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| 1 | +"""One-off perf script for the tag-intersection query. |
| 2 | +
|
| 3 | +Picks a real thread that carries the largest tag set in the database, then |
| 4 | +issues GETs to /questions/tags:t1,t2,.../ for increasing tag counts so the |
| 5 | +intersection always returns at least one question. Times each request with |
| 6 | +warm-up + repeats so the numbers are stable enough to compare branches. |
| 7 | +
|
| 8 | +Usage: |
| 9 | + cd askbot_site |
| 10 | + ../env-md/bin/python ../perf_tag_search.py --base-url http://127.0.0.1:8000 |
| 11 | +
|
| 12 | +The dev server must already be running (manage.py runserver, gunicorn, etc.) |
| 13 | +on the URL passed in. Run the script once before applying the optimization |
| 14 | +and once after; compare the columns. |
| 15 | +""" |
| 16 | +import argparse |
| 17 | +import os |
| 18 | +import statistics |
| 19 | +import sys |
| 20 | +import time |
| 21 | +import urllib.error |
| 22 | +import urllib.parse |
| 23 | +import urllib.request |
| 24 | + |
| 25 | +import django |
| 26 | + |
| 27 | + |
| 28 | +def setup_django(): |
| 29 | + os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'askbot_site.settings') |
| 30 | + if os.getcwd() not in sys.path: |
| 31 | + sys.path.insert(0, os.getcwd()) |
| 32 | + django.setup() |
| 33 | + |
| 34 | + |
| 35 | +def pick_tag_set(min_count, max_count): |
| 36 | + """Return a list of tag names that all co-occur on the same thread. |
| 37 | +
|
| 38 | + Uses the thread carrying the most tags so the intersection is guaranteed |
| 39 | + non-empty for any prefix of the returned list. |
| 40 | + """ |
| 41 | + from askbot.models import Thread |
| 42 | + from django.db.models import Count |
| 43 | + |
| 44 | + threads = ( |
| 45 | + Thread.objects |
| 46 | + .annotate(n_tags=Count('tags')) |
| 47 | + .filter(n_tags__gte=min_count) |
| 48 | + .order_by('-n_tags') |
| 49 | + ) |
| 50 | + thread = threads.first() |
| 51 | + if thread is None: |
| 52 | + raise SystemExit( |
| 53 | + f'No thread has at least {min_count} tags - lower --min-tags or ' |
| 54 | + 'load a larger dataset.' |
| 55 | + ) |
| 56 | + names = list(thread.tags.values_list('name', flat=True)) |
| 57 | + if max_count: |
| 58 | + names = names[:max_count] |
| 59 | + print(f'Using thread id={thread.id} with {len(names)} tags: {names}') |
| 60 | + return names |
| 61 | + |
| 62 | + |
| 63 | +def build_url(base_url, tags): |
| 64 | + encoded = urllib.parse.quote(','.join(tags), safe=',+.-_') |
| 65 | + return f'{base_url.rstrip("/")}/questions/tags:{encoded}/' |
| 66 | + |
| 67 | + |
| 68 | +def time_request(url, timeout): |
| 69 | + start = time.perf_counter() |
| 70 | + with urllib.request.urlopen(url, timeout=timeout) as resp: |
| 71 | + body = resp.read() |
| 72 | + status = resp.status |
| 73 | + elapsed = time.perf_counter() - start |
| 74 | + return elapsed, status, len(body) |
| 75 | + |
| 76 | + |
| 77 | +def run(base_url, tags, repeats, warmups, timeout, sleep): |
| 78 | + header = f'{"N tags":>6} | {"min ms":>8} | {"med ms":>8} | {"max ms":>8} | {"bytes":>8} | status' |
| 79 | + print(header) |
| 80 | + print('-' * len(header)) |
| 81 | + for n in range(1, len(tags) + 1): |
| 82 | + url = build_url(base_url, tags[:n]) |
| 83 | + last_status = None |
| 84 | + last_size = None |
| 85 | + for _ in range(warmups): |
| 86 | + _, last_status, last_size = time_request(url, timeout) |
| 87 | + if sleep: |
| 88 | + time.sleep(sleep) |
| 89 | + samples = [] |
| 90 | + for _ in range(repeats): |
| 91 | + elapsed, last_status, last_size = time_request(url, timeout) |
| 92 | + samples.append(elapsed * 1000) |
| 93 | + if sleep: |
| 94 | + time.sleep(sleep) |
| 95 | + print( |
| 96 | + f'{n:>6} | {min(samples):>8.1f} | {statistics.median(samples):>8.1f} | ' |
| 97 | + f'{max(samples):>8.1f} | {last_size:>8} | {last_status}' |
| 98 | + ) |
| 99 | + print(f' url: {url}') |
| 100 | + |
| 101 | + |
| 102 | +def main(): |
| 103 | + parser = argparse.ArgumentParser(description=__doc__) |
| 104 | + parser.add_argument('--base-url', default='http://127.0.0.1:8000', |
| 105 | + help='Base URL of the running askbot site.') |
| 106 | + parser.add_argument('--min-tags', type=int, default=2, |
| 107 | + help='Skip threads that carry fewer tags than this.') |
| 108 | + parser.add_argument('--max-tags', type=int, default=8, |
| 109 | + help='Cap the tag list length (0 = no cap).') |
| 110 | + parser.add_argument('--repeats', type=int, default=5, |
| 111 | + help='Timed requests per tag count.') |
| 112 | + parser.add_argument('--warmups', type=int, default=1, |
| 113 | + help='Untimed requests per tag count before timing.') |
| 114 | + parser.add_argument('--timeout', type=float, default=60.0, |
| 115 | + help='Per-request timeout in seconds.') |
| 116 | + parser.add_argument('--sleep', type=float, default=1.5, |
| 117 | + help='Pause between requests to avoid the rate limiter.') |
| 118 | + args = parser.parse_args() |
| 119 | + |
| 120 | + setup_django() |
| 121 | + tags = pick_tag_set(args.min_tags, args.max_tags) |
| 122 | + print(f'Base URL: {args.base_url}') |
| 123 | + print(f'Repeats: {args.repeats}, warmups: {args.warmups}') |
| 124 | + print() |
| 125 | + try: |
| 126 | + run(args.base_url, tags, args.repeats, args.warmups, args.timeout, |
| 127 | + args.sleep) |
| 128 | + except urllib.error.URLError as exc: |
| 129 | + print(f'Request failed - is the dev server running? {exc}', file=sys.stderr) |
| 130 | + sys.exit(1) |
| 131 | + |
| 132 | + |
| 133 | +if __name__ == '__main__': |
| 134 | + main() |
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