sam ghods vp technology. the simplest way for businesses to share and access data, anywhere
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Sam GhodsVP Technology
The simplest way for businesses to share and access data, anywhere
12 months ago…
400M files40M folders
One MySQL database
Need to scale!
NoSQL!
“NoSQL” goodies
• Easy to scale– Just add machines!– Sharding handled by the database– Linearly scales, shared-nothing, no serious SPOF
• Fast, fairly simple CRUD operations• Schema-less
Not so fast.
We sharded MySQL instead.
Why???
If you use a NoSQL store, but need any advanced features in your data
store, you have to rebuild them from scratch yourself.
If you are willing to partition your data yourself, you can use
MySQL’s fancy features.
Inter-Row Consistency
Inter-Row ConsistencyFile trees must remain consistent
• Folder A– Test File– Test File
• Solution: unique index• Solution: lock folder A
Inter-Row ConsistencyModify data structure and log event
• Folder A– Test File 1
Inter-Row ConsistencyModify data structure and log event
• Folder A– Test File 2
• Solution: Use transactions rename event
Inter-Row ConsistencyDenormalizations
• Folder A– Test File 1
• Solution: transactions
delete this must be deleted too
Indexes
• Indexes are way more awesome than people give them credit for– Guaranteed to be consistent– Extremely fast– Data locality – Only access and pull the data you
need– No maintenance required except initial ALTER cost
• SELECT files ORDER BY name (or updated time, or size, etc…)
Tools
• How do you know what’s happening in your data store?– SHOW FULL PROCESSLIST– innotop
• Benchmarking tools– mysqlslap
• pt-query-digest– github.com/box/anemometer
Maturity/Reliability
• Biggest companies in the world have been using MySQL for primary data storage for over a decade– Facebook, Google, Twitter, every other
company ever• When you’re dealing with the crown jewels
of your company, you can’t experiment
HBase!
HBase
• Currently using it as a massive event-propagation store (which can be recreated from MySQL data)
• Started a 3-person task force to learn and productionalize it
• Considering moving more to it in the future but likely need few more years of production experience
Final Thoughts
• Don’t choose a database just because “it scales”
• “Wade, don’t jump into new technologies.”• If you go with new technology, be aware that
crazy things might happen• Make sure you’re not rebuilding MySQL