The document defines a distributed system and provides examples. It outlines the challenges in designing distributed systems, including heterogeneity, openness, security, scalability, failure handling, concurrency, and transparency. Distributed systems divide tasks across networked computers and aim to appear as a single computer to users.
A brief introduction to Process synchronization in Operating Systems with classical examples and solutions using semaphores. A good starting tutorial for beginners.
A brief introduction to Process synchronization in Operating Systems with classical examples and solutions using semaphores. A good starting tutorial for beginners.
Synchronization in distributed computingSVijaylakshmi
Synchronization in distributed systems is achieved via clocks. The physical clocks are used to adjust the time of nodes. Each node in the system can share its local time with other nodes in the system. The time is set based on UTC (Universal Time Coordination).
Operating system 18 process creation and terminationVaibhav Khanna
Information associated with each process
(also called task control block)
Process state – running, waiting, etc
Program counter – location of instruction to next execute
CPU registers – contents of all process-centric registers
CPU scheduling information- priorities, scheduling queue pointers
Memory-management information – memory allocated to the process
Accounting information – CPU used, clock time elapsed since start, time limits
I/O status information – I/O devices allocated to process, list of open files
Inter-Process Communication in distributed systemsAya Mahmoud
Inter-Process Communication is at the heart of all distributed systems, so we need to know the ways that processes can exchange information.
Communication in distributed systems is based on Low-level message passing as offered by the underlying network.
Peer-to-peer Systems – Introduction – Napster and its legacy – Peer-to-peer – Middleware – Routing overlays. Overlay case studies: Pastry, Tapestry- Distributed File Systems –Introduction – File service architecture – Andrew File system. File System: Features-File model -File accessing models – File sharing semantics Naming: Identifiers, Addresses, Name Resolution – Name Space Implementation – Name Caches – LDAP.
This presentation provide a brief overview of Compuware's Mobility Center of Excellence. Compuware is enabling customers to realize the benefits of a value-driven mobile strategy by delivering commercial quality mobile applications.
Synchronization in distributed computingSVijaylakshmi
Synchronization in distributed systems is achieved via clocks. The physical clocks are used to adjust the time of nodes. Each node in the system can share its local time with other nodes in the system. The time is set based on UTC (Universal Time Coordination).
Operating system 18 process creation and terminationVaibhav Khanna
Information associated with each process
(also called task control block)
Process state – running, waiting, etc
Program counter – location of instruction to next execute
CPU registers – contents of all process-centric registers
CPU scheduling information- priorities, scheduling queue pointers
Memory-management information – memory allocated to the process
Accounting information – CPU used, clock time elapsed since start, time limits
I/O status information – I/O devices allocated to process, list of open files
Inter-Process Communication in distributed systemsAya Mahmoud
Inter-Process Communication is at the heart of all distributed systems, so we need to know the ways that processes can exchange information.
Communication in distributed systems is based on Low-level message passing as offered by the underlying network.
Peer-to-peer Systems – Introduction – Napster and its legacy – Peer-to-peer – Middleware – Routing overlays. Overlay case studies: Pastry, Tapestry- Distributed File Systems –Introduction – File service architecture – Andrew File system. File System: Features-File model -File accessing models – File sharing semantics Naming: Identifiers, Addresses, Name Resolution – Name Space Implementation – Name Caches – LDAP.
This presentation provide a brief overview of Compuware's Mobility Center of Excellence. Compuware is enabling customers to realize the benefits of a value-driven mobile strategy by delivering commercial quality mobile applications.
This presentation contains the basics of cryptography. I have developed this presentation as a course material of Cryptography during my honors final year examination
distributed system chapter one introduction to distribued system.pdflematadese670
distributed system chapter one introduction to distribued system
Your score increases as you pick a category, fill out a long description and add more tags distributed system chapter one introduction to distribued system distributed system chapter one introduction to distribued system distributed system chapter one introduction to distribued system
Le nuove frontiere dell'AI nell'RPA con UiPath Autopilot™UiPathCommunity
In questo evento online gratuito, organizzato dalla Community Italiana di UiPath, potrai esplorare le nuove funzionalità di Autopilot, il tool che integra l'Intelligenza Artificiale nei processi di sviluppo e utilizzo delle Automazioni.
📕 Vedremo insieme alcuni esempi dell'utilizzo di Autopilot in diversi tool della Suite UiPath:
Autopilot per Studio Web
Autopilot per Studio
Autopilot per Apps
Clipboard AI
GenAI applicata alla Document Understanding
👨🏫👨💻 Speakers:
Stefano Negro, UiPath MVPx3, RPA Tech Lead @ BSP Consultant
Flavio Martinelli, UiPath MVP 2023, Technical Account Manager @UiPath
Andrei Tasca, RPA Solutions Team Lead @NTT Data
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
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Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
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.
