Click here to close now.

SYS-CON MEDIA Authors: Liz McMillan, Carmen Gonzalez, Blue Box Blog, Lori MacVittie, Plutora Blog

Related Topics: Big Data Journal, Java, Microservices Journal, Linux, AJAX & REA, Web 2.0

Big Data Journal: Article

Software Quality Metrics for Your Continuous Delivery Pipeline | Part 2

The metrics around database access

No matter how often you deploy your application or how sophisticated your delivery pipeline is, you always need to know the quality status of the software you are building. That can only be done if you measure it; but measure what exactly? In Part 1 we introduced the Concept of Quality Metrics in CD (Continuous Delivery) by looking at the metric # of Requests per End User Action. In Part 2 we will focus on metrics around database access.

You need to be aware of bad database access patterns right when they get introduced in your code. Whether the reason is incorrectly configured O/R (Object Relational) Mappers such as Hibernate, TopLink or JDO, or because of bad coding. Finding these problems immediately by looking at the right metrics will make it is easier for developers to fix the problem, which will reduce test cycles and give operations more confidence that a new deployment will not blow their current database server.

Examples of Bad Database Access Patterns
The following example is taken from a web application that displays an account report with 25 items per page that contains the names and high-level statuses of these accounts. The developers decided to go with Hibernate in order to access these account objects stored in the database. A closer look at the generated SQL queries when generating this report reveals that Hibernate not only loads the account objects that match the search query, but actually loads all account objects including all referenced objects in a related history table. These history objects are not needed at all to generate the report. The way Hibernate is used by the application (premature loading of all objects and referenced objects) results in more than 4000 SQL executions contributing 6s to the total page load time:

The way Hibernate is used by the application results in 4k+ individual SQL Statements, returning much more data than is actually needed for the report

If you want to learn more about database access problems check out load balancers cause database locks, when it is really the database to blame or the "Understanding Hibernate" Series: Part I - Session Cache, Part II - Query Cache and Part III - Second Level Cache.

Metric: Total Number of SQL Statements per Transaction
The first metric you want to take a closer look at is the total number of SQL executions per transaction. If you want to go a step further you can even monitor SELECT, INSERT, DELETE and UPDATE statements separately.

If you're always aware how many database statements are executed for your individual transactions (Login, Search, Checkout) and you monitor this along the delivery pipeline for every build, you will immediately see how the newly added functionality impacts the load on your database. The following screenshot shows a way to track this number across builds and across your different deployment stages. In this scenario, Developers extended the search feature in Build #3 by making an additional call to a 3rd party recommendation service. Build #3 suddenly shows a huge spike in SQL queries in the Load Stage and Production. Why is that?

A new call to an external third-party service introduced with Build 3 has major impacts on the load (capacity stage) and production environment when this new feature has to deal with real production data

What can we learn from these metrics above?

  • Commit stage: The executed Unit Tests in that stage didn't catch the problem because the call to the third-party service was mocked and therefore no actual DB calls were executed by that service.
  • Acceptance stage: A change in behavior was detected due to the additional call to the recommendation service which executed 2 additional SQLs. This could already be a warning sign but will probably still stay unnoticed.
  • Capacity stage: a 200x increase in DB calls must stop this deployment so that it never reaches Live. The reason why we have 200x and not only two should also trigger the integration tests to be executed against more than sample database content.
  • Production: 4k SQLs instead of just two is a huge impact on production. This again can be explained because the production database has "real life" data and the database access pattern of this third-party service queries every piece of data. If this really makes it into production and we monitor this data down to the transaction level, it is easy to pull this change back and engineering can immediately start working on the problematic area. Most important, however, is that this build never makes it into production because the problem was found in testing already!

How to Measure on Dev Workstations
Developers can look at this data by either turning on certain SQL Logging options of the frameworks that they are using, e.g., Hibernate (see stackoverflow discussion). They can profile their code using the profiler that comes with their IDE or use tools such as the Development Edition of dynaTrace (or the 15 Days Free Trial) to see all database calls made by their own code or the code that they are calling. The following shows a screenshot taken from Database Access Patterns Gone Wild and shows which data can be analyzed on a local machine:

Developers can analyze which SQL statements are executed by their own code or third-party frameworks they use. In this case it was code executed by Telerik to populate .NET control data.

For more measurement tips, and for further insight, click here for the full article

More Stories By Andreas Grabner

Andreas Grabner has been helping companies improve their application performance for 15+ years. He is a regular contributor within Web Performance and DevOps communities and a prolific speaker at user groups and conferences around the world. Reach him at @grabnerandi

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.


Latest Stories
There is no doubt that Big Data is here and getting bigger every day. Building a Big Data infrastructure today is no easy task. There are an enormous number of choices for database engines and technologies. To make things even more challenging, requirements are getting more sophisticated, and the standard paradigm of supporting historical analytics queries is often just one facet of what is needed. As Big Data growth continues, organizations are demanding real-time access to data, allowing immed...
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on T...
SYS-CON Events announced today that MangoApps will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY., and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. MangoApps provides private all-in-one social intranets allowing workers to securely collaborate from anywhere in the world and from any device. Social, mobile, and eas...
WebRTC defines no default signaling protocol, causing fragmentation between WebRTC silos. SIP and XMPP provide possibilities, but come with considerable complexity and are not designed for use in a web environment. In his session at @ThingsExpo, Matthew Hodgson, technical co-founder of the Matrix.org, discussed how Matrix is a new non-profit Open Source Project that defines both a new HTTP-based standard for VoIP & IM signaling and provides reference implementations.
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, a...
There are 182 billion emails sent every day, generating a lot of data about how recipients and ISPs respond. Many marketers take a more-is-better approach to stats, preferring to have the ability to slice and dice their email lists based numerous arbitrary stats. However, fundamentally what really matters is whether or not sending an email to a particular recipient will generate value. Data Scientists can design high-level insights such as engagement prediction models and content clusters that a...
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Ras...
The Internet of Things is not new. Historically, smart businesses have used its basic concept of leveraging data to drive better decision making and have capitalized on those insights to realize additional revenue opportunities. So, what has changed to make the Internet of Things one of the hottest topics in tech? In his session at @ThingsExpo, Chris Gray, Director, Embedded and Internet of Things, discussed the underlying factors that are driving the economics of intelligent systems. Discover ...
Database apps on mobile devices shouldn't stop working when there's limited or no network connectivity. In his session at 16th Cloud Expo, Bradley Holt, a Developer Advocate for IBM Cloudant, will discuss how to bring data stored in a cloud database to the edge of the network (and back again), whenever an Internet connection is available. He will demonstrate techniques for replicating cloud databases with mobile devices in order to build offline-enabled mobile apps that can provide a better,...
This talk focuses on the application of DevOps fundamentals to include network infrastructure. It draws from real deployment case studies on the extension of today's paradigms to address the challenges of the network infrastructures' ability to seamlessly and cohesively integrate into agile workflows. In this session at DevOps Summit, Arista Networks will focus on configuration management using automation with a nod to future work necessary to include telemetry and ephemeral state information....
Scott Jenson leads a project called The Physical Web within the Chrome team at Google. Project members are working to take the scalability and openness of the web and use it to talk to the exponentially exploding range of smart devices. Nearly every company today working on the IoT comes up with the same basic solution: use my server and you'll be fine. But if we really believe there will be trillions of these devices, that just can't scale. We need a system that is open a scalable and by using ...
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
The cloud has transformed how we think about software quality. Instead of preventing failures, we must focus on automatic recovery from failure. In other words, resilience trumps traditional quality measures. Continuous delivery models further squeeze traditional notions of quality. Remember the venerable project management Iron Triangle? Among time, scope, and cost, you can only fix two or quality will suffer. Only in today's DevOps world, continuous testing, integration, and deployment upend...
Cloud and Big Data present unique dilemmas: embracing the benefits of these new technologies while maintaining the security of your organization's assets. When an outside party owns, controls and manages your infrastructure and computational resources, how can you be assured that sensitive data remains private and secure? How do you best protect data in mixed use cloud and big data infrastructure sets? Can you still satisfy the full range of reporting, compliance and regulatory requirements? In...
There are lots of challenges in IoT around secure, scalable and business friendly infrastructure for enterprises. For large corporations, IoT implementations are one of the top priorities of the decade. All industries are seeing a competitive need to sustain by investing in IoT initiatives. The value addition comes from improved customer service, innovative product and additional revenue streams. The data from these IP-connected devices can be leveraged for a variety of business applica...