# Lucandra comparison? **URL:** \ **Category:** Elasticsearch\ **Created:** [July 28, 2010, 12:21am UTC](https://discuss.elastic.co/t/lucandra-comparison/3161 "2010-07-28T00:21:18Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![zellster](https://avatars.discourse-cdn.com/v4/letter/z/ea666f/32.png) [@zellster](https://discuss.elastic.co/u/zellster)\ **Post date:** [July 28, 2010, 12:21am UTC](https://discuss.elastic.co/t/lucandra-comparison/3161/1 "2010-07-28T00:21:18Z")
Hello, Has anyone looked at [http://github.com/tjake/Lucandra](http://github.com/tjake/Lucandra)? It is Lucene + Cassandra. I would be interested in any pros/cons vs. ES. -- Adam [zellster@gmail.com](mailto:zellster@gmail.com) ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [July 28, 2010, 6:10am UTC](https://discuss.elastic.co/t/lucandra-comparison/3161/2 "2010-07-28T06:10:15Z")
Hi looked a bit at Lucandra and glossed over the code. Its an interesting idea, but very problematic when it comes to scaling Lucene (based on my experience). There are two problems with it: 1. The way Lucene works, a single IndexWriter can index an index. This means that with Lucandra, you can only have a single JVM indexing your content to the same index. You can't scale it. 2. When searching, there is a lot of additional data that Lucene stores on the "searcher/reader" level that is problematic to scale when working with a single reader against a large index. For example, FieldCache loads certain fields terms into memory, and it is used when sorting or very often used in facets implementations, custom scoring and so on. This data is, a lot of times, very problematic to load on a single JVM. So, to sum it, you can get into scaling problems both when indexing and when searching when using just Lucandra. The solution for that is to then "shard" your indices between different JVMs, parallelize you index on several smaller indices, and have search executed on all the different shards and reduced (of course, this is just the tip of the iceberg). This are all things elasticsearch already does. One cool thing that can be done is to have Lucandra used on the shard level in elasticsearch. I had a look at the code of Lucandra, have some concerns here and there. Simply have not found the time to try and hack something in that area. -shay.banon On Wed, Jul 28, 2010 at 3:21 AM, Adam Zell [zellster@gmail.com](mailto:zellster@gmail.com) wrote: > Hello, > > Has anyone looked at [GitHub - tjake/Lucandra: Lucandra has moved to Solandra](http://github.com/tjake/Lucandra)? It is Lucene + > Cassandra. I would be interested in any pros/cons vs. ES. > > -- > Adam > [zellster@gmail.com](mailto:zellster@gmail.com) ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 4:21am UTC](https://discuss.elastic.co/t/lucandra-comparison/3161/3 "2017-07-06T04:21:30Z")
Closed on July 6, 2017, 4:21am UTC