Hello, I am currently experimenting with tuning of max merged segment MB parameter on TieredMergePolicy in Lucene 3.5, and seeing significant gains in index writing speed from values dramatically lower than the default (5 Gb). For instance, when setting it to 5 or 10 MB, I can see my writing tests run anywhere from 25% to 40% faster, depending on physical storage type (rotational vs Fusion IO), data size and type, and possibly thread access pattern.
In practice, our usage of Lucene can result in merged segment files whose size sometimes exceeds even the default merge limit, so forcing partition of these into much smaller chunks raises a concern over how much of a decrease in search performance I should expect for each improvement in indexing speed. Is the dependency linear, are there any specific guidelines to follow here? Are there other tunable settings related to segment merging to try out that might have a similar impact? Thank you, -V --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
