Welcome!

Microservices Expo Authors: Elizabeth White, Pat Romanski, Liz McMillan, Derek Weeks, Lori MacVittie

Related Topics: Microservices Expo, Java IoT, Linux Containers, IoT User Interface, Agile Computing, @BigDataExpo

Microservices Expo: Article

Understanding Application Performance on the Network | Part 5

Processing Delays

In Part IV, we wrapped up our discussions on bandwidth, congestion and packet loss. In Part V, we examine the four types of processing delays visible on the network, using the request/reply paradigm we outlined in Part I.

Server Processing (Between Flows)
From the network's perspective, we allocate the time period between the end of a request flow and the beginning of the corresponding reply flow to server processing. Generally speaking, the server doesn't begin processing a request until it has received the entire flow, i.e., the last packet in the request message; similarly, the server doesn't begin sending the reply until it has finished processing the request. We sometimes refer to these delays between flows as "pure" processing delays, distinct from another type of intra-flow processing delay we call starved for data and discuss later. Server processing delays occur as a result of a request message, and therefore always occur within a thread.

Transaction Trace Illustrations
These "pure" server processing delays are generally relatively simple to detect, to understand, and to prove. Transaction Trace's Node Processing table lists all of the observed processing delays for an operation in tabular format; by splitting this table with the Bounce Diagram and highlighting a row of interest, the Bounce Diagram will display the last packet of the request flow and the first packet of the corresponding reply flow, effectively diagramming the measurement.

Use the Node Processing Table split with the Bounce Diagram to illustrate node processing delay

You may also use the Thread Analysis split with the Bounce Diagram; this will provide a view of the request and reply packet flows as well as the processing measurement.

Split the Thread View with the Bounce Diagram to illustrate the request flow, node processing and reply flow

Starved for Data (Sending Node, Within a Flow)
Sometimes, the network interface will be able to transmit data at a rate faster than the sending application can deliver to the TCP socket. For example, a busy ftp server may momentarily interrupt sending a large file because of a disk, memory or CPU bottleneck. We refer to these pauses that occur in the middle of a flow as "starved for data" conditions; there is nothing on the network (no TCP flow control constraint) preventing the request or reply flow from continuing, so the cause must be internal to the sending node. Starved for data bottlenecks occur within a flow (instead of between flows), and are related to the sending node - either the client or server.

Transaction Trace Illustration
These cases can be more difficult to visualize. Since the condition is generally not too common, it is often best to rule out other performance bottlenecks first, before checking for data starvation. When it does occur, the condition has the effect of extending the duration of a request or reply flow, and starved for data delays are included in Transaction Trace's Node Sending measurements. Sort the rate column of the Node Sending Table and split the window with the Bounce Diagram; the Bounce Diagram will illustrate the packets associated with a sending measurement. For those sending measurements where you suspect a starved for data condition, look for idle periods of time where the sending node's flow has been interrupted. Importantly, a starved for data delay will terminate with the transmission of a data packet that resumes the sender's flow, not a TCP ACK from the receiver that might suggest a TCP or application window constraint.

The Node Sending table is split with the Bounce Diagram to help illustrate Starved for Data conditions; note the pause in transmission that resumes independent of any TCP ACK.

Client Processing (Between Flows)
From the network's perspective, we allocate the time period between the end of a reply flow and the beginning of the next request flow to client processing. Generally speaking, the client cannot begin processing a reply until it has received the entire reply flow, i.e., the last packet of the reply message; similarly, the client doesn't begin sending the next (new) request until it has completed processing the reply. (This correlation generally applies to request/reply flows on the same TCP connection.)

Transaction Trace Illustrations
Similar to server processing delays, client delays are relatively simple to understand. In most cases, client delays occur between threads; in other words, after one thread has completed but before the next thread begins. For tasks with thread-level decodes, Transaction Trace's Thread Analysis Gantt chart view can illustrate these delays well.

Gaps between threads are associated with client processing delays

Discounting Client Processing
Note that we assume strict adherence to the definition of "operation" here; click to screen update. If the trace has captured multiple steps - say the user navigates through a series of operations - then the user "think time" between steps will appear as client processing delay, with corresponding gaps between threads. You may still use these multi-step tasks for analysis, remembering to discount client processing delays. Alternatively, you can save each step as a separate task by selecting a sequence of threads from the Thread table.

For more network strategies, click here for the full article.

More Stories By Gary Kaiser

Gary Kaiser is a Subject Matter Expert in Network Performance Analytics at Dynatrace, responsible for DC RUM’s technical marketing programs. He is a co-inventor of multiple performance analysis features, and continues to champion the value of network performance analytics. He is the author of Network Application Performance Analysis (WalrusInk, 2014).

