Programming on the Edge

Scribe 2.0: Fastest JVM Logger in the World!

Published by Matt Hicks under , , , , , , , , , , on Tuesday, February 06, 2018
An intentionally provocative heading, but one I stand behind until someone can prove otherwise (and I welcome just that).  Scribe 1.x was pretty fast (, but was not written with performance in mind.  When I came back around and realized just how fast log4j2 is, I could see no reason why a Scala logging solution shouldn't be able to run circles around it.

Note: the benchmarks below are tested using simple file logging to represent the most common production logging scenario.

Log4J Comparison

Now, for people like me that often want to skip all the blustering, explanations, and bravado, I'll cut straight to the result graph of the performance comparison between log4j 2.10.0 and Scribe 2.0.0:

Like I said, log4j2 is fast, but Scribe 2 is just shy of a 50% performance boost on that.  If we look at the over-time graph it provides additional insights:

You can see that log4j does well, but operations increase in cost partway through, while Scribe is smooth and steady for the entire run.

Method and Line Numbers

This is all compelling but practically speaking, 99% of applications won't even notice the difference between 1,500 nanoseconds and 800 nanoseconds per record logging.  Thus far I've been comparing Apples to Oranges though.  In Scribe, the method and line numbers are integrated into the log records by default.  If we add that to the logging (which any reasonable logging framework should have) we see a different story:

Shocking, right?  If you know Java, you'll probably realize why this is.  In Java, the only way to get access to method and line numbers in your logging is by walking the stack trace.  This is a very expensive operation to be doing and slows the logging to a crawl.  This is why it's not on by default, and why you don't see this talked about much in Java logging frameworks.  However, Scala Macros come to the rescue!  In Scribe, we get all of that for free.  The method and line number information are extracted at compile-time so you can see that Scribe is just as fast whether method and line number logging is enabled or not.

Typesafe Scala Logging

In 1.x my focus was the comparison with Scala Logging.  As you can see below, we're not even in the same ballpark:

It's a pretty pathetic comparison.  In Scribe, 1.x Scribe was noticeably faster, but this shows just how inefficient Scala Logging is.

All Loggers

If you'd like to see the side-by-side comparisons of all the competitors:

Though the log4jTrace and scalaLogging results dwarf the performance distinction between log4j and Scribe, if you've seen all the results here, Scribe is the clear performance winner here.  I'll make another post to show why it's also more powerful, but I'll save that for another day.


I'm not a master with log4j or Scala Logging, so it's possible I'm not giving ideal running circumstances for these loggers to "show their stuff".  The original source code is posted in the repository:

The JMH benchmark results were also saved to a JSON file if you want the raw results to make sure I'm not trying to pull a fast one:

Getting Started

To learn more about Scribe and start using it, check it out here:

Please feel free to email me if you find any mistakes in anything I've said to set me straight, or you can publicly shame me by writing a comment on this post.  I welcome criticism and praise, but criticism gives me something to learn from, so it is more appreciated.

Logging Performance

Published by Matt Hicks under , , , , , , , , , , on Thursday, January 12, 2017
I've never been a fan of the setup of logging frameworks as far back as when I was a Java developer.  The hassle and complexity of configuring and managing the logging framework was always a big hassle and would often create serious problems in the application if not done right.  Even today in Scala it doesn't feel much better.  Certainly we have Macros that give some additional compile-time optimizations, but it's amazing how little has changed.

A while back I created a Scala logging framework called Scribe.  Honestly, the primary reason had more to do with giving greater flexibility to control configuration in code over performance or anything else.  However, by not building on top of log4j, logback, slf4j, or JUL, I found that the system was not only far more simplistic and configurable, but it was also faster.

I recently did a comparison between Lightbend's Scala Logging framework to see how it performs.  Without any additional optimizations the results were pretty impressive.  I configured both Scribe and Scala Logging to avoid writing to standard out as that would be the primary bottleneck of performance and simply wrote a custom Writer / Appender that would simply count the log entries:

Over sixty seconds I recorded how many records could be logged.  Scala Logging was able to log 474k records and Scribe was able to log 610k.  Now, obviously this is far more logging than any reasonable application should be doing, but the point was to prove that not only can Scribe keep up with the most popular Scala logging framework (Scala Logging) on top of the most popular Java logging framework (Logback), but it quite a bit faster.

The second thing I measured was memory consumption over the run.  Memory usage is a very important factor with regard to logging as it should have a very small footprint to give maximum allocation to the application itself.  Again, my finding were pretty strongly in favor of Scribe:

While Scala Logging utilized 704kb of memory Scribe utilized on 596kb.  Again, not a substantial difference when we're discussing hundreds of thousands of records being logged, but this is meant to prove that Scribe is the better performer.

