@sockeye-js/collect-ws

Collector for the ws library, part of sockeye.

npm install @sockeye-js/collect-ws @sockeye-js/store-memory

import { attachWsMonitor } from '@sockeye-js/collect-ws';
import { createMemoryStore } from '@sockeye-js/store-memory';

const store = createMemoryStore();
attachWsMonitor(wss, store);

Every frame received and every frame sent is recorded with its exact wire size, binary frames included.

ws has no broadcast of its own, so fanning a message out to a room is a loop of send in your own code, and each recipient is already measured on its own. Every frame therefore counts as exactly one recipient, and the dashboard shows the same number whichever way it counts.

Sizes are the frames your app hands to ws, before permessage-deflate compresses them, so the real traffic on the wire is often smaller.

Naming messages

ws knows nothing about your protocol. By default, JSON frames are named after their type, event, name or action field, binary frames are grouped under <binary>, and anything else under <unnamed>. Override it when your protocol differs:

attachWsMonitor(wss, store, {
  nameOf: (data, isBinary) => (isBinary ? 'blob' : String(data).split('|')[0]),
});

Namespaces

Group messages by path, or by anything you can read off the upgrade request:

attachWsMonitor(wss, store, {
  namespaceOf: (request) => new URL(request.url, 'http://x').pathname,
});

Response times

ws has no acknowledgement mechanism, so there is nothing to time automatically. If your protocol has a notion of a reply, measure it with @sockeye-js/collect-websocket:

const pending = monitor.start('report:generate', payload);
pending.end(await generateReport(payload));

Other exports

• monitorWsSocket(socket, store, options) instruments a single socket you manage yourself.
• attachWsMonitor returns a function that stops monitoring new connections.

License

This package is part of sockeye, under the GNU AGPL v3.0 or later.