Sunday, November 14, 2021

How email system works

  •  A user u1 opens outlook and accesses mail host abc.com.
    • That mail host can be a Linux system running some mail server daemon e.g. postfix.
    • On that host, multiple users are created. 
  • User u1 from outlook logs in as a user at abc.com.
    • User writes a mail and send it to u5@xyz.com.
  • The mail first goes to mail server for domain abc.com.
  • abc.com sends it to mail server for xyz.com
  • The user u5 can access the host for domain xyz.com and read the mail.
  • on Mail client e.g. outlook a MUA(Mail user agent) runs, with which user writes and sends mails.
  • MTA (Mail Transfer Agent) i.e mail server transports the messages over internet.
  • Why we have used Agents?
    • Each type of operation is done through some agent(program).
  • Mail server runs a POP or IMAP server to hold users' mails.
  • SMTP(Simple Mail Transfer Protocol) is used to transfer mails.


Notes and doubts

  • Outlook == mail client = mail user agent
    • mail
    • Elm
    • Outlook
  • MTA == mail server, which uses SMTP
    • postfix
    • sendmail
    • Courier
  • Host == mail domain == A Mail server services a domain
  • There can be a mail exchange server for the domain.
  • User1 on Host abc.com ==> u1@abc.com
  • User5 on Host xyz.com ==> u5@xyz.com    
  • We can configure mail server on a linux machine. And without login, we can send and receive mails.



Thursday, November 11, 2021

Daily writing 12 Nov 2021

  •  need to write about:
    • what you learnt
    • How you did something
    • What you want to do
  • Writer daily in evening one hour
  • Write in a manner as you are teaching to someone
    • all successful people write
      • Saints, Sages, Leaders, 
  • write story about your journey in Perf team
  • story about you learned in perf team and profiler team
  • story about what you learned till now in your career
  • What are things on top of your mind:
    • Be aware of latest Tech, how?
      • Security, VPN?
      • Coding, Automation, Testing tools
      • networking - latest research papers
      • how technology evolved and where is it going?
    • watch yourself and analyse how you do what you do.
    • jmeter rewriter test and how you created test plan
    • Perf Report - Write about how you made progress
    • Testing course by James bach, writer what you learnt
      • Changed mindset
      • How people make good mindmaps quickly and write scripts quickly
      • writing good bug reports
      • creating good test strategy and test plan
      • ........
    • Performance testing - Brendan Gregg
    • Think like a programmer - solve problems
    • Learn about Ruby and Python
      • Make one language your goto language, means expertise in that
    • Books you recently bought or downloaded
      • TCP/IP
      • Gitapress
        • Eknath charit
        • Bhakt Narsi Mehta
        • Kalyan
      • Raman Maharishi teachings
      • four noble truths
    • Books you want to buy and read
      • Linux administration and commands

Tuesday, January 26, 2021

Learn to make sustainable house; possible to be built up by owner

I want to learn how to make a house by my hands; like village people used to make. materials, space, . Do I have that intuition? What do I have to unlearn ? 


Do I need some space , some teacher? 


Why?

  1. to learn some skill
  2. time pass
  3. some fancy imaginations, never something like this   
  4. I hope that it will be a good experience 
  5. Influenced
  6. if successful, will try to make cheap houses for people

Saturday, April 13, 2019

Goal - Software Developer


  • Web developer
    • HTML and CSS 
      • by replicating static websites
      • HTML templating
    • Javascript 
      • by replicating some online client side games
      • AJAX
      • Promises, callbacks
      • jQuery
    • Client side frameworks
      • Angular
      • React
    • backend
      • Learning Django from MDN
      • Learn node express from MDN
    • Create personal website
      • host it on hosting servers
      • create own web server
  • Programming
    • Learn C
      • Let us C
      • Dennis Ritchie
    • how data is stored in memory
    • Solve problems
      • coderbyte.com
      • Cracking coding interview
    • Think like a programmer
    • The art and craft of problem solving
    • Practice Python, Perl
  • How to write algorithms
  • How to write pseudo code
  • Operating system concepts

Sunday, October 11, 2015

Can old practices be re-established?

It is my strong belief that in ancient and not more ancient(100 years ago or probably 30 years ago) times, our daily life was more active and valuable to society than today.

Friday, September 25, 2015

Practical Learning

Vinoba Bhave(A great saint and spiritual Guru of Mahatma Gandhi) has written:

"We should learn while living the life. Now a days the situation has become such that people waste their most valuable time (early years of life) in school and then suddenly they are dropped in the struggle of life.
Lord Krishna gave the lesson of Gita to Arjuna on the field of war, not gave lesson first in classroom and then went on war!"

