Finishing Initial Comparisons and LibreFoodPantry Retreat

Last Wednesday night I finished my comparisons between GitLab Gold and GitHub Free. I’m happy that I managed to get through all of the features before the LibreFoodPantry retreat the following day. I found that most of the features left for GitLab Gold did not have comparable versions in GitHub. This is more of what I was originally expecting and so the remainder of the table has a lot of features marked GitLab Gold exclusives. There was also a trend with the GitLab features that most of them would relate to one overall feature such as having Epics so since GitHub doesn’t have a native Epics feature it wouldn’t have any advanced features related to managing and tracking Epics like GitLab does. I also found that some of these features were harder to compare between platforms since most of them were more advanced, enterprise grade features than the earlier ones. This is again also due to how well the documentation for both platforms explains the features and how to use them.

Thursday was the beginning of the LibreFoodPantry Retreat. We started off by going to lunch and having casual conversations before the meetings began. I enjoyed this as I got to know everyone a little bit before getting down to business. Once we got back from lunch, all of the members who taught a course last semester developing software for LibreFoodPantry had a retrospective detailing the good and the bad and developing ideas and solutions to the issues. I found this process interesting to observe, especially after learning about software management processes this spring and now I got to see it in action with a real project. My advisor and I briefly described our summer research project and how it relates to what was currently happening with LibreFoodPantry. Through the first day I began to learn about issues that the group was encountering and areas where I can focus my research. Some items I will need to look for is assigning issues to multiple people or groups.

Friday continued with the second day of the LibreFoodPantry Retreat. I came in after lunch and immediately saw a whole whiteboard along one wall covered in sticky notes with labels. I soon found out that this was all of the user story mapping that was worked on while I wasn’t there. Dr. Jackson went through the whole story mapping briefly with me, explaining the user groups and the features and how they all fit together. It was eventually decided that this story map should be stored in the LibreFoodPantry organization/group on whichever platform we end up using and I should try to create a small version of this board on each platform. We then moved on to discussing infrastructure and workflow. Additional things I will be looking at now will be setting up continuous integration in GitLab and see how this works. I will also be fixing my platform features table so that features have consistent naming with their respective platform and that they are directly comparable across rows. Overall, I really enjoyed going to the LibreFoodPantry Retreat and seeing the processes and discussions involved in creating an open source software project.

From the blog CS@Worcester – Chris' Computer Science Blog by cradkowski and used with permission of the author. All other rights reserved by the author.

Continuing Platform Comparisons

Last week I continued researching the features of the GitLab Gold and GitHub Free platforms. I continued going down the list of the features listed for GitLab Gold on its feature comparison page and then seeing if GitHub Free had similar implementations of these features. I originally thought that most of the GitLab Gold features would be exclusive to this platform, but to my surprise GitHub Free supports quite a few of GitLab Gold’s advanced features. I found that GitLab Gold does have some features that GitHub Free doesn’t though, some of these are either advanced features geared more towards enterprise environments, others seem to fall under more advanced user permissions such as selecting which users can approve merge requests. I found that GitLab Gold’s issue board system is much better than GitHub’s project boards with the ability to create more advanced boards than GitHub, such as a board with user assignee lists or a milestone list. I am again finding that certain features between the GitHub and GitLab platforms are easily comparable and have a direct counterpart such as requiring commits to be signed and other features are a bit more ambiguous such as supporting what GitLab calls “backlog management”. I am finding this is largely due to how clearly GitHub’s and GitLab’s websites document and explain the features the platforms offer. Another thing that I am finding that makes this comparison process harder is that the description for the feature on GitLab Gold’s product comparison page doesn’t always match exactly with the features described in the documentation it links to, or sometimes the links provided from the feature comparison page don’t go to a specific section of the online document. I have also begun to use the test groups to see for myself what features are available in these platforms. I have been mainly using the GitHub organization to compare its project board features to GitLab Gold’s issue board features as I find it is easier to actually see what’s available in GitHub than to use its website guides. I have also started to take note of what I think should be tested in the workflows between GitHub and GitLab, this includes the project/issue boards and some of the more advanced options GitLab Gold offers, along with other user permission settings GitLab has such as push rules.  I am hoping that at the meeting later this week we will refine the workflow so I can begin testing these features. I plan to finish the comparisons between GitHub Free and GitLab Gold before the meeting at the end of this week so that I have a good idea of all the advertised features of all of the platforms.

