Monthly Archives: November 2020

Deep Dive Into Cloud Computing: Docker and Kubernetes and Basics

What is docker ?
Instance of redis in my computer

Why we use docker ?
Docker makes it really easy to install and run software without worrying about setup and depenedenies

Docker ecosystem-> Docker client Docker server Docker machine Docker images Docker hub Docker compose

 

Advanced Formal Modelling Excercise-1

Let Rz={(a,b)|a,b is belongs to Z^+ and a-b is an odd positive integer}.

The set of integers is represented by the letter Z. An integer is any number in the infinite set,

Z={.., -3,-2,-1, 0, 1, 2 ,3, …}
Z+ is the set of all positive integers(1,2,3,….) there is no 0 here
Z- is the set of all negative integers (…,-3,-2,-1) there is no 0 here
Z^nonneg is the set of all positive integers including 0, while Z^nonpos is the set of all negative integers including 0

Source: https://calculus.nipissingu.ca/tutorials/numbers.html#:~:text=An%20integer%20is%20any%20number,%2D2%2C%20%2D1).

Soln:
Set R1 is reflexive because
Q1) For every a is belongs to Z+ . (a,a) is belongs to R . a-a = 0 is not an odd  number. So, R is not reflexive.

For every a,b is belongs to Z+ : if a,b is positive, then b-a is negative. That if( a,b) is belongs R then (b,a) is not belongs to R. So not symmetric.

Due to the same reason, as above, (a,b) and (b,a) cannot be simultaneously in R . So the condition in the definition of anti symmetry is false.

The implication holds trivially , R is anti symmetric.

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Cloud Computing Lectures and Notes Winter 2020/21

1st week:
Task: Choose a team with topic is the exercise.

You need to chose a software solution, you need make it and present.
You need to submit it before February and every week prof. needs update
It should be multi node implementation

No exam this time only project that mean

Your installation guide should provide detailed steps how to deploy,
configure and use the service
[Latex diye koire fellam]
IOT er tao kore fellam tate  duita laav hoilo
[Dui dhoroner help pawa gelo + practice]

The client-server architecture consists of 2 layers and is called two-tier model
(tier = layer)

Parental Computing is company provided the service[47 minutes in recording]

According to their areas of responsibility, 4 types of clients exist:
1 Text-/X-Terminals
2 Thin/Zero Clients
3 Applet Clients
4 Fat Clients

— My Topic For Project: Kubernetes and Docker
– Most of the cloud/DevOps engineer needs this skill and First experience in the public cloud environment (AWS or AZURE)
– good knowledge of object-oriented languages ​​(e.g. Java, Python, PowerShell or NET) and containerization strategies

References:
https://www.educative.io/blog/roadmap-to-cloud-engineer-jobs
https://www.educative.io/courses/cloud-computing-101-master-the-fundamentals

The goal of the project:
|Linux administration
Documentation reading
Architecture Building
Not so hardcore programming
If you don’t do project you will fail

 

2nd week:
We shared our topic name maybe we may change the topic name if needed.
Topic: Content Delivery Network with Kubernetes and Docker
We have 3 team members, Syed Ahmed Zaki, Daniel Von Barany, Kranthi kumar reddy Kasireddy
– We want to make a system in different server which distributes content like images, mp3, text known as content delivery networking
-We are very new to Kubernetes and Docker still researching about this
– We want to deploy in cloud maybe Minio in multi node environment or openNebula it is serverless
– It will be scalable
– Any of your suggestion Prof. ?
– My other team members and colleagues will share the details

Learned from Youtube this week about Docker and little bit Kubernetes

 

3rd week:
Notes from class lecture:
Heteregenous is better because one system and multi computer
Failover and Failback

Some multinode tutorials:
How docker works: https://aws.amazon.com/docker/

https://medium.com/@rubenafo/some-tips-to-run-a-multi-node-hadoop-in-docker-9c7012dd4e26

https://www.digitalocean.com/community/tutorials/how-to-set-up-multi-node-deployments-with-rancher-2-1-kubernetes-and-docker-machine-on-ubuntu-18-04

https://medium.com/better-programming/build-your-own-multi-node-kubernetes-cluster-with-monitoring-346a7e2ef6e2

https://github.com/rubenafo/docker-spark-cluster

 

Difference Between multi-cluster, multi-master, multi-tenant & federated Kubernetes

 

https://www.mirantis.com/blog/multi-kubernetes-kdc-quick-and-dirty-guide/

Docker book: https://docker-curriculum.com/

Awesome projects from the Docker community

Real Time Computing Personal Note

What does real time mean ?

It means correctness and execution time of the results are guaranteed.

In non-Real time systems normally only the correctness of the result is guaranteed.

In other words: A real time system will also guaranty that a certain deadline is met.

From wikipedia professor also said:
Hard – missing a deadline is a total system failure.
Firm – infrequent deadline misses are tolerable, but may degrade the system’s quality of service. The usefulness of a result is zero after its deadline.
Soft – the usefulness of a result degrades after its deadline, thereby degrading the system’s quality of service.

