perf(core): eliminate PHP session file lock contention on API/metrics, tune PHP-FPM pool, and remove redundant Keepalived restarts on sync

install.sh

@@ -524,6 +524,16 @@ chmod +x /etc/profile.d/nexus-motd.sh
 echo -e "${C_GREEN}[8/8] Démarrage et activation des services système...${C_RESET}"
 systemctl daemon-reload
 
+# Optimisation de la réserve de processus PHP-FPM pour supporter la télémétrie temps réel et le cluster HA
+for pool in /etc/php/*/fpm/pool.d/www.conf; do
+    if [ -f "$pool" ]; then
+        sed -i 's/^pm.max_children = .*/pm.max_children = 25/' "$pool"
+        sed -i 's/^pm.start_servers = .*/pm.start_servers = 4/' "$pool"
+        sed -i 's/^pm.min_spare_servers = .*/pm.min_spare_servers = 2/' "$pool"
+        sed -i 's/^pm.max_spare_servers = .*/pm.max_spare_servers = 6/' "$pool"
+    fi
+done
+
 # Redémarrage PHP-FPM (rechargement de l'appartenance au groupe asterisk)
 systemctl restart php*-fpm 2>/dev/null || true
 PHP_SVC=$(systemctl list-unit-files --type=service 2>/dev/null | grep -E "php.*-fpm" | awk '{print $1}' | head -n 1 || echo "php8.4-fpm")