In addition to continuing research on the platforms, I also began to learn more about the LibreFoodPantry project. I did this by going through all of the past meeting minutes that were sent to me. I wanted to get a better idea and background on the project to see what decisions have been made so far and how my research into version control software fits in to this. I also wanted to this before the meeting later this week, so I could get a better idea of my purpose in these meetings.

From the blog CS@Worcester – Chris' Computer Science Blog by cradkowski and used with permission of the author. All other rights reserved by the author.

Beginning My Summer Research Project

This summer I will be conducting research under the Aisiku Undergraduate Research Fellowship which is awarded to STEM projects for students at Worcester State University. The goal of this project is to research and select the best version control software to use for the LibreFoodPantry projects which fall under the category of Humanitarian Free and Open Source Software. I will be looking at the GitHub Free, GitLab Free, and GitLab Gold packages and selecting which one out of these three is the most suitable for contributing to and maintaining the LibreFoodPantry projects. I will be writing weekly blog posts to keep track of what I learned and did during the week while working on this project throughout the summer.

 

This week I began the project by looking at the features of GitHub Free, GitLab Free, and GitLab Gold. I created a table in a document with a column for each one of these and started listing out the features that are provided in the product comparisons page for GitHub and GitLab. Once I listed out all the provided features for all three of these I started to do a comparison between the features listed for the GitHub and GitLab plans. The comparison for GitLab Free and GitLab Gold is easier since GitLab Gold has the same base options as GitLab Free in addition to other advanced features which are listed in the plan comparison page. I then started going through all the features listed in GitHub Free’s plan page and seeing if the GitLab versions had them and if they were similar features. I kept track of differences by highlighting the text of the features in the table with different colors. I ended up finding that most of the GitHub features were comparable to GitLab such as having code owners or project boards. I found out that GitHub has a couple of features that both versions of GitLab we are looking at doesn’t such as an apps marketplace. GitHub also has a couple of features it does better than GitLab such as offering repository insights. There were also a couple of features that GitLab does do better such as having built-in continuous integration and continuous delivery. Overall I found that I started to prefer the GitLab platform by the end of the first week and their website offers better and more thorough documentation for its features than GitHub’s does. At the end of the week I had a meeting with my faculty advisor for the project to go over my progress and findings so far. In the beginning of the meeting we both came to the conclusion that the research being done for this project is applicable outside of the scope of just the LibreFoodPantry projects and can be used for other open source projects. We decided that I would continue looking at the features between the platforms during the second week. My advisor also created testing groups on each of the platforms and added me as an administrator so that we can start testing workflows after I finish comparing features. We also discussed the details about an upcoming meeting for LibreFoodPantry (which should help refine the workflows we will be examining in this project) and my involvement in this.

 

From the blog CS@Worcester – Chris' Computer Science Blog by cradkowski and used with permission of the author. All other rights reserved by the author.

Data Structures Primer

I’ve been a tutor for this past semester to students taking Introduction to Programming. Many who have come to my session are moving on to Data Structures next semester. They asked if they could have a primer as to what to expect.

