CONFIDENTIAL - FOR GARTNER USE ONLY © Scality 20161

Node.js @ScalityExperiences and Lessons Learned

Giorgio Regni, CTOLauren Spiegel, Software Engineer

Disrupting storage – unlimited & everywhere

When to use object storage?

1. Need for capacities beyond 100 TB and growing fast

2. Very large number of clients accessing isolated data

3. Object must be > 100KB, otherwise use a Database

Bucket 1

Object A

Object B

Object C

Bucket 2

Object A

Object B

Object …

Object Z

Our first Node.js project

Copyright Scality 2014Copyright Scality 2014

Our first node.js project - Building a Tivo in the Cloud• 25 million users -> Designed for high degree of

parallelism

• TB/sec –> Need very efficient network transfer

• Scales out by adding nodes and drives

• Proved 30 GB/sec of ingest with 10 servers and 360 drives

Test Case Latency (seconds)

Duration Recordings Batch Size Sockets RPM per Client

Threads per Client Average at 95% at 99%

2 hours 20,000 2500 1000 270 63 0.159 0.319 0.426

The teamSF & Paris

S3-Server AWS S3 compatible server Open source

https://github.com/scality/s3 Can use local storage

S3-MetaData A distributed metadata database service Supports fast Bucket & object listing Stores ACL and Users/Groups

S3-Vault Security, Identity & Authentication Service Provides Accounts/Keys Supports AWS IAM Users & Groups Interoperable with user directory services (via SAML)

What we built: Three Key Components

7

What have we learned??

Logging is hard

• Challenges• Logging is expensive as it taxes the Node.js process• UDP datagrams have expensive DNS lookups• Redundant transformations by bunyan and bunyan-logstash

• Solution: Werelogs• Produces raw JSON logs with the least resistive path• Forward logs to ELK using Filebeat for indexing• Avoids expensive and redundant transformations• Ability to track requests across the components with UIDs• Dump log history on errors

Open source -> http://github.com/scality/werelogs

Our first Node.Js project

Performance, performance & performance

The performance cycleCode, Benchmark, … Repeat

• Socket & Nagle algorithm on by default -> very high latencies

• The event loop can get backed up quickly -> hunt for all cpu intensive tasks in the main loop

• Buffers are much more efficient when writing server response

• Micro optimizations: Date.now() > new Date()• Beware of libraries doing way too many things for you• ES6 support, Babel5 was killing performance -> Babel6

Nifty Node Tools

Nifty Node ToolsGetting going

• Airbnb JavaScript Style Guide + Eslint

• babel — babel5 to babel6 with just imports, destructuring and default parameters

• Commander — cool cli tools in minutes

• Async

Nifty Node ToolsGetting serious

• Level — LevelDB wrapper for node

• Memcached — client library for node

• xml — <parse>yes</parse>

• Profiler — Go fast or go home

Nifty Node ToolsMight as well test

• Mocha

• Istanbul

• lolex

• aws-node-sdk

Nifty Node ToolsDocs and Open Source Code

• Docs are good, but

• Code is even better

• Read the readable stream code and take a nap.

• Then read the transform stream code and create new universes.

What can you do with this thing?

Download the code!

http://s3.scality.com/https://github.com/scality/s3

Lauren:github: laurenspiegeltwitter: @notfollowingyet

Giorgio:github: @giorgioregnitwitter: @giorgioregni