For institutions conducting mission-critical, large-scale computer-based tests (CBTs), system reliability and uptime are non-negotiable. Addmen’s High Availability (HA) Architecture ensures uninterrupted exam delivery, strong security, and performance even under peak user load. This solution is part of our Professional CBT offering, engineered for exams that must never fail.
Dual Application Servers (Frontend): Two frontend servers running in parallel for load balancing and redundancy. If one server fails, the other immediately handles traffic—ensuring continuity.
Central Database Server (Backend): A dedicated database server accessed only by the application servers. Database access is protected via IP restrictions.
Licensing: Requires two licenses of the online exam software to enable the dual‑server setup.
Load Balancing & Redundancy: With two application servers, the system balances user requests and fails over cleanly if one frontend goes offline.
Real-Time Database Mirroring: The database is centrally maintained and mirrored (where needed) to avoid data loss or downtime.
Encrypted Question Paper Caching: Optionally, question papers can be cached/encrypted on application servers to reduce database load during exam start times.
IP-Restricted Access: Restrict database access to known frontend server IPs; restrict user logins to specified networks for enhanced security.
Scalable Configuration: As demand increases (more simultaneous users or exams), you can add more servers/licenses to meet requirements.
This setup is especially suited to:
Government & public sector examinations
University & college entrance tests
Corporate or professional certifications with mass participation
Remote or mission-critical assessments where downtime is unacceptable
Exams with strict compliance, legal or regulatory obligations
Load sharing between front-end servers to distribute traffic efficiently
Tiered server deployment (regional servers + centralized backbone) for geographically distributed candidates
Encrypted caching for frequently accessed files like question papers to reduce DB stress
Custom scheduled backups, failover drills to ensure readiness
No direct public network access to the database server
Application servers communicate with the database via whitelisted IP addresses only
User login restrictions by IP to enforce that only users from approved networks can access the exam
Enterprise-level security protocols, audit trails, encrypted data storage
The HA architecture requires 2 software licenses and 3 servers (2 application/front‑end + 1 database/backend)
Base setup for configuring the HA setup & linking licenses (for simple version)
Additional costs for premium features like real‑time mirroring, encrypted caching, advanced IP restrictions, enhanced backup mechanisms
Virtually zero downtime during exams
Stronger security and risk mitigation for high‑stakes environments
Better user experience for test‑takers (less lag, failures, or interruptions)
Scalable for growth in user numbers or exam frequency
Enhanced reliability fosters trust in the examination process
Addmen Group Copyright 2024. All Rights Reserved.
