Welcome!

Microservices Expo Authors: Liz McMillan, Elizabeth White, Ruxit Blog, Pat Romanski, Sematext Blog

Related Topics: Java IoT, Microservices Expo, Open Source Cloud, IoT User Interface, @CloudExpo

Java IoT: Article

Real-World Application Performance with MongoDB

Choosing a data mapping technology

Recently FireScope Inc. introduced the general availability of its Stratis product. Stratis brings all of the FireScope Unify capabilities to the cloud, with the added advantage of a new architecture that delivers near infinite scalability. Moreover, the new Stratis architecture provides scalability at all application layers including its back-end operations, which were newly designed to leverage the benefits of MongoDB. In this article we will discuss several of the architecture choices that were made as part of this effort with the hope that others might benefit from the research and analysis that was performed to bring this product to market.

As background a functioning FireScope deployment has the ability to gather metrics from all forms of existing IT assets, normalize the gathered metrics, provide historical analysis of the metrics, and most importantly provide service views for worldwide operations which is unparalleled in the IT industry. In the early phases of designing the Stratis product, FireScope undertook significant research into the scalable persistence architectures that were production ready at the time of this effort. FireScope ultimately chose MongoDB for its ability to scale and its flexibility in supporting an easy transition from a relational persistence model to a NoSQL model. While researching MongoDB FireScope took the time to understand the application impact of the following architecture facets:

  1. Data mapping technologies
  2. Minimal field retrieval vs full document retrieval
  3. Data aggregation
  4. Early space allocation

In this article we detail each of the above mentioned research efforts and discuss the impact that our subsequent choices had on the FireScope Stratis product.

Application performance was a key driver in all research activities. Even though we were deploying these new application elements to the cloud, ignoring the importance of performance would mean more resources would be needed to get the job done. It's also worth noting that not all applications have the same considerations, so what may be an appropriate technology or architecture choice for FireScope Stratis might not be the appropriate choice for your application. With that said, let's address these research efforts in more detail.

Data Mapping Technologies
The FireScope Stratis application accesses persistent storage via Java, and PHP. As a result, we needed to make persistence access choices that would be compatible between Java and PHP. While Java and PHP were both requirements the main performance driven consideration was access via Java. In considering how to get information into and out of the database with Java, FireScope researched access using the following two approaches:

  1. Java Mongo driver with an in-house developed DAO layer
  2. Spring Data

We built narrowly focused prototype access solutions using both of these options. We saved and retrieved the same large graph of objects and compared the relative performance for each approach. One of the key findings in this analysis was the performance impact of "single binding" versus "double binding" of retrieved data.

When data is returned via the MongoDB Java driver each document is returned in the form of a HashMap where the fields of the persisted document form the keys of the HashMap and the corresponding values associated with each field are stored as HashMap values. FireScope designed its domain model to use getters and setters that simply accessed the appropriate field in the HashMap and ensured that each corresponding field has the correct Java type. In this model there is no additional overhead to bind each field to a corresponding Java field, we simply referenced the data in the HashMap. We refer to this model as "single binding" because the only binding performed is that of the Mongo Java driver.

By contrast, when Spring Data is used to render a document from MongoDB all fields in the HashMap returned by the Mongo Java driver are subsequently bound to a member field in the appropriate Java object. This binding is performed using reflection during the object retrieval process. We refer to this model as "double binding" because the initial HashMap rendering is then reflectively bound to the appropriate Java object fields and the initial HashMap is subsequently discarded.

In our comparative analysis we found that the "double binding" process used by Spring Data carried with it a performance overhead of greater than 2X but less than 4X. These comparative results were derived from multiple runs using each technology retrieving and saving the same large data graph on the same hardware. Furthermore, we alternated between technology choices in order to prevent differences in class loading, network, CPU, disk, and garbage collection from obscuring the analysis results.

