Category Archives: Performance

Beware the cursorMark, my son!

Posted on October 24, 2023 by Toke Eskildsen

Efficient export of stored text content from multi-shard Solr setups using cursorMark for individual shards and merging the results externally. Continue reading →

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DocValues jump tables in Lucene/Solr 8

Posted on March 12, 2019 by Toke Eskildsen

Lucene/Solr 8 is about to be released. Among a lot of other things is brings LUCENE-8585, written by your truly with a heap of help from Adrien Grand. LUCENE-8585 introduces jump-tables for DocValues, is all about performance and brings speed-ups … Continue reading →

Posted in eskildsen, Hacking, Low-level, Lucene, Performance, Solr, Uncategorized | 7 Comments

Faster DocValues in Lucene/Solr 7+

Posted on October 2, 2018 by Toke Eskildsen

This is a fairly technical post explaining LUCENE-8374 and its implications on Lucene, Solr and (qualified guess) Elasticsearch search and retrieval speed. It is primarily relevant for people with indexes of 100M+ documents. Teaser We have a Solr setup for … Continue reading →

Posted in eskildsen, Hacking, Low-level, Lucene, Performance, Solr | 1 Comment

70TB, 16b docs, 4 machines, 1 SolrCloud

Posted on November 30, 2016 by Toke Eskildsen

At Statsbiblioteket we maintain a historical net archive for the Danish parts of the Internet. We index it all in Solr and we recently caught up with the present. Time for a status update. The focus is performance and logistics, … Continue reading →

Posted in Hacking, Low-level, Performance, Solr, Statsbiblioteket, Uncategorized | 6 Comments

The ones that got away

Posted on November 13, 2015 by Toke Eskildsen

Two and a half ideas of improving Lucene/Solr performance that did not work out. Track the result set bits At the heart of Lucene (and consequently also Solr and ElasticSearch), there is a great amount of doc ID set handling. … Continue reading →

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Speeding up core search

Posted on October 5, 2015 by Toke Eskildsen

Issue a query, get back the top-X results. It does not get more basic with Solr. So great win if we can improve on that, right? Truth be told, the answer is still “maybe”, but read on for some thoughts, … Continue reading →

Posted in eskildsen, Hacking, Low-level, Lucene, open source, Performance, Solr, Uncategorized | 2 Comments

Sampling methods for heuristic faceting

Posted on July 30, 2015 by Toke Eskildsen

Initial experiments with heuristic faceting in Solr were encouraging: Using just a sample of the result set, it was possible to get correct facet results for large result sets, reducing processing time by an order of magnitude. Alas, further experimentation … Continue reading →

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Dubious guesses, counted correctly

Posted on June 19, 2015 by Toke Eskildsen

We do have a bit of a performance challenge with heavy faceting on large result sets in our Solr based Net Archive Search. The usual query speed is < 2 seconds, but if the user requests aggregations based on large … Continue reading →

Posted in eskildsen, Faceting, Low-level, open source, Performance, Solr | 1 Comment

Heuristically correct top-X facets

Posted on May 30, 2015 by Toke Eskildsen

For most searches in our Net Archive, we have acceptable response time, due to the use of sparse faceting with Solr. Unfortunately as well as expectedly, some of the searches are slow. Response times in minutes slow, if we’re talking … Continue reading →

Posted in eskildsen, Faceting, Hacking, Low-level, Performance, Solr | 1 Comment

Alternative counter tracking

Posted on April 30, 2015 by Toke Eskildsen

Warning: Bit-fiddling ahead. The initial driver for implementing Sparse Faceting was to have extraction-time scale with the result set size, instead of with the total number of unique values in the index. From a performance point of view, this works … Continue reading →

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