part one:

You work for a software consulting service provider and have been assigned to the account of a client who was previously serviced by Bob, a colleague who has recently left your organization. Bob supplied your client with a series of bash scripts that are meant to execute concurrently. However, your client has reached out to you because they have noticed some inconsistencies with the performance of the bash scripts and would like you to troubleshoot the issue and provide a better solution. The client's original request was for a one-line command that would execute several processes concurrently. Bob's solution was to create a text file with a list of commands that the client is free to edit. This list of commands is passed through a pipe to the xargs command, which executes each command in the list. See below for Bob's one-liner and an example of

commands.txt: cat commands.txt | xargs -I CMD bash -c CMD

echo command 1

ls

echo command 2

ls

echo command 3

ls

The client states they have been using this one-liner and command list for some time to automate some routine tasks that are performed overnight. However, they have just recently started dabbling in web development and one of their employees tried to use this to host some basic web pages on different ports. Apparently, when they use this script to start hosting the web pages, only one web page appears to be active. Is this script actually performing concurrency?

Specification:

Performs true concurrency with multiple processes or threads

Allows all three (or more) of the client's web pages to be accessible at once (product of concurrency)

Allows any 100 arbitrary, unique processes to be executed concurrently (for example, you may use 1 echo command, 1 ls command, etc.) with output appended to a single text file.

Write a report describing the following:

The function of Bob's one-liner as seen above. Walk through the behavior and describe what is happening.

Any modifications to existing commands or other changes to the one-liner or scripts necessary to facilitate concurrency.

A thorough explanation of the state of concurrency before and after you made any modifications.

You must show evidence of concurrent execution of processes.

An examination of the behavior of the provided shell scripts that host web pages. How do they work? Did you need to make any changes? Why or why not?

How the multiple writes to a single file were accomplished without causing a deadlock. Support your conclusions with any evidence your system can provide.

part two:

If you modify start_server_1.sh, start_server_2.sh, and start_server3.sh to each run off of the same port number, you will find that a different page loads in your browser each time you refresh, apparently in a certain order. Your client is interested in knowing if you can provide a bash script by which the order of these pages can be controlled upon script execution (for example, the ability to pre-select the execution of my_website_1, my_website_3, and my_website_2 in a browser). These must remain concurrent processes, and all other previous requirements apply.

Note: To complete this assignment, you will need the following files:

commands (txt)

start_server_1 (sh)

start_server_2 (sh)

start_server3 (sh)

my_website_1 (sh)

my_website_2 (sh)

my_website_3 (sh)