What's new in cqlengine 0.7
Recently we released version 0.7 of cqlengine, the Python object mapper for CQL3. We’ve been steadily moving towards full support of all of CQL3 for both queries and for table configuration. This post will outline the new features and provide examples on how to use them.
Counters
With counter support finally included it’s now possible to create and use tables with counter columns. They are exposed to the Python application as simple integers, and changes to their values will be sent as deltas to Cassandra. Let’s take a look at an example. I’ll assume you already have Cassandra running locally.
Cassandra, CQL3, and Time Series Data with timeuuid
Cassandra is a BigTable inspired database created at Facebook. It was open sourced several years ago and is now an Apache project.
In cassandra, a row can be very wide and is identified by a key. Think of it as more like a giant array. The data is stored on disk sorted by the key you pick, meaning if you pick the right sort option and key you can have some really fast queries. Here we’ll go over a time series.
Setting up RAID0 in Ubuntu 12.04 in AWS High I/O
Amazon announced high I/O instances today. This is huge for anyone with a database larger than available memory, as it’s been a complete nightmare dealing with EBS up till now. Now your Cassandra, MongoDB, MySQL, or whatever your using should be able to perform well without requiring keeping your entire dataset in memory.
With each instance you get 2x1TB of disk. In this tutorial I’ll be setting it up as a RAID0 to get a single 2TB disk which should deliver excellent performance.