Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Redis Hacks
Search
David Cramer
May 03, 2014
Technology
3
210
Redis Hacks
Python Nordeste 2014 - Lightning Talk
David Cramer
May 03, 2014
Tweet
Share
More Decks by David Cramer
See All by David Cramer
Mastering Duct Tape (PyCon Balkan 2018)
zeeg
2
850
Open Source as a Business (PyCon SG 2014)
zeeg
0
270
Angular.js Workshop (PyCon SG 2014)
zeeg
0
210
Architecting a Culture of Quality
zeeg
2
300
Release Faster
zeeg
12
1.3k
Open Source as a Business (EuroPython 2013)
zeeg
18
17k
Building to Scale (PyCon TW 2013)
zeeg
18
1.2k
Building to Scale
zeeg
28
24k
Lessons in Testing - DjangoCon 2012
zeeg
8
1.3k
Other Decks in Technology
See All in Technology
地理空間データ可視化・解析・活用ソリューション Pacific Spatial Solutions (PSS)
pacificspatialsolutions
0
330
どうするコスト最適化のトレードオフ
tetsuyaooooo
1
690
ServiceNow Now Platform 最新版Washington, D.C.リリース
manarobot
0
100
【SORACOM UG 東海】あらゆるモノがつながる社会へ、IoT と SORACOM
soracom
PRO
1
130
ゼロから始めるVue.jsコミュニティ貢献 / first-vuejs-community-contribution-link-and-motivation
lmi
1
150
[新卒向け研修資料] テスト文字列に「うんこ」と入れるな(2024年版)
infiniteloop_inc
4
17k
TechFeed Experts Night#27 〜 フロントエンドフレームワーク最前線 (Svelte)
baseballyama
2
590
よく聞くけど使ったことないソフトウェアNo.1 KafkaとSnowflake
foursue
4
470
非同期推論システムによるコスト削減と信頼性向上
koki_nishihara
1
350
R3のコードから見る実践LINQ実装最適化・コンカレントプログラミング実例
neuecc
3
1.7k
AOAI をきっかけに 社内の Azure 管理を見直した話
recruitengineers
PRO
1
430
Amplify 🩷 Bedrock 〜生成AI入門〜
minorun365
PRO
7
350
Featured
See All Featured
Designing on Purpose - Digital PM Summit 2013
jponch
111
6.5k
The World Runs on Bad Software
bkeepers
PRO
61
6.7k
How STYLIGHT went responsive
nonsquared
92
4.8k
Build your cross-platform service in a week with App Engine
jlugia
226
17k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
275
13k
Ruby is Unlike a Banana
tanoku
96
10k
Gamification - CAS2011
davidbonilla
76
4.6k
Testing 201, or: Great Expectations
jmmastey
29
6.4k
Web development in the modern age
philhawksworth
203
10k
"I'm Feeling Lucky" - Building Great Search Experiences for Today's Users (#IAC19)
danielanewman
222
21k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
21
1.4k
Building Your Own Lightsaber
phodgson
100
5.7k
Transcript
David Cramer twitter.com/zeeg Redis Hacks (or “How Sentry Scales”)
Buffering Writes
r = Redis() ! def incr(type, id): key = 'pending:{}'.format(type)
! r.zincrby(key, id, 1)
r = Redis() ! def flush(type): key = 'pending:{}'.format(type) result
= r.zrange(key, 0, -1, withscores=True) ! for id, count in result: prms = {'type': type, 'count': count, 'id': id} ! sql(""" update %(type)s set count = count + % (count)d where id = %(id)s """, prms)
Rate Limiting
r = Redis() ! def process_hit(project_id): epoch = time() /
60 key = ‘{}:{}’.format(project_id, epoch) ! pipe = r.pipeline() pipe.incr(key) pipe.expire(key, 60) result = pipe.execute() ! # return current value return int(result[0])
def request(project_id): result = process_hit(project_id) if result > 20: return
Response(status=429) return Response(status=200)
Time Series Data
def count_hits_today(project_id): start = time() end = now + DAY_SECONDS
! pipe = r.pipeline() for epoch in xrange(now, end, 10): key = ‘{}:{}’.format( project_id, epoch) pipe.get(key) results = pipe.execute() ! # remove non-zero results results = filter(bool, results) # coerce remainder to ints results = map(int, results) # return sum of buckets return sum(results)
Good-enough Locks
from contextlib import contextmanager ! r = Redis() ! @contextmanager
def lock(key, nowait=True): while not r.setnx(key, '1'): if nowait: raise Locked('try again soon!') sleep(0.01) ! # limit lock time to 10 seconds r.expire(key, 10) ! # do something crazy yield ! # explicitly unlock r.delete(key)
def do_something_crazy(): with lock('crazy'): print 'Hello World!'
Basic Sharding via Nydus
from nydus.db import create_cluster ! redis = create_cluster({ 'backend': 'nydus.db.backends.redis.Redis',
'hosts': { 0: {'db': 0}, 1: {'db': 1}, }, 'router': 'nydus.db.routers.keyvalue.PartitionRouter', })
def count_hits_today(project_id): start = time() end = now + DAY_SECONDS
! keys = [] for epoch in xrange(now, end, 10): key = '{}:{}'.format(project_id, epoch) keys.append(key) ! with redis.map() as conn: results = map(conn.get, keys) ! # remove non-zero results results = filter(bool, results) # coerce remainder to ints results = map(int, results) # return sum of buckets return sum(results)