Welcome!

Microservices Expo Authors: Yeshim Deniz, Elizabeth White, Pat Romanski, Jason Bloomberg, Mark Leake

Related Topics: @DevOpsSummit, Linux Containers, Containers Expo Blog

@DevOpsSummit: Blog Feed Post

The Speed Index | @DevOpsSummit @Catchpoint #DevOps #WebPerf #DX #AI

There’s a lot of buzz around the speed index metric, but what exactly is this metric and how is it calculated?

Understanding Speed Index
By Moiz Khan

There’s a lot of buzz around the speed index metric, but what exactly is this metric and how is it calculated? Even more so, why do we need a new metric when there are so many already on the plate? This article gives you detailed answers to these questions.

What is speed index?
User expectations have changed drastically, webpages are expected to load faster with all elements rendering as soon as possible; user frustration increases if the visual content of the page is slow to load.

There are several metrics used to measure user experience, but do these give us a clear enough picture? Not really. For example, render start indicates when the page started painting, but this could mean it loaded a white background, a random object, or just a dot on the page; the user, however, may still be looking at a blank page. The document complete metric, which flags the onLoad event, may not be important from an end user’s perspective as it considers below-the-fold requests as well; there could be instances where the Document complete is triggered even when the page is blank.

Speed Index is an abstract score that was introduced to overcome the limitations of the current set of metrics. It measures user experience and unlike render start or document complete, it is not a timing metric, therefore the smaller the score, the better it is. Speed index takes into account the visual completeness of the page above-the-fold. It does a much better job of measuring the perceived performance of a page, but does this mean other metrics are irrelevant? This is debatable. Instead, the choice of a metric depends on the scenario and the nature of the website being analyzed.

How relevant is speed index?
Speed index will let you know if the visible content is loading quickly or not. The lower the score, the better is the user experience, and vice versa. The speed index score indicates whether you need to optimize your page or not. To maintain a good score, there are two critical aspects that you should look at: optimizing content efficiency and optimizing the critical rendering path.

Web applications continue to grow in terms of functionality, scope, and usability; hundreds of resources make up these applications and fetching each resource adds to the page load time. Maintaining performance is possible only when the resources and content that make up the page are optimized. Speed index plays a critical role in monitoring the performance of visible content.

How is it calculated?
Speed index lets you measure how quickly a page’s content is visible. However, it can be a little tricky to understand what it means and what factors contribute to the score.

Speed index uses film strips to calculate the score, each frame is scored for visual completeness above the fold – the score is 0% for a blank screen and 100% for a visually complete screen. The score for each frame is calculated using this formula:

interval time*(1 – visual complete %/100)

The process is repeated for every frame and the cumulative of all the scores gives you the speed index of that page.

Let’s take an example:

Adding all of the scores gives the speed index score:

500 + 450 + 350 + 200 + 50 = 1550

Here is another example:

Let’s add up the score:

500 + 500 + 475 + 400 + 350 = 2225

From a performance point of view, the lower the score the better it is. There is no defined benchmark for speed index, however, a score of <1000 is considered good. User experience is better if above-the-fold content is displayed faster, and this is what speed index determines.

Measuring speed index using Catchpoint
To check speed index, you will need to enable the “Capture Filmstrip” option under Advanced Settings of a test. It is displayed along with other metrics in the charts, and you can also view it in the waterfall graphs. Here are a few examples that illustrate how pages that load the visual content faster have a better speed index score.

Example 1:

In the above example, the page has a good speed index score of 1260. If you look at the film strip, the interval is of 500ms, and from the second frame the visual content is visible, which is about 1 second. Frame three has almost all the content loaded. From a user’s point of view, we have engaged them from the very first second due to the fact that the page is optimized.

Example 2:

In the above image, the visual is visible in the third frame. The first two frames are blank, which is why the speed index score of 1741 is higher than the first example. The user views content at 1.6 seconds, unlike the first example where the user viewed the content within a second.

Example 3:

Based on the final example above, we are able to understand what is happening. The first two frames are blank and in the third frame visual content starts to load. However, the completeness is less compared to the other two images in the same frame. The visual content continues to load in the fourth frame, but it’s not complete until the fifth frame. This means that the user needs to wait for 1.6 seconds to see something on the page, and another 2.8 seconds to view the complete visual content.