Very often I hear that a developer won't use a framework because there aren't enough developers using it.  Obviously this creates a chicken / egg situation as you can't get developers using it because not enough developers use it.

Hopefully this short post will give some additionally credibility to the value of Scribe that people will start comparing features and see just how much it has to offer.  If there's something missing that your existing logging framework has, just create a ticket.

Publicity in Open-Source

Published by Matt Hicks under , , , , , , on Wednesday, January 04, 2017
To my relatively small number of followers, it should come as no surprise that my biggest failing is actually getting much visibility for my vast number of open-source projects I write.  To that end I've been doing some research and asking other developers to give me some suggestions on how to get more visibility for me projects.  I've made it a goal for this year to get more visibility for my open-source projects so they will hopefully reach a larger audience.

I decided that I would post the results of my research in a blog post so hopefully others can benefit from this research as well, or at least I can have an easy place to reference back to it for myself.

Speaking / Conferences

The most common suggestion for visibility for a project was speaking about it both in local groups and at conferences.  Several developers said that's how they learned about a useful framework they are using.  This is a good idea and something I'm planning on doing more of this year, even though I really prefer to write code than talk about it, but this is a bit of a longer-term objective than immediate visibility.


There are lots of "awesome" lists. Often more than one for each language. This is a no-brainer presuming you can get someone to merge your pull request:


Apparently there are people that use that site and a common source of information for developers.  I must admit, I haven't been a big user, and this is something I think is going to have to change.  I'll have to get involved in the Scala group and reference my projects there.


Yet another thing I am terrible about not keeping up with.  For a very long time I simply had all of my GitHub commits logging to Twitter, but I'm thinking that personalized messages on Twitter with relevant hashtags might be a very good way to get my projects noticed.  Many developers I talked to get most of their news and information from Twitter.

Mailing Lists

Though a bit old-school, this is something a lot of developers still follow and perhaps a good way to get visibility directly into people's inbox of a new framework that should be using.

Based on this research it's clear that my aversion to social media has a direct correlation to my difficulty in getting visibility for my projects.  Shocking right?  I suppose the moral of the story is, if you don't like people, don't expect them to like you either.

Play Framework for Scala: An Evaluation

Published by Matt Hicks under , , , , , , , , , , , , on Friday, June 03, 2016
I often speak to clients and developers that are pushing the Play Framework as the ideal web framework when developing Scala web applications.  I started considering why Play is the framework that people tend to settle on, especially large companies.  I think there are a few reasons:

  1. It's supported by Typesafe *cough*, I mean Lightbend. Certainly Lightbend is the main company supporting Scala and to many people that means you should use whatever technology they are pushing.
  2. It has commercial support. This is a bleed-over from point #1, but I think warrants its own point.  Especially for big companies having the ability to get commercial support is very important.  It is unfortunate that truly open-source projects that are entirely community driven are seen as riskier, but typically that is the mentality.
  3. Play is actively maintained. It has been around for years and is sure to be around and maintained for many to come. Having a long history seems to give a lot of credibility to frameworks whether they deserve it or not.
  4. It's huge! There are a ton of modules and features that Play has available for your various needs and that provides a compelling option to companies that want to grow and expand and may need those nifty features in the future.
  5. Easy to get going. The handy-dandy Activator makes creating and managing your application stupid simple (with an emphasis on "stupid").  Especially for people building initial prototypes and evaluating the options available often find this compelling.  Activator helps get them going fast without much fussing with the build tools or framework.
  6. Big companies use it so it must be good! LinkedIn and the Guardian use it and certainly others, so it must be a good choice, right?
These are all important and mostly valid points, but for a developer that has created many web frameworks over the years and has built his fair share of web applications most of these points are not as valid as it might seem on the surface.  I'll attempt to address each of them and hopefully give some insight into why I think Play Framework is not the right tool for the job and no matter what you are writing in Scala there are better options available.
  1. Lightbend backing the framework is definitely a solid point in favor of the framework, but it doesn't mean it's the best framework for Scala. For example, Lightbend also supports Slick, but there are serious performance problems in that framework which led me to create ScalaRelational.  For an overview of the crazy performance distinctions between the two frameworks see here (this just scratches the surface, there are simple queries that should take milliseconds to complete that take minutes and up to hours to run).
  2. Though perhaps one of the most compelling points in favor of Play Framework, commercial support doesn't mean the primary active development on any "supported" framework by Lightbend is being done by Lightbend.  These are primarily open-source frameworks that Lightbend has taken it upon themselves to commercially support and most of the actual development is still being done by the open-source community.
  3. Actively maintained is a very good sign in any framework.  Not actively maintained frameworks are incredibly risky unless they have a specific function and aren't currently being maintained because they fulfill that function well and don't need further development.  For a web framework that's certainly not the case.  The Spring Framework for Java is still actively maintained, but it's a monolithic and painful platform that inspired self-loathing and hate.  Many projects start off good or at least good intentioned only to eventually expand themselves into something that has long since lost the focus and benefits of its original intent.  I wouldn't say Play has gotten as bad as Spring, but once you get past the dead-simple getting started tutorial, the nitty-gritty of the framework starts to seep into your bones causing maintenance and maintainability nightmares.
  4. Though having support for the various features you may eventually need built as modules to your framework is very nice, it also often results in the framework itself trying to solve too many problems and ending up solving nothing very well.  I try to focus on using frameworks that specifically focused to a specific problem and solve that problem well.  When a framework tries to solve too many problems it starts making compromises and watering down the overall benefits of the framework.
  5. Oh Activator, how I loathe thee!  I'm sure it seemed like a good idea to create a shiny wrapper around SBT to help create your project, run it, and even deploy it without being bothered with understanding how building your Scala project actually works.  However, it's when you need to manually do something and you realize you don't have a clue how the stupid thing works that it becomes a maintenance nightmare.  I'm a software developer, and software developers should be smart enough to create a new project from scratch without needing a tool to hold your hand.  If you aren't smart enough to create your build from scratch then you're either an idiot, or the tools are far too complicated.  Instead of dumbing down the complex tools by wrapping it, why not attempt to solve the problem by making the tools themselves less painful to learn?  Yes, I'm talking to you SBT!  What used to be Simple Build Tool has had to change its name to stop the laughter in derision (now Scala Build Tool).  SBT has definitely improved recently, but there is still far too much complexity to manage and maintain.
  6. Big companies make stupid decisions constantly.  Web frameworks are one the primary areas in which they make stupid mistakes.  You may argue, "but their site works, so it must have been the right choice", but take a look at Facebook's architectural history and you'll see a good example of sheer stupidity leading down a path of pain and the only way they could stay afloat was due to their popularity they could keep throwing money at it.  Don't use big business as an example of what you should do.  Most companies can't just keep throwing money at a solution until it works, and even ones that can't would be better off spending that money on other things and keep their programmers sane.  I've worked for and more recently have consulted for lots of big businesses and even for the US government (the biggest and most wasteful business in the world).  I try to avoid consulting for big companies when I can now for this very reason.
These points hopefully address at least the primary reasons many people choose Play Framework, but the answers themselves aren't evidence of why it shouldn't be used, they are simply responses to the common reasoning I hear.  My specific reasons why I try to avoid Play are a bit different:
  1. Templates with their own dialect and learning curve and injecting code directly within.  This is just wrong on so many levels.  The time it takes to learn Play's specific template dialect is problematic, the injection of code in your templates make things incredibly messy, and don't get me started on the nightmare of trying to refactor code.
  2. Play Project Structure. Why? Seriously! There is no logical reason to break from the standard of normal Scala projects "src/main/scala" to the mess that is Play's arbitrary and rigid project structure.  Not only does this further increase the learning curve, but it makes your code very different from every other Scala project.  Again, why?  There is no explicit gain from their mediocre project structure changes, and in the latest version you can override it, but it says it's "experimental" and might cause problems.
  3. Routes file.  Again, why?  It's a freakin' text file that compiles to Scala.  It's unfortunate that Scala doesn't have a powerful DSL that would make more sense than writing a text file...oh wait, it does!  I have spent a great deal of time contemplating this and I really have no idea why they would do this.  If we were talking about a configuration file that could be changed in production without rebuilding your project that would be one thing, but the routes file is compiled and built into your project.
  4. Performance is bad.  Six months ago I was working on a project and they were experiencing serious performance issues in their web services.  They were using Play and PlayJSON.  After a little bit of testing I found that the major bottleneck was Play.  I quickly swapped out for Spray and uPickle and the performance was then lightning fast, it was fewer lines of code, and the code was much clearer and easier to maintain.  Now, I can't generically defend that Play's performance is always bad, and it's possible in the latest releases that it is no longer an issue at all, but the framework has been around for years and there is just no excuse for serious performance issues like that making it into the code.
  5. Distraction from simplicity.  When I work on a project my mantra is, "make it as simple as possible, no more and no less".  Developers working on projects have a tendency to over-complicate things and especially among Scala developers attempt to be clever and end up creating a maintenance nightmare for themselves.  Developers also focus too much on simplicity and leave glaring holes in functionality or paint themselves into a corner that they can't code themselves out of.  A project should be as simple as possible while keeping in mind the overarching goals and a consideration of where the project is going.  Play is not a very flexible framework and when you need to diverge for business needs they make it painful to do so.
Wow, I got through an entire post without writing any code.  I think this is a first.  In summary, yes, I've spewed a lot of hatred towards Play Framework, and though most of it is justified, it is not a horrible framework.  I think there are better frameworks like Scala.js, Spray, Finagle, and possibly even Akka-HTTP now if they've resolved some of the missing features and performance problems.  I know it's a Java framework, but I've also been pretty impressed with Undertow.

