Ruby, Redis and Lua - Customised Scripts to Improve Performance

Redis, the famous NoSQL DB, have a nice feature to improve performance and compute more complex logic: Lua. The database have native support to this language to execute scripts and commands.

Due for atomic nature of some operations, you can use it on high concurrency applications.

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1. Ruby, Redis and Lua - Customised Scripts to Improve Performance Marcelo Pinheiro http://salizzar.net - @salizzar
3. $ whoami • Fireman / Problem Solver / Programmer since 2000 • Ruby, Python, Golang, Java, C#, Classic ASP, PHP, Coldfusion, Erlang and others • Fought, made coffee, negotiated deadlines • Software & DevOps Engineer
4. Not just K/V store NoSQL database O’rly?
5. Redis: not only K/V store NoSQL database • Beyond basic types with redis you can use: • Lists • Sets • Sorted Sets • Hashes • Bitmaps
6. Redis: not only K/V store NoSQL database • HyperLogLogs (available since 2.8.9) • WAT • Data structure based on approximation algorithm of the cardinality from a set • In practice, you can count elements of a set with minimal amount of memory
7. Redis for High Performance Some tips
8. Redis for High Performance • Based on your needs, Redis can be a good choice in a high performance system. • Pub/Sub messaging • Many Redis commands are O(1) • Fast, low RAM consumption
9. Redis for High Performance • It seems so good, but… • Captain Obvious: depends. • KNOW. YOUR. PROBLEM. SERIOUSLY. • Redis suffer from bad use because is a hype, as other tools; KNOW WHAT YOU WANT TO USE.
10. Redis Transactions Are totally different from relational database transactions.
11. Redis Transactions: WTF • Redis transaction commands: • MULTI: start a transaction, queueing following commands called after • EXEC: execute enqueued commands • DISCARD: obviously discard enqueued commands • WATCH: check-and-set behaviour to detect changes on a key; if watched key is changed from a concurrent connection between WATCH and EXEC command transaction will fail • UNWATCH: obviously stop to check changes on a key
12. Redis Transactions: WTF • If a Redis transaction started by MULTI contains a command failure, caused by wrong operation inside a structure per example, following commands will be called anyway when EXEC is executed. • Redis not have rollback mechanism. • Be careful using it.
13. Redis and Lua Runs fast.
14. Redis and Lua • Since 2.6.0 Redis have embedded support to Lua scripts • What is Lua? • Brazilian Scripting Programming Language • Fast, lightweight and simple • Famous on game development ecosystem • Ruby, Java, Python support
15. Is fast, believe me. https://github.com/salizzar/tdc-nosql-redis
16. Questions? It’s real?
17. Thank you! :)