Web

Use these sites to test whether a service is up from other locations:

• https://testlocal.ly
• https://www.locasnap.com
• https://www.uptrends.com/tools/uptime
• https://www.site24x7.com/check-website-availability.html

And use these sites to ping/mtr from other locations (keeping in mind, of course, that some hosts block ping/mtr replies even when working normally):

• https://dnstools.ws
• https://ping.pe
• https://perfops.net/mtr-from-world

Just to show how wide-ranging the DNS ecosystem is, some DNS RFC Collections:

• ttkzw's DNS RFCs - pictographs of a DNS RFC timeline and relationships
• DNS Camel Viewer - a list of 297 RFCs relevant to DNS which can be filtered in various ways - use the 'BEST_CURRENT_PRACTICE' selection with 'INTERNET STANDARD' to see Domain Names, IPv6, DNSSEC, DKIM, and EDNS. Camel is O'Reilly's animal on their DNS handbooks.
• DNS RFCs - a curated list of DNS RFC's, as a subset of a much larger collection of Internet Technical Documents

Online Self-Evolving Anomaly Detection in Cloud Computing Environments

Modern cloud computing systems contain hundreds to thousands of computing and storage servers. Such a scale, combined with ever-growing system complexity, is causing a key challenge to failure and resource management for dependable cloud computing. Autonomic failure detection is a crucial technique for understanding emergent, cloud-wide phenomena and self-managing cloud resources for system-level dependability assurance. To detect failures, we need to monitor the cloud execution and collect runtime performance data. These data are usually unlabeled, and thus a prior failure history is not always available in production clouds. In this paper, we present a \emph{self-evolving anomaly detection} (SEAD) framework for cloud dependability assurance. Our framework self-evolves by recursively exploring newly verified anomaly records and continuously updating the anomaly detector online. As a distinct advantage of our framework, cloud system administrators only need to check a small number of detected anomalies, and their decisions are leveraged to update the detector. Thus, the detector evolves following the upgrade of system hardware, update of the software stack, and change of user workloads. Moreover, we design two types of detectors, one for general anomaly detection and the other for type-specific anomaly detection. With the help of self-evolving techniques, our detectors can achieve 88.94\% in sensitivity and 94.60\% in specificity on average, which makes them suitable for real-world deployment.

I need to expand on this, but for reference, I found this on reddit - A good C++ (or C, honestly, so long as it works) HTTP server/library, and can be modified to suit:

httperf --hog --num-conns=1024 --num-calls=1 --rate=128 --server localhost --port 8080

Consider Nikto, a web server scanner which performs comprehensive tests against web servers for multiple items, including over 6700 potentially dangerous files/programs, checks for outdated versions of over 1250 servers, and version specific problems on over 270 servers. It also checks for server configuration items such as the presence of multiple index files, HTTP server options, and will attempt to identify installed web servers and software. Scan items and plugins are frequently updated and can be automatically updated.

Another tool for HTTP regression and debugging: siege which is a Debian package supplied by Joe Dog Software.

• Comparison of browser engines (CSS support) - from wikipedia

As a user with far too many FireFox open tabs, memory seems to disappear far too quickly. Knowing which of my many tabs contributes the most to the memory consumption would be helpful. But it seems as though Firefox doesn't make troubleshooting for that very easy. Here are a few tools which might help in narrowing my focus to determine granular memory consumption.

With recent versions of Firefox, there are some built-in tools which help to diagnose cpu and memory issues:

• about:performance - shows memory and cpu consumption
• about:memory?verbose - shows detailed memory consumption - not easily to digest
• about:cache?device=memory

Add-ons which provided in-tab memory consumption have been obsoleted. But one add-on which itemizes tabs: Tab Stats

Limiting the amount of RAM a program can use shows how on a Linux system to use cgroups to limit an application's memory footprint. The old 'ulimit' command is deprecated, and may not work.

Regarding the about:memory tool, more details can be found at Limit memory usage per Tab without blocking things? which points to about:memory and Memory.

Based upon How to Reduce Firefox Memory Usage using about:config it is possible to reduce memory caching with:

• 'about:config' in the address bar
• right click and create a 'new' -> 'integer'
• variable name is: browser.cache.memory.capacity (which is maximum RAM in KB) (further details at Browser.cache.memory.capacity) via About:config entries.

It seems that in the last day or so, Mozilla forgot to renew an intermediate certificate in their FireFox browser. The result is that the browser has mass-disabled add-ons.

One temporary solution someone mentioned (which may only work on a Dev version, and/or Linux version):

Simple temporary fix is to browse to "about:config" and change the value for "xpinstall.signatures.required" to false. Well, that worked for me, anyway. When Mozilla fixes whatever the issue is, I'll set it back to true.

The 'studies based' alternate solution:

You can turn on the Studies option under Privacy & Security for a little while, then check about:studies and you should see one or two in there regarding the xpi verification/signing. Once you have those two studies, you can disable Studies again.

