I’m working on a complex WebSocket system. It uses Node.js servers with Redis adapter, Google Cloud Pub/Sub, and Python chat servers. Clients connect to Node.js through Socket.IO. The setup works like this:
- Node.js publishes events to Pub/Sub
- Python servers process these events
- Python sends responses back via Redis using socket_io_emitter
- Node.js should get these responses and send them to clients
But sometimes, events from Python don’t reach the clients. I can’t figure out where they’re getting lost. Is it between Python and Node.js, or Node.js and the client?
I’ve tried to log Redis messages like this:
subClient.pSubscribe('socket.io#*', (message, count) => {
console.log('Redis message:', message, 'Count:', count);
});
But it’s not helping much. How can I track these events better? I need a way to see exactly where they’re disappearing. Any ideas on how to debug this?
Having worked with similar distributed systems, I can suggest a few debugging approaches. First, implement detailed logging at each stage of the event pipeline. This includes logging in Python when events are sent, in Redis when they’re received and published, and in Node.js when they’re picked up. Use unique identifiers for each event to track them through the system.
Consider implementing a heartbeat mechanism between your services to ensure connectivity. This can help identify if there are intermittent network issues or service failures.
It’s also worth checking if your Redis configuration is set up for persistence. If not, you might be losing messages during Redis restarts or failures. Additionally, review your Pub/Sub QoS settings to ensure messages aren’t being dropped due to overload.
Lastly, use a distributed tracing tool like Jaeger or Zipkin. These can provide end-to-end visibility into your event flow, making it easier to pinpoint where events are getting lost in your complex setup.
hmm, have u tried a message queue like rabbitmq? it may boost reliability. adding timestamps on events might help u track delays. and how about a simple monitor to catch errors early? what other ideas have u considered?
yo alex, sounds like a tricky situation. have u tried adding more detailed logging in ur python code? like, log when u send stuff and when u receive. maybe theres a timeout or connection issue somewhere. also, check ur redis config, sometimes it drops msgs if overloaded. good luck mate!