is presented to the network:

  • On-Premises: SafeKit manages VIP load balancing directly on the application servers using efficient kernel-level filtering. Failover is handled by sending GARP (Gratuitous ARP) packets to local switches, which reassigns the IP to the active nodes instantaneously.
  • In the Cloud: Because cloud networks do not support GARP, the Virtual IP is hosted by a Cloud Load Balancer. In this configuration, SafeKit provides the intelligent health checks required to determine node status. This enables the Load Balancer to detect active nodes in real-time and route traffic automatically, ensuring seamless failover across Availability Zones.

Why choose a unified All-in-One HA solution over fragmented tools?

Unlike "bolt-on" solutions that combine separate products for clustering, SafeKit integrates Virtual IP, Network Load Balancing, Automatic Failover, Automatic Failback and Synchronous Real-time File Replication into a single engine.

This eliminates the "house of cards" risk where updates break fragile links between disparate tools, provides a single point of accountability for the entire HA stack, and reduces human error by providing a single interface for Azure application HA.

Is it possible to set up a Azure farm cluster without clustering skills?

Yes. This article explains how to quickly implement a Azure farm cluster without the need for specialized and complex clustering skills. By using SafeKit’s health checks to handle the Virtual IP network load balancing and SafeKit's application monitoring and restart, you get a robust scalable solution that is significantly simpler to deploy and maintain than traditional NLB clustering solutions.

Beyond Azure, which applications and environments can SafeKit protect?

SafeKit is a versatile high-availability solution for both Windows and Linux that extends far beyond Azure farm cluster. It enables mirror clusters with synchronous real-time replication and automatic failover for a wide range of critical workloads, including:

  • Virtual & Physical Environments: Complete Hyper-V or KVM virtual machines.
  • Container Orchestration: Docker, Podman, and K3s (Kubernetes) environments.
  • Data & Services: Individual file directories, services, and various databases.
  • Cloud Infrastructure: High availability for Cloud applications.

Explore the full list of supported HA solutions here.

How the SafeKit farm cluster works with Azure?

How Network Load Balancing (NLB) works for Azure

  • Multi-AZ Deployment: Nodes are distributed across multiple Availability Zones (Multi-AZ) to ensure maximum resilience against data center outages.
  • Active-Active Redundancy: The critical Azure application runs simultaneously across all nodes in the farm.
  • Intelligent Traffic Routing: Users connect via a virtual IP address managed by the Azure load balancer.
  • Real-Time Health Monitoring: The load balancer leverages SafeKit’s Health Check URL. SafeKit returns an HTTP 200 OK when a node is healthy and an HTTP 404 (or timeout) upon failure, allowing the load balancer to automatically route traffic only to operational nodes.

How High Availability (HA) works for Azure

  • Advanced Application Checking: SafeKit constantly monitors the Azure application using built-in process checkers and customizable scripts.
  • Self-Healing Capabilities: In the event of a software glitch, SafeKit automatically attempts to restart the application locally using pre-configured restart scripts.
  • Seamless Failover: If local restarts fail, SafeKit stops responding to health checks, triggering the load balancer to execute an immediate failover to the remaining healthy nodes.
  • Simplified Maintenance: Each node includes a SafeKit web console connector, providing a "one-click" interface to manually exclude nodes from the cluster for hardware or software maintenance.
Diagram showing a SafeKit farm cluster for Azure with Multi-AZ redundancy, showing a load balancer using HTTP health checks to route traffic between active nodes and handle automatic failover.
SafeKit NLB and HA Architecture for Azure

How to configure the load balancer rule: is the Azure application stateful or stateless?

The configuration of your load balancer depends on whether your application is stateful or stateless:

Stateful Configuration (Session Affinity)

For a stateful Azure application, session affinity (persistence) is required. This ensures that a specific client remains connected to the same node across multiple TCP sessions to maintain their application context. In this scenario, the load balancer is configured with a rule based on the Client IP address. Consequently, while an individual client is locked to a specific node, traffic from different clients is distributed across the various nodes in the farm.

Stateless Configuration (No Affinity)

Conversely, for a stateless Azure application, session affinity is not required. Since no local context is stored on the node between sessions, a single client can be balanced across different nodes for each new TCP session. In this case, the load balancer rule is configured based on the TCP session identity. This configuration provides the most efficient distribution of traffic across the farm, but it is only applicable to services designed without session dependency.

How to configure a SafeKit farm cluster in Azure?

SafeKit Web Console: Farm cluster configuration for network load balancing and virtual IP management.

The SafeKit farm cluster is designed for high availability and scalability of services. The configuration focuses on distributing incoming traffic across both nodes simultaneously:

  • Load Balanced Services (Macros tab): Define the specific application services (e.g., Apache, IIS, Nginx) to be kept active on all nodes.
  • Heartbeat network(s): Communication path(s) used to detect if a node has left the farm.
  • Virtual IP (Farm VIP): For on-premises deployment, configure the VIP directly in the SafeKit web console. For cloud deployment, configure the Virtual IP in the Cloud Load Balancer using SafeKit's health check.
  • Load Balancing Rules: For on-premises deployment, configure the traffic distribution policy based on the source IP address or port in the SafeKit web console. For cloud deployment, configure the policy in the Cloud Load Balancer.
  • Checkers: Monitor the application's health and trigger automatic restart if a process failure is detected.

