monster world at amazon ec2

1

Monster World at Amazon EC2!

Hosting a social game with one million daily active users!

Jesper Richter-Reichhelm!Head of Engineering!wooga !

© wooga

2 About!

About wooga

Founded January 2009

Funding: Founders, Balderton Capital, Holtzbrinck Ventures (total of €5m+)

InternaIonal team of 60 from 15 countries in Berlin

Key stats

4 games on Facebook; 16m acIve users

Biggest european social game developer

Only 5% of users from adverIsing

70% of users are female (age 20-‐60)

About Monster World

Launched May 2010

Biggest seller of magic wands in the world

Total team size is 15 (2x backend, 3x frontend)

Key stats

Hosted at Facebook

Flash client

Ruby on Rails backend

MySQL + Redis DB

© wooga

3 Monster World at Amazon EC2!

 Starting Point!

 Finding Helpers!

 Challenges and Solutions!

 Looking back!

© wooga

4 Starting Point!

  In October 2009 we set out to build a backend for woogaʼs first game with a persistent world.!

 Our goal was to have more than 1,000,000 daily active users.!

 We have never done something like this before (who had?)!

© wooga

5 Hosting model must fit the needs!

 Small team dedicated to a single game!  2 backend folks to do both development and operation!

  “Extreme” life cycle of a game!!(graphic by Rightscale)!

 We simply did not know what to expect!  Scale up hosting when you are successful – not before!!

© wooga

 Starting Point!

 Finding Helpers!


 Looking back!


© wooga

7 Focus on what you do best…!and get help for the rest!

 Amazon Web Services!  Easy to scale up and down!  No limitations!

 Scalarium!  Making operation of a large cluster easy!  Provides default setup!  Provides consultancy if needed!  Based in Berlin => better communication!

© wooga

 Starting Point!

 Finding Helpers!


 Looking back!


© wooga

9 Challenge: Growing traffic!

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

4/22/14 5/22/14 6/22/14 7/22/14 8/22/14 9/22/14 10/22/14 11/22/14

© wooga

10 Solution:Scale up and out easily!

 Scaling up!  Application servers: 2 cores => 8 cores!  DB servers: 7.5GB => 68GB!

 Scaling out!  Application servers: 2 => up to 50!  MySQL servers: 2 => 16 => 8!

 Easy installation by automation!  Chef recipes managed by Scalarium make that easy!

© wooga

11 Challenge: Idle servers cost money, too!

peak : valley ratio 20:1 @ VZ 5:1 @ FB

© wooga

12 Solution!Run servers only when needed!

 Scalarium offers time and load based instances!  Start and stop instances based on time!  Start and stop instances based on load!

© wooga

13 Solution!Run servers only when needed!

© wooga

14 Challenge!Itʼs hard to scale out MySQL!

 Standard recipes would not work!  Almost all HTTP requests were changing something in DB!

 We optimized our MySQL configuration!  Perconaʼs XtraDB, innodb_flush_method = O_DIRECT!  Patches to ActiveRecord and data_fabric gem!

 Still I/O performance of EBS was a hard limit!  Maximum of 1,000 write transactions / sec / server!  But already 5,000 writes / sec at peak for 8 masters!

 We sharded our MySQL databases!  But handling 16 DBs is no fun…!  … and at that time we only had 300,000 users!

© wooga

15 Solution!Pick a DB thatʼs better suited!

 Redis was our choice!  Master runs in-memory only (45,000 writes / sec / server)!  Slaves backup data to disk every 15 minutes!  Rich data model that is way beyond simple key/value!

 We migrated most write heavy tables to Redis!  Currently Redis has 2.5x transactions / sec than MySQL!  But MySQL has still more data (256 GB vs. 40 GB)!

© wooga

16 Challenge Handling Data (Bases) is hard!

 MySQL has its problems!  Making a backup of 64GB takes about 30 minutes…!  But restoring it can take 6 hours or more!

 Redis is not perfect, too!  Memory consumption of process grows over time!  If too much memory is used backup to disk no longer works!  Every two weeks we had to replace servers to “reset” RAM!

© wooga

17 Challenge Redis memory fragmentation!

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18 Solution (not really)Having temporary servers helps a bit!

 Scaling up MySQL DBs!  Start up new master / slave and restore backup!  Make master slave of existing slave!  Wait until replication in sync again (some hours)!  Switch to new master and remove old master / slave!

 Replacing Redis DBs!  Same procedure as above!  But everything can be done in 30 minutes!

m01a s01a m01b s01b

© wooga

19 Solution (hopefully)Have an elastic persistence storage!

 Currently investigating “elastic” alternative!  Riak, MemBase, Hbase, Cassandra etc.!  Can they provide a similar latency as MySQL?!

 A cloud helps with setting up test clusters!  Different test clusters (node count, EBS RAID levels etc.)!  Easy manual cluster setup!  Automated test runs!

© wooga

24 Know what it meansto be in a Cloud!

 Using a cloud has some disadvantages!  Another game with dedicated HW has 8x better performance!  I/O and network performance of EC2 is quite … err … limited!  You cannot pick the best hardware possible!  All hosts have the same chance of failure!

 But offers unique advantages!  Having unlimited servers on demand is just awesome!!  You pay only for what you need when you need it!  You can concentrate on your product!  Itʼs very easy to experiment!

© wooga

25 Play to its strengthsand adjust for its weaknesses!

 Play to its strengths!  Program your infrastructure, automate as much as possible!  Measure closely and react to changes!  Scaling up and out is quite easy!  Sit back and relax…!

 And adjust for its weaknesses!  Avoid I/O – consider an in memory database or caching!  Be prepared that every host can fail!

monster world at amazon ec2

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