The Metaverse and AI: how can decision-makers harness the Metaverse for their...Jen Stirrup
The Metaverse is popularized in science fiction, and now it is becoming closer to being a part of our daily lives through the use of social media and shopping companies. How can businesses survive in a world where Artificial Intelligence is becoming the present as well as the future of technology, and how does the Metaverse fit into business strategy when futurist ideas are developing into reality at accelerated rates? How do we do this when our data isn't up to scratch? How can we move towards success with our data so we are set up for the Metaverse when it arrives?
How can you help your company evolve, adapt, and succeed using Artificial Intelligence and the Metaverse to stay ahead of the competition? What are the potential issues, complications, and benefits that these technologies could bring to us and our organizations? In this session, Jen Stirrup will explain how to start thinking about these technologies as an organisation.
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/
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
zkStudyClub - Reef: Fast Succinct Non-Interactive Zero-Knowledge Regex ProofsAlex Pruden
This paper presents Reef, a system for generating publicly verifiable succinct non-interactive zero-knowledge proofs that a committed document matches or does not match a regular expression. We describe applications such as proving the strength of passwords, the provenance of email despite redactions, the validity of oblivious DNS queries, and the existence of mutations in DNA. Reef supports the Perl Compatible Regular Expression syntax, including wildcards, alternation, ranges, capture groups, Kleene star, negations, and lookarounds. Reef introduces a new type of automata, Skipping Alternating Finite Automata (SAFA), that skips irrelevant parts of a document when producing proofs without undermining soundness, and instantiates SAFA with a lookup argument. Our experimental evaluation confirms that Reef can generate proofs for documents with 32M characters; the proofs are small and cheap to verify (under a second).
Paper: https://eprint.iacr.org/2023/1886
Enhancing Performance with Globus and the Science DMZGlobus
ESnet has led the way in helping national facilities—and many other institutions in the research community—configure Science DMZs and troubleshoot network issues to maximize data transfer performance. In this talk we will present a summary of approaches and tips for getting the most out of your network infrastructure using Globus Connect Server.
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
2. Objectives
To define what is a distributed system
To know the consequences of the
definition
To identify the challenges in designing and
building a distributed system
4. ♦ Data are Distributed
» If data must exist in multiple computers for admin and ownership
reasons
♦ Computation is Distributed
» Applications taking advantage of parallelism, multiple processors,
» particular feature
» Scalability and heterogeneity of Distributed System
♦ Users are Distributed
» If Users communicate and interact via application (shared objects)
5. Definition of A Distributed System
“A distributed system is a collection of independent
computers that appear to the users of the system as a
single computer.” [Tanenbaum]
“A distributed system is a collection of autonomous
computers linked by a network with software designed
to produce an integrated computing facility.”
[Coulouris, Dollimore, Kindberg]
“A system of multiple autonomous processing
elements, cooperating in a common purpose or to
achieve a common goal.” [Burns & Wellings 1997]
6. ”A system that consists of a collection of two or more
independent computers, that are connected by a
network, which coordinate their processing through the
exchange of synchronous or asynchronous message
passing. They may be on separate continents, in the
same building or the same room”.
Definition from our textbook
8. Introduction
Motivation for A Distributed System
Load balancing / distribution
breaking a problem into smaller pieces enables you to solve larger
problems without resorting to larger computer
MAINFRAME – 10 X faster but 1000 X expensive
Increased Processing Power
independent processors working on the same task
Distributed systems consisting of collections of microcomputers
may have processing powers that no single computer will ever
achieve
10000 CPUs, each running at 50 MIPS, yields 500000 MIPS
instruction to be executed in 0.002 nsec equivalent to light
distance of 0.6 mm any processor chip of that size would melt
immediately
9. Introduction
Motivation for A Distributed System
Fault tolerance
If any of the machine gets down, others can still run
Availability
Anytime, anywhere access
Resource sharing
All clients can be server or vice versa to provide resources
(data, files, services)
The main motivator for DS
15. Challenge: Heterogeneity
Heterogeneity = variety and difference
Heterogeneity of
underlying network infrastructure (ethernet, ISDN, token ring etc),
computer hardware and software (e.g., operating systems, compare UNIX
sockets and Winsock calls),
programming languages (java, C, python : in particular, data
representations),
implementations by different developers
Heterogeneity needs to be masked
Distributed Computing
16. determines whether the system can be
extended and re-implemented in various
ways
Determined primarily by the degree to
which new resource-sharing services can be
added and be made available for use by
variety of client programs
Detailed interfaces of components need to
be standardized and published.
