How do I run geospatial queries at scale with NoSQL?
I am preparing to build an Android/iOS app that will require me to make complex polygon and containment geospatial queries. I like Apache Cassandra's no single point of failure, fault tolerance and data center awareness. Cassandra does not have direct support for geospatial queries (that I am aware of) but MongoDB and Couchbase Server do. MongoDB has scaling issues and I'm not sure if Couchbase would be a better alternative than Cassandra with Solr or Elasticsearch.
Would I be making a mistake by going with Datastax Enterprise (DSE), Cassandra and Elasticsearch over Couchbase Server? Will there be a noticeable difference in load times for web pages with the Cassandra/ES back end vs. Couchbase?
Answer
Aerospike just released Server Community Edition 3.7.0, which includes Geospatial Indexes as a feature.
Aerospike can now store GeoJSON objects and execute various queries, allowing an application to track rapidly changing Geospatial objects or simply ask the question of “what’s near me”. Internally, we use Google’s S2 library and Geo Hashing to encode and index these points and regions. The following types of queries are supported:
- Points within a Region
- Points within a Radius
- Regions a Point is in
This can be combined with a User-Defined Function (UDF) to filter the results – i.e., to further refine the results to only include Bars, Restaurants or Places of Worship near you – even ones that are currently open or have availability. Additionally, finding the Region a point is in allows, for example, an advertiser to figure out campaign regions that the mobile user is in – and therefore place a geospatially targeted advertisement. Internally, the same storage mechanisms are used, which enables highly concurrent reads and writes to the Geospatial data or other data held on the record. Geospatial data is a lot of fun to play around with, so we have included a set of examples based on Open Street Map and Yelp Dataset Challenge data.
Geospatial is an Experimental feature in the 3.7.0 release. It’s meant for developers to try out and provide feedback. We think the APIs are good, but in an experimental feature, based on the feedback from the community, Aerospike may choose to modify these APIs by the time this feature is GA. It’s not intended for Production usage right now (though we know some developers will go directly to Production ...)