Welcome!

IoT User Interface Authors: Scott Allen, Roger Strukhoff, Liz McMillan, Pat Romanski, Elizabeth White

Related Topics: Java IoT, IoT User Interface

Java IoT: Article

Behind the Scenes of Serialization in Java

The right serialization strategy is central for achieving performance and scalability

When building distributed applications one of the central performance-critical components is serialization. Most modern frameworks make it very easy to send data over the wire. In many cases you don’t see at all what is going on behind the scenes. Choosing the right serialization strategy however is central for achieving good performance and scalability. Serialization problems affect CPU, memory, network load and response times.

Java provides us with a large variety of serialization technologies. The actual amount of data which is sent over the wire can vary substantially. We will use a very simple sample where we send the firstname, lastname and birthdate over the wire. Then we’ll see how big the actual payload gets.

Binary Data
As a reference we start by sending only the payload. This is the most efficient way of sending data, as there is no overhead involved. The downside is that due to the missing metadata the message can only be de-serialized if we know the exact serialization method. This approach also has a very high testing and maintenance effort and we have to handle all implementation complexity ourselves. The figure below shows what our payload looks like in binary format.

Binary Representation of Address Entity

Binary Representation of Address Entity

Java Serialization
Now we switch to standard serialization in Java. As you can see in below we are now transferring much more metadata. This data is required by the Java Runtime to rebuild the transferred object at the receiver side. Besides structural information the metadata also contains versioning information which allows communication across different versions of the same object. In reality, this feature often turns out to be harder than it initially looks. The metadata overhead in our example is rather high. This is caused by large amount of data in the GregorianCalendar Object we are using. The conclusion that Java Serialization comes with a very high overhead per se, however is not valid. Most of this metadata will be cached for subsequent invocations.

 

Person Entity with Java Serialization

Person Entity with Java Serialization
Java also provides the ability to override the Serialization behavior using the Externalizable interface. This enables us to implement a more efficient serialization strategy. In our example we could only serialize the birthdate as a long rather than a full object. The downside again is the increased effort regarding testing an maintainability

Java Serialization is by default used in RMI communication when not using IIOP as a protocol. Application server providers also offer their own serialization stacks which are more efficient than default serialization. If interoperability is not important, provider-specific implementations are the better choice.

Alternatives
The Java ecosystem also provides interesting alternatives to Java Serialization. A widely known one is Hessian which can be easily used with Spring. Hessian allows an easy straightforward implementation of services. Underneath it uses a binary protocol. The figure below shows our data serialized with Hessian. As you can see the transferred data is very slim. Hessian therefore provides an interesting alternative to RMI.

Hessian Binary Representation of Person Object

Hessian Binary Representation of Person Object

JSON
A newcomer in serialization formats is JSON (JavaScript Object Notation). Originally used as a text-based format for representing JavaScript objects, it’s been more and more adopted in other languages as well. One reason is the rise of Ajax applications, but also the availability of frameworks for most programming languages.

As JSON is a purely text-based representation it comes with a higher overhead than the previously shown serialization approaches. The advantage is that it is more lightweight than XML and it has good support for describing metadata. The Listing below shows our person object represented in JSON.

{"firstName":"Franz",
"lastName":"Musterman",
"birthDate":"1979-08-13"
}

XML
XML for sure is the standard format for exchanging data in heterogeneous systems. One nice feature of XML is the out-of-the-box support for data validation, which is especially important in integration scenarios. The amount of metadata, however, can become really high – depending on the used mapping. All data is transferred in text format by default. However the usage of CDATA tags enables us to send binary data. The listing below shows our person object in XML. As you can see the metadata overhead is quite high.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<person>
  <birthDate>1979-08-13T00:00:00-07:00</birthDate>
  <firstName>Franz</firstName>
  <lastName>Musterman</lastName>
</person>

Fast InfoSet
Fast InfoSet
is becoming a very interesting alternative to XML. It is more or less a lightweight version of XML, which reduces unnecessary overhead and redundancies in data. This leads to smaller data set and better serialization and deserialization performance.

When working with JAX-WS 2.0 you can enable Fast InfoSet serialization by using the @FastInfoset annotation. Web Service stacks then automatically detect whether it can be used for cross service communication using HTTP Accept headers.

When looking at data serialized using Fast InfoSet the main difference you will notice is that there are no end tags. After their first occurrence there are only referenced by an index. There are a number of other indexes for content, namespaces etc.

Data is prefixed with its length. This allows faster and more efficient parsing. Additionally binary data can avoid being serialized in base64 encoding as in an XML.

In tests with standard documents the transfer size could be shrunk down to only 20 percent of the original size and the serialization speed could be doubled. The listing below shows our person object now serialized with Fast InfoSet. For Illustration purposes I skipped the processing instructions and I used a textual representation instead of binary values. Values in curly braces refer to indexed values. Values in brackets refer to the use of an index.

