Is there a way to overload Node.js event loop using websoket

Question

I'm having issues with Node.js and the "WS" implementation of websocket (https://www.npmjs.com/package/ws). After a surge (plenty of messages in a short window of time), I'm having data that suggests that I've "missed" a message.

• I've contacted the owner of the emitter server and he assures me that all messages have been sent on his side.
• I've logger every message received on my side (at the start of the function on('message', () => {}), and I can't seem to find the message, so my assumption is that it doesn't even reached this point

So I'm wondering:

• Messages are reveived and treated in a FIFO order. During the treatment of the current message, new ones will be stacked in the node event loop to be computed immediatly after. Correct ? Is there a way for that event loop to be "too big" that may drop new incomming messages ? If so, does it drop it quietly ? or does the program crashes vigorously (in other words, how can I see if a message has been dropped this way ?)
• Does the 'ws' module have any kind of kown limitations for a maximum number of message received ? Does it have an internal way of dropping messages ?
• Is there a better alternative than the 'ws' module ?
• Is there any other ways to explain a "missed" message ?

Thanks a lot for your insights,

Answer 1

I use ws in nodejs to handle large message flows from many clients simultaneously in production, and I have never had it lose messages. Each server handles several thousand messages each second from hundreds of different client connections. The way my system works, if ws dropped messages or changed their order, my users would complain loudly.

That makes me guess you are not hitting any limitation of ws.

Early in my programming work I had the not-so-bright idea of putting incoming messages in queue objects in my nodejs code and processing them "later." That led to a hideously confusing message flow through my server. It sometimes looked like I had lost ws messages. I was happy to delete all that code, and dispatch every message completely within its message event handler.

Websocket connections sometimes close abnormally. Because network. You can catch those situations with error and close event handlers. It can take a while for the sender of a message, or the receiver, to detect that a network fault of some kind disrupted its connection. That can lead to disagreement about message count between sender and receiver. It's worth investigating.

I adorn ws's connection objects with message counts ("adorn" -- add an application-specific property to an object) and put those message counts into the log when a connection closes.