Please do not take from the above that I have some issue with Spring Data. I absolutely love Spring, and nearly everything they do is 100% top notch! It just so happens that in this instance our performance-centric considerations directed us away from the use of Spring Data for FireScope's Stratis back-end operations. We do however use Spring in nearly every other area of the FireScope Stratis product. As a final thought, we also briefly considered the use of Morphia, but due to time constraints we never completed a comparative analysis using Morphia.

Minimal Field Retrieval
One of the key performance impacting areas of the FireScope Stratis product is the data normalization engine. Every metric retrieved by FireScope passes through this engine and as a result the ability to do more with less is critically important to FireScope. In an effort to verify our architecture choices, FireScope performed another analysis comparing the relative performance of retrieving all fields of a queried document to an alternative scenario where only one-fourth of the full fields were retrieved. The intent here is that many use cases do not need all of the data for a given object. Of course we knew that reducing the bandwidth between the database servers and the application servers would be a good thing, but being new to Mongo we weren't sure if the overhead of filtering some fields from the document would outweigh the benefits of the reduced bandwidth between the servers.

In this analysis we setup long running retrieve / save operations. Once again, we alternated between retrieve / save operations where the full document was passed, and retrieve / save operations where the one-fourth populated document was passed. Alternation was used to prevent the impact of class loading, network, CPU, disk, and garbage collection from obscuring the analysis results. When the one-fourth populated document was used we specified a set of fields for Mongo to retrieve. For the full document no field specification was provided and as a result the full document was retrieved.

The analysis results indicated an overwhelming 9X performance benefit to using limited field retrieval. But be aware that using limited field retrieval also has its downside. If other developers on your team are not keenly aware that the object they just queried for might not have all of its fields populated, then application defects can easily result from using this approach. To avert possible defects, FireScope leverages an extensive unit testing, functional testing, and peer review / test process to ensure that such defects do not arise.

Data Aggregation
A portion of the section is based on ideas from this blog.

We acknowledge and thank Foursquare Labs Inc. for its contributions.

The suggestion offered in the blog is to aggregate a series of historical entries into a single document, rather than creating a separate document for each historical record. The motivation for aggregation is to improve the locality of associated information and as a result improve its future access time. While the FireScope system performance is not driven by user access, it does rely extensively on aggregated historical metrics collected throughout a day and we leveraged aggregation to achieve improved locality.

What was not discussed in the Foursquare Labs blog was a second and equally significant benefit of aggregation which is a huge reduction in the size of an index for the FireScope historical records. For those not familiar with Mongo it is important to understand that Mongo attempts to keep all indexes in memory for fast access. As a result any reduction in the size of an index allows Mongo to keep more data in memory which improves overall system performance.

For better understanding consider the following two data storage scenarios where a reference id, time stamp, and value of several collected metrics are stored using two alternative approaches:

  1. Collected metrics are simply added to a collection which is indexed on the ref_id + time fields.
    { ref_id : ABC123, time : 1336780800, value : XXX }
    { ref_id : ABC123, time : 1336780800, value : ZZZ }
  2. All collected metrics for one day are added to an array. The document for the day is indexed on the ref_id and midnight fields.
    { ref_id : ABC123, midnight : 1336780800, values : [ time : 1336780805, value : XXX, ... ] }

Note that for option 1 both the ref_id and the time are two elements in an index. If the system collects this metric once every 5 minutes, then the system would collect 288 ref_id, time, value entries in one day. If each entry is added to an index then the corresponding index size will be significantly larger for option 1 above than for option 2, because option 2 does not index the actual collection time but only midnight of the current day. As a result, the index size is reduced nearly 300 to one due to the aggregation of data with no loss of information.

Early Space Allocation
If documents are created from metrics collected throughout the day, then both space allocation, as well as index updates are required throughout the day as a part of normal business operations. As discussed above if documents are nested then locality of accessed information is improved. But if normal operations append to an existing document then in most instances, the document must be moved and all associated indexes must be updated in order to accomplish the document append operations.

