Click here to close now.



Welcome!

Microservices Expo Authors: Jason Bloomberg, Elizabeth White, Anders Wallgren, Pat Romanski, Cloud Best Practices Network

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
If we look at slow, traditional IT and jump to the conclusion that just because we found its issues intractable before, that necessarily means we will again, then it’s time for a rethink. As a matter of fact, the world of IT has changed over the last ten years or so. We’ve been experiencing unprecedented innovation across the board – innovation in technology as well as in how people organize and accomplish tasks. Let’s take a look at three differences between today’s modern, digital context...
The battle over bimodal IT is heating up. Now that there’s a reasonably broad consensus that Gartner’s advice about bimodal IT is deeply flawed – consensus everywhere except perhaps at Gartner – various ideas are springing up to fill the void. The bimodal problem, of course, is well understood. ‘Traditional’ or ‘slow’ IT uses hidebound, laborious processes that would only get in the way of ‘fast’ or ‘agile’ digital efforts. The result: incoherent IT strategies and shadow IT struggles that lead ...
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, 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, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management...
As software organizations continue to invest in achieving Continuous Delivery (CD) of their applications, we see increased interest in microservices architectures, which–on the face of it–seem like a natural fit for enabling CD. In microservices (or its predecessor, “SOA”), the business functionality is decomposed into a set of independent, self-contained services that communicate with each other via an API. Each of the services has their own application release cycle, and are developed and depl...
SYS-CON Events announced today that Alert Logic, Inc., the leading provider of Security-as-a-Service solutions for the cloud, will exhibit at 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. Alert Logic, Inc., provides Security-as-a-Service for on-premises, cloud, and hybrid infrastructures, delivering deep security insight and continuous protection for customers at a lower cost than traditional security solutions. Ful...
At the heart of the Cloud Native model is a microservices application architecture, and applying this to a telco SDN scenario offers enormous opportunity for product innovation and competitive advantage. For example in the ETSI NFV Ecosystem white paper they describe one of the product markets that SDN might address to be the Home sector. Vendors like Alcatel market SDN-based solutions for the home market, offering Home Gateways – A virtual residential gateway (vRGW) where service provider...
SYS-CON Events announced today that VAI, a leading ERP software provider, will exhibit at 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. VAI (Vormittag Associates, Inc.) is a leading independent mid-market ERP software developer renowned for its flexible solutions and ability to automate critical business functions for the distribution, manufacturing, specialty retail and service sectors. An IBM Premier Business Part...
SYS-CON Events announced today that Catchpoint Systems, Inc., a provider of innovative web and infrastructure monitoring solutions, has been named “Silver Sponsor” of SYS-CON's DevOps Summit at 18th Cloud Expo New York, which will take place June 7-9, 2016, at the Javits Center in New York City, NY. Catchpoint is a leading Digital Performance Analytics company that provides unparalleled insight into customer-critical services to help consistently deliver an amazing customer experience. Designed...
SYS-CON Events announced today that AppNeta, the leader in performance insight for business-critical web applications, will exhibit and present at SYS-CON's @DevOpsSummit at Cloud Expo New York, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. AppNeta is the only application performance monitoring (APM) company to provide solutions for all applications – applications you develop internally, business-critical SaaS applications you use and the networks that deli...
In the Bimodal model we find two areas of IT - the traditional kind where the main concern is keeping the lights on and the IT focusing on agility and speed, where everything needs to be faster. Today companies are investing in new technologies and processes to emulate their most agile competitors. Gone are the days of waterfall development and releases only every few months. Today's IT and the business it powers demands performance akin to a supercar - everything needs to be faster, every sc...
The (re?)emergence of Microservices was especially prominent in this week’s news. What are they good for? do they make sense for your application? should you take the plunge? and what do Microservices mean for your DevOps and Continuous Delivery efforts? Continue reading for more on Microservices, containers, DevOps culture, and more top news from the past week. As always, stay tuned to all the news coming from@ElectricCloud on DevOps and Continuous Delivery throughout the week and retweet/favo...
In most cases, it is convenient to have some human interaction with a web (micro-)service, no matter how small it is. A traditional approach would be to create an HTTP interface, where user requests will be dispatched and HTML/CSS pages must be served. This approach is indeed very traditional for a web site, but not really convenient for a web service, which is not intended to be good looking, 24x7 up and running and UX-optimized. Instead, talking to a web service in a chat-bot mode would be muc...
More and more companies are looking to microservices as an architectural pattern for breaking apart applications into more manageable pieces so that agile teams can deliver new features quicker and more effectively. What this pattern has done more than anything to date is spark organizational transformations, setting the foundation for future application development. In practice, however, there are a number of considerations to make that go beyond simply “build, ship, and run,” which changes ho...
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 ad...
With microservices, SOA and distributed architectures becoming more popular, it is becoming increasingly harder to keep track of where time is spent in a distributed application when trying to diagnose performance problems. Distributed tracing systems attempt to address this problem by following application requests across service boundaries, persisting metadata along the way that provide context for fine-grained performance monitoring.
Web performance issues and advances have been gaining a stronger presence in the headlines as people are becoming more aware of its impact on virtually every business, and 2015 was no exception. We saw a myriad of major outages this year hit some of the biggest corporations, as well as some technology integrations and other news that we IT Ops aficionados find very exciting. This past year has offered several opportunities for growth and evolution in the performance realm — even the worst failu...
Are you someone who knows that the number one rule in DevOps is “Don’t Panic”? Especially when it comes to making Continuous Delivery changes inside your organization? Are you someone that theorizes that if anyone implements real automation changes, the solution will instantly become antiquated and be replaced by something even more bizarre and inexplicable?
Welcome to the first top DevOps news roundup of 2016! At the end of last year, we saw some great predictions for 2016. While we’re excited to kick off the new year, this week’s top posts reminded us to take a second to slow down and really understand the current state of affairs. For example, do you actually know what microservices are – or aren’t? What about DevOps? Does the emphasis still fall mostly on the development side? This week’s top news definitely got the wheels turning and just migh...
Test automation is arguably the most important innovation to the process of QA testing in software development. The ability to automate regression testing and other repetitive test cases can significantly reduce the overall production time for even the most complex solutions. As software continues to be developed for new platforms – including mobile devices and the diverse array of endpoints that will be created during the rise of the Internet of Things - automation integration will have a huge ...
Providing a full-duplex communication channel over a single TCP connection, WebSocket is the most efficient protocol for real-time responses over the web. If you’re utilizing WebSocket technology, performance testing will boil down to simulating the bi-directional nature of your application. Introduced with HTML5, the WebSocket protocol allows for more interaction between a browser and website, facilitating real-time applications and live content. WebSocket technology creates a persistent conne...