Derek C. Ashmore's Blog, page 4

Active Conference Presentation Abstracts

Speaking at conferences has become a regular activity for me. To save time for both me and conference organizers, I maintain this list of presentations I'm actively submitting to conferences and user groups. My presentations are updated frequently to reflect current industry changes and events. If you're a conference organizer, I'm always willing to discuss enhancements that will allow one of my presentations to more closely fit your upcoming event.  As always, I'm interested in suggesti...

Making Unit Testing Private Methods Easier

Earlier this year I blogged about testing private methods (here). I noted that FieldUtils utility from Apache Commons Lang product has one-line utilities to access private fields. While explaining to readers that Lang's MethodUtils utility should have a one-line utility to access private methods so that we can more easily test them directly. I explained that this is preferable to over-exposing those methods (e.g. making them protected) merely so they can be tested. 
As a result I fil...

AWS Lambda Reading List

I'm hearing a lot about AWS Lambda these days and "serverless" architectures. By "serverless", I mean the concept, not the product (here). Basically, AWS Lambda is computing power without management. You provide your code, AWS Lambda runs it. You have minimal setup and no responsibility for maintaining servers on which to run that code.
As with all new technology fads, there's a lot of buzz and a flurry of unorganized content. My intent with this entry is to keep a current list of relevant Lam...

"Microservices for Java Architects" has been released!

Microservices for Java Architects is a companion for the Java EE Architect’s Handbook that details Microservices Architectures. This eBook will define microservices and provide an overview of costs and benefits. As with the handbook, I’ll go on to address architecture, design, and implementation concerns specific to microservices architecture.
DetailsGiven the published success stories from Netflix, Amazon, and many organizations; companies are increasingly adopting microservices architecture....

Book Review: The Art of Business Value by Mark Schwartz

I just read the book "The Art of Business Value" by Mark Schwartz. I came upon this book as I follow Adrian Cockcroft on Twitter and he tweeted about it. Mr. Cockcroft also has a blurb for the book on the back cover.  That was enough to get me to buy and read the book.  As a technical author myself, Amazon does not let me post reviews on technical books. As a result, my review is here.
Even with agile methodologies, IT has trouble delivering business value. The book starts with some...

Using Maven to produce Docker imarges

Docker is fast becoming the deployable artifact of choice. There are good reasons for this. It standardizes deployables across all technical stacks. This has the effect of streamlining work for a DevOps team working to manage large numbers of deployables. It allows developers to control the technical stack under which they deploy without and any tooling able to deploy Docker containers will just work. The reasons go on and on.
As a result, I've begun adding Docker artifacts to my standard buil...

Considerations for adopting Canary releases

A canary release is a tactic for reducing deployment risk. The idea is to deploy a new release to one or two nodes in a service cluster, let them handle some portion of the work load, and see if any unexpected errors result. In effect, this is a kind of "testing" in production. The term comes from the practice of miners to bring canaries with them into the mines; if the canaries died, then the air wasn't safe to breathe and they should evacuate. Like all strategies, there are advantages and d...

Exception Throwing Etiquette

Nothing irritates me more than investigating reported exceptions where the developer didn't take the time to record the context with the exception.  That is, you get an error message like "Field XXX value not valid" or something like that.  What value was provided that was invalid?  What are the valid values for that field?  What were the other arguments to the method being thrown so that it's quick and easy to construct a test case for fixing the bug?  
These are all...

How Apache Mesos Adds Business Value

The Apache Mesos product adds business value.  An incredible amount of it.  But the source of that value isn't what most people think.  Most think that the business value is simplification of deployment for developers so that they spend more time developing features instead of worrying about the deployment infrastructure.  There is value for developers, but there's more.
Mesos eliminates cloud vendor lock in.   Mesos slaves run on virtual machines with prerequisite soft...

Testing Private Methods in Unit Tests

Covering private code in unit tests can be problematic as they aren't directly executable from unit tests.  I've seen developers take one of two approaches.  One approach is to embed tests for private code in unit tests for protected or public methods.  Another is to escalate the declaration in the code being tested from private to protected, so that they can be more easily handled in unit tests.  Both approaches are problematic.
Testing private methods indirectly through p...