Click here to close now.


Java IoT Authors: Brad Thies, Liz McMillan, Anders Wallgren, Elizabeth White, Pat Romanski

Related Topics: Java IoT

Java IoT: Article

Go Fast It Runs Too Slow

"Speed Is as Speed Does"

Go fast, it runs too slow, you've got to make the number show. Diddle de bop, da la de doop, sitting around and feeling groovy.

Speed Is as Speed Does
Many moons ago I was working on a project that had to be sped up and we had the benefit of a very experienced consultant to help us out. Fresh from his business-class flight and clutching his pay-as-you-go expense account lunch, our management team eagerly led him over to where our assembled developers waited in awe (and with a certain amount of natural coder-sapiens resistance to the hired gun who'd come to town to sheriff us).

Like a surgeon approaching a sick patient we expected a briefcase to be opened revealing dozens of tools for analyzing memory leakage, profiling garbage collection across multiple threads, searching out deadlocks and everything else we assumed was slowing down the program. Instead all he produced was a simple red stopwatch.

All that matters to the user is how long a given scenario takes and whether it's perceived as slow or not. The first thing to do was to identify which tasks were too slow, figure out what response time would be acceptable, and then keep working back against that benchmark.

Apples and Apples
The idea is to focus on real user scenarios and their actual end-to-end response times. Instead of our zippy high-end boxes, dust off older, slower machines and dedicate them to doing the benchmarks. Us spoiled developers often run the latest wizzo kit and don't appreciate the realities of the boxes our code actually runs (or walks on) in the field.

Look Under the Hood
Having identified the slow scenarios, the next step is to identify where the time is going. Probably no single tool can yield all that information, and techniques can vary from simple tracelogs of the current clock time at various stages in the program through to powerful local and total time method breakdowns. Garbage collection, file I/O, page faults, all need to be observed and understood.

Fix What's Broke, Forget What's Not
Looking at the analysis from the running application can yield a bunch of fix candidates. But rather than jumping in and starting to redesign everything, it's good to prove first that there will be a real benefit before doing any work. Like writing a unit test before programming, it may be better to create dummy fixes that simulate the corrected code without being functionally complete. The exercise might involve changing a method to hard coding a result instead of an expensive piece of computation, or putting data in a stale cache and running performance tests to see if the fancy auto-rebuilding dancing cache is really worth doing. Before creating a solution, you have to know there's a real problem as opposed to a perceived one you just feel like polishing. Patch fixes can be created for dummy fixes, applied and run against a full build on the benchmark box to see what affect they have and, by extrapolation, the benefit fully functional fixes will bring to the bottom line.

Optimize Code Paths
Sometimes single method calls result in an explosion of code where a leaf method is being executed thousands of times. With the execution time of the lowest-level method being gauged in fractions of milliseconds, this becomes significant. The solution is to rewrite the code path to avoid such a deluge. The change itself might not be particularly difficult but without a good tool to get the problem on the radar, perhaps as a result of an n squared or even n to the n algorithm, it might never even be considered a possible problem.

Minimize IO
One way to produce big performance improvements is to reduce the amount of file reads and writes and socket access. Some data needs to be re-read frequently because it's volatile, but objects such as icons or definition files are good candidates to access once and cache in library registries. Socket I/O is another place to look as well. We found that the problem with one application was in the latency of the conversation, not in the amount of data being sent across the wire. It was overcome by batching data packets together into larger-grained messages.

Cache Model Data
Using a cache to speed something up can be either a silver bullet or fool's gold. The latter is like someone who claims they get great mileage from their car by not driving it. If the program is fast enough to begin with, caches aren't needed, so the first port of call should be to see if there are other unexplored avenues to make things quicker. If a cache is required then it comes with the health warning that you not only have to build it, you need to know when the data you're caching might become stale.

Leave Your Assumptions at the Door
One of the most startling things about tuning a program is that sometimes a lot of fancy code that was initially designed to help performance isn't that useful. Ironically the clever algorithms might actually cause harm. While they may add nothing significant to the bottom line, they can make the code harder to read and understand and affect its maintainability. This is part of the philosophy behind the XP mantra "Make it work, make it right, make it fast." Until you know what's slow, don't try to make it faster.

More Stories By Joe Winchester

Joe Winchester, Editor-in-Chief of Java Developer's Journal, was formerly JDJ's longtime Desktop Technologies Editor and is a software developer working on development tools for IBM in Hursley, UK.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

