Socket connection congests whole nodejs application - node.js

Question

I have a socket connection using zmq.js client:
// routerSocket.ts
const zmqRouter = zmq.socket("router");
zmqRouter.bind(`tcp://*:${PORT}`);
zmqRouter.on("message", async (...frames) => {
try {
const { measurementData, measurementHeader } =
await decodeL2Measurement(frames[frames.length - 1]);
addHeaderInfo(measurementHeader);
// Add cell id to the list
process.send(
{ measurementData, measurementHeader, headerInfoArrays },
(e: any) => {
return;
},
);
} catch (e: any) {
return;
}
});
I run this socket connection within a forked process in index.ts:
// index.ts
const zmqProcess = fork("./src/routerSocket");
zmqProcess.on("message", async (data: ZmqMessage) => {
if (data !== undefined) {
const { measurementData, measurementHeader, headerInfoArrays } = data;
headerInfo = headerInfoArrays;
emitHeaderInfo(headerInfoArrays);
// Emit the message to subscribers of the rnti
const a = performance.now();
io.emit(
measurementHeader.nrCellId,
JSON.stringify({ measurementData, measurementHeader }),
);
// Emit the message to the all channel
io.emit("all", JSON.stringify({ measurementData, measurementHeader }));
const b = performance.now();
console.log("time to emit: ", a - b);
}
});
There is data coming in rapidly, about one message per ms, to the zmqRouter object, which it then processes and sends onto the main process where I use socket.io to distribute the data to clients. But as soon as the stream begins, node can't do anything else. Even a setInterval log stops working when the stream begins.
Thank you for your help!