IoT 2: It's Why I Got Moving
Last Updated on October 1, 2021
I got moved this blog from Blogger to this website.
The reasons are described as below.
1. To maintain and enhance my skill to make websites:
Blogger is a nice choice, but it's an easy order. To study the system overall, it's the best to build and manage a website at all.
2. Easy to maintain texts in this website through command lines:
This website uses a database-less approach. Each post are based on a text file. To search and/or replace strings in text files, command lines on the terminal is effective. In Linux, "grep" is good for searching strings, "sed -i" is good for replacing strings, and "rename" is good for renaming files at one time. In fact, these command lines can be executed on a website through any CGI script. You can resize a lot of images with one command line through ImageMagick. You can also transfer files to your remote server on command lines using LFTP. Anyway, Linux is good for developing website. If you want to debug PHP, you can install Apache HTTP Server in the system. Git gives you a good management of updating contents.
# Search "ab" Followed by a Character Except "c" in HTML Files in a Folder by Command Line (Debian GNU/Linux)
cd /ver/www/html
grep 'ab[^c]' ./*.html
# Replace All Strings "ab" with "cd" in HTML Files in a Folder
sed -i 's|ab|cd|g' ./*.html
# Rename Files .html to .xhtml in a Folder
sudo apt-get update
sudo apt-get install rename
rename 's/\.html$/\.xhtml/' ./*.html
# Resize JPEG Images in a Folder
# 50% for Width 40% for Height
# Remove Meta Data with -strip Option
sudo apt-get install imagemagick
mogrify -strip -resize 50x40% ./*.jpg
# Install LFTP for File Transfer to Your Remote Server
sudo apt-get install lftp
# To Use FTPS Explicit Mode (Port No. 21), Add "set ftp:ssl-auth TLS" to /etc/lftp.conf
# "-p 21" may not be needed because the port No. 21 is the default number of a FTP server.
lftp -u username -p 21 ftp.servername
# Show Help and Command Detail of "exit"
lftp username@ftp.servername:/> help
lftp username@ftp.servername:/> help exit
# Exit from LFTP
lftp username@ftp.servername:/> exit
* On the beginning of Internet, transactions based on texts are intended. So, HTML as the front-end phase has not been changed ever. However, methods to make HTML are various, human-handed static, dynamic by a system, etc. In the process of dynamically making HTML by system, commercial databases have been often used. Several content management systems (CMS) are intended to be used with commercial databases. Using these databases need some costs. As an individual or small business, costs for databases are bigger than positive effect in the life or the business because the costs consider of the merit of scale in client's business. As long as you enjoy hobbies and showcase small amount of products, you don't need to use any database at all. Don't forget that you shouldn't use anything that you can't pay out at all because the cost will be needed to be paid by you in the future with causality.
3. Because of Anxiety on Internet Nowadays:
As I mentioned at IoT 1, Internet nowadays has an actual odd. I think independence from major Internet services is the big deal for content creators, otherwise creators may encounter annoying things other than creation. So, I calculated that costs in a data center for storaging data have been still so small, but costs for transactions have not been small. Internet has a dilemma that a larger amount of data needs less effective transactions because of packeting. So, you can search things on IoT at this time (August 2020), especially live streaming and gaming, and you can feel amazing about the things. The big platform for video conference met an "outage", and staketakers on gaming started legal battles. I believe the formula to calculate the transaction cost of Internet. In precise, it's the formula to calculate the cost of Ethernet, as the physical layer and the data link layer of Internet protocol.
Transaction Cost (C1) in Some Limited Region to "So Called" Broadcasting by Ethernet:
C1 = V1 * N1 + F1
Transaction Cost (C2) in Some Limited Region to Broadcasting by Radio:
C2 = F2
V is the variable cost, N is the number of viewers, F is the fixed cost.
So, how can I propaganda the merit of broadcasting by Ethernet? OK, F2 is bigger than F1 because it needs a big antenna and a real estate. BTW, can Ethernet be defined as a broadcasting tool even if the cost has the variable cost depending on viewers? Ethernet is now the main infrastructure of telephone companies who serve peer-to-peer (P2P) communications, but not broadcasting. I think the reason of Media's biasing nowadays is caused from their movements to prefer to P2P rather than broadcasting. P2P never need supervising!
* "So called" Broadcasting by Ethernet: "So called", in another word, "madia". In fact, Ethernet has methods to broadcast and multicast using special physical (MAC) addresses. However, these methods are not used for "Media" broadcasting in higher layers. "Media" broadcasting and multicasting have already been studied in 1990's (e.g., MBone), and it was not spreaded because of the difficulty of its physical networking. These methods have a premise all clients are on the same physical network that can share spedial MAC addresses even if clients are distanced. Nowadays, the technology enhances networking so that one physical network of Ethernet can be built in a vast region. However engineers, who studied these methods well, have already retired, and are now farming vegetables with their pickup tracks.
* "Limited Region": Recent Internet networking gives you "anycast" that means you get content from a nearest server. Severs of the content delivery network (CDN) share an IP address and respond a request from the geographically closest server. Plus, to increase the capacity of responses, Internet services use DNS load balancing such as round-robin. I think in static media distribution, the cost from regional distancing is the same between Ethernet and Radio. But in dynamic live Media, the cost makes difference and we need to add the multiplier D1/D2 to each formulas.