|By Gary Kaiser||
|July 14, 2014 08:45 AM EDT||
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.
SYS-CON Events announced today that AppNeta, the leader in performance insight for business-critical web applications, will exhibit and present at SYS-CON's @DevOpsSummit at Cloud Expo New York, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. AppNeta is the only application performance monitoring (APM) company to provide solutions for all applications – applications you develop internally, business-critical SaaS applications you use and the networks that deli...
Feb. 9, 2016 10:30 AM EST Reads: 371
Father business cycles and digital consumers are forcing enterprises to respond faster to customer needs and competitive demands. Successful integration of DevOps and Agile development will be key for business success in today’s digital economy. In his session at DevOps Summit, Pradeep Prabhu, Co-Founder & CEO of Cloudmunch, covered the critical practices that enterprises should consider to seamlessly integrate Agile and DevOps processes, barriers to implementing this in the enterprise, and pr...
Feb. 9, 2016 10:00 AM EST Reads: 352
Let’s face it, embracing new storage technologies, capabilities and upgrading to new hardware often adds complexity and increases costs. In his session at 18th Cloud Expo, Seth Oxenhorn, Vice President of Business Development & Alliances at FalconStor, will discuss how a truly heterogeneous software-defined storage approach can add value to legacy platforms and heterogeneous environments. The result reduces complexity, significantly lowers cost, and provides IT organizations with improved effi...
Feb. 9, 2016 08:15 AM EST Reads: 223
Data-as-a-Service is the complete package for the transformation of raw data into meaningful data assets and the delivery of those data assets. In her session at 18th Cloud Expo, Lakshmi Randall, an industry expert, analyst and strategist, will address: What is DaaS (Data-as-a-Service)? Challenges addressed by DaaS Vendors that are enabling DaaS Architecture options for DaaS
Feb. 9, 2016 08:00 AM EST Reads: 335
One of the bewildering things about DevOps is integrating the massive toolchain including the dozens of new tools that seem to crop up every year. Part of DevOps is Continuous Delivery and having a complex toolchain can add additional integration and setup to your developer environment. In his session at @DevOpsSummit at 18th Cloud Expo, Miko Matsumura, Chief Marketing Officer of Gradle Inc., will discuss which tools to use in a developer stack, how to provision the toolchain to minimize onboa...
Feb. 9, 2016 07:45 AM EST
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
Feb. 9, 2016 07:15 AM EST Reads: 215
The principles behind DevOps are not new - for decades people have been automating system administration and decreasing the time to deploy apps and perform other management tasks. However, only recently did we see the tools and the will necessary to share the benefits and power of automation with a wider circle of people. In his session at DevOps Summit, Bernard Sanders, Chief Technology Officer at CloudBolt Software, explored the latest tools including Puppet, Chef, Docker, and CMPs needed to...
Feb. 9, 2016 06:45 AM EST Reads: 290
The cloud promises new levels of agility and cost-savings for Big Data, data warehousing and analytics. But it’s challenging to understand all the options – from IaaS and PaaS to newer services like HaaS (Hadoop as a Service) and BDaaS (Big Data as a Service). In her session at @BigDataExpo at @ThingsExpo, Hannah Smalltree, a director at Cazena, will provide an educational overview of emerging “as-a-service” options for Big Data in the cloud. This is critical background for IT and data profes...
Feb. 9, 2016 06:45 AM EST Reads: 167
SYS-CON Events announced today that Men & Mice, the leading global provider of DNS, DHCP and IP address management overlay solutions, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. The Men & Mice Suite overlay solution is already known for its powerful application in heterogeneous operating environments, enabling enterprises to scale without fuss. Building on a solid range of diverse platform support,...
Feb. 9, 2016 06:15 AM EST Reads: 175
With the proliferation of both SQL and NoSQL databases, organizations can now target specific fit-for-purpose database tools for their different application needs regarding scalability, ease of use, ACID support, etc. Platform as a Service offerings make this even easier now, enabling developers to roll out their own database infrastructure in minutes with minimal management overhead. However, this same amount of flexibility also comes with the challenges of picking the right tool, on the right ...
