Continuous Deployment talk at Yahoo! Large Scale Production Engineering (LPSE)
Last night I gave a talk at the Yahoo! Large Scale Production Engineering (LPSE) meetup. They said I had about 20 minutes to talk about continuous deployment at Wealthfront so I went fast, but there were at least another 20 minutes of questions so I was happy to oblige! Thanks to Chris Westin of Yahoo!… Read more
GUI Testing, Without The Gooey Parts
Alright, so I know that Java on the desktop has never reached the level of popularity that it enjoys on the server side, but regardless of popularity, there are cases where the requirements favor or maybe even necessitate a desktop solution. Testing a user interface can get kinda sticky, but with the right abstractions, you’ll… Read more
Monitoring Long Running MySQL Queries with Nagios
We’ve been using Nagios as part of our monitoring infrastructure from some time now and it has been very useful to monitor our databases. To look at long running queries (those whose running time is measured in seconds) we use the show processlist command. Here is what the output looks like on an empty machine…. Read more
Less IO for your Unit Tests with a Java SecurityManager
Our quest for a truly test-driven engineering team has enabled us to confidently ship our software every few minutes. Automated testing is the keystone of continuous deployment, and as a result our unit tests and smoke tests are thorough. Perhaps, a bit too thorough. (Our last unit testing extravaganza in the form of a cyclomatic-complexity-driven… Read more
Computation: “There is no try”
Often a complex, multi-step calculation requires your code to react to many circumstances. Typically you use exception handling to separate the normal control flow from error handling: Option<BigDecimal> result = Option.none(); try { result = compute(); } catch (WhateverException e) { // Perhaps rethrow. } if (result.isEmpty()) { // Perhaps retry, or set a dummy… Read more
If you ever write a varags method…
In some specific cases, methods with a variable argument list might greatly improve the usability of an API. However, it is very easy to overuse or misuse this language feature, leading to cumbersome APIs. Varags methods shine when the programmer knows how many arguments must be passed to a specific invocation of the method when… Read more