# High Availability Architecture **High Availability (HA) Architecture** is designed for **mission‑critical systems** where continuous service availability is essential.\ This architecture is suitable for systems that must continue operating even when certain components experience failures or errors. The design of High Availability Architecture is driven by the need to meet defined **Service Level Agreements (SLAs)**, ensuring acceptable levels of uptime, reliability, and performance for business‑critical applications. *** ### Architecture Overview In a High Availability Architecture, the ONEWEB Platform is deployed with **redundancy and distribution** across multiple servers to eliminate single points of failure and improve system resilience.
This architecture typically extends the standard three‑tier model (Web, Application, and Database) by introducing additional components such as load balancers and redundant servers. *** ### Key Design Principles The effectiveness of High Availability Architecture is based on several key principles. **Avoid Single Points of Failure**\ To maximize availability, the system must eliminate components whose failure would cause the entire platform to stop functioning.\ This is achieved by introducing **redundancy** and distributing workloads across multiple machines, commonly through horizontal scaling. *** ### Redundancy Strategies To support high availability, ONEWEB environments typically implement the following redundancy strategies. **Hardware Redundancy**\ Hardware redundancy reduces the risk of physical server failures impacting the system. Common approaches include: * **Active‑Active configuration**, where multiple application servers run concurrently and share the workload * **Active‑Standby configuration**, where a backup server takes over when the primary server fails **Process Redundancy**\ Process redundancy ensures that application processes are isolated and replicated across servers.\ If a process or server fails, other healthy instances continue processing requests without service disruption. *** ### Load Balancing (Active‑Active) **Load balancing** is a core component of High Availability Architecture. In an Active‑Active setup, load balancing: * Distributes incoming client requests across multiple servers * Prevents individual servers from becoming overloaded * Improves performance and responsiveness * Enables horizontal scaling as demand increases Load balancing ensures that system resources are utilized efficiently while maintaining consistent service availability. *** ### Fail‑Over Support (Active‑Standby) **Fail‑over mechanisms** ensure that the system can continue processing client requests even when one or more components become unavailable. In an Active‑Standby configuration: * Standby components continuously monitor active components * Traffic is redirected automatically when a failure is detected * Service interruption is minimized during component failure or maintenance Fail‑over support is essential for meeting strict availability and recovery objectives. *** ### When to Choose High Availability Architecture High Availability Architecture is recommended when: * The application supports critical business operations * Downtime must be minimized or avoided * Service availability is governed by formal SLAs * The system must tolerate hardware or process failures Compared to Standalone Architecture, HA Architecture introduces additional complexity and cost, but provides significantly higher reliability and operational resilience. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.onewebstack.com/getting-started/installation-guide/plan-your-oneweb-installation/design-oneweb-architecture/high-availability-architecture.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.