Solr on Cloud

Tallinn University of Technology

Introduction to Development in Cloud by Anton Vedešin

Road Management Team

What is              ?

Solr is the popular, blazing-fast open source enterprise search platform built on Apache Lucene

Solr powers the search and navigation features of many of the world's largest internet sites.

What            is not ?            

Key aspects of                 

  • highly reliable
  • scalable
  • fault tolerant
  • provides distributed indexing
  • replication
  • load-balanced querying
  • automated failover and recovery
  • centralised configuration

Why we need           ?        

  • optimised for search
  • larges volumes of documents
  • text-centric
  • results sorted by relevance
  • read-dominant
  • document-oriented
  • flexible schema

How it works?

All terms in the index map to one or more documents.

Terms in the inverted index are sorted in ascending lexicographical order

Inverted index

Finding sets of documents

Relevancy calculation

  • term frequency (tf)
  • inverse document frequency (idf)
  • term boosts (t.getBoost)
  • field normalisation (norm)
  • coordination factor (coord)
  • query normalisation (queryNorm)


Inverse term frequency (itf)

Not all search terms or created equal !

Unstructured data

Text-centric data 



Flexible schema

Keyword search

  • relevant results must be returned quickly
  • spelling correction is needed
  • autosuggestions save keystrokes
  • synonyms of query terms must be recognised
  • phrase handling is needed
  • queries with common words must be handled
  • show more results if the top results aren’t satisfactory

Ranked retrieval

Faceted search


cache management

concurrent queries

CPU & I/O constraints

query throughput

number of documents indexed




number of documents indexed

Geospatial search

Multilingual support

Near real-time search (NRT)

Data modeling features

  • Result grouping/field collapsing 
  • Flexible query support 
  • Joins
  • Document clustering 
  • Importing rich document formats such as PDF, Word  
  • Importing data from relational databases 

flat denormalised document

Other important features

  • Atomic updates with  optimistic concurrency
  • Real-time get
  • Write-durability using a transaction log


  •  centralised configuration
  • distributed indexing with no SPoF
  • automated failover to a new shard leader
  • queries can be sent to any node in a cluster to trigger a full, distributed search across all shards, with failover and load-balancing support built in.

fault-tolerance & high availability

Not to use           !          

  • request a large result set
  • do deep analytic tasks
  • querying across relationships
  • document-level security


Thank you!


Postgres DBA @ 2ndQuadrant

Studying MSc Comp. & Systems Eng. @ Tallinn University of Technology

Studied BSc Maths Eng. @ Yildiz Technical University

Writes blog on 2ndQuadrant blog

Does some childish paintings

Loves independent films


Skype: gulcin2ndq

Github: gulcin

Solr on Cloud

By Gülçin Yıldırım Jelínek

Solr on Cloud

This presentation is created for Introduction to Development in Cloud lecture at Tallinn University of Technology, 24th of November, 2015.

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