Benchmarking MongoDBFor Fame and Fortune

Tim Callaghan : @acmebench

Benchmarking MongoDB

For Fame and Fortune

Tim Callaghan : @acmebench

Who am I?● Professional technical benchmarker at

VoltDB (09-11) and Tokutek (11-15)● Amateur technical benchmarker at www.

acmebenchmarking.com● Lifelong fan of fast databases and

performance engineering● Apologies for the number of

Where is the Fortune?MongoDB “bug hunts” for each major release

- Free MongoDB/World Pass- Reserved front-row keynote seat- Amazon gift card

Google AdWords/Blog?

3 Steps of Benchmarking1. Create the benchmark2. Execute the benchmark3. Publish your results (and explain them)

www.acmebenchmarking.com/2015/02/how-to-benchmark-mongodb.html

Create the Benchmark● Should be something people can understand

○ “Real-world”○ Better yet, mimic your workload

■ We need a lot more of this!○ Be prepared to explain in detail

● Open source it!○ www.github.com/tmcallaghan○ Sysbench and iiBench for MongoDB

Execute the Benchmark● Measure everything

○ CPU, RSS, IO, mongostat, db.serverStatus()● Multiple runs are key

○ 2 out of 3 (eliminate bad results)● Make 1 change, rerun

○ Memory, compression type, data size● Lather, rinse, repeat

Pro-tips for Benchmarking● Use Linux (sorry Windows)● Get good at bash● Learn from others

○ www.acmebenchmarking.com/2015/02/how-to-benchmark-mongodb.html

Publish Your Results● Start a blog● Describe the benchmark in detail● Include steps to reproduce● Come to a conclusion

○ Make some sort of comparison○ MongoDB v2.6 vs. 3.0○ WiredTiger vs. MMAPv1○ DirectIO vs. BufferedIO

Getting Started● Good blogs

○ www.acmebenchmarking.com○ http://smalldatum.blogspot.com/○ https://www.percona.com/blog/

● Google “mongodb benchmark” or “mysql benchmark”● Get some good (and cheap) hardware

○ Desktops are fine○ www.acmebenchmarking.com/2015/04/how-to-purchase-benchmarking-hardware.html

Questions?

Tim Callaghan@acmebench

Deck available at http://www.slideshare.net/tmcallaghan