Answering the Database Scale Out Problem: SSDs in the Data Center April 14, 2010 Dan Marriott Director - Production Operations

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ReferenceAnswers 3

WikiAnswers: Q&A the Wiki Way 4

Database layer MySQL b20-percona MySQL a 5

Challenges Keep site fast  while site traffic and stored data are ever-increasing Replication lag = 0  or users get stale data Forever being forced to further optimize queries  constantly vying for dev resources to do this Controlling hardware growth (Cap & OpEx $$$)  regularly adding servers to handle growth 6

Handling high growth – database tier Separate reads and writes Add more read DB slaves Use Memcached where possible Optimize Queries Partition large databases _________ Started hitting a wall: Replication Lag even when servers handling modest # queries/sec 7

Typical DB read cluster 8

Fusion-io for HP Blade Servers March ’09: HP announce IO Accelerator card for blades (manuf. by Fusion-io) Sizes:  80 & 160GB SLC  320GB MLC April ’09: received two cards – began testing 9

Easy to install One man job. Takes 60 secs. 10

Performance Tests Test Blade Server – SAS HDDs Blade Server – Fusion-io cardImprovement 11 Additionally, CPU load dropped from 30% to 18% (even with Fusion-io driver overhead) Replication catch-up time (after restore) > 6 hours12½ mins 3,000% Max Queries/sec (Seconds_Behind_Master: 0) 350 Q/sec3,500 Q/sec 900% Application response time 100 ms70 ms 30% Full DB server recovery > 8 hours 55 mins800%

Typical DB read cluster 12

Fusion-io Value Add for Answers.com Scalability. >Twice the performance capacity on 1/4 servers 100% ROI on day of purchase (repurpose other 3/4) 75% reduction in operating costs:  Rack Space, Power and Cooling  Server Administration  Database Administration 75% fewer failure points 13

Other SSD uses in the Data Center Varnish (Web caching layer) DB Backup Servers Log Analysis Data Warehouse 14

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