import { config } from './config.js';
import { logDebug, logWarn } from './observability.js';
interface HttpServerTuningTarget {
headersTimeout?: number;
requestTimeout?: number;
keepAliveTimeout?: number;
keepAliveTimeoutBuffer?: number;
maxHeadersCount?: number | null;
maxConnections?: number;
on?: (event: string, listener: (...args: unknown[]) => void) => void;
closeIdleConnections?: () => void;
closeAllConnections?: () => void;
}
const DROP_LOG_INTERVAL_MS = 10_000;
function setIfDefined<T>(
value: T | undefined,
setter: (resolved: T) => void
): void {
if (value === undefined) return;
setter(value);
}
function assignServerValue<T extends keyof HttpServerTuningTarget>(
server: HttpServerTuningTarget,
key: T,
value: HttpServerTuningTarget[T] | undefined
): void {
setIfDefined(value, (resolved) => {
server[key] = resolved;
});
}
export function applyHttpServerTuning(server: HttpServerTuningTarget): void {
const {
headersTimeoutMs,
requestTimeoutMs,
keepAliveTimeoutMs,
keepAliveTimeoutBufferMs,
maxHeadersCount,
maxConnections,
} = config.server.http;
assignServerValue(server, 'headersTimeout', headersTimeoutMs);
assignServerValue(server, 'requestTimeout', requestTimeoutMs);
assignServerValue(server, 'keepAliveTimeout', keepAliveTimeoutMs);
assignServerValue(server, 'keepAliveTimeoutBuffer', keepAliveTimeoutBufferMs);
assignServerValue(server, 'maxHeadersCount', maxHeadersCount);
if (typeof maxConnections === 'number' && maxConnections > 0) {
server.maxConnections = maxConnections;
if (typeof server.on === 'function') {
let lastLoggedAt = 0;
let droppedSinceLastLog = 0;
const onDrop = (data: unknown): void => {
droppedSinceLastLog += 1;
const now = Date.now();
if (now - lastLoggedAt < DROP_LOG_INTERVAL_MS) return;
logWarn('Incoming connection dropped (maxConnections reached)', {
maxConnections,
dropped: droppedSinceLastLog,
data,
});
lastLoggedAt = now;
droppedSinceLastLog = 0;
};
server.on('drop', onDrop);
}
}
}
export function drainConnectionsOnShutdown(
server: HttpServerTuningTarget
): void {
if (typeof server.closeIdleConnections === 'function') {
server.closeIdleConnections();
logDebug('Closed idle HTTP connections during shutdown');
}
}