With FireScope Stratis optimal update operations are achieved by allocating a full days worth of history records for each expected metric. Each history record contains default values for the expected collection interval. The space for one day's worth of data is created in a scheduled operation that is run once per day. Then as metrics are collected throughout the day the appropriate bucket (array entry) is simply updated. Since the update does not change the size of the document no document movements are needed throughout the day nor are index updates needed. The end result is a system that achieves optimal performance. While I am unable to share actual performance metrics for this approach, I can share that the relative performance difference is significant. It is also worth noting that you would need to take great care in measuring the performance impact of this architecture choice because MongoDB has the inherent ability to queue update operations, thus masking the real performance benefit of this enhancement.

Conclusion
If you are undertaking a transition to MongoDB, or new development on MongoDB then choosing a data mapping technology wisely can have a significant impact on your application performance. Consider also the performance benefits of Minimal Field Retrieval, Data Aggregation, and Early Space Allocation as vehicles to optimize your applications' performance. You may also realize additional benefits, such as the reduced network bandwidth that comes with minimal field retrieval, and the reductions of index size that might result from data aggregation. We sincerely hope that you have benefited from the time invested in reading this article and wish you the best in all of your Mongo development endeavors.

References

More Stories By Pete Whitney

Pete Whitney is a Solutions Architect for Cloudera. His primary role at Cloudera is guiding and assisting Cloudera's clients through successful adoption of Cloudera's Enterprise Data Hub and surrounding technologies.

Previously Pete served as VP of Cloud Development for FireScope Inc. In the advertising industry Pete designed and delivered DG Fastchannel’s internet-based advertising distribution architecture. Pete also excelled in other areas including design enhancements in robotic machine vision systems for FSI International Inc. These enhancements included mathematical changes for improved accuracy, improved speed, and automated calibration. He also designed a narrow spectrum light source, and a narrow spectrum band pass camera filter for controlled machine vision imaging.

Pete graduated Cum Laude from the University of Texas at Dallas, and holds a BS in Computer Science. Pete can be contacted via Email at [email protected]

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.