Feb. 9, 2016 05:30 AM EST Reads: 127
In most cases, it is convenient to have some human interaction with a web (micro-)service, no matter how small it is. A traditional approach would be to create an HTTP interface, where user requests will be dispatched and HTML/CSS pages must be served. This approach is indeed very traditional for a web site, but not really convenient for a web service, which is not intended to be good looking, 24x7 up and running and UX-optimized. Instead, talking to a web service in a chat-bot mode would be muc...
Feb. 9, 2016 05:15 AM EST Reads: 223
More and more companies are looking to microservices as an architectural pattern for breaking apart applications into more manageable pieces so that agile teams can deliver new features quicker and more effectively. What this pattern has done more than anything to date is spark organizational transformations, setting the foundation for future application development. In practice, however, there are a number of considerations to make that go beyond simply “build, ship, and run,” which changes ho...
Feb. 9, 2016 05:15 AM EST Reads: 185
With an estimated 50 billion devices connected to the Internet by 2020, several industries will begin to expand their capabilities for retaining end point data at the edge to better utilize the range of data types and sheer volume of M2M data generated by the Internet of Things. In his session at @ThingsExpo, Don DeLoach, CEO and President of Infobright, will discuss the infrastructures businesses will need to implement to handle this explosion of data by providing specific use cases for filte...
Feb. 9, 2016 04:30 AM EST Reads: 140
The battle over bimodal IT is heating up. Now that there’s a reasonably broad consensus that Gartner’s advice about bimodal IT is deeply flawed – consensus everywhere except perhaps at Gartner – various ideas are springing up to fill the void. The bimodal problem, of course, is well understood. ‘Traditional’ or ‘slow’ IT uses hidebound, laborious processes that would only get in the way of ‘fast’ or ‘agile’ digital efforts. The result: incoherent IT strategies and shadow IT struggles that lead ...
Feb. 8, 2016 06:00 PM EST Reads: 447
SYS-CON Events announced today that VAI, a leading ERP software provider, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. VAI (Vormittag Associates, Inc.) is a leading independent mid-market ERP software developer renowned for its flexible solutions and ability to automate critical business functions for the distribution, manufacturing, specialty retail and service sectors. An IBM Premier Business Part...
Feb. 8, 2016 03:00 PM EST Reads: 583
SYS-CON Events announced today that Alert Logic, Inc., the leading provider of Security-as-a-Service solutions for the cloud, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Alert Logic, Inc., provides Security-as-a-Service for on-premises, cloud, and hybrid infrastructures, delivering deep security insight and continuous protection for customers at a lower cost than traditional security solutions. Ful...
Feb. 8, 2016 02:00 PM EST Reads: 386
SYS-CON Events announced today that Catchpoint Systems, Inc., a provider of innovative web and infrastructure monitoring solutions, has been named “Silver Sponsor” of SYS-CON's DevOps Summit at 18th Cloud Expo New York, which will take place June 7-9, 2016, at the Javits Center in New York City, NY. Catchpoint is a leading Digital Performance Analytics company that provides unparalleled insight into customer-critical services to help consistently deliver an amazing customer experience. Designed...
Feb. 8, 2016 02:00 PM EST Reads: 350
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 18th Cloud Expo, which will take place on June 7-9, 2015 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 ad...
Feb. 8, 2016 12:45 PM EST Reads: 367
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 18th International Cloud Expo, which will take place on June 7–9, 2016, at the Javits Center in New York City, NY, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management...
Feb. 8, 2016 10:45 AM EST Reads: 397
The (re?)emergence of Microservices was especially prominent in this week’s news. What are they good for? do they make sense for your application? should you take the plunge? and what do Microservices mean for your DevOps and Continuous Delivery efforts? Continue reading for more on Microservices, containers, DevOps culture, and more top news from the past week. As always, stay tuned to all the news coming from@ElectricCloud on DevOps and Continuous Delivery throughout the week and retweet/favo...
Feb. 8, 2016 09:45 AM EST Reads: 185