In all of the examples, the render start is triggered before the user views anything on the page. In the second example, the render start happens at 1195ms and the visible content starts to load at 1604ms. In the third example, the render start happens at 1296ms and the visible content starts to load at 1597ms. This is the uniqueness of speed index. With a highly unoptimized website, the difference could be extremely high, with render start happening quickly but the visible content loads quite late. You need these insights to optimize your websites.

Limitations of Speed Index
When running transaction tests for dynamic sites or single page applications that use ajax, the score is always good in the steps that follow once the page is opened. This is because the page does not refresh after it is loaded. Pages featuring carousels that rotate automatically may be penalized because they continue to change even after the page load is completed.

Summary
Speed index indicates the visual completeness of the page; however, it does not indicate if the content was critical or non-critical for the user. As such, it should not be a replacement for other metrics and should be considered a rather useful and much-needed addition to the list of metrics. You will still need to look at render start and document complete to understand the overall performance. Speed index gives you a different perspective of the user experience that your site delivers.

The post Understanding Speed Index appeared first on Catchpoint's Blog - Web Performance Monitoring.

More Stories By Mehdi Daoudi

Catchpoint radically transforms the way businesses manage, monitor, and test the performance of online applications. Truly understand and improve user experience with clear visibility into complex, distributed online systems.

Founded in 2008 by four DoubleClick / Google executives with a passion for speed, reliability and overall better online experiences, Catchpoint has now become the most innovative provider of web performance testing and monitoring solutions. We are a team with expertise in designing, building, operating, scaling and monitoring highly transactional Internet services used by thousands of companies and impacting the experience of millions of users. Catchpoint is funded by top-tier venture capital firm, Battery Ventures, which has invested in category leaders such as Akamai, Omniture (Adobe Systems), Optimizely, Tealium, BazaarVoice, Marketo and many more.

