Files
shopdb-flask/scripts/loadtest/burst_arrival.py
benjamin.baker 0d5b9730e3 Add load test harness for pool and fleet sizing
Adds the scripts used to size the connection pool and validate fleet polling under load: burst arrival and mixed workload drivers, pool and resource samplers, a UI probe, host seed/drop SQL, and a gevent Dockerfile. Hosts are addressed by compose service name (api:5001) rather than a local path, so the harness runs against any stack rather than one machine.

loadtest_token.py mints a scoped collector token named LOADTEST and prints the secret once, then revokes only that token by name so a real collector token is never touched. envkeyfallback is false, so the harness needs a genuine managed token rather than an env key.
2026-09-07 12:39:53 -04:00

220 lines
8.1 KiB
Python

"""Patch-day burst simulator: synchronized cold start of an endpoint fleet.
WHY this is separate from mixed_workload.py: that harness RAMPS agents in over
~20s and measures steady state, which deliberately avoids a thundering herd.
Patch day is the opposite case and stresses different machinery:
- a fresh TLS handshake per agent, all at once (handshakes are CPU-heavy)
- _resolve_asset_for_hostname runs on every arrival, so the DB pool is hit by
a synchronized burst rather than the smooth churn of steady state
- no warm connections in the pool, no warm caches
Modelled on the real agent (verified in agent/ShopDbEndpointAgent.Core/):
- CommandWorker.ExecuteAsync polls IMMEDIATELY, no startup delay, no jitter
- TelemetryWorker also reports immediately; its jitter applies only BETWEEN
runs, so first contact is synchronized too. Patch day is therefore TWO
simultaneous bursts per endpoint, not one.
- transient failures retry at a FIXED 10s (TransientRetryDelay), not
exponential-with-jitter, so a herd that fails together re-arrives together
--arrivalseconds is the spread of the reboot window. 0 means every agent hits at
once (single maintenance window, worst case); 60 approximates a staged ring.
Stdlib asyncio only, so it needs no dependency install in the container.
Usage:
python burst_arrival.py --fleet 700 --arrivalseconds 0 --seconds 120
"""
import argparse
import asyncio
import json
import os
import random
import ssl
import statistics
import time
STOP = False
def percentile(values, fraction):
if not values:
return 0.0
ordered = sorted(values)
index = min(int(len(ordered) * fraction), len(ordered) - 1)
return ordered[index]
async def request(host, port, context, method, path, timeout,
api_key=None, body=None):
"""One HTTP/1.1 request over a FRESH connection, so each call pays a full
TLS handshake - which is the point on patch day."""
started = time.monotonic()
writer = None
try:
reader, writer = await asyncio.wait_for(
asyncio.open_connection(host, port, ssl=context), timeout=timeout)
handshake = time.monotonic() - started
headers = [
'%s %s HTTP/1.1' % (method, path),
'Host: %s' % host,
'Accept: application/json',
'Connection: close',
]
if api_key:
headers.append('X-API-Key: %s' % api_key)
payload = b''
if body is not None:
payload = json.dumps(body).encode()
headers.append('Content-Type: application/json')
headers.append('Content-Length: %d' % len(payload))
writer.write(('\r\n'.join(headers) + '\r\n\r\n').encode() + payload)
await writer.drain()
header = await asyncio.wait_for(reader.readuntil(b'\r\n'), timeout=timeout)
status = int(header.split()[1])
await asyncio.wait_for(reader.read(), timeout=timeout)
return status, time.monotonic() - started, handshake
except Exception as error:
return type(error).__name__, time.monotonic() - started, None
finally:
if writer is not None:
try:
writer.close()
except Exception:
pass
def record(results, bucket, status, elapsed, handshake=None, first=False):
entry = results.setdefault(bucket, {
'times': [], 'status': {}, 'handshakes': [], 'firsttimes': []})
entry['times'].append(elapsed * 1000.0)
if handshake is not None:
entry['handshakes'].append(handshake * 1000.0)
