web real time analytics dashboard: which technologies should use? (node/django, cassandra/mongodb...)

Question

we want to develop a dashboard to analyze geospatial data. This is a small and close approach to what we want to do: http://adilmoujahid.com/images/data-viz-talkingdata.gif

Our main concerns are about the backend technologies to be used. (front will be D3.js, DC.js, leaflet.js...)

Between Django and node.js, we think that we will use node.js, cause we've read than its faster than Django for this kind of tasks. But we are not sure and we are open to ideas.

But about Mongo or Cassandra, we are so confused. Our data is mostly structured, so store it in tables like Cassandra would make it easy to manage, also Cassandra seems to have better performance. However, we also have IoT devices data, with lots of real-time GPS location...

Which suggestions can you give to us to achieve our goal?

TL;DR Summary;

• Dashboard with hundreds of simultaneous users.
• Stored data will be mostly structured text/numbers, but will include also images, GPS-arrays, IoT sensors, geographical data (vector-polygons & rasters)
• Databases will receive high write load coming from sensors.
• Dashboard performance is so important. Its more important to read data in real time, than keeping it uncorrupted/secure.
• Most calculus/math will be calculated in the client's browser, the server will try to avoid mathematical operations.

Answer 1

JaguarDB has very strong support of geospatial data (2D and 3D). It allows you to store multi-measurements per point location while other databases support only one measurement (pointm). Many complex queries such as Voronoi polygon, convexhull are also supported. It is open source, distributed and sharded, multiple columns indexes, etc.

Answer 2

Concerning Postgresql and Cassandra, is there much difference in RAM/CPU/DISK usage between them?

Our use case does not require transactions, it will be in a single node and we will have IoT devices writing data up to 500 times per second. However ive read that Geographical data that works better with Potstgis than cassandra...

According to this use case, do you recommend Cassandra or Postgis?

Answer 3

Disclaimer: I'm a DataStax employee so I'll comment on the Cassandra piece.

Cassandra is a good choice for this if your dashboard can be planned around a set of known queries. If those users will be doing ad-hoc queries directly to the database from the dashboard, you'll want something with a little more flexibility like ElasticSearch or (shameless plug) DataStax Search. Especially if you expect the queries/database to handle some of the geospatial logic.