@MicroservicesExpo Stories
Cloud Expo, Inc. has announced today that Andi Mann and Aruna Ravichandran have been named Co-Chairs of @DevOpsSummit at Cloud Expo Silicon Valley which will take place Oct. 31-Nov. 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. "DevOps is at the intersection of technology and business-optimizing tools, organizations and processes to bring measurable improvements in productivity and profitability," said Aruna Ravichandran, vice president, DevOps product and solutions marketing...
@DevOpsSummit at Cloud Expo taking place Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center, Santa Clara, CA, is co-located with the 21st International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is ...
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business - from apparel to energy - is being rewritten by software. From planning to development to management to security, CA creates software that fuels transformation for companies in the applic...
What's the role of an IT self-service portal when you get to continuous delivery and Infrastructure as Code? This general session showed how to create the continuous delivery culture and eight accelerators for leading the change. Don Demcsak is a DevOps and Cloud Native Modernization Principal for Dell EMC based out of New Jersey. He is a former, long time, Microsoft Most Valuable Professional, specializing in building and architecting Application Delivery Pipelines for hybrid legacy, and cloud ...
In his session at Cloud Expo, Alan Winters, an entertainment executive/TV producer turned serial entrepreneur, presented 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 ma...
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...
"When we talk about cloud without compromise what we're talking about is that when people think about 'I need the flexibility of the cloud' - it's the ability to create applications and run them in a cloud environment that's far more flexible,” explained Matthew Finnie, CTO of Interoute, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
In 2014, Amazon announced a new form of compute called Lambda. We didn't know it at the time, but this represented a fundamental shift in what we expect from cloud computing. Now, all of the major cloud computing vendors want to take part in this disruptive technology. In his session at 20th Cloud Expo, Doug Vanderweide, an instructor at Linux Academy, discussed why major players like AWS, Microsoft Azure, IBM Bluemix, and Google Cloud Platform are all trying to sidestep VMs and containers wit...
A common misconception about the cloud is that one size fits all. Companies expecting to run all of their operations using one cloud solution or service must realize that doing so is akin to forcing the totality of their business functionality into a straightjacket. Unlocking the full potential of the cloud means embracing the multi-cloud future where businesses use their own cloud, and/or clouds from different vendors, to support separate functions or product groups. There is no single cloud so...
Both SaaS vendors and SaaS buyers are going “all-in” to hyperscale IaaS platforms such as AWS, which is disrupting the SaaS value proposition. Why should the enterprise SaaS consumer pay for the SaaS service if their data is resident in adjacent AWS S3 buckets? If both SaaS sellers and buyers are using the same cloud tools, automation and pay-per-transaction model offered by IaaS platforms, then why not host the “shrink-wrapped” software in the customers’ cloud? Further, serverless computing, cl...
Hybrid IT is today’s reality, and while its implementation may seem daunting at times, more and more organizations are migrating to the cloud. In fact, according to SolarWinds 2017 IT Trends Index: Portrait of a Hybrid IT Organization 95 percent of organizations have migrated crucial applications to the cloud in the past year. As such, it’s in every IT professional’s best interest to know what to expect.
The taxi industry never saw Uber coming. Startups are a threat to incumbents like never before, and a major enabler for startups is that they are instantly “cloud ready.” If innovation moves at the pace of IT, then your company is in trouble. Why? Because your data center will not keep up with frenetic pace AWS, Microsoft and Google are rolling out new capabilities. In his session at 20th Cloud Expo, Don Browning, VP of Cloud Architecture at Turner, posited that disruption is inevitable for comp...
For most organizations, the move to hybrid cloud is now a question of when, not if. Fully 82% of enterprises plan to have a hybrid cloud strategy this year, according to Infoholic Research. The worldwide hybrid cloud computing market is expected to grow about 34% annually over the next five years, reaching $241.13 billion by 2022. Companies are embracing hybrid cloud because of the many advantages it offers compared to relying on a single provider for all of their cloud needs. Hybrid offers bala...
Containers, microservices and DevOps are all the rage lately. You can read about how great they are and how they’ll change your life and the industry everywhere. So naturally when we started a new company and were deciding how to architect our app, we went with microservices, containers and DevOps. About now you’re expecting a story of how everything went so smoothly, we’re now pushing out code ten times a day, but the reality is quite different.
"We are a monitoring company. We work with Salesforce, BBC, and quite a few other big logos. We basically provide monitoring for them, structure for their cloud services and we fit into the DevOps world" explained David Gildeh, Co-founder and CEO of Outlyer, 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.
If you cannot explicitly articulate how investing in a new technology, changing the approach or re-engineering the business process will help you achieve your customer-centric vision of the future in direct and measurable ways, you probably shouldn’t be doing it. At Intellyx, we spend a lot of time talking to technology vendors. In our conversations, we explore emerging new technologies that are either disrupting the way enterprise organizations work or that help enable those organizations to ...
For organizations that have amassed large sums of software complexity, taking a microservices approach is the first step toward DevOps and continuous improvement / development. Integrating system-level analysis with microservices makes it easier to change and add functionality to applications at any time without the increase of risk. Before you start big transformation projects or a cloud migration, make sure these changes won’t take down your entire organization.
There's a lot to gain from cloud computing, but success requires a thoughtful and enterprise focused approach. Cloud computing decouples data and information from the infrastructure on which it lies. A process that is a LOT more involved than dragging some folders from your desktop to a shared drive. Cloud computing as a mission transformation activity, not a technological one. As an organization moves from local information hosting to the cloud, one of the most important challenges is addressi...
Companies have always been concerned that traditional enterprise software is slow and complex to install, often disrupting critical and time-sensitive operations during roll-out. With the growing need to integrate new digital technologies into the enterprise to transform business processes, this concern has become even more pressing. A 2016 Panorama Consulting Solutions study revealed that enterprise resource planning (ERP) projects took an average of 21 months to install, with 57 percent of t...
Microservices are increasingly used in the development world as developers work to create larger, more complex applications that are better developed and managed as a combination of smaller services that work cohesively together for larger, application-wide functionality. Tools such as Service Fabric are rising to meet the need to think about and build apps using a piece-by-piece methodology that is, frankly, less mind-boggling than considering the whole of the application at once. Today, we'll ...