Welcome!

Machine Learning Authors: Elizabeth White, Yeshim Deniz, Pat Romanski, AppNeta Blog, Derek Weeks

Related Topics: Java IoT, Microservices Expo, Open Source Cloud, Machine Learning , @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.


@CloudExpo Stories
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
@DevOpsSummit has been named the ‘Top DevOps Influencer' by iTrend. iTrend processes millions of conversations, tweets, interactions, news articles, press releases, blog posts - and extract meaning form them and analyzes mobile and desktop software platforms used to communicate, various metadata (such as geo location), and automation tools. In overall placement, @DevOpsSummit ranked as the number one ‘DevOps Influencer' followed by @CloudExpo at third, and @MicroservicesE at 24th.
SYS-CON Events announced today that Auditwerx will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Auditwerx specializes in SOC 1, SOC 2, and SOC 3 attestation services throughout the U.S. and Canada. As a division of Carr, Riggs & Ingram (CRI), one of the top 20 largest CPA firms nationally, you can expect the resources, skills, and experience of a much larger firm combined with the accessibility and attent...
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 20th Cloud Expo, which will take place on June 6-8, 2017 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 add...
MongoDB Atlas leverages VPC peering for AWS, a service that allows multiple VPC networks to interact. This includes VPCs that belong to other AWS account holders. By performing cross account VPC peering, users ensure networks that host and communicate their data are secure. In his session at 20th Cloud Expo, Jay Gordon, a Developer Advocate at MongoDB, will explain how to properly architect your VPC using existing AWS tools and then peer with your MongoDB Atlas cluster. He'll discuss the secur...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
In his session at Cloud Expo, Alan Winters, an entertainment executive/TV producer turned serial entrepreneur, will present a success story of an entrepreneur who has both suffered through and benefited from offshore development across multiple businesses: The smart choice, or how to select the right offshore development partner Warning signs, or how to minimize chances of making the wrong choice Collaboration, or how to establish the most effective work processes Budget control, or how to max...
Imagine having the ability to leverage all of your current technology and to be able to compose it into one resource pool. Now imagine, as your business grows, not having to deploy a complete new appliance to scale your infrastructure. Also imagine a true multi-cloud capability that allows live migration without any modification between cloud environments regardless of whether that cloud is your private cloud or your public AWS, Azure or Google instance. Now think of a world that is not locked i...
In his General Session at 16th Cloud Expo, David Shacochis, host of The Hybrid IT Files podcast and Vice President at CenturyLink, investigated three key trends of the “gigabit economy" though the story of a Fortune 500 communications company in transformation. Narrating how multi-modal hybrid IT, service automation, and agile delivery all intersect, he will cover the role of storytelling and empathy in achieving strategic alignment between the enterprise and its information technology.
In his session at 20th Cloud Expo, Scott Davis, CTO of Embotics, will discuss how automation can provide the dynamic management required to cost-effectively deliver microservices and container solutions at scale. He will discuss how flexible automation is the key to effectively bridging and seamlessly coordinating both IT and developer needs for component orchestration across disparate clouds – an increasingly important requirement at today’s multi-cloud enterprise.
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" ...
The essence of cloud computing is that all consumable IT resources are delivered as services. In his session at 15th Cloud Expo, Yung Chou, Technology Evangelist at Microsoft, demonstrated the concepts and implementations of two important cloud computing deliveries: Infrastructure as a Service (IaaS) and Platform as a Service (PaaS). He discussed from business and technical viewpoints what exactly they are, why we care, how they are different and in what ways, and the strategies for IT to transi...
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound e...
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...
Niagara Networks exhibited at the 19th International Cloud Expo, which took place at the Santa Clara Convention Center in Santa Clara, CA, in November 2016. Niagara Networks offers the highest port-density systems, and the most complete Next-Generation Network Visibility systems including Network Packet Brokers, Bypass Switches, and Network TAPs.
Extreme Computing is the ability to leverage highly performant infrastructure and software to accelerate Big Data, machine learning, HPC, and Enterprise applications. High IOPS Storage, low-latency networks, in-memory databases, GPUs and other parallel accelerators are being used to achieve faster results and help businesses make better decisions. In his session at 18th Cloud Expo, Michael O'Neill, Strategic Business Development at NVIDIA, focused on some of the unique ways extreme computing is...
My team embarked on building a data lake for our sales and marketing data to better understand customer journeys. This required building a hybrid data pipeline to connect our cloud CRM with the new Hadoop Data Lake. One challenge is that IT was not in a position to provide support until we proved value and marketing did not have the experience, so we embarked on the journey ourselves within the product marketing team for our line of business within Progress. In his session at @BigDataExpo, Sum...
"We host and fully manage cloud data services, whether we store, the data, move the data, or run analytics on the data," stated Kamal Shannak, Senior Development Manager, Cloud Data Services, IBM, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
Interoute has announced the integration of its Global Cloud Infrastructure platform with Rancher Labs’ container management platform, Rancher. This approach enables enterprises to accelerate their digital transformation and infrastructure investments. Matthew Finnie, Interoute CTO commented “Enterprises developing and building apps in the cloud and those on a path to Digital Transformation need Digital ICT Infrastructure that allows them to build, test and deploy faster than ever before. The int...