Download pdf - Mendeley Suggest: Engineering a Personalised Article Recommender System

Mendeley Suggest: Engineering a

Personalised Article Recommender System

Kris Jack, PhDChief Data Scientist

https://twitter.com/_krisjack

➔ What's Mendeley?

➔ What's Mendeley Suggest?

➔ Computation Layer

➔ Serving Layer➔ Architecture➔ Technologies➔ Deployment

➔ Conclusions

Overview

What's Mendeley?

➔ Mendeley is a platform that connects researchers, research data and apps

Mendeley Open API

➔ Mendeley is a platform that connects researchers, research data and apps

➔ Startup company with ~20 R&D engineers

Mendeley Open API

What's Mendeley Suggest?

Use Case

➔ Good researchers are on top of their game➔ Difficult with the amount being produced

➔ There must be a technology that can help

➔ Help researchers by recommending relevant research

Mendeley Suggest

Computation Layer

Mendeley Suggest

Mendeley Suggest

Mendeley Suggest

Running on Amazon's Elastic Map Reduce

On demand use and easy to cost

Nor

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No. Good Recommendations/10

Mahout'sPerformance

1.5M Users, 50M ArticlesComputation Layer

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Costly & Bad Costly & Good

Cheap & Bad Cheap & Good

Mahout'sPerformance


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Mahout'sPerformance


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Mahout'sPerformance


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0

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0 0.5 1 1.5 2 2.5



3

Mahout'sPerformance


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6.5K, 1.5Orig. item-based

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0

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Cust. item-based➔2.4K, 1.5

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Mahout'sPerformance


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0

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-4.1K(63%)

Mahout'sPerformance

ParitionersMR allocation


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0

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Orig. user-based➔1K, 2.5

3

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0

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-1.4K(58%)

+1 (67%)

Mahout'sPerformance


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0

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Cust. user-based➔0.3K, 2.5

Mahout'sPerformance


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-0.7K(70%)

Mahout'sPerformance

-4.1K(63%)


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-6.2K(95%)

Mahout'sPerformance

+1 (67%)


Mahout as the Computation Layer

➔ Out of the box, didn't work so well for us➔ Needed to understand Hadoop better➔ Contributed patch back to community (user-user)

➔ Next step, the serving layer...

Serving Layer

MendeleyHadoopCluster

UserLibraries

Cascading

Architecture

ComputationLayer

AWS

MendeleyHadoopCluster

DynamoDB ElasticBeanstalk

ElasticBeanstalk

ElasticBeanstalk

UserLibraries

Map Reduce

Architecture

ComputationLayer

ServingLayer

➔ Spring dependency injection framework➔ Context-wide integration testing is easy, including pre-loading

of test data➔ Allows other Spring features (cache, security, messaging)

➔ Spring MVC 3.2.M1➔ Annotated controllers, type conversion 'for free'➔ Asynchronous Servlet 3.0 supports thread 'parking'

➔ AlternatorDB➔ In-memory DynamoDB implementation for testing

Technologies

Recommendation<K>

LongRecommendation UuidRecommendation

DocumentRecommendationGroupRecommendation PersonRecommendation

➔ Build once, employ in several use cases

Technologies

➔ AWS ElasticBeanstalk➔ Managed, auto-scaling, health-checking .war container

➔ Jenkins continuous integration (CI) server➔ Maven build tool (useful dependency management)➔ beanstalk-maven-plugin (push a button to deploy)

➔ Deploys to ElasticBeanstalk➔ Replaces existing application version if required➔ 'Zero downtime' updates (tested at ~300ms)➔ Triggered by Jenkins

Deployment

Putting it all together... $$$

➔ Real-time article recommendations for 2 million users➔ 20 requests per second➔ $65.84/month

➔ $34.24 ElasticBeanstalk➔ $28.17 DynamoDB➔ $2.76 bandwidth

➔ $30 to update the computation layer periodically

Conclusions

Conclusions

➔ Mendeley Suggest is a personalised article recommender➔ Built by small team for big data➔ Uses Mahout as computation layer

➔ Needs some love out of the box➔ Serves from AWS

➔ Reduces maintenance costs and is reliable➔ Intend to release Mendeley Suggest to all users this year

We're Hiring!

➔ Data Scientist➔ apply recommender technologies to Mendeley's data

➔ work on improving the quality of Mendeley's research catalogue

➔ starting in first quarter of 2013

➔ 6 month secondment in KNOW Center, TU Graz, Austria as part of the EC FP7 TEAM project (http://team-project.tugraz.at/)

➔ http://www.mendeley.com/careers/

www.mendeley.com