I have some resources that I have found helpful both while taking the course and tutoring it in the past. It will take me a little bit to compile a good list of those, but for now, here is a bare-bones list of topics of topics you might expect to see for a data structures course:

Part 1:
– Running time of code segments (Big-O Notation)
– Abstract Data Type (ADT)
– Interfaces (when to use “implements”, cannot instantiate them, what inheritance is)
– Superclass, subclass, method overriding/overloading
– Abstract classes

Part 2:
– Binary Search Trees
– Stacks (and its four methods — push, pop, peek, empty)
– Linked list (single, double, circular)
– Prefix and postfix notation (compare to infix)

Part 3:
– Min/Max Heap
– Hash Tables – Open and closed hashing. How to insert into a hash table given a probe sequence.
– Binary Trees (AVL and Red/BLack)
– AVL Trees – how to construct one, worst case AVL-tree
– Red Black Trees
– B-Trees, especially deletion from one
– Know recursive code and how to trace it

Bear in mind, this is an incomplete list. The topics may be presented in different order as well. The “parts” are how I remember it and might not be accurate.

I’m not sure if I’ll be able to compile a complete list of resources, but here is probably the best one for visualizing data structures: https://www.cs.usfca.edu/~galles/visualization/Algorithms.html

Another one is CodingBat.com/java. This is especially helpful for learning recursive code. I don’t know if any of the other sections would be helpful, but they might be.

Best of luck! It will be tough, but you got it! Even if you know one or two topics from each part, you will have a leg up on learning this material.

From the blog Sam Bryan by and used with permission of the author. All other rights reserved by the author.

Sprint 6 Retrospective

During this last sprint I spent my time working on two things, that of continuing to try to get the styles to work for the buttons on our program and our teams final presentation. In continuing with the styles of the buttons from the bottom navigation bar, I finally tried to create and apply a palette. Ignite UI uses a thing called palettes which is a built in feature that takes two colors as primary and secondary, as well as a few other built in color groups, to create a large “palette” of colors that you can reference. To do this you create an SCSS file, short for Sassy CSS, which is a super set of CSS allowing the programmer to create variables, nested rules, functions, etc.. When you create this SCSS file, you have to import the Ignite UI style index, as well as provide the primary and secondary colors. From here you can define a custom gray scale palette, or take the one automatically created which has a default color of black. Finally once the palettes have been set, this is where the SCSS comes in, by allowing you to create color variables which can be used over and over. To create these variables Ignite UI provides a function for creating these colors, with 3 inputs; palette, color, and variant. The palette is one that you have created, the color is one of the 8 available through Ignite UI, and then finally a number for the variant with the default being 500, lighter shades being 50-400, and darker shades from 600-900. An example of one of these color variables would be “$my-primary-600: igx-color($my-palette, ‘primary’, 600);” I did all of this trying to hopefully change the styles of the individual button elements of the bottom navigation bar, but instead it would apply to most or all of the document. Although I did not get what I had wanted working, I feel that I did learn a lot of the way that this Ignite UI worked during this sprint, having spent many hours trying several different possible solutions. I feel with more time I would have been able to figure out this problem but my team also had to start planning and creating our final presentation for the class. For this my portion of the presentation was to be on the Ignite UI as well as some of the style stuff involving SCSS. To help me with this I spent a long time reviewing the Ignite UI website which was very expansive and almost like a Wiki. On thing that was very helpful with there website was the inclusion of examples using Stack Blitz, which gave examples of how the code would be run, and which could also be changed. This sort of program example helped a lot in trying to understand how a certain element they have in the Ignite UI worked when compiled into code, and I would highly recommend a version of it being used in future classes.

From the blog CS@Worcester – James' Blog by jdenesha and used with permission of the author. All other rights reserved by the author.

Read Constantly

An algorithm is a set of rules to be followed in order to solve mathematical problems in numerous steps that usually involve repetition of an operation. Sometimes algorithm problems do not show up at the beginning of a project. As Steven S. Skiena states, different programmers find them out as subproblems, which appear to be … Continue reading Read Constantly

From the blog cs-wsu – Kristi Pina's Blog by kpina23 and used with permission of the author. All other rights reserved by the author.

Dig Deeper

We live in a world where different complex software projects have different deadlines and they use a variety of tools to finish the projects. Most of the time employers cannot afford to hire too many specialists to fill every role. You learn only enough about any tool to get today’s job done. You select some … Continue reading Dig Deeper

From the blog cs-wsu – Kristi Pina's Blog by kpina23 and used with permission of the author. All other rights reserved by the author.