Play Framework developers: If you read this, I apologize for the harshness, but hopefully this can be taken as constructive criticism and I would happily recant in a future post.

Mobile Development Hell

Published by Matt Hicks under , , , , , , , , on Friday, July 31, 2015
I've been writing a pretty large mobile application for a client recently and am finally getting close to releasing it, but thought it might be worthwhile to write a little bit about the experience I've had.

The Frameworks

I expected jumping into development for Android and iOS would be fairly straight-forward. Mobile development has been around for quite a while now and there dozens if not hundreds of tools to get the job done.

I began researching frameworks that would allow me to have a shared code-base across Android and iOS and was disturbed at my options:

Option 1: Write Two User Interfaces

Using RoboVM you can deploy your JVM-based application to iOS without any noticeable performance penalty, but you must still create your user interface for each separately.  In many cases this is preferred if you want to maintain compliance for device-specific standards.  However, in my case the client had a very rigid design that they want to see on both devices and writing it twice just seemed painful and wasteful.

Option 2: Phonegap

There is a huge trend for Phonegap and derivatives that let you write your mobile application in HTML and JavaScript and then deploy it to Android and iOS.  In some ways this is a compelling option since you have standards-based tools that you can use to create your user interface and can even potentially reuse some functionality from your web application.  However, on closer inspection the performance is horrible and the UI feels very clunky.  I have yet to see an application written using this methodology that feels like a native application.

Option 3: Write a Game

I'm fairly well known for taking the road less travelled and will write entire libraries to do something "the right way" in my opinion.  After rejecting the above options I realized the only common UI target between Android and iOS is OpenGL ES.  This is the graphical library games are built on and though it might seem like a crazy idea, I created a simple prototype to see if I could write a UI framework on top of it.  Though incredibly painful to write the preliminary foundation, it worked quite well.

Writing an Engine

In an effort to support my app development needs I began to write a framework that provided complete UI functionality using OpenGL ES so I could have a common User Interface.  At this point that framework has been developed out pretty far and I'm extremely happy with the results.


I chose to build on top of LibGDX as it provides some basic building blocks for UI already, although extremely limited and focused toward game development.  I build my framework to add all the niceties for transitions, components, dynamic font loading, etc. to provide for my UI needs.  One of the big wins here is that I am able to rapidly test on the desktop without having to run an emulator or deploy to a device.

PSD to Scala

I love writing Scala code and decided to build this application entirely in Scala. However, the design mockups were created in Photoshop.  This is a common problem converting from design to implementation.  I decided to write a tool that would load the PSD file and allow me to customize options and then export to generate a screen in Scala.  This provided me with the ability to take a design mockup and create a perfect 1 to 1 representation in the final product.  Additionally, this saved me a massive amount of time as I simply needed to integrate the real data with the design then.

Bitmap Font Service

One of the biggest problems with User Interfaces in OpenGL is drawing fonts. The most common way is to use Bitmap Fonts that is a rasterized image representation of all of the characters instead of the vector data you get with a true-type font.  In order to properly support this I created a web service that the mobile app could request fonts from and it would dynamically generate the Bitmap Font on-demand to deliver back to the mobile app. The mobile app could then cache the data for future use.

Scaling for Screens

Another huge problem on mobile devices is that the screen sizes are so wildly different from one device to another.  After lots of consideration I wrote a scaling framework that takes in a virtual width and height that the application is designed for and the content is automatically scaled to properly and intelligently fit to the screen.  For raster images this means some dynamic scaling or multiple size options if pixel perfection is desired.  For fonts it simply means that the font size is scaled before making a request to the Bitmap Font Service so that the font is properly scaled according to the dimensions available to it.  The result is an incredibly clean looking UI at any resolution.  Additionally, since I only have to think about my virtual width and height, layout is incredibly easy.