Mozilla has an Update Regarding Add-ons in Firefox, but does not apply to Firefox ESR (my Debian Linux install) or FireFox for Android.

Another link about resolution: Certificate issue causing add-ons to be disabled or fail to install

There are a few web sites which have had quite a bit of work done to them to make available colour selections.

I think paletton is probably my favorite. They have a two part selector choosing a colour once choosing a variant of: a) monochromatic, b) adjacent 3 colour, c) triad 3 colour, d) tetrad 4 colour, or e) free style with 4 colour. Once chosen, you can emit the colour selection as html, css, sas, text, or a couple of other styles.

Next up is the Adobe Color CC. It has variants of analogous, monochromatic, triad, complementary, compound, shades, and custom.

A few other choosers:

• Colors on the Web Color Wizard
• HTML Color Picker from w3schools
• Color Emotion Guide using a chart of existing logos
• csscolors.io - added here 2019/0/3/06, I think similar to others, just different presentation
• Colour Hunt linked from Hacker News

There are many many web frameworks out there. The newer ones seem to be very JavaScript/FrontEnd oriented, and then one has to jump through hoops to get the data to the server and back again.

I have been starting to compare web frameworks against what I would call a gold standard (yes, I am biased). That standard would be wt, a C++ Web Toolkit. It can do modularised back end, it deals with smart as well as dumb browsers, it knows how to get data back and forth from the browser and server, and it can get javascript to the browser when needed.

I came across a Go based solution Ponzu, but comments say it is a bit immature, but is making quick inroads.

For less inclusive solutions, React seems to be taking off. It is a "Javascript library for building user interfaces". For the server side, maybe python-react might be useful.

While on the subject of Python, Django would be a goto CMS in that language. There are Angular (racing tad pole) and, as mentioned in the previous paragraph, React (django-react).

To get an idea of the number of tools sets out there: TodoMVC.

ReactJS vs AngularJS is a detailed discussion between the two libraries. One of the interesting observations:

The first difference is that AngularJS puts JavaScript into HTML, while ReactJS puts HTML into JavaScript.

ELM emits JavaScript. Is said to create more reliable, faster to load pages. I don't know how many lines in total are emitted by the other frameworks, but the 'hello world' example emits 7840 lines of inline script.

2017/07/31 Elm In Production is an article describing the conversion process from Javascript to Elm. Having written lambda based code in C++, the Elm functional programming paradigm makes sense.

2017/09/06 svelte technologies: a kind of javascript compiler to prevent having to send a framework's library to the browser (The magical disappearing UI framework).

2017/09/20 diesel is a Safe, Extensible ORM and Query Builder for Rust, where Rust is a systems programming language that runs blazingly fast, prevents segfaults, and guarantees thread safety. Not sure how Web2.0 it is, but ...

2017/11/27 Web Frameworks: Conclusions: testing Angular 2+, React + Redux, vue.js, dojo 2, ember, and aurelia

2019/01/16 hacker news points to Tech Choices I Regret at Spectrum, and article which suggests that the author should have used react-native-web. Further into the article, the author suggested server sided rendering is a good thing. This reinforces my opinion that using Wt is a good decision as it provides server side rendering, and uses native javascript for client specialist functions.

2019/07/07 Angular vs React vs Vue: Which is the Best Choice for 2019? - Vue is upcoming (virtual DOM), React is popular (virtual DOM), and Angular is heavy and opinonated (real DOM).

2019/12/23

• React.js vs Angular by Davison Pro, an article from Oct 3, 2018, where at that time, Angular is falling behind React.
• React vs Angular: how a library can compete with a framework from 2019/02/12 - a note in there which says "Angular is a JavaScript framework created on the basis of TypeScript".

2020/02/10 - Things I wish I knew about state management when I started writing React apps - a HackerNews entry

This is not something you want to leave on, nor make generally available to those arriving at a web site. If you take a look at web logs, you'll see that there are many attempts at looking at this file. The file has very extensive information in it, information which could you used against you as a web site owner.

So use this to see stuff, then take it out. I'd say maybe use .htaccess on it, but that is a bad thing for high usage websites, as .htaccess reduces the performance of the server by requiring the service to perform additional latency inducing disk accesses.

The meat of the article -- into a file called phpinfo.php, put the following line:

<?php phpinfo(); ?>

This provides PHP version information, as well as a listing of modules and other useful information.

To present my code and command snippets, I should be using <code>...</code> rather than <pre>...</pre> enclosures. But since the 'pre' enclosure gets things closer to what I want in the first place, force of habit has kept me there, rather than using the more correct 'code' enclosure.

Anyway, to get decent looking monospaced fonts into my 'pre' enclosures, the following CSS snippet offers an ordered sequence of fonts to try:

pre {
  font-family: "Lucida Console", "Andale Mono", "OCR A Extended", "Fixedsys",
                   "Terminal", "Courier", 'Courier New', monospace;
  font-size: 110%;
}

The above is the result of a long list of comments at Bytes IT.

There were also some references to structured text recommendations:

• www.w3.org
• www.codestyle.org