@MicroservicesExpo Stories
SYS-CON Events announced today that LeaseWeb USA, a cloud Infrastructure-as-a-Service (IaaS) provider, will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. LeaseWeb is one of the world's largest hosting brands. The company helps customers define, develop and deploy IT infrastructure tailored to their exact business needs, by combining various kinds cloud solutions.
Adding public cloud resources to an existing application can be a daunting process. The tools that you currently use to manage the software and hardware outside the cloud aren’t always the best tools to efficiently grow into the cloud. All of the major configuration management tools have cloud orchestration plugins that can be leveraged, but there are also cloud-native tools that can dramatically improve the efficiency of managing your application lifecycle. In his session at 18th Cloud Expo, ...
SYS-CON Events announced today that Venafi, the Immune System for the Internet™ and the leading provider of Next Generation Trust Protection, will exhibit at @DevOpsSummit at 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Venafi is the Immune System for the Internet™ that protects the foundation of all cybersecurity – cryptographic keys and digital certificates – so they can’t be misused by bad guys in attacks...
Ovum, a leading technology analyst firm, has published an in-depth report, Ovum Decision Matrix: Selecting a DevOps Release Management Solution, 2016–17. The report focuses on the automation aspects of DevOps, Release Management and compares solutions from the leading vendors.
SYS-CON Events has announced today that Roger Strukhoff has been named conference chair of Cloud Expo and @ThingsExpo 2016 Silicon Valley. The 19th Cloud Expo and 6th @ThingsExpo will take place on November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. "The Internet of Things brings trillions of dollars of opportunity to developers and enterprise IT, no matter how you measure it," stated Roger Strukhoff. "More importantly, it leverages the power of devices and the Interne...
This is a no-hype, pragmatic post about why I think you should consider architecting your next project the way SOA and/or microservices suggest. No matter if it’s a greenfield approach or if you’re in dire need of refactoring. Please note: considering still keeps open the option of not taking that approach. After reading this, you will have a better idea about whether building multiple small components instead of a single, large component makes sense for your project. This post assumes that you...
DevOps at Cloud Expo – being held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's largest enterprises – and delivering real results. Am...
The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportuni...
SYS-CON Events announced today that Isomorphic Software will exhibit at DevOps Summit at 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Isomorphic Software provides the SmartClient HTML5/AJAX platform, the most advanced technology for building rich, cutting-edge enterprise web applications for desktop and mobile. SmartClient combines the productivity and performance of traditional desktop software with the simp...
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform and how we integrate our thinking to solve complicated problems. In his session at 19th Cloud Expo, Craig Sproule, CEO of Metavine, will demonstrate how to move beyond today's coding paradigm ...
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 19th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo Silicon Valley Call for Papers is now open.
In his session at @DevOpsSummit at 19th Cloud Expo, Yoseph Reuveni, Director of Software Engineering at Jet.com, will discuss Jet.com's journey into containerizing Microsoft-based technologies like C# and F# into Docker. He will talk about lessons learned and challenges faced, the Mono framework tryout and how they deployed everything into Azure cloud. Yoseph Reuveni is a technology leader with unique experience developing and running high throughput (over 1M tps) distributed systems with extre...
Node.js and io.js are increasingly being used to run JavaScript on the server side for many types of applications, such as websites, real-time messaging and controllers for small devices with limited resources. For DevOps it is crucial to monitor the whole application stack and Node.js is rapidly becoming an important part of the stack in many organizations. Sematext has historically had a strong support for monitoring big data applications such as Elastic (aka Elasticsearch), Cassandra, Solr, S...
Right off the bat, Newman advises that we should "think of microservices as a specific approach for SOA in the same way that XP or Scrum are specific approaches for Agile Software development". These analogies are very interesting because my expectation was that microservices is a pattern. So I might infer that microservices is a set of process techniques as opposed to an architectural approach. Yet in the book, Newman clearly includes some elements of concept model and architecture as well as p...
"We provide DevOps solutions. We also partner with some key players in the DevOps space and we use the technology that we partner with to engineer custom solutions for different organizations," stated Himanshu Chhetri, CTO of Addteq, in this SYS-CON.tv interview at DevOps at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Keeping pace with advancements in software delivery processes and tooling is taxing even for the most proficient organizations. Point tools, platforms, open source and the increasing adoption of private and public cloud services requires strong engineering rigor – all in the face of developer demands to use the tools of choice. As Agile has settled in as a mainstream practice, now DevOps has emerged as the next wave to improve software delivery speed and output. To make DevOps work, organization...

Let's just nip the conflation of these terms in the bud, shall we?

"MIcro" is big these days. Both microservices and microsegmentation are having and will continue to have an impact on data center architecture, but not necessarily for the same reasons. There's a growing trend in which folks - particularly those with a network background - conflate the two and use them to mean the same thing.

They are not.

One is about the application. The other, the network. T...

If you are within a stones throw of the DevOps marketplace you have undoubtably noticed the growing trend in Microservices. Whether you have been staying up to date with the latest articles and blogs or you just read the definition for the first time, these 5 Microservices Resources You Need In Your Life will guide you through the ins and outs of Microservices in today’s world.
Before becoming a developer, I was in the high school band. I played several brass instruments - including French horn and cornet - as well as keyboards in the jazz stage band. A musician and a nerd, what can I say? I even dabbled in writing music for the band. Okay, mostly I wrote arrangements of pop music, so the band could keep the crowd entertained during Friday night football games. What struck me then was that, to write parts for all the instruments - brass, woodwind, percussion, even k...
This digest provides an overview of good resources that are well worth reading. We’ll be updating this page as new content becomes available, so I suggest you bookmark it. Also, expect more digests to come on different topics that make all of our IT-hearts go boom!