chunkloris: ws (node)
on this page
part of the chunkloris per-chunk amplification survey. this page is the per-server record for ws (Node) under websocket text frames.
at a glance
- server: ws (Node)
ws 8.18.0 on node 22-slim - runtime: node-22
- ecosystem: node
- concurrency model: event-loop
- parser: ws/lib/receiver.js (JS state machine; per-message event)
- delivery granularity:
per-recv-batched - chunk-limit helper: none exposed by the framework
- verdict: batches correctly — the implementation coalesces wire units before waking the application, either via an explicit per-stream frame credit, a pipelined reader, or a similar batching primitive. mode b cpu cost is in the band you would expect from a per-
recv()batched delivery. - scaling exponent (mode a): 0.70 (wall time vs N, log-log slope across common cells)
measurements
all cells run on a 1-vcpu docker container. cpu cost is derived from the target container’s cgroup v2 cpu.stat usage_usec delta around each cell.
| mode | N | wall (s) | server cpu % | µs / frame | basis | ok |
|---|---|---|---|---|---|---|
A-ws-bridge | 50,000 | 0.024 | — | 0.490 | wall | ✓ |
A-ws-bridge | 100,000 | 0.032 | — | 0.320 | wall | ✓ |
A-ws-bridge | 250,000 | 0.058 | — | 0.230 | wall | ✓ |
B-ws-paced-100us | 50,000 | 5.407 | — | 8.150 | server-cpu-overhead | ✓ |
B-ws-paced-100us | 100,000 | 10.491 | — | 4.910 | server-cpu-overhead | ✓ |
B-ws-paced-100us | 250,000 | 26.266 | — | 5.060 | server-cpu-overhead | ✓ |
what this means
the implementation batches wire units before waking the application (either via an explicit per-stream frame credit, a pipelined reader, or an equivalent primitive). the cpu cost under paced mode b is in the band you would expect from a per-recv() batched delivery.
what to do today
- this implementation already batches; the cpu cost in mode b is in the per-
recv()band.
reproducer
the full reproducer for this server is in the paper repo. the docker container pins ws (Node) ws 8.18.0 on node 22-slim and constrains the test container to a single cpu (--cpus=1). the prober script implements mode a (bridge-coalesced) and mode b (paced 100 µs) per the methodology section.
see the draft pdf for the full per-framework discussion.