# Multi-thread vs Multi-processing in Nodejs

### Summary

| | Multi-thread | Multi-processing |
| -------------------- | ---------------------------------------------------------------------------------------- | ------------------------------------------------------------------- |
| Implementation | `worker-threads` | `cluster`, `child-process` |
| Communication | Messages, SharedArrayBuffer | Messages |
| Synchronization | Atomics | - |
| Prometheus metrics | Need to manually deliver metrics to the main thread | Need another HTTP server and metrics endpoint for process |
| Data transfer (JSON) | 1) Structured clone serialization <br>2) Transfer data via messages or via shared buffer | 1) Structured clone serialization <br>2) Transfer data via messages |
| Data transfer (Any) | 1) Need custom Serializer <br>2) Transfer data via messages or via shared buffer | 1) Need custom Serializer <br>2) Transfer data via messages |

### Multi-thread

Node.js page [worker threads](https://nodejs.org/api/worker_threads.html)

#### Multi-processing

Node.js page [child_process](https://nodejs.org/api/child_process.html)
Node.js page [cluster](https://nodejs.org/api/cluster.html)