Journey into “Craft Over Art” (An Individual Apprenticeship Pattern)

On this Software Development Capstone journey part of my assignment is to choose 10 Individual Apprenticeship Patterns out of 35 patterns among Chapters 2-6 from the book Apprenticeship Patterns: Guidance for the Aspiring Software Craftsmanby Dave Hoover and Adewale Oshineye. For my tenth and final individual Apprenticeship pattern I decided to blog about “Craft Over Art” pattern.

Summary

The pattern “Craft over Art” is the idea of choosing the craft of programming and making thing functional. Rather than choosing art of programming and making the program look beautiful but not so functional for the customer. Even though you may find an opportunity taking your customer problem and making something nice that will impress your coworkers, it is best that you put the customer needs before your own selfish wants or needs. When it comes to dealing with customer your goal should always be choosing creating a functional valuable product, rather than something else that only advance your own self interest. When dealing with customers it is more important to choose the craft of software development rather than feeding that desire to creating something beautiful, yet not truly functional or deliverable in the real world. This pattern is not telling you that things can’t be beautiful it more saying that whatever you build for your customer must be functional and useful, therefore you must be willing to sacrifice beauty over utility. “The more useful a piece of software, the more important it is that the software be high quality. But quality takes time. You will have to work toward a suitable level of quality by repeatedly making trade-offs between beauty and utility.”

My Reaction

This pattern helps you understand the impotence of building “Craft over Art” because it reminds you that creating something useless yet beautiful is not craftsmanship. I agree with this idea because crating a useful software program far more important than a beautiful non-functional one. I found this pattern to be interesting but also useful and thought-provoking. This pattern has definitely changed the way I think about my profession and the way I think, the reason being is that I should always be willing to sacrifice beauty before sacrificing usefulness.

Thank you for your time. This has been YessyMer in the World Of Computer Science, until next time.

From the blog cs@Worcester – YessyMer In the world of Computer Science by yesmercedes and used with permission of the author. All other rights reserved by the author.

Draw Your Own Map

According to my next Apprenticeship Pattern blog I chose “Draw Your Own Map,” as one of the most interesting patterns and which fits perfectly in my logic. When you decide to enter the Software Development world, you may think that it’s a hard and tough game, or sometimes you believe that your career will always … Continue reading Draw Your Own Map

From the blog cs-wsu – Kristi Pina's Blog by kpina23 and used with permission of the author. All other rights reserved by the author.

MINIX3: Wrapping Up

I haven’t written a blog post for MINIX3 in some time (sorry Professor), and I figured that it would probably be wise to wrap up what I managed to complete this semester after I managed to get past all the stress I was feeling.

About halfway through the semester I started meeting weekly with my professor in order to discuss ways to approach my project. He knew I was pretty darn stressed about it, but was also pleased with how much I had learned about MINIX3 and Operating Systems in general. When we started meeting, I hadn’t done any actual programming in the scheduler, and I was still fuzzy on how the whole scheduler worked as one unit. I had also not realized this at the time, but the scheduling algorithm in the official MINIX3 Book was an older version. It doesn’t reflect the design found in this report, which describes the current scheduling algorithm (found in versions 3.3.0 and newer, I believe). This was adding to the confusion in how to approach the system, because I was getting my information on the implementation of the scheduler from both sources.

I’ve talked about this a bit in my previous blogs, but I figured I’d recap in this one now that I have a better understanding of the system. In the official MINIX3 book, the scheduler is still built into the Kernel. This meant that any scheduling changes that were to be implemented involved editing kernel code, which could end up being pretty complex in the event of errors, etc. What the scheduling report outlines is the move of the scheduler into the user mode level of MINIX’s layered design system. There still is a small default scheduler that had to be implemented, but the main scheduling policy is implemented within the user mode scheduler.

