This blog post originated in a talk I presented at the Prairie.Code() 2016 conference. As web developers, we often need to build services that query data from multiple sources in complex ways. To improve performance, these services often pre-compute materialized views and store them in caches. In this article, we’ll explore a few problems with…
Druid is a time-series database. It indexes events that occur over time, and is good at answering queries that involve aggregating values over time. In this blog post we’ll explore how Druid indexes data, examine the information it stores and see how it answers various queries. Understanding these details will help us use Druid effectively to…
We’ve been learning a lot about Docker, Mesos and Marathon lately at Banno and have big plans to use these technologies in our infrastructure. Mesos will let us treat all of our servers as one uniform pool of resources, on which we’ll run our applications packaged into convenient Docker containers, with Marathon figuring out the…
Titan is a distributed graph database that runs on top of Cassandra or HBase to achieve both massive data scale and fast graph traversal queries. There are benefits to Titan on only a single server and it seamlessly scales up from there. It’s great to know that Titan scales but when first starting out you may…
If you are building Debian packages for your own libraries and applications (that are not open source), you are probably familiar with the pain of managing and hosting your own private Apt repository. This post shows how to easily manage your own Apt repo and host it on S3 so that only your servers can…
Using a build tool that provides the full power of a real programming language makes many tasks much easier than build tools that use a declarative markup language. To cut to the chase, I’m referring to sbt vs Maven (or Ant). Just wanted to write a quick post that shows how we have customized our…
We’ve been slowly migrating our Lift web app to more of an event-driven architecture. This approach offloads non-essential processing out of the HTTP request/response cycle into actors, and makes things a lot more flexible on the back-end. However, as we’ve discovered during this process, there are several things to be aware of by doing database…
We’ve been doing some profiling on http://pongr.com recently and have started using Ostrich. Our site uses Lift and I thought I’d put together a brief tutorial showing how to use Ostrich in a Lift-based web app. Our approach was heavily inspired by the usage of Ostrich in ESME, is described below and is available on…
At Pongr, our RESTful web services are built using Jersey, Guice and Scala (among many other technologies). Here’s a quick post that shows how to set up an example project that uses all three. By the end we’ll be able to declare Guice bindings in our own custom module and have them injected into Jersey…
We often need to pull a large number of rows from a database table, split those rows up into n groups, and write each group out to a separate text file. These text files are then processed by another application. Each text file starts with the number of rows in the file on the first…
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