The Elasticsearch Learning to Rank plugin uses machine learning to improve search relevance ranking. It's powering search at places like Wikimedia Foundation and Snagajob!
What this plugin does...
- Allows you to store features (Elasticsearch query templates) in Elasticsearch
- Logs features scores (relevance scores) to create a training set for offline model development
- Stores linear, xgboost, or ranklib ranking models in Elasticsearch that use features you've stored
- Ranks search results using a stored model
Where's the docs?
We recommend taking time to read the docs. There's quite a bit of detailed information about learning to rank basics and how this plugin can ease learning to rank development.
I want to jump in!
If you want to just jump in, go straight to the demo. The demo uses Ranklib, a relatively straightforward Java Learning to Rank library, to train models. Follow the directions in the demo README, edit code, and have fun!
See the full list of prebuilt versions. If you don't see a version available, see the link below for building.
To install, you'd run a command such as:
./bin/elasticsearch-plugin install http://es-learn-to-rank.labs.o19s.com/ltr-1.0.0-RC2-es5.6.4.zip
(It's expected you'll confirm some security exceptions, you can pass
elasticsearch-plugin to automatically install)
Notes if you want to dig into the code or build for a version there's no build for.
1. Build with Gradle Wrapper
./gradlew clean check
This runs the tasks in the
esplugin gradle plugin that builds, tests, generates a Elasticsearch plugin zip file.
2. Install with
./bin/elasticsearch-plugin install file:///path/to/project/build/distributions/ltr-1.0.0-RC2-es5.6.4.zip
Who built this?
- Initially developed at OpenSource Connections.
- Significant contributions by Wikimedia Foundation, Snagajob Engineering, and Bonsai
Other Acknowledgments & Stuff To Read
- Bloomberg's Learning to Rank work for Solr
- Our Berlin Buzzwords Talk, We built an Elasticsearch Learning to Rank plugin. Then came the hard part
- Blog article on How is Search Different from Other Machine Learning Problems
- Also check out our other relevance/search thingies: book Relevant Search, projects Elyzer, Splainer, and Quepid