Category Archives: eskildsen

The ones that got away

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

Posted in eskildsen, Hacking, Low-level, Lucene, open source, Performance, Solr | Leave a comment

Speeding up core search

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 | 1 Comment

Light validation of Solr configuration

This week we were once again visited by the Edismax field alias bug in Solr: Searches with boosts, such as foo^2.5, stopped working. The problem arises when an alias with one or more non-existing fields is defined in solrconfig.xml and … Continue reading

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Sampling methods for heuristic faceting

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

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

Net Archive Search building blocks

An extremely webarchive-discovery and Statsbiblioteket centric description of some of the technical possibilities with Net Archive Search. This could be considered internal documentation, but we like to share. There are currently 2 generations of indexes at Statsbiblioteket: v1 (22TB) & … Continue reading

Posted in eskildsen, open source, Solr | 2 Comments

Heuristically correct top-X facets

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