@ThingsExpo Stories
Microservices are a very exciting architectural approach that many organizations are looking to as a way to accelerate innovation. Microservices promise to allow teams to move away from monolithic "ball of mud" systems, but the reality is that, in the vast majority of organizations, different projects and technologies will continue to be developed at different speeds. How to handle the dependencies between these disparate systems with different iteration cycles? Consider the "canoncial problem" in this scenario: microservice A (releases daily) depends on a couple of additions to backend B (re...
With all the incredible momentum behind the Internet of Things (IoT) industry, it is easy to forget that not a single CEO wakes up and wonders if “my IoT is broken.” What they wonder is if they are making the right decisions to do all they can to increase revenue, decrease costs, and improve customer experience – effectively the same challenges they have always had in growing their business. The exciting thing about the IoT industry is now these decisions can be better, faster, and smarter. Now all corporate assets – people, objects, and spaces – can share information about themselves and thei...
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessions, I wanted to share some of my observations on emerging trends. As cyber security serves as a fou...
Discussions of cloud computing have evolved in recent years from a focus on specific types of cloud, to a world of hybrid cloud, and to a world dominated by the APIs that make today's multi-cloud environments and hybrid clouds possible. In this Power Panel at 17th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the importance of customers being able to use the specific technologies they need, through environments and ecosystems that expose their APIs to make true change and transformation possible.
There are over 120 breakout sessions in all, with Keynotes, General Sessions, and Power Panels adding to three days of incredibly rich presentations and content. Join @ThingsExpo conference chair Roger Strukhoff (@IoT2040), June 7-9, 2016 in New York City, for three days of intense 'Internet of Things' discussion and focus, including Big Data's indespensable role in IoT, Smart Grids and Industrial Internet of Things, Wearables and Consumer IoT, as well as (new) IoT's use in Vertical Markets.
Container technology is shaping the future of DevOps and it’s also changing the way organizations think about application development. With the rise of mobile applications in the enterprise, businesses are abandoning year-long development cycles and embracing technologies that enable rapid development and continuous deployment of apps. In his session at DevOps Summit, Kurt Collins, Developer Evangelist at, examined how Docker has evolved into a highly effective tool for application delivery by allowing increasingly popular Mobile Backend-as-a-Service (mBaaS) platforms to quickly crea...
The Internet of Things (IoT) is growing rapidly by extending current technologies, products and networks. By 2020, Cisco estimates there will be 50 billion connected devices. Gartner has forecast revenues of over $300 billion, just to IoT suppliers. Now is the time to figure out how you’ll make money – not just create innovative products. With hundreds of new products and companies jumping into the IoT fray every month, there’s no shortage of innovation. Despite this, McKinsey/VisionMobile data shows "less than 10 percent of IoT developers are making enough to support a reasonably sized team....
The cloud. Like a comic book superhero, there seems to be no problem it can’t fix or cost it can’t slash. Yet making the transition is not always easy and production environments are still largely on premise. Taking some practical and sensible steps to reduce risk can also help provide a basis for a successful cloud transition. A plethora of surveys from the likes of IDG and Gartner show that more than 70 percent of enterprises have deployed at least one or more cloud application or workload. Yet a closer inspection at the data reveals less than half of these cloud projects involve production...
As organizations realize the scope of the Internet of Things, gaining key insights from Big Data, through the use of advanced analytics, becomes crucial. However, IoT also creates the need for petabyte scale storage of data from millions of devices. A new type of Storage is required which seamlessly integrates robust data analytics with massive scale. These storage systems will act as “smart systems” provide in-place analytics that speed discovery and enable businesses to quickly derive meaningful and actionable insights. In his session at @ThingsExpo, Paul Turner, Chief Marketing Officer at...
Internet of @ThingsExpo, taking place June 7-9, 2016 at Javits Center, New York City and Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 18th International @CloudExpo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo New York Call for Papers is now open.
We all know that data growth is exploding and storage budgets are shrinking. Instead of showing you charts on about how much data there is, in his General Session at 17th Cloud Expo, Scott Cleland, Senior Director of Product Marketing at HGST, showed how to capture all of your data in one place. After you have your data under control, you can then analyze it in one place, saving time and resources.
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York and Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound cha...
We are rapidly moving to a brave new world of interconnected smart homes, cars, offices and factories known as the Internet of Things (IoT). Sensors and monitoring devices will touch every part of our lives. Let's take a closer look at the Internet of Things. The Internet of Things is a worldwide network of objects and devices connected to the Internet. They are electronics, sensors, software and more. These objects connect to the Internet and can be controlled remotely via apps and programs. Because they can be accessed via the Internet, these devices create a tremendous opportunity to inte...
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Day 2 Keynote at 17th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, wil...
Cloud computing delivers on-demand resources that provide businesses with flexibility and cost-savings. The challenge in moving workloads to the cloud has been the cost and complexity of ensuring the initial and ongoing security and regulatory (PCI, HIPAA, FFIEC) compliance across private and public clouds. Manual security compliance is slow, prone to human error, and represents over 50% of the cost of managing cloud applications. Determining how to automate cloud security compliance is critical to maintaining positive ROI. Raxak Protect is an automated security compliance SaaS platform and ma...
SYS-CON Events announced today that Kintone has been named "Bronze Sponsor" of SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. kintone promotes cloud-based workgroup productivity, transparency and profitability with a seamless collaboration space, build your own business application (BYOA) platform, and workflow automation system.
Today air travel is a minefield of delays, hassles and customer disappointment. Airlines struggle to revitalize the experience. GE and M2Mi will demonstrate practical examples of how IoT solutions are helping airlines bring back personalization, reduce trip time and improve reliability. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Dr. Sarah Cooper, M2Mi’s VP Business Development and Engineering, explored the IoT cloud-based platform technologies driving this change including privacy controls, data transparency and integration of real time context with p...
Just over a week ago I received a long and loud sustained applause for a presentation I delivered at this year’s Cloud Expo in Santa Clara. I was extremely pleased with the turnout and had some very good conversations with many of the attendees. Over the next few days I had many more meaningful conversations and was not only happy with the results but also learned a few new things. Here is everything I learned in those three days distilled into three short points.
DevOps is about increasing efficiency, but nothing is more inefficient than building the same application twice. However, this is a routine occurrence with enterprise applications that need both a rich desktop web interface and strong mobile support. With recent technological advances from Isomorphic Software and others, rich desktop and tuned mobile experiences can now be created with a single codebase – without compromising functionality, performance or usability. In his session at DevOps Summit, Charles Kendrick, CTO and Chief Architect at Isomorphic Software, demonstrated examples of com...
In his General Session at 17th Cloud Expo, Bruce Swann, Senior Product Marketing Manager for Adobe Campaign, explored the key ingredients of cross-channel marketing in a digital world. Learn how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects).