Internet servers hosting online applications need to be scalable to handle large numbers of simultaneous users. There are three main techniques for load balancing across replicated servers: DNS rotation, cooperative offloading using TCP handoff, and load balancing routers. DNS rotation requires few changes but has rigid policies while cooperative offloading and load balancing routers can be more adaptive but require changes to servers, clients, or routers.
My presentation on Linked Data during the Open Web session at Defrag 2009. Licensing and Open Data were covered in the preceding presentation by Svein-Magnus Sørensen, upon which this builds.
My presentation on Linked Data during the Open Web session at Defrag 2009. Licensing and Open Data were covered in the preceding presentation by Svein-Magnus Sørensen, upon which this builds.
Presentation about nice functional programming things you can do with python. and some simple techniques you can use to do a good and functional design
Given what a beautiful and mature functional programming language R is, there is a surprising, though understandable, lack of visibility of functional programming techniques in R. This is a talk given to the Mumbai R meetup group in October/November, 2014, meant to introduce the audience to Functional Programming in R.
Presentation about nice functional programming things you can do with python. and some simple techniques you can use to do a good and functional design
Given what a beautiful and mature functional programming language R is, there is a surprising, though understandable, lack of visibility of functional programming techniques in R. This is a talk given to the Mumbai R meetup group in October/November, 2014, meant to introduce the audience to Functional Programming in R.
Why Load Testing from the Cloud Doesn't WorkCompuware APM
You might think that with web applications in the cloud, that load testing from the cloud provides all the testing you need. You might think that testing from the cloud can tell you if your website can handle peak traffic loads, driven by marketing campaigns, or seasonal events. Unfortunately you may be wrong. In the Web 2.0 world; applications are combined on the fly inside the browser, from third-party and shared services both in the cloud and from behind the firewall. Imad Mouline, CTO of Gomez will tell you — the cloud is not the answer.
Join Imad Mouline, on Wednesday September 8th for this provocative session around today’s highly complex, distributed Web applications and how to test them. Imad is a veteran of software architecture, research & development and an expert in Web application development, testing and performance management.
In this session, Mouline will discuss:
* The evolution architecture and structure of Web applications
* The current state of load testing approaches and how they apply to a variety of architectures
* How existing and emerging testing techniques are applied to different types of applications
* The future architecture of Web applications and what it means to the future of testing
This is lecture of Advanced GIS (ITM 524), MSc in Information Technology for Natural Resources Management, Bogor Agricultural University.
This topics covered: Internet & World Wide Web, Web Mapping, Internet GIS, Web Mapping Services Model, Spatial Data Infrastructure.
3scale Webinar #1 on how to Unleash the Power of your API.
1. An API ? What for ?
2. The core value of APIs - Real life examples
3. The benefits of having a “managed” API
4. The 3scale solution and its added value
Full video of the webinar including demonstration of the 3scale API Management Solution:
http://www.viddler.com/explore/3scale/videos/11/
Heard about Cloud Foundry? Already a Spring, Grails, Ruby, Node.js, Scala, or generalist programmer looking to understand what Cloud Foundry, the open source PaaS from VMware, means to you? Are you an architect trying to understand where PaaS fits it, and what it brings to the table? If you answered "yes" to any of those questions, then join the experts in this bootcamp to Cloud Foundry.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
FIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdf
Scalable Internet Servers and Load Balancing
1. Computer Networks 11/11/2009
Internet Online Applications
Scalable Internet Servers and
Load Balancingg Internet online applications
Applications accessible to online users through Internet
Internet.
Examples
Online keyword search engine: Google.
Web email: Gmail.
News: CNN, NBC news.
Web directory: Yahoo!, MSN.
Kai Shen
Scalability requirements
Many simultaneous user accesses; large amount of hosted
data, …
Internet servers
Computer systems that host these online applications
11/11/2009 CSC 257/457 - Fall 2009 1 11/11/2009 CSC 257/457 - Fall 2009 2
Internet Servers are at the Search Engine as An Example:
Application Layer Step 1 – Crawling
Normally on the end hosts, involving no routers
Function on transport-layer protocols TCP/UDP Crawling – get all these Web pages out there:
g g p g
First retrieve some root pages;
Parse their content and follow hyperlinks to retrieve more
pages;
Depth-first search or breadth-first search? Remove
Internet duplicates.
Google
Yahoo!
CNN
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CSC 257/457 - Fall 2009 1
2. Computer Networks 11/11/2009
Performance Analysis for Search Engine as An Example:
Crawling Step 2 – Indexing
What are the resources involved?
CPU processing for TCP/HTTP protocol handling and the
p g p g Indexing
parsing of page content
f crawled raw web pages are not easy to search.
writing to disk storage we index them to formats that are easy to search.
network bandwidth to remote web sites
As part of indexing, we need to give each page an ID
Assume average page size 10KB using a hash function.
raw processing power of a single CPU
……
1000 requests/sec
Computer: Page #123 Page #357
I/O to a single disk
100 seeks/sec up to 100 requests/sec
network bandwidth from/to the Internet
T1 link (1.5Mbit/s) 12 requests/sec
Networks: Page #124 Page #468 ……
T3 link (45Mbit/s) 360 requests/sec
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Search Engine as An Example:
Step 3 – Online Search Partitioning and Replication
Index servers
(partition 1)
Index server
Firewall/
Firewall Router
Local-
Local-area
network
Web server/
Query handler Local-
Local-area
Internet Internet network Index servers
(partition 2)
Page server
Web server/
Query handlers
Page servers
Scalability, reliability
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CSC 257/457 - Fall 2009 2
3. Computer Networks 11/11/2009
Load Balancing on Internet Servers
Load Balancing over Internet
Technique 1 - DNS Rotation
Servers
128.111.1.2
Popular sites like Google or CNN receive tens or
hundreds of millions of hits per day
day. IP address of
CNN.com?
A large number of replicated servers are used at Firewall/ 128.111.1.3
these sites. Router
IP address of
Key question: how to balance client requests over CNN.com? Internet
these servers?
128.111.1.4
128.111.1.2
Web servers
for CNN.com
128.111.1.3
DNS server
for CNN.com
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Load Balancing on Internet Servers
Discussions on DNS Rotation Technique 2 – Cooperative Offloading
128.111.1.2
Advantages
Require almost no change on the existing Internet
architecture
Firewall/ 128.111.1.3
Router
Problems
DNS Caching Internet
Rigid load balancing policy
can’t balance based on runtime load changes
128.111.1.4
slow or no adjustment in response to failures
Web servers
for CNN.com
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CSC 257/457 - Fall 2009 3
4. Computer Networks 11/11/2009
Discussions on Cooperative Cooperative Offloading with
Offloading TCP Handoff [Pai et al. ASPLOS1998]
128.111.1.2
What does 1.3 do?
Can be combined with the DNS rotation.
What does 1.4 do?
Advantages:
More flexible policy is possible clt IP Firewall/ 128.111.1.3
Router
Be more responsive to runtime workload and server 1.3
failures (to a certain degree) clt IP
Internet 1.4
Problems: 128.111.1.4
Need software changes on servers 1.3
13
Longer delay clt IP Web servers
for CNN.com
All packets in a TCP
connection must
offload to one server?
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Cooperative Offloading vs. Load Balancing on Internet Servers
TCP Handoff Technique 3 – Load Balancing Router
128.111.1.2
clt IP
Software changes on the servers
g 1.2
1.2
clt IP
clt IP
Delays 128.111.1.3
Firewall
1.1 LB Router
Internet 128.111.1.1
1.1
clt IP 128.111.1.4
Web servers
for CNN.com
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CSC 257/457 - Fall 2009 4
5. Computer Networks 11/11/2009
More About Load Balancing Router Summary
How deep do we look into the network protocol stack? Scalable Internet servers
Network layer (IP)? partitioning
replication
Transport layer (TCP/UDP)?
Application layer? Load balancing for Internet servers
DNS rotation
Load balancing policies in LB routers (Goal: transparency, cooperative offloading (w. TCP handoff)
plug-and-play) Load balancing router
Simple rotation Changes required on the components:
components
DNS server??
Least number of active requests
Web server??
Shortest response time client??
router??
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CSC 257/457 - Fall 2009 5