Hard real-time systems are used when it is imperative that an event be reacted to within a strict deadline. Such strong guarantees are required of systems for which not reacting in a certain interval of time would cause great loss in some manner, especially damaging the surroundings physically or threatening human lives (although the strict definition is simply that missing the deadline constitutes failure of the system). Some examples of hard real-time systems:

  • car engine control system is a hard real-time system because a delayed signal may cause engine failure or damage.
  • Medical systems such as heart pacemakers. Even though a pacemaker’s task is simple, because of the potential risk to human life, medical systems like these are typically required to undergo thorough testing and certification, which in turn requires hard real-time computing in order to offer provable guarantees that a failure is unlikely or impossible.
  • Industrial process controllers, such as a machine on an assembly line. If the machine is delayed, the item on the assembly line could pass beyond the reach of the machine (leaving the product untouched), or the machine or the product could be damaged by activating the robot at the wrong time. If the failure is detected, both cases would lead to the assembly line stopping, which slows production. If the failure is not detected, a product with a defect could make it through production, or could cause damage in later steps of production.
  • Hard real-time systems are typically found interacting at a low level with physical hardware, in embedded systems. Early video game systems such as the Atari 2600 and Cinematronics vector graphics had hard real-time requirements because of the nature of the graphics and timing hardware.
  • Softmodems replace a hardware modem with software running on a computer’s CPU. The software must run every few milliseconds to generate the next audio data to be output. If that data is late, the receiving modem will lose synchronization, causing a long interruption as synchronization is reestablished or causing the connection to be lost entirely.
  • Many types of printers have hard real-time requirements, such as inkjets (the ink must be deposited at the correct time as the printhead crosses the page), laser printers (the laser must be activated at the right time as the beam scans across the rotating drum), and dot matrix and various types of line printers (the impact mechanism must be activated at the right time as the print mechanism comes into alignment with the desired output). A failure in any of these would cause either missing output or misaligned output.

In the context of multitasking systems the scheduling policy is normally priority driven (pre-emptive schedulers). In some situations, these can guarantee hard real-time performance (for instance if the set of tasks and their priorities is known in advance). There are other hard real-time schedulers such as rate-monotonic which is not common in general-purpose systems, as it requires additional information in order to schedule a task: namely a bound or worst-case estimate for how long the task must execute. Specific algorithms for scheduling such hard real-time tasks exist, such as earliest deadline first, which, ignoring the overhead of context switching, is sufficient for system loads of less than 100%.[6] New overlay scheduling systems, such as an adaptive partition scheduler assist in managing large systems with a mixture of hard real-time and non real-time applications.

Firm real-time systems are more nebulously defined, and some classifications do not include them, distinguishing only hard and soft real-time systems. Some examples of firm real-time systems:

  • The assembly line machine described earlier as hard real-time could instead be considered firm real-time. A missed deadline still causes an error which needs to be dealt with: there might be machinery to mark a part as bad or eject it from the assembly line, or the assembly line could be stopped so an operator can correct the problem. However, as long as these errors are infrequent, they may be tolerated.

Soft real-time systems are typically used to solve issues of concurrent access and the need to keep a number of connected systems up-to-date through changing situations. Some examples of soft real-time systems:

  • Software that maintains and updates the flight plans for commercial airliners. The flight plans must be kept reasonably current, but they can operate with the latency of a few seconds.
  • Live audio-video systems are also usually soft real-time. A frame of audio that’s played late may cause a brief audio glitch (and may cause all subsequent audio to be delayed correspondingly, causing a perception that the audio is being played slower than normal), but this may be better than the alternatives of continuing to play silence, static, a previous audio frame, or estimated data. A frame of video that’s delayed typically causes even less disruption for viewers. The system can continue to operate and also recover in the future using workload prediction and reconfiguration methodologies.[7]
  • Similarly, video games are often soft real-time, particularly as they try to meet a target frame rate. As the next image cannot be computed in advance, since it depends on inputs from the player, only a short time is available to perform all the computing needed to generate a frame of video before that frame must be displayed. If the deadline is missed, the game can continue at a lower frame rate; depending on the game, this may only affect its graphics (while the gameplay continues at normal speed), or the gameplay itself may be slowed down (which was common on older third- and fourth-generation consoles

WCET(Worst Case Execution Time):
It must not be less than the real WCET (otherwise the
deadline will be execced sometime).
2 It should be as near as possible to the real WCET (otherwise
computing power will be wasted −→ the system gets more
expansive)

Two methods:
Statical WCET Analysis: Calculating execution time
based on the computer program.
Dynamical WCET Analysis: Measurement of an
adequate number of execution runs on a certain
hardware

 

Reference: https://www.geeksforgeeks.org/real-time-systems/
https://en.wikipedia.org/wiki/Real-time_computing

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