1. Parts of the Guitar

• Body: the main part of the guitar
• Soundboard: the top piece of wood on the body
• Soundhole: the round part on the middle of the body
• Rosette: the decorated part along the edge of the soundhole.
• Bridge: the wood used to connect the strings to the soundboard
• Saddle: means a small piece of hard material like a piece of bone that supports the strings on the bridge
• Strings: means the vibrating elements that produce sound
• Neck: the board where we put our left-hand fingers
• Fretboard: on top of the neck, traditionally made by rosewood or maple
• …

1. Basic Installation

First, we have to install VirtualBox and Vagrant.

• Download and install the latest version of VirtualBox here.
• Download and install the latest version of vagrant here.
• Windows: Download and install git here.

Ubuntu users may want to use the following commands to install Virtualbox and Vagrant,

$ sudo apt-get install virtualbox
$ sudo apt-get install vagrant

2. Setup the Environment

First, let’s make a new folder named cs6265-tut,

$ cd ~
$ mkdir cs6265-tut
$ cd cs6265-tut

Then let’s download the environment configuration files from the internet by wget,

$ wget https://tc.gts3.org/cs6265/tut/tut.tar.gz

After we download this file, we…

1. OS Scheduling

(1) Linux O(1) Scheduler

0 being the highest (ts = 100 ms) and 139 (ts = 10 ms) is the lowest. The default level is 120. The pointer of the two arrays should be swapped.

• O(1) Vs. CFS: CFS is better for interactive operations.

(2) Fedorova’s Paper

Conclusion: workloads of mixed CPI result in better performance

Problem: real workload CPIs have little difference

Example 1-1. Round-Robin Scheduler

On a single CPU system, consider the following workload and conditions:

• 10 I/O-bound tasks and 1 CPU-bound task
• I/O-bound tasks issue an I/O operation once every 1 ms of CPU computing
• …

1. OS Scheduling

(1) Metrics for OS Scheduling

• throughput: task per second
• the average time it took for tasks to complete
• the average time that tasks spent waiting before they were scheduled
• the overall CPU utilization

1. Cache

(1) Locality

• Temporal Locality: If an address has been accessed recently, it will likely be accessed again
• Spatial Locality: If an address has been accessed, it is likely that addresses close to it will be accessed

(2) AMAT

1. Introduction to Data Centers

(1) Internet Services

Internet service is any type of service that’s accessible via the web interface. The common way in which these services are used is end-users send web requests via web browsers and then receive a response. Most commonly, these types of services are then composed into three components,

• a presentations component (static content) that interfaces with the end-users
• a business logic component (dynamic and user-specific content)
• a database tier component responsible for all the data storage and management

(2) Technology Solutions

Actually, for implementing these three components, there are many open-source and proprietary solutions…

1. Introduction to Distributed Shared Memory (DSM)

(1) Recall: the DFS States, Nodes, and Services

In the previous lesson, we talked about DFS, and we said that the DFS was an example of the distributed file service where the states (aka. files) were stored on some nodes (aka. file servers), and these nodes were accessed by many distribute nodes’ clients. All the file access operations open, read, and write on these files where then the service was provided by these servers, and the clients will then request from them.

Our primary focus of the DFS was the caching mechanisms. These are…

1. Introduction to Distributed File System (DFS)

(1) Review: File Systems

In our previous discussion about file systems, we have said that the modern OS (e.g. Linux) hides the fact that there may be multiple types of internal file system organizations. And this is done by exporting a higher-level virtual file system (VFS) interface.