This tells a lot about current days' situation. We learn all subjects in school and college: Maths, Physics, Chemistry, Biology, History, Geography, English, Hindi, Sanskrit. But if think honestly, it comes to know that we do not learn any skill to live our life. Only one exam to be eligible to give another exam. Not even a simple formula from math comes in my daily use. No lesson from Physics seems to be useful in my daily life. No chemical formula is useful enough which can tell me which medicine should I take or not. Biology did not throw light upon the value of life of animals in my environment. History never gave a non-prejudicial view of past. It never inspired us to research into the past and to question about common perceptions such as when life started on earth. Geography never connects with economics of the places, it never connect with history of that locality, never connects with the trade which happens between two communities. Subjects on different languages like English, Hindi, Sanskrit never told us that language is only a medium to express ourselves. There should not be any compulsion to learn any particular language. Mother tongue should be the medium of learning and in future learner can learn a language if  he is ready.

Every day we deal with food. It is necessary to live. We want to eat healthy and nutritious. We want to know how much we should eat to avoid digestion problems. But in school curriculum, this things do not get any place, and if get, in very theoretical form.

Thursday, September 17, 2015

Art and Daily Work in older days

There is a sense in me which tells me that world has not evolved in greater technology and life style but it is degraded in lifestyle and technology. Now a days every body tells that now technology is much developed, we can reach to others fast, we can talk to anybody sitting in any corner of world.
But Why? Why do we need to talk to persons sitting in other corner, why not sitting besides me or living besides me? Our lifestyle has become so low and unsatisfied that we are unable to entertain ourselves. We are bored very often. We have TV, Computers, Internet etc. still we are bored. So we come to conclusion that these things can not entertain us for long time.

Now I want to go a little back.  I have seen my mother and grandmother in my childhood, they were never bored, always busy in something, and even then got some leisure time. My statement may look contradictory, but if we try to understand it makes sense.

There was some form of art involved in every daily work of their life. For 3 times they would cook food, 2 times they would prayer to God, cleaning home once in morning. This is daily routine. Other than this there are many works which are not in daily routine, but these works collectively cover all the days. And these works used to be done in groups of ladies from neighborhood. There were usually different songs for each of these works. The sound of collective singing would always be so sweet to hearing glands.  Following is a list of these different kind of works:

1. Making pickle of different fruits like raw mango, lemon, Amla. And these would be made in their respective seasons. e.g. raw mango comes in April, May and it is cheap also that time. They would use a tool called Sarota for cutting raw mango in small peaces. And then recipe itself is very specific, you can not miss even one ingredient, otherwise pickle will become inedible soon.

2. Making Laddoos of different source material like Til, Cholai, Besan (gram flour),  Wheat flour etc. These also are according to seasons. E.g. Til is hot by nature, so Til Laddoos are made only in winter time. Especially on Makar Sakranti (14 January).

3. In our home we never bought flour from market. We would bring wheat in our home, clean it, wash it and dry it. Then we would take it to some grinding machine (In Uttarakhand we have gharats, which use the power of water) and will bring wheat flour back. Thus A very less amount of nutrition wastes.
(I am sure that in older days, people had hand grinding machine in their houses, so that they would make the flour in house only, it would also improve their health and no nutrition would be wasted).

4. In older days, we used to make our beds (charpai) also at home. We would bring a wooden frame of charpai from a carpenter and buy some rope (made from Jute) or Taat ( i dont have its english name), and would weave out charpai ourself.

5. On Festivals, mothers used to prepare edible things, things for Pooja, and other things much before the festival day. E.g. on Holi, My mother used to prepare Chaat, Pani Puri, Gujiya, and many other things 4-5 days ahead. (I am sure, people used to make colors for Holi also at home, not in our home)

On Diwali, we would prepare many decorative things like bandanvaar, Gralands etc. days ahead of diwali.

6. Some people would also do gardening , and grow some basic vegetables and fruits. We had a big Guava tree, in our garden. My mother and grandmother used to grow tomatoes, Chili, Lady Finger, Mooli, etc.

7.  At special occasions like marriage ladies from neighborhood and relation will gather and will celebrate with dance, music, songs and many things.

These all things require a great work of Art. Thus art was  a inseparable part of life at that time. We are losing this art and searching art in other things, we go to museums, concerts and many other places. I am not saying that we should not go to these places, as they are also a form of art, but after loosing it from our daily life searching it anywhere else is not wise.