Is Disney's FastPass Valid and/or Useful Queue Theory

At Disney World, they use a system called Fastpass to create a second, shorter line for popular rides. The idea is that you can wait in the standard line, often with a wait longer than an hour,...

Use cases of the Workflow Engine

I'd like to know about specific problems you - the SO reader - have solved using Workflow Engines and what libraries/frameworks you used if you didn't roll your own. I'd also like to know when a...

ConcurrentLinkedQueue$Node remains in heap after remove()

I have a multithreaded app writing and reading a ConcurrentLinkedQueue, which is conceptually used to back entries in a list/table. I originally used a ConcurrentHashMap for this, which worked...

How do I establish clock synchronization in the cloud (AWS, heroku, etc) across many nodes?

I would like to run a large cluster of nodes in the cloud (AWS, Heroku, or maybe self-manged VMS), whose clocks must be synchronized with a predefined tolerance in mind. I'm looking for a...

Multiple websocket connections

Is there any advantages of having two distinct websocket connections to the same server from the same client? To me this seems a bad design choice, but is there any reason why/where it should work...

Creating a heap in C with arbitrary node types. How to free it?

Asking for a sanity check on this design choice. I'm writing a heap sort in C by creating a heap data structure that can accept node types of string or numerical. (I'm creating my own private heap...

How much does using htaccess files slow down website performance (especially with solid state disks)?

The Apache docs say (http://httpd.apache.org/docs/2.4/howto/htaccess.html), "You should avoid using .htaccess files completely if you have access to httpd main server config file. Using .htaccess...

Rationale for pre-C99 C not having initial declarations in for loops?

Why did the original C language not support initial declarations in for loop initializations? Obviously the original creators, and then the pre-C99 standardizations, didn't specify it that way....

Extending Layout .xml files not working in child theme in different <vendor> as to parent theme: Magento 2.0.4

Steps to reproduce Installed Magento 2.0.4 on WAMP server 3.0 , Windows 10 Pro - 32bit, PHP 5.6.15, MySQL 5.7.9 Created a child theme themeparent of Magento_blank in...

Update k8s ConfigMap or Secret without deleting the existing one

I've been using K8S ConfigMap and Secret to manage our properties. My design is pretty simple, that keeps properties files in a git repo and use build server such as Thoughtworks GO to...

Handling very large data with mysql

Sorry for the long post! I have a database containing ~30 tables (InnoDB engine). Only two of these tables, namely, "transaction" and "shift" are quite large (the first one have 1.5 million rows...

Try-Catch vs If performance in C#

I'm trying to both learn more about the implications of various design choices, and find the most performant solution for preventing errors in my code. Before diving in, allow me to briefly and...

Attempting to resolve blurred tkinter text + scaling on Windows 10 high DPI displays, but concerned my approach is not Pythonic or is unsafe

After hours of tweaking I have settled on this code which allows me to get round the familiar problem of blurry / fuzzy text in Windows 10 on high DPI displays when using Tkinter interfaces in...

Swift- Change font on an HTML string that has its own Styles

I am dinamically getting an HTML string from a Wordpress API and parsing it into an Attributed String to show it in my app. Since the string has its own styles, it shows different fonts and sizes,...

Spring Boot: run liquibase migrations without starting app

In Spring Boot, the documentation seems to encourage running migrations on app startup. This is fine, but sometimes app startup may have side effects / dependencies that I don't want to bother...

Information-hiding in Groovy (using closures? naming conventions?)

This follows from my unsuccessful attempt to find an answer to this question from 2014. It's not clear to me whether there might in fact be some techniques in Groovy to use closures, specifically,...

Hide Title Bar In Xamarin.Android

I just started out with Xamarin. Spent literally a day fixing stupid debugging issues even in VS 2019. Anyways, i guess all the Xamarin devs reading this post already knows how much of a pain in...

How do I give my MacOS app permission to create "WAL" file to open an SQLite DB with journal-mode=WAL?

I'm an experienced programmer, but this is my first MacOS app (on 10.15.2), which needs to read an sqlite db of the user's choice (potentially anywhere on the machine) At first it wouldn't open...

Load balancer and API Gateway confusion

I have always worked on mobile technologies and now I am stepping into backend systems, more specifically systems design. I keep coming across conflicting statements for the roles of api gateway...

Blazor Server: How to reliably handle the delay of user actions?

Comparing Blazor Server with Blazor WebAssembly, I find one striking difference that might/should have a great impact on the application design. Let me outline that difference on the basis of a...

Can a Telegram bot run a poll with multiple questions?

I am part of a social science research team where we run field surveys using very limited resources (i.e. we don't have the resources to design our own apps). In many cases our surveys take place...

Is XQuery 3.1 designed for advanced JSON editing?

XQuery 3.1 introduced several JSON functions. I was wondering if these functions were designed with advanced JSON editing in mind. As far as I can tell, these functions only work for simple JSONs,...

Kivy apk built by buildozer crashes soon after displaying presplash screen

I am new to Kivy and using buildozer. However, I've followed the instructions from buildozer.readthedocs and run "buildozer -v android debug deploy run logcat > my_log.txt" as best as I can, yet,...

Why is std::priority_queue sorting its container's elements?

I noticed that std::priority_queue stores the elements in sorted manner. Obviously storing elements in sorted manner would be a bad design choice as time complexity of push and pop would shoot up...

Zoho Deluge : What criteria to consider for deciding which data structure to use map, list or collection?

Is there any practical benefits/reasons to use a collection instead of a map or collection instead of a list? In reading through the Zoho Creator Deluge documentation there doesn’t look to be...

Axios/Nuxt "Certificate has expired" only when directly opening page, but not for a link from another page

I have a website I am helping to maintain (but did not build myself), using Nuxt.js and Axios. It is currently showing an odd server behavior on the Home page. If I directly visit the home page...

Parameterized Types in Haskell

Why do types in Haskell have to be explicitly parameterized in the type constructor parameter? For example: data Maybe a = Nothing | Just a Here a has to be specified with the type. Why can't...

Django: how store multiple data types to the same model field

I want to create a database model somewhat similar to the example below: The idea is that User (or any model) can have multiple different features (or whatever) with different values. Feature can...

Sharing the same style/look/design/ux between React, React Native and Angular

We have 3 sets of products that area each built on a different technology: React, React Native and Angular. The group built on React is using a shared component library with documentation written...

How to register for 32-Bit COM interop using Visual Studio 2022

I am having difficulty registering a C# component for COM interop using Visual Studio 2022. I thought I understood the problem, but even so, I have failed to get it working. This is the basic...