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
The Jevons Paradox suggests that when technological advances increase efficiency of a resource, it results in an overall increase in consumption. Writing on the increased use of coal as a result of technological improvements, 19th-century economist William Stanley Jevons found that these improvements led to the development of new ways to utilize coal. In his session at 19th Cloud Expo, Mark Thiele, Chief Strategy Officer for Apcera, will compare the Jevons Paradox to modern-day enterprise IT, e...
DevOps at Cloud Expo, taking place Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th 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 no time to wait for long dev...
In this strange new world where more and more power is drawn from business technology, companies are effectively straddling two paths on the road to innovation and transformation into digital enterprises. The first path is the heritage trail – with “legacy” technology forming the background. Here, extant technologies are transformed by core IT teams to provide more API-driven approaches. Legacy systems can restrict companies that are transitioning into digital enterprises. To truly become a lea...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
Information technology is an industry that has always experienced change, and the dramatic change sweeping across the industry today could not be truthfully described as the first time we've seen such widespread change impacting customer investments. However, the rate of the change, and the potential outcomes from today's digital transformation has the distinct potential to separate the industry into two camps: Organizations that see the change coming, embrace it, and successful leverage it; and...
19th Cloud Expo, taking place November 1-3, 2016, 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. Meanwhile, 94% of enterpri...
SYS-CON Events announced today that LeaseWeb USA, a cloud Infrastructure-as-a-Service (IaaS) provider, will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. LeaseWeb is one of the world's largest hosting brands. The company helps customers define, develop and deploy IT infrastructure tailored to their exact business needs, by combining various kinds cloud solutions.
DevOps at Cloud Expo – being held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's largest enterprises – and delivering real results. Am...
With emerging ideas, innovation, and talents, the lines between DevOps, release engineering, and even security are rapidly blurring. I invite you to sit down for a moment with Principle Consultant, J. Paul Reed, and listen to his take on what the intersection between these once individualized fields entails, and may even foreshadow.
In case you haven’t heard, the new hotness in app architectures is serverless. Mainly restricted to cloud environments (Amazon Lambda, Google Cloud Functions, Microsoft Azure Functions) the general concept is that you don’t have to worry about anything but the small snippets of code (functions) you write to do something when something happens. That’s an event-driven model, by the way, that should be very familiar to anyone who has taken advantage of a programmable proxy to do app or API routing ...
Much of the value of DevOps comes from a (renewed) focus on measurement, sharing, and continuous feedback loops. In increasingly complex DevOps workflows and environments, and especially in larger, regulated, or more crystallized organizations, these core concepts become even more critical. In his session at @DevOpsSummit at 18th Cloud Expo, Andi Mann, Chief Technology Advocate at Splunk, showed how, by focusing on 'metrics that matter,' you can provide objective, transparent, and meaningful f...
With the rise of Docker, Kubernetes, and other container technologies, the growth of microservices has skyrocketed among dev teams looking to innovate on a faster release cycle. This has enabled teams to finally realize their DevOps goals to ship and iterate quickly in a continuous delivery model. Why containers are growing in popularity is no surprise — they’re extremely easy to spin up or down, but come with an unforeseen issue. However, without the right foresight, DevOps and IT teams may lo...
Cloud Expo 2016 New York at the Javits Center New York was characterized by increased attendance and a new focus on operations. These were both encouraging signs for all involved in Cloud Computing and all that it touches. As Conference Chair, I work with the Cloud Expo team to structure three keynotes, numerous general sessions, and more than 150 breakout sessions along 10 tracks. Our job is to balance the state of enterprise IT today with the trends that will be commonplace tomorrow. Mobile...
To leverage Continuous Delivery, enterprises must consider impacts that span functional silos, as well as applications that touch older, slower moving components. Managing the many dependencies can cause slowdowns. See how to achieve continuous delivery in the enterprise.
There is little doubt that Big Data solutions will have an increasing role in the Enterprise IT mainstream over time. Big Data at Cloud Expo - to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA - has announced its Call for Papers is open. Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is...
Digitization is driving a fundamental change in society that is transforming the way businesses work with their customers, their supply chains and their people. Digital transformation leverages DevOps best practices, such as Agile Parallel Development, Continuous Delivery and Agile Operations to capitalize on opportunities and create competitive differentiation in the application economy. However, information security has been notably absent from the DevOps movement. Speed doesn’t have to negat...
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform and how we integrate our thinking to solve complicated problems. In his session at 19th Cloud Expo, Craig Sproule, CEO of Metavine, will demonstrate how to move beyond today's coding paradigm ...
Large enterprises today are juggling an enormous variety of network equipment. Business users are asking for specific network throughput guarantees when it comes to their critical applications, legal departments require compliance with mandated regulatory frameworks, and operations are asked to do more with shrinking budgets. All these requirements do not easily align with existing network architectures; hence, network operators are continuously faced with a slew of granular parameter change req...
Your business relies on your applications and your employees to stay in business. Whether you develop apps or manage business critical apps that help fuel your business, what happens when users experience sluggish performance? You and all technical teams across the organization – application, network, operations, among others, as well as, those outside the organization, like ISPs and third-party providers – are called in to solve the problem.
SYS-CON Events announced today the Kubernetes and Google Container Engine Workshop, being held November 3, 2016, in conjunction with @DevOpsSummit at 19th Cloud Expo at the Santa Clara Convention Center in Santa Clara, CA. This workshop led by Sebastian Scheele introduces participants to Kubernetes and Google Container Engine (GKE). Through a combination of instructor-led presentations, demonstrations, and hands-on labs, students learn the key concepts and practices for deploying and maintainin...