if first:
entry['firsttimes'].append(elapsed * 1000.0)
key = str(status)
entry['status'][key] = entry['status'].get(key, 0) + 1
async def agent(index, host, port, context, api_key, results, arrivalseconds):
"""One endpoint coming back from a patch reboot.
Fires its telemetry report and its first command poll at the same instant,
mirroring the two workers both starting with no delay.
"""
if arrivalseconds > 0:
await asyncio.sleep(random.uniform(0, arrivalseconds))
hostname = 'LOADTEST%04d' % (index + 1)
async def telemetry():
status, elapsed, handshake = await request(
host, port, context, 'POST', '/api/collector/heartbeat',
timeout=120.0, api_key=api_key, body={'hostname': hostname})
record(results, 'telemetry_firstcontact', status, elapsed, handshake,
first=True)
telemetry_task = asyncio.ensure_future(telemetry())
path = '/api/endpoints/commands/next?hostname=%s' % hostname
first = True
while not STOP:
status, elapsed, handshake = await request(
host, port, context, 'GET', path, timeout=120.0, api_key=api_key)
record(results, 'fleet', status, elapsed, handshake, first=first)
if first:
first = False
if not isinstance(status, int):
# Mirrors CommandWorker TransientRetryDelay: fixed 10s, no jitter,
# so a herd that fails together re-arrives together.
await asyncio.sleep(10.0)
else:
await asyncio.sleep(0.05)
await telemetry_task
async def ui_user(host, port, context, results, think_seconds):
while not STOP:
status, elapsed, handshake = await request(
host, port, context, 'GET', '/api/dashboard/health', timeout=120.0)
record(results, 'ui', status, elapsed, handshake)
await asyncio.sleep(think_seconds)
async def main():
global STOP
parser = argparse.ArgumentParser()
parser.add_argument('--fleet', type=int, default=700)
parser.add_argument('--users', type=int, default=5)
parser.add_argument('--arrivalseconds', type=float, default=0.0)
parser.add_argument('--seconds', type=int, default=120)
parser.add_argument('--host', default='api')
parser.add_argument('--port', type=int, default=5001)
parser.add_argument('--think', type=float, default=3.0)
arguments = parser.parse_args()
api_key = os.environ.get('LOADTEST_TOKEN', '')
if not api_key:
raise SystemExit('LOADTEST_TOKEN not set')
context = ssl.create_default_context()
context.check_hostname = False
context.verify_mode = ssl.CERT_NONE
results = {}
tasks = []
for _ in range(arguments.users):
tasks.append(asyncio.ensure_future(ui_user(
arguments.host, arguments.port, context, results,
arguments.think)))
# Let the UI baseline establish before the storm hits.
await asyncio.sleep(5.0)
burst_started = time.monotonic()
for index in range(arguments.fleet):
tasks.append(asyncio.ensure_future(agent(
index, arguments.host, arguments.port, context, api_key, results,
arguments.arrivalseconds)))
await asyncio.sleep(arguments.seconds)
STOP = True
await asyncio.sleep(2.0)
for task in tasks:
task.cancel()
summary = {
'fleet': arguments.fleet,
'arrivalseconds': arguments.arrivalseconds,
'users': arguments.users,
'seconds': arguments.seconds,
'classes': {},
}
for bucket, entry in sorted(results.items()):
times = entry['times']
block = {
'samples': len(times),
'status': entry['status'],
'median_ms': round(statistics.median(times), 1) if times else 0.0,
'p95_ms': round(percentile(times, 0.95), 1),
'max_ms': round(max(times), 1) if times else 0.0,
}
if entry['handshakes']:
block['handshake_median_ms'] = round(
statistics.median(entry['handshakes']), 1)
block['handshake_p95_ms'] = round(
percentile(entry['handshakes'], 0.95), 1)
block['handshake_max_ms'] = round(max(entry['handshakes']), 1)
if entry['firsttimes']:
block['firstcontact_median_ms'] = round(
statistics.median(entry['firsttimes']), 1)
block['firstcontact_p95_ms'] = round(
percentile(entry['firsttimes'], 0.95), 1)
block['firstcontact_max_ms'] = round(max(entry['firsttimes']), 1)
summary['classes'][bucket] = block
print(json.dumps(summary, indent=2))
if __name__ == '__main__':
asyncio.run(main())