What is Cookies and Why it is Used?

What is Cookies?

Cookies are little text files that websites save on the user’s device (such as a computer or mobile device) when the user visits the website. These files include information that the website may download and utilize the next time the visitor visits the site.

HTTP cookies are required for modern Internet use, yet they compromise your privacy. HTTP cookies, which are a required aspect of online browsing, assist web developers in providing you with more personalized, easy website visits. Websites may remember you, your website logins, shopping carts, and other information via cookies. They may, however, be a goldmine of private information for crooks to snoop on.

Different types of cookies – Magic Cookies and HTTP Cookies

Magic cookies :- The term “magic cookies” originated in the early days of computers and describes data packets that are delivered and received unchanged. This is frequently used to enter into computer databases, such a company’s internal network. The term “cookie” as we know it today predates this concept.

HTTP cookies :- HTTP cookies are a modified form of the “magic cookie” designed for web browsing. The “magic cookie” inspired web browser creator Lou Montulli in 1994. When he assisted a website for online shopping in repairing its overburdened servers, he duplicated this idea for browsers.

What Are Cookies Used For?

Websites utilize HTTP cookies to improve the user experience. Without cookies, you would have to log back in each time you left a website or, if you accidently closed the browser, rebuild your shopping cart. making cookies a crucial component of using the internet.

Session management :- Transient cookies and per-session cookies are other names for session cookies. While a person is browsing a website, session cookies save data. Once the user ends the session, these cookies are removed.

Persistent cookie :- Cookies that are persistent are kept for a certain period of time. Until they are erased or they expire, these cookies stay on your device. Because they are used to gather user data including browsing patterns and preferences, persistent cookies are also known as tracking cookies.

First-party and third-party cookies :- Cookies that are set by websites that users visit directly are known as first-party cookies. These cookies typically store data relevant to or related with the website, such as user preferences or location.
Cookies that are associated with third-party content, such as embedded videos, advertisements, web banners, and scripts, are referred to as third-party cookies. Third-party cookies are frequently used by advertisers to monitor user behaviour.

Tracking :- Shopping sites use cookies to keep track of the items that users have previously viewed, allowing the sites to propose more things that they may be interested in and store products in their shopping carts while customers browse elsewhere.


Unsecured cookies may potentially provide a security risk to website owners and users. The original website or a third party receives unencrypted data about an insecure cookie over HTTP. That’s a low danger if the information is something straightforward, like if the person has already visited the site. Some websites, however, may use cookies to store user data, including personally identifying information such as login passwords and payment card details. Unencrypted transmissions of such kind of data leave them open to interception and misuse by criminals. A secure cookie only permits the transmission of cookie data via HTTPS and does not carry the same danger.

Tagged : / / / / / / / /

Setup Docker service to use insecure(http) registry instead of https

By default docker use https to connect to docker registry. But there can be use cases to use insecure registry. Here are the steps to use insecure registry.

In ubuntu
edit the file /etc/default/docker and update DOCKER_OPTS e.g


where is ipaddress of registry and 5000 is your port on which registry is configured.

In Centos
Edit the file /etc/docker/daemon.json e.g.

"insecure-registries" : [""]

where is ipaddress of registry and 5000 is your port on which registry is configured.

Restart docker
$ service docker restart

Tagged : / / / / /

What is HTTP (HyperText Transfer Protocol)

Short for HyperText Transfer Protocol, the underlying protocol  used by the World Wide Web. HTTP defines how messages are formatted and transmitted, and what actions Web servers and browsers  should take in response to various commands. For example, when you enter a URL in your browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page.

The other main standard that controls how the World Wide Web works is HTML, which covers how Web pages are formatted and displayed.

HTTP is called a stateless protocol because each command is executed independently, without any knowledge of the commands that came before it.

Tagged : / / / /

Apache and HTTP Interview Questions and Answers – Interview Guide


Apache and HTTP Interview Questions and Answers – Interview Guide

List of Apache and HTTP Interview Questions: –

<!– /* Font Definitions */ @font-face {font-family:”Cambria Math”; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:1; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:0 0 0 0 0 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:””; margin-top:0in; margin-right:0in; margin-bottom:10.0pt; margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:”Calibri”,”sans-serif”; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:”Times New Roman”; mso-bidi-theme-font:minor-bidi;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:”Times New Roman”; mso-bidi-theme-font:minor-bidi;} .MsoPapDefault {mso-style-type:export-only; margin-bottom:10.0pt; line-height:115%;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:1388797391; mso-list-template-ids:-480605428;} ol {margin-bottom:0in;} ul {margin-bottom:0in;} –>

  1. On a fresh install, why does Apache have three config files – srm.conf, access.conf and httpd.conf? – The first two are remnants from the NCSA times, and generally you should be ok if you delete the first two, and stick with httpd.conf.
  2. What’s the command to stop Apache? – kill the specific process that httpd is running under, or killall httpd. If you have apachectl installed, use apachectl stop.
  3. What does apachectl graceful do? – It sends a SIGUSR1 for a restart, and starts the apache server if it’s not running.
  4. How do you check for the httpd.conf consistency and any errors in it? – apachectl configtest
  5. When I do ps -aux, why do I have one copy of httpd running as root and the rest as nouser? – You need to be a root to attach yourself to any Unix port below 1024, and we need 80.
  6. But I thought that running apache as a root is a security risk? – That one root process opens port 80, but never listens to it, so no user will actually enter the site with root rights. If you kill the root process, you will see the other kids disappear as well.
  7. Why do I get the message “… no listening sockets available, shutting down”? – In Apache 2 you need to have a listen directive. Just put Listen 80 in httpd.conf.
  8. How do you set up a virtual host in Apache?
    <VirtualHost www.techinterviews.com>
    ServerAdmin admin@techinterviews.com
    DocumentRoot /home/apache/share/htdocs/hostedsites
    ServerName www.techinterviews.com
    ErrorLog /home/apache/logs/error/hostedsites/error_log
    TransferLog /home/apache/logs/access/hostedsites/access_log
  9. What is ServerType directive? – It defines whether Apache should spawn itself as a child process (standalone) or keep everything in a single process (inetd). Keeping it inetd conserves resources. This is deprecated, however.
  10. What is mod_vhost_alias? – It allows hosting multiple sites on the same server via simpler configurations.
  11. What does htpasswd do? – It creates a new user in a specified group, and asks to specify a password for that user.
  12. If you specify both deny from all and allow from all, what will be the default action of Apache? – In case of ambiguity deny always takes precedence over allow.
Tagged : / / / / / / / / / / / / / / / / / / /