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#!/usr/bin/env python
import asyncio
import statistics
import sys
import time
import websockets
LATENCIES = {}
async def log_latency(interval):
while True:
await asyncio.sleep(interval)
p = statistics.quantiles(LATENCIES.values(), n=100)
print(f"clients = {len(LATENCIES)}")
print(
f"p50 = {p[49] / 1e6:.1f}ms, "
f"p95 = {p[94] / 1e6:.1f}ms, "
f"p99 = {p[98] / 1e6:.1f}ms"
)
print()
async def client():
try:
async with websockets.connect(
ping_timeout=None,
) as websocket:
async for msg in websocket:
client_time = time.time_ns()
server_time = int(msg[:19].decode())
LATENCIES[websocket] = client_time - server_time
except Exception as exc:
print(exc)
async def main(count, interval):
asyncio.create_task(log_latency(interval))
clients = []
for _ in range(count):
clients.append(asyncio.create_task(client()))
await asyncio.sleep(0.001) # 1ms between each connection
await asyncio.wait(clients)
if __name__ == "__main__":
try:
count = int(sys.argv[1])
interval = float(sys.argv[2])
except Exception as exc:
print(f"Usage: {sys.argv[0]} count interval")
print(" Connect <count> clients e.g. 1000")
print(" Report latency every <interval> seconds e.g. 1")
print()
print(exc)
else:
asyncio.run(main(count, interval))