Challenge: Openness
Distributed Computing
17. Security for information resources has three components:
Confidentiality
protection against disclosure to unauthorized individuals
Integrity
protection against alteration or corruption
Availability
protection against interference with the means of accessing the
resources
The challenge: sending sensitive information in a network
message in a secure manner efficiently
Not just to conceal the info but to ensure that the sender and
recipients are the rightful owners of the messages
Challenge: Security
Distributed Computing
18. Challenge: Scalability
A distributed system is scalable if it remains effective
as the number of users and/or resources increase
Challenges:
Controlling resource costs
Controlling performance loss
Preventing resources from running out
Avoiding performance bottlenecks
Distributed Computing
19. Challenge: Failure Handling
Failures more common than in centralized systems
and usually partial
Failure handling includes
Detection (may be impossible)
Masking/hiding
Tolerance
Recovery
Redundancy
Distributed Computing
20. Challenge: Failure Handling
Detection
Some possible (e.g., using transmission errors via
checksums)
Some impossible (crashed remote server vs. slow
remote server)
Challenge: manage failures that cannot be detected, but
suspected
Distributed Computing
21. Challenge: Failure Handling
Masking/hiding
Some failures can be hidden or made less severe
Replication in space/time
Space: e.g., writing to multiple disks
Time: e.g., transmission of multiple messages
May not work in worst cases, e.g., all disks may have
been corrupted
Distributed Computing
22. Challenge: Failure Handling
Tolerance
Sometimes not feasible to hide all failures
E.g., user has to tolerate if web service has failed rather than wait
until service is up again
Only feasible for certain classes of applications/systems, e.g., DNS
vs. Internet addresses
Recovery
Restoring a correct system state
Roll back using log files
Distributed Computing
23. Challenge: Failure Handling
Redundancy
Tolerate failures by using redundant components
Provided through replication
E.g., redundant routes in network, replication of name tables in
multiple domain name servers
Goal of failure handling: high availability
availability of a system is a measure of the proportion of time that
the system is available for use
Distributed Computing
24. Challenge: Concurrency
Concurrency control
Handling several simultaneous requests for a resource
Consistent scheduling of concurrent threads (so that
dependencies are preserved, e.g., in concurrent transactions)
Synchronized operations (semaphores)
Safest, but limits throughput
Shared objects/resources must guarantee correctness in a
concurrent environment
Avoidance of deadlocks
Distributed Computing
25. Challenge: Transparency
Concealing the heterogeneous and distributed nature
of the system so that it appears to the user like one
system
Eight types (ANSA/ISO)
access, location, concurrency, replication, failure,
mobility, performance and scaling transparencies
Distributed Computing
26. Challenge: Transparency
•Access transparency:
•enables local and remote resources to be accessed using identical
operations.
For instance, from a user's point of view, access to a remote service such as
a printer should be identical with access to a local printer.
From a programmers point of view, the access method to a remote object
may be identical to access a local object of the same class.
•E.g., Same user interface and operations offered in order to access either
local or remote resources
Distributed Computing
27. Challenge: Transparency
•Location transparency:
•enables resources to be accessed without knowledge of their location.
•The details of the topology of the system should be of no concern to the
user.
•The location of an object in the system may not be visible to the user or
programmer.
•This differs from access transparency in that both the naming and access
methods may be the same. Names may give no hint as to location.
•E.g., URL or e-mail addresses.
• www.google.com (IP address is the physical location)
Distributed Computing
28. Challenge: Transparency
•Concurrency transparency:
•enables several processes to operate concurrently using shared resources
without interference between them.
•E.g., no conflict occur when 2 or more users accessing the same system
Distributed Computing
29. Challenge: Transparency
•Replication transparency:
•enables multiple instances of resources to be used to increase reliability
and performance without knowledge of the replicas by users.
•This kind of transparency should be mainly incorporated for the distributed file
systems, which replicate the data at two or more sites for more reliability. The client
generally should not be aware that a replicated copy of the data exists. The clients
should also expect operations to return only one set of values.
•The examples are Distributed DBMS and Mirroring of Web pages.
•Failure transparency:
•enables the concealment of faults, allowing users and application
programs to complete their tasks despite the failure of hardware or
software components.
•E.g., retransmission of e-mail messages
•Mobility transparency:
•allows the movement of resources and clients within a system without
affecting the operation of users or programs.Distributed Computing
30. Challenge: Transparency
•Mobility transparency:
•allows the movement of resources and clients within a system without
affecting the operation of users or programs.
•E.g., caller and callee undergoing different places while on the phone
Distributed Computing
31. Challenge: Transparency
•Performance transparency:
•allows the system to be reconfigured to improve performance as loads
vary.
•Eg:Video On Demand (VOD) System
•Scaling transparency:
•allows the system and applications to expand in scale without change to
the system structure or the application algorithms.
•Eg: P2P apps
Distributed Computing
32. Transparency Description
Access
Hide differences in data representation and how a
resource is accessed
Location Hide where a resource is located
Migration Hide that a resource may move to another location
Relocation
Hide that a resource may be moved to another
location while in use
Replication Hide that a resource may be replicated
Concurrency
Hide that a resource may be shared by several
competitive users
Failure Hide the failure and recovery of a resource
Persistence
Hide whether a (software) resource is in memory or on
disk
33. 1. Name a program that is using distributed computing and freely
available to the masses
2. Name 1 research field that is relying heavily on distributed computing
34. Summary
A distributed system is a collection of independent
and autonomous computers that appear to the
users of the system as a single computer.”
Based on the above definition, there are three
significant consequences :
Concurrency
No global clock
Independent failures
Several challenges need to be addressed in
designing and building DS
Heterogeneity, openness, security, scalability, failure
handling, concurrency and transparency.
Distributed Computing