Let’s talk scheduling policies. Both the kernel-level and the user-level schedulers implement a Round Robin scheduling algorithm by default. As outlined in the report, the easiest policies to implement with the user mode scheduler are round robin, priority, staircase, and some other queue-based policies. Whilst I was googling information about implementing priority-based algorithms, I found this wonderful project done by a GitHub user named Akshita Mittel. It includes a few test files and the changes necessary to make to some of MINIX3’s files in order to implement different algorithms. It is very similar to the project I had intended on doing, so whilst I did not copy it directly (licensing and copyright issues and whatnot), I did use it as a resource for implementing my own project.

Since I wanted to deviate my project slightly from the resources I found online, instead of just implementing more than one scheduling policy, I elected to compare the default scheduling policy with a priority scheduling algorithm, and vary the number of queues by +- 25%. This left me with 3 variations of the default Round Robin policy — one with 12 queues, one with the standard 16 queues, and one with 20 queues. It also left me with 3 variants of a scheduler using a priority algorithm, again with 12, 16, and 20 queues. My goal was to run the same test across each of these 6 variations and see if there was some notable runtime difference.

Before I go into the test, I figured I’d explain the difference between Round Robin and Priority style scheduling. Round Robin policies assign each process within the priority queues a time slice, called quantum. As processes run out of quantum, they’re moved to a higher (the higher the number, the lower the priority) priority queue. In MINIX3, after a certain number of ticks, the queues are rebalanced. This means that all processes who have had their priority changed get that priority reset. The difference between round robin and priority scheduling algorithms is fairly simple — round robin policies aim to be fair, which is why they implement queue feedback. Priority policies are designed without fairness in mind. You might want some processes to always have the highest priority. Therefore, it simply disables process feedback from happening. Processes don’t move around between queues. A diagram of the structure of the priority queues are shown below.

Based on an image from Operating Systems: Design and Implementation by Andrew S. Tanenbaum

The test I used was based on Akshita’s that I found on GitHub. The test program would log system time, do some work with a process, then log the system time again, and find the difference between the start and end times. I found the average running time for 100 tests for each of the variations. The results are displayed below.

As you can see, there wasn’t much consistency across the tests. I’m sure that, before I even ran the tests, I could have reasonably come to the conclusion that there wouldn’t have been much of a difference in run times given my particular approach. The test I ran was mostly CPU bound as opposed to I/O bound, which very well could have made a difference. I think CPU bound tests could have made a bigger impact if I had implemented a different policy than priority. On top of designing a better test for what I was doing in particular, I think that theoretically the number of queues within a round robin scheduler wouldn’t make much of a difference unless the processes existed within them for a very long period of time. Also, I think that the number of queues within a priority scheduler wouldn’t make a significant difference either, since processes tend to live where are they spawned. Aside from the crowding of the queues, I don’t see it having a large impact on the overall runtime. Therefore, I think that the results I got make sense.

I’m not upset that my small “research project” didn’t yield great results. The point of this independent study was for me to better understand operating systems, as I felt as though I was seriously lacking in that area. While I know there’s still a tremendous amount of knowledge to be gained in OS’s, I’m happy with the work I did this semester and feel far more confident when discussing OS concepts in general. It was a very stressful project at first, but now that I’ve wrapped it up, I think it was absolutely worth it. Hands-on operating system practice is a great way to go about learning the subject. In fact, this independent study has sparked quite a bit of interest in systems programming for me, and I’m looking forward to continue learning about it in the future!

(Side-note, this is my last school-related blogpost. At first, I felt extremely uncomfortable writing these things. Now, I think it’s something I’d like to do once a week, or at least regularly. I appreciate my professor requiring us to start these blogs — writing is something I never really saw myself doing enjoying, and after doing it for a couple of semesters now, I get it. Who would’ve guessed that recording what you learn is both both enjoyable and rewarding. Thanks, Professor Wurst!)

From the blog CS@Worcester – James Blash by jwblash and used with permission of the author. All other rights reserved by the author.