Next Steps

At this point I now have a pretty powerful engine for mobile application development. One that rivals any framework I have seen to-date.  The question is: what do I do with it now?

I'm considering open-sourcing it to allow anyone to use it, but it's entirely written in Scala, so the audience that would take advantage of it is relatively low.  Another option is to continue to improve it as a closed-source project and focus more on providing OUTR Technologies the capability of creating more powerful mobile applications.


Almost immediately after posting this I received several requests from people that were very interested in using the framework so here you go:

It's very rough and needs lots of documentation as it was written entirely for internal use but that will change as I go forward. I'll try to create a G8 project to help create new projects in the near future. 

Mocking should be Mocked

Published by Matt Hicks under , , , , , on Wednesday, February 25, 2015
I've worked with and for a lot of companies over the years and with the ones that actually care about unit testing Mocking (Mockito or some other variation) typically quickly enters the scene. My argument is that in proper coding you should be able to write proper unit tests without any mock objects. I'll go a step further and say that encouraging mocking in your tests actually encourages poor code quality.

What's the purpose of Mocking?

Mocking is extremely common in unit tests, but why?  The basic idea is that you are attempting to test one specific "unit" of functionality, but you don't want calls to the database, third-party calls, or other side-effects creeping into your unit tests. On the surface this seems like a valid use-case.

Why is Mocking bad?

There are many problems related to mocking that I'll try to quickly step through.

Unnecessary Complexity and Decreased Modularity

Though the purpose of mocking is actually to reduce complexity it very often increases the complexity of your unit tests because you often end up with confusing and complicated mocking to avoid running aspects of your code that you don't want executed in your tests.  You often end up pulling your hair out trying to figure out how the internals of the system are supposed to work in order to get the mocks to operate as expected and then all your tests start breaking as soon as that internal logic changes.  You often end up in a scenario where your code works fine because it's written modularly to continue working but your unit tests break because they are essentially implementing the internal functionality via mocks.

Unit tests testing the Mocking framework

In extremely complex unit tests or even simpler unit tests that are managed over a long time or through many developers it becomes more and more confusing what the purpose of the test actually is. I can cite dozens of examples where I've been auditing unit tests only to find out that the unit test does nothing but test the mocking framework instead of the code.

Need for Mocking Represents Bad Code Separation

This is what my entire complaint really boils down to.  If you actually need mocking in your unit tests, your actual code that you're testing is poorly written in the first place.  You should be writing code in proper units to allow individual testing without the need for mocking at all.

For example:

You might have a scenario similar to the code above and you want to test the checkout functionality of your system, but you don't want the payment gateway to be called and you don't want it actually persisting to the database so you might mock those out to avoid those being called. Instead, consider the idea that there are four units of functionality clearly defined in this case:
  1. Validating the Order
  2. Calling the Payment gateway
  3. Persisting the information to the database
  4. Creating a Receipt
Herein lies the problem. You have tight coupling in your code of dissimilar things making mocking necessary. If instead you were to refactor your code to look more like this:

You can see now that each unit of functionality has been broken out into its own method that can be individually tested as needed without the necessity of mocking. Further, the code is significantly cleaner and more maintainable as a result of this refactoring. Not only does it make our unit tests cleaner and easier to maintain without mocks, but it also enforces a higher level of code quality through modularity in your code than was there before.

If you ever decided that the checkout method needed to be unit tested you could refactor it so it takes in a PaymentGateway implementation and Persistance implementation as arguments to avoid side-effects and allowing a test instance to be created to fulfill those needs. Though this is a form of mocking, it follows a better paradigm of consistency and modularity than mocking frameworks do.

As you can see, this is an all-around better way to write code and though it is understood that in existing projects mocking still may be necessary, there is no excuse for such to be necessary in new code.

Nabo TV: Next Generation Media Center

Published by Matt Hicks under , , , , , , on Monday, December 01, 2014

For years media centers, DVRs, and video streaming sites have existed to watch TV and Movies. Over the past several years these services have stagnated. Though there are no shortage of media centers, they all seem to be doing pretty much the exact same thing. For years we have watched and longed for a more featureful interface on our TV to be able to watch the content we're looking for, and for years we have been disappointed.

This is where Nabo TV comes in. We want to bring innovation back to the TV and push the boundaries of what is currently being done on the TV, not just as a product company, but as individuals who enjoy watching media on our TVs.

I just started a Kickstarter to help fund and increase visibility for this endeavor.  Please help me get the word out.