{0}<person>
{1}<birthDate>{0}1979-08-13T00:00:00-07:00
{2}<firstName>{1}Franz
{3}<lastName>{2}Musterman

The real advantage however can be seen when we look what the next address object would look like. As the listing below shows we can work mostly with index data only.

[0]<>
[1]<>{0}
[2]<>{3}Hans
[3}<>{4}Musterhaus

Object Graphs
Object graphs can get quite tricky to serialize. This form of serialization is not supported by all protocols. As we need to work with reference to entities, the language used by the serialization approach must provide a proper language construct. While this is no problem in serialization formats which are used for (binary) RPC-style interactions, it is often not supported out-of-the-box by text-based protocols. XML itself, for example, supports serializing object graphs using references. The WS-I however forbids the usage of the required language construct.

If a serialization strategy does not support this feature it can lead to performance and functional problems, as entities get serialized individually for each occurrence of a reference. If we are, for example, serializing addresses which have reference to country information, this information will then be serialized for each and every address object leading to large serialization sizes.

Conclusion
Today there are numerous variants to serialize data in Java. While binary serialization keeps being the most efficient approach, modern text-based formats like JSON or Fast Infoset provide valid alternatives – especially when interoperability is a primary concern. Modern frameworks often allow using multiple serialization strategies at the same time. So the approach can even be selected dynamically at runtime.

Related reading:

  1. Behind the scenes of ASP.NET MVC 2 – Understand the internals to build better apps With Visual Studio 2010, Microsoft is shipping the next version...
  2. 52 weeks of Application Performance – The dynaTrace Almanac 2010 is over and there has been a log going...
  3. 7 Rules to Improve your Application Performance Practices In this post I discuss the seven most important steps...
  4. Is There a Business Case for Application Performance? We all know that slow performance – and service disruption...
  5. Applying Maslow’s Pyramid to Application Performance This time I take an a bit unconventional approach towards...

More Stories By Alois Reitbauer

Alois Reitbauer works as a Technology Strategist for dynaTrace Software where he is leading the Methods and Technology team. As part of the R&D team he influences the dynaTrace product strategy and works closely with key customers in implementing performance management solution for the entire lifecylce. Alois has 10 years experience as architect and developer in the Java and .NET space. He is a frequent speaker at technology conferences on performance and architecture related topics and regularly publishes articles blogs on blog.dynatrace.com

