VICIdial Performance Tuning: Server Optimization for 500+ Agents

You've got the cluster built. Four telephony servers, two web servers, a dedicated database box. VICIdial installs cleanly, agents log in, calls start flowing. Everything looks great at 50 agents. At 150 agents, real-time reports start lagging. At 300 agents, calls drop during peak hours. At 400, the telephony servers hit 100% CPU at 2 PM every day and you're playing whack-a-mole with screen sessions that silently die. The hardware is there. The architecture is right. But nobody tuned the operating system, nobody sized the Asterisk channels, nobody touched the default Apache config, and the kernel is still running with settings designed for a general-purpose web server — not a machine that needs to manage 2,000 concurrent SIP channels while a dozen Perl daemons hammer the database every second. This is the guide that turns good hardware into a 500+ agent VICIdial deployment that actually holds under load. VICIdial's performance ceiling is almost never about the software itself. Matt Fl