Welcome!

Related Topics: @BigDataExpo, Java IoT, Microservices Expo, Linux Containers, Machine Learning , Agile Computing

@BigDataExpo: 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
21st International Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Me...
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
SYS-CON Events announced today that Datera, that offers a radically new data management architecture, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datera is transforming the traditional datacenter model through modern cloud simplicity. The technology industry is at another major inflection point. The rise of mobile, the Internet of Things, data storage and Big...
"With Digital Experience Monitoring what used to be a simple visit to a web page has exploded into app on phones, data from social media feeds, competitive benchmarking - these are all components that are only available because of some type of digital asset," explained Leo Vasiliou, Director of Web Performance Engineering at Catchpoint Systems, in this SYS-CON.tv interview at DevOps Summit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"Outscale was founded in 2010, is based in France, is a strategic partner to Dassault Systémes and has done quite a bit of work with divisions of Dassault," explained Jackie Funk, Digital Marketing exec at Outscale, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"We were founded in 2003 and the way we were founded was about good backup and good disaster recovery for our clients, and for the last 20 years we've been pretty consistent with that," noted Marc Malafronte, Territory Manager at StorageCraft, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"DivvyCloud as a company set out to help customers automate solutions to the most common cloud problems," noted Jeremy Snyder, VP of Business Development at DivvyCloud, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
Kubernetes is an open source system for automating deployment, scaling, and management of containerized applications. Kubernetes was originally built by Google, leveraging years of experience with managing container workloads, and is now a Cloud Native Compute Foundation (CNCF) project. Kubernetes has been widely adopted by the community, supported on all major public and private cloud providers, and is gaining rapid adoption in enterprises. However, Kubernetes may seem intimidating and complex ...
While the focus and objectives of IoT initiatives are many and diverse, they all share a few common attributes, and one of those is the network. Commonly, that network includes the Internet, over which there isn't any real control for performance and availability. Or is there? The current state of the art for Big Data analytics, as applied to network telemetry, offers new opportunities for improving and assuring operational integrity. In his session at @ThingsExpo, Jim Frey, Vice President of S...
DX World EXPO, LLC., a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
"We focus on SAP workloads because they are among the most powerful but somewhat challenging workloads out there to take into public cloud," explained Swen Conrad, CEO of Ocean9, Inc., in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"As we've gone out into the public cloud we've seen that over time we may have lost a few things - we've lost control, we've given up cost to a certain extent, and then security, flexibility," explained Steve Conner, VP of Sales at Cloudistics,in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"We provide IoT solutions. We provide the most compatible solutions for many applications. Our solutions are industry agnostic and also protocol agnostic," explained Richard Han, Head of Sales and Marketing and Engineering at Systena America, in this SYS-CON.tv interview at @ThingsExpo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"We are focused on SAP running in the clouds, to make this super easy because we believe in the tremendous value of those powerful worlds - SAP and the cloud," explained Frank Stienhans, CTO of Ocean9, Inc., in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"DX encompasses the continuing technology revolution, and is addressing society's most important issues throughout the entire $78 trillion 21st-century global economy," said Roger Strukhoff, Conference Chair. "DX World Expo has organized these issues along 10 tracks with more than 150 of the world's top speakers coming to Istanbul to help change the world."