@CloudExpo Stories
"We work in the area of Big Data analytics and Big Data analytics is a very crowded space - you have Hadoop, ETL, warehousing, visualization and there's a lot of effort trying to get these tools to talk to each other," explained Mukund Deshpande, head of the Analytics practice at Accelerite, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Cloud Expo, Inc. has announced today that Andi Mann returns to 'DevOps at Cloud Expo 2016' as Conference Chair The @DevOpsSummit at Cloud Expo will take place on November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. "DevOps is set to be one of the most profound disruptions to hit IT in decades," said Andi Mann. "It is a natural extension of cloud computing, and I have seen both firsthand and in independent research the fantastic results DevOps delivers. So I am excited t...
SaaS companies can greatly expand revenue potential by pushing beyond their own borders. The challenge is how to do this without degrading service quality. In his session at 18th Cloud Expo, Adam Rogers, Managing Director at Anexia, discussed how IaaS providers with a global presence and both virtual and dedicated infrastructure can help companies expand their service footprint with low “go-to-market” costs.
Basho Technologies has announced the latest release of Basho Riak TS, version 1.3. Riak TS is an enterprise-grade NoSQL database optimized for Internet of Things (IoT). The open source version enables developers to download the software for free and use it in production as well as make contributions to the code and develop applications around Riak TS. Enhancements to Riak TS make it quick, easy and cost-effective to spin up an instance to test new ideas and build IoT applications. In addition to...
IoT is rapidly changing the way enterprises are using data to improve business decision-making. In order to derive business value, organizations must unlock insights from the data gathered and then act on these. In their session at @ThingsExpo, Eric Hoffman, Vice President at EastBanc Technologies, and Peter Shashkin, Head of Development Department at EastBanc Technologies, discussed how one organization leveraged IoT, cloud technology and data analysis to improve customer experiences and effi...
Internet of @ThingsExpo has announced today that Chris Matthieu has been named tech chair of Internet of @ThingsExpo 2016 Silicon Valley. The 6thInternet of @ThingsExpo will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
"Avere Systems is a hybrid cloud solution provider. We have customers that want to use cloud storage and we have customers that want to take advantage of cloud compute," explained Rebecca Thompson, VP of Marketing at Avere Systems, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Presidio has received the 2015 EMC Partner Services Quality Award from EMC Corporation for achieving outstanding service excellence and customer satisfaction as measured by the EMC Partner Services Quality (PSQ) program. Presidio was also honored as the 2015 EMC Americas Marketing Excellence Partner of the Year and 2015 Mid-Market East Partner of the Year. The EMC PSQ program is a project-specific survey program designed for partners with Service Partner designations to solicit customer feedbac...
The cloud promises new levels of agility and cost-savings for Big Data, data warehousing and analytics. But it’s challenging to understand all the options – from IaaS and PaaS to newer services like HaaS (Hadoop as a Service) and BDaaS (Big Data as a Service). In her session at @BigDataExpo at @ThingsExpo, Hannah Smalltree, a director at Cazena, provided an educational overview of emerging “as-a-service” options for Big Data in the cloud. This is critical background for IT and data profession...
Let’s face it, embracing new storage technologies, capabilities and upgrading to new hardware often adds complexity and increases costs. In his session at 18th Cloud Expo, Seth Oxenhorn, Vice President of Business Development & Alliances at FalconStor, discussed how a truly heterogeneous software-defined storage approach can add value to legacy platforms and heterogeneous environments. The result reduces complexity, significantly lowers cost, and provides IT organizations with improved efficie...
In the world of DevOps there are ‘known good practices’ – aka ‘patterns’ – and ‘known bad practices’ – aka ‘anti-patterns.' Many of these patterns and anti-patterns have been developed from real world experience, especially by the early adopters of DevOps theory; but many are more feasible in theory than in practice, especially for more recent entrants to the DevOps scene. In this power panel at @DevOpsSummit at 18th Cloud Expo, moderated by DevOps Conference Chair Andi Mann, panelists discusse...
Predictive analytics tools monitor, report, and troubleshoot in order to make proactive decisions about the health, performance, and utilization of storage. Most enterprises combine cloud and on-premise storage, resulting in blended environments of physical, virtual, cloud, and other platforms, which justifies more sophisticated storage analytics. In his session at 18th Cloud Expo, Peter McCallum, Vice President of Datacenter Solutions at FalconStor, discussed using predictive analytics to mon...
What does it look like when you have access to cloud infrastructure and platform under the same roof? Let’s talk about the different layers of Technology as a Service: who cares, what runs where, and how does it all fit together. In his session at 18th Cloud Expo, Phil Jackson, Lead Technology Evangelist at SoftLayer, an IBM company, spoke about the picture being painted by IBM Cloud and how the tools being crafted can help fill the gaps in your IT infrastructure.
Most organizations prioritize data security only after their data has already been compromised. Proactive prevention is important, but how can you accomplish that on a small budget? Learn how the cloud, combined with a defense and in-depth approach, creates efficiencies by transferring and assigning risk. Security requires a multi-defense approach, and an in-house team may only be able to cherry pick from the essential components. In his session at 19th Cloud Expo, Vlad Friedman, CEO/Founder o...
"There's a growing demand from users for things to be faster. When you think about all the transactions or interactions users will have with your product and everything that is between those transactions and interactions - what drives us at Catchpoint Systems is the idea to measure that and to analyze it," explained Leo Vasiliou, Director of Web Performance Engineering at Catchpoint Systems, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York Ci...
Ask someone to architect an Internet of Things (IoT) solution and you are guaranteed to see a reference to the cloud. This would lead you to believe that IoT requires the cloud to exist. However, there are many IoT use cases where the cloud is not feasible or desirable. In his session at @ThingsExpo, Dave McCarthy, Director of Products at Bsquare Corporation, will discuss the strategies that exist to extend intelligence directly to IoT devices and sensors, freeing them from the constraints of ...
The pace of innovation, vendor lock-in, production sustainability, cost-effectiveness, and managing risk… In his session at 18th Cloud Expo, Dan Choquette, Founder of RackN, discussed how CIOs are challenged finding the balance of finding the right tools, technology and operational model that serves the business the best. He also discussed how clouds, open source software and infrastructure solutions have benefits but also drawbacks and how workload and operational portability between vendors ...
The U.S. Army Intelligence and Security Command (INSCOM) has awarded BAE Systems a five-year contract worth as much as $75 million to provide enhanced geospatial intelligence technical and analytical support. The award was issued under the INSCOM Global Intelligence indefinite delivery, indefinite quantity contract.
Connected devices and the industrial internet are growing exponentially every year with Cisco expecting 50 billion devices to be in operation by 2020. In this period of growth, location-based insights are becoming invaluable to many businesses as they adopt new connected technologies. Knowing when and where these devices connect from is critical for a number of scenarios in supply chain management, disaster management, emergency response, M2M, location marketing and more. In his session at @Th...
The initial debate is over: Any enterprise with a serious commitment to IT is migrating to the cloud. But things are not so simple. There is a complex mix of on-premises, colocated, and public-cloud deployments. In this power panel at 18th Cloud Expo, moderated by Conference Chair Roger Strukhoff, Randy De Meno, Chief Technologist - Windows Products and Microsoft Partnerships at Commvault; Dave Landa, Chief Operating Officer at kintone; William Morrish, General Manager Product Sales at Interou...