How to monitor a SafeKit farm cluster in Azure?

SafeKit Console: Monitoring a 2-node Farm cluster showing both nodes in UP state with active load balancing.

Monitoring a farm cluster provides visibility into the Active-Active nature of the infrastructure, where all nodes contribute to the application's performance (showing 2 nodes in this example):

  • UP State (50% on 2 nodes): In a healthy farm, both nodes are in the "UP" (50%) state, meaning they are both actively receiving and processing client requests via the shared Virtual IP.
  • Automatic Re-balancing: If one node fails, the console visually shows the remaining node taking 100% of the traffic. The failover delay depends on the Cloud load balancer's health check polling interval.
  • Node Insertion: When a repaired node is restarted, it transitions from "STOP" to "UP" and automatically starts receiving its portion of the load without administrator intervention.
  • No Data Sync: Note that in a farm cluster, there is no "Orange" resynchronization state, as nodes are expected to be stateless or share a backend database (which can be protected separately in a mirror cluster).

Beyond simple status icons, the interface provides one-click node management, allowing you to manually stop or start a node for planned maintenance while the shared Virtual IP automatically redistributes traffic without interrupting user activity.

Comparison: SafeKit Farm Cluster On-Premises vs. SafeKit Farm Cluster in the Cloud

Technical comparison of SafeKit Farm Cluster On-Premises vs. in the Cloud
Feature SafeKit On-Premises (Physical/VM) SafeKit in the Cloud (AWS, Azure, GCP)
Virtual IP (VIP) Management SafeKit manages the VIP directly via Gratuitous ARP (GARP). The Virtual IP is hosted by a Cloud Load Balancer (NLB).
Traffic Distribution Handled by the SafeKit Kernel Filtering Algorithm across local nodes. Handled by the Cloud Load Balancer based on SafeKit health status.
Health Monitoring Internal heartbeats monitor node health. The Load Balancer polls a SafeKit Health Check URL (HTTP 200/404).
Deep Monitoring & Self-Healing SafeKit monitors application processes and executes local restart scripts before failing over. SafeKit monitors application processes and stops responding to the Cloud LB health check to trigger failover.
Failover Mechanism VIP is moved instantly between nodes on the local network. Load Balancer stops routing traffic to the failed node automatically.
Infrastructure Requirement Standard Layer 2 network (same subnet for VIP). Multi-AZ (Availability Zones) for maximum resilience.

Conclusion

Whether on-premises or in the cloud, SafeKit ensures that your critical applications remain resilient, scalable, and easy to manage through a single, unified interface. For software editors, the SafeKit software-only nature is the ultimate choice for adding a High Availability option to your product catalog. Unlike hardware-dependent or cloud-specific solutions, SafeKit is 100% agnostic, allowing you to provide a consistent HA experience regardless of whether your customers deploy on-premises, in virtualized environments, or across public clouds.

Video Guide: Configuring a SafeKit Farm NLB Cluster

SafeKit Video: Network Load Balancing and Virtual IP Management (5:03)

This video demonstrates a SafeKit on-premises deployment. The configuration is very similar to a cloud deployment, with the primary difference being the Virtual IP setting (which is replaced by a cloud load balancer).

Learn how to implement a virtual IP address to provide a single entry point for a 2-node cluster. SafeKit simplifies network load balancing by automatically managing the virtual IP, ensuring that client traffic is distributed across nodes and redirected instantly during a failover.

Video Highlights

  1. Architecture: Preparing 2 nodes for a shared Virtual IP (0:13)
  2. Configuration: Setting up the farm.safe module and Virtual IP address (2:20)
  3. Validation: Failover testing and Virtual IP redirection on server crash (2:30)

🔍 SafeKit High Availability Navigation Hub

Explore SafeKit: Features, technical videos, documentation, and free trial
Resource Type Description Direct Link
Key Features Why Choose SafeKit for Simple and Cost-Effective High Availability? See Why Choose SafeKit for High Availability
Deployment Model All-in-One SANless HA: Shared-Nothing Software Clustering See SafeKit All-in-One SANless HA
Partners SafeKit: The Benchmark in High Availability for Partners See Why SafeKit Is the HA Benchmark for Partners
HA Strategies SafeKit: Infrastructure (VM) vs. Application-Level High Availability See SafeKit HA & Redundancy: VM vs. Application Level
Technical Specifications Technical Limitations for SafeKit Clustering See SafeKit High Availability Limitations
Proof of Concept SafeKit: High Availability Configuration & Failover Demos See SafeKit Failover Tutorials
Architecture How the SafeKit Mirror Cluster works (Real-Time Replication & Failover) See SafeKit Mirror Cluster: Real-Time Replication & Failover
Architecture How the SafeKit Farm Cluster works (Network Load Balancing & Failover) See SafeKit Farm Cluster: Network Load Balancing & Failover
Competitive Advantages Comparison: SafeKit vs. Traditional High Availability (HA) Clusters See SafeKit vs. Traditional HA Cluster Comparison
Technical Resources SafeKit High Availability: Documentation, Downloads & Trial See SafeKit HA Free Trial & Technical Documentation
Pre-configured Solutions SafeKit Application Module Library: Ready-to-Use HA Solutions See SafeKit High Availability Application Modules