Discussion Assignment Unit 4 PDF

Preview

Summary

In unit 4, we are introduced to the concepts of abstraction and scheduling
For your Discussion Forum Post:
Using one of the referenced website articles or an article of your choice,
To discuss single-queue versus multi-queue scheduling.

...

Description

Discussion Assignment Unit 4

In unit 4, we are introduced to the concepts of abstraction and scheduling For your Discussion Forum Post: Using one of the referenced website articles or an article of your choice, To discuss single-queue versus multi-queue scheduling. After you respond to the assignment, you are then required to both give a rating and also leave a 250-word significant comment, to at least three (3) of your peers' responses, in order to receive full credit. Rate only the substantial responses that contribute to the promotion of the discussion, and not the comments of your peers. Please use your coursebook as your main source - it helps when you begin taking the upcoming graded quizzes and final exam. *PLEASE, read the documents I posted in the Course Forum. **Make sure you understand "MLFQ", some of you may see it AGAIN. *** What is log2 ?, you will need to know this later in the course **** learn how to convert Hexadecimal to Binary

Additional References Arpaci-Dusseau, R. H., & Arpaci-Dusseau, A. C. (2018). Operating Systems: Three Easy Pieces, Chapters 10.4-10.5. Madison, WI: Arpaci-Dusseau Books. Retrieved from http://pages.cs.wisc.edu/~remzi/OSTEP/ Ellingwood, J. (2014). CIDR Notation. Understanding IP Addresses, Subnets, and CIDR Notation for Networking. DigitalOcean. Retrieved from https://www.digitalocean.com/community/tutorials/understanding-ip-addresses-subnets-and-cidrnotation-for-networking GeeksforGeeks. (n.d.). Multilevel feedback queue scheduling (MLFQ) CPU scheduling. A computer science portal for geeks. Retrieved from https://www.geeksforgeeks.org/multilevel-feedback-queue-scheduling-mlfq-cpu-scheduling/ (n. d.). Parallel Programming Concepts and High-Performance Computing: Synchronization Overhead. Cornell Virtual Workshop. Retrieved from https://cvw.cac.cornell.edu/Parallel/synch

Answer: Discuss single-queue versus multi-queue scheduling. According to Arpaci-Dusseau, R. H., & Arpaci-Dusseau, A. C. (2018) we can understand that SQMS is the short form for single queue multiprocessor scheduling. SQMS characterized by its simplicity and is not in need of much work to hold a present policy to choose which is best to run next and to modify it if there are two CPUs. Although of those advantages, on the other hand, SQMS has obvious disadvantages. One of those disadvantages is the lack of scalability. This is can be obvious and we can see this issue when the developers lock the code to make sure that the "scheduler works correctly on multiple CPUs" Also, developers insert those lucks to ensure the proper outcome arises when "SQMS code accesses the single queue" The issue and the major problem about luck, they reduce performance especially when "the number of CPUs in the systems grows". Cache affinity is the second major issue with SQMS. This issue is explained by an illustration example in the textbook by assuming if we have five jobs to run and we have 4 processors, how scheduling queue will look like. MQMS is the short form for multi-queue multiprocessor scheduling. This processor comes as a solution to the issues caused in single-queue schedulers. The scheduling framework of the MQMS contains multiple scheduling queues. Each queue follows a specific scheduling discipline that can be any algorithm can be used. As soon as a job comes to the system, it will be located in one scheduling queue that can be "random or pick one with fewer jobs than others". The schedule for each queue will be independent to avoid the issues found in the single-queue such as synchronization and information sharing. The basic issue with MQMS is load imbalance. This issue appears when some jobs get more CPU than others. To overcome load imbalance is by using a technique called migration. The usage of single-queue and multi-queue scheduling in real-life. According to JRNIA (2020), single-queue is used in business to provide distinct benefits among customers where the first to arrive will be the first served. This is will create an appreciation among customers and they will feel that they deal fairly. A multi-queue is used in business to improve customer services where it will help customers to "straightforward access to the services they need". Also, it will estimate a waiting time for customers. Regarding a business staff, a multi-queue will help them determine the kind of services customers need. According to JRNIA (2020), To set up a single queue system, the system should include the following features The system has to include check-in options to allow the customers to join the queue, a Centralized dashboard to check the state of the queue and monitor queue length to estimate a wait time, Estimated wait times to provide accurate wait times, Data analysis to analyze the services According to JRNIA (2020), To set up a multiple queue system, the system should include all the previous features with some more additional options such as the ability to configure multiple queues and capacity to match customers with qualified staff. References

Arpaci-Dusseau, R. H., & Arpaci-Dusseau, A. C. (2018). Operating Systems: Three Easy Pieces, Chapters 10.4-10.5. Madison, WI: Arpaci-Dusseau Books. Retrieved from http://pages.cs.wisc.edu/~remzi/OSTEP/ Single vs. multiple queues: Which is right for you? JRNI. https://www.jrni.com/blog/single-queuesvs-multiple-queues....