What is HTTPS?

HTTPS stands for Hyper Text Transfer Protocol Secure, which is an internet communication protocol used to transfer data securely between web servers and web browsers. It is the secure version of HTTP, which is the protocol used to transfer data between a web browser and a website. When you visit a website that uses HTTPS, your browser establishes a secure connection with the website's server using SSL/TLS (Secure Sockets Layer/Transport Layer Security) encryption. SSL/TLS encryption ensures that the data transmitted between your browser and the website's server is encrypted and cannot be intercepted by third parties. Examples of applications that use HTTPS include online banking, e-commerce websites, email services, and social media platforms. Let's say you are shopping online and want to purchase a product from an e-commerce website. When you enter the website's URL into your web browser and click enter, your browser sends a request to the website's server to establish a connection. The website's server responds by sending a SSL/TLS certificate to your browser, which your browser uses to establish a secure connection. Once a secure connection is established, any data that you enter on the website, such as your personal and payment information, is encrypted and transmitted securely to the website's server. This ensures that your data is protected from hackers and other third parties who may try to intercept your information. In summary, HTTPS provides a secure way for web browsers and web servers to communicate and transfer data. It is essential for protecting sensitive information and ensuring the privacy and security of online transactions.

SSL (Secure Socket Layer)

SSL (Secure Socket Layer) is a protocol for securing communication between a client and a server over the internet. It is now known as TLS (Transport Layer Security), which is the newer and improved version of SSL. The primary purpose of SSL is to provide a secure, encrypted connection between two parties, which ensures that the data exchanged between them cannot be intercepted, modified, or read by any third party. Here's a simple example of how SSL works: Suppose you want to buy a product from an online store, and you need to provide your credit card information to complete the purchase. When you click on the "checkout" button, your browser sends a request to the online store's server to establish a secure SSL/TLS connection. The server responds with its digital certificate, which contains its public key and other identifying information. Your browser verifies the authenticity of the server's digital certificate by checking its signature against a trusted Certificate Authority (CA), such as Verisign or Thawte. Once the browser verifies the server's identity, it generates a unique session key for the session and encrypts it with the server's public key. The encrypted session key is sent to the server, which decrypts it using its private key. Both parties can now use the session key to encrypt and decrypt all data sent between them during the session, including your credit card information. This process ensures that your credit card information is protected from prying eyes while it travels over the internet. SSL is widely used for securing online transactions, email, and other forms of communication that require confidentiality and integrity. It is also used to secure sensitive information such as passwords, credit card details, and personal information. In summary, SSL is a protocol that provides a secure, encrypted connection between a client and a server, ensuring that sensitive information remains private and confidential.

SSH - Secure Shell

SSH (Secure Shell) is a network protocol used to securely communicate between two computers over an unsecured network, such as the internet. It provides a secure channel for remote access to a computer or server, allowing users to log in and execute commands on a remote system. SSH works by encrypting all the data that is transmitted between the client and the server. This ensures that any data intercepted by an attacker would be unreadable. The encryption is achieved using cryptographic algorithms, such as AES or RSA, which are considered to be highly secure. SSH provides several key features, including authentication, encryption, and compression. When a user logs in to a remote system using SSH, they are required to provide their username and password, which are authenticated by the remote system. Once authenticated, all communication between the client and server is encrypted, ensuring that sensitive information is kept private. Additionally, SSH can compress data to speed up the transfer of large files or streams of data. SSH is widely used in the IT industry to remotely manage servers, routers, and other network devices. It is also used by individuals who want to access their home computer or network from a remote location. SSH clients are available for all major operating systems, including Windows, Mac OS, and Linux.

JVM Heap

Min Heap :6G Max Heap :6G -XX:NewSize=3072M -XX:+UseCMSInitiatingOccupancyOnly -XX:CMSInitiatingOccupancyFraction=70 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC Min Heap: 6G and Max Heap: 6G indicate the minimum and maximum heap memory sizes set for the JVM, respectively. The heap is the area of memory where objects are allocated and managed by the JVM. -XX:NewSize=3072M sets the initial size of the young generation heap, which is where newly created objects are first allocated. -XX:+UseCMSInitiatingOccupancyOnly and -XX:CMSInitiatingOccupancyFraction=70 are options for the Concurrent Mark and Sweep (CMS) garbage collector, which is used for managing the heap memory in this configuration. UseCMSInitiatingOccupancyOnly means that CMS will only start when the heap occupancy reaches a certain level, as determined by CMSInitiatingOccupancyFraction (70% in this case). -XX:+UseParNewGC enables the Parallel New (ParNew) garbage collector, which is used to manage the young generation heap. -XX:+UseConcMarkSweepGC enables the CMS garbage collector for managing the old generation heap. This collector works concurrently with the application, meaning that garbage collection can occur simultaneously with other tasks, reducing the likelihood of application pauses.

Add environment variable to a systemd service - Redhat linux 7.x

sudo mkdir /etc/systemd/system/apache-ignite@.service.d sudo vi /etc/systemd/system/apache-ignite@.service.d/apache-ignite.conf [Service] Environment=IGNITE_JMX_PORT=49005 sudo systemctl daemon-reload sudo systemctl restart apache-ignite@ignite-server.xml

Change ulimit values in red hat

sudo vi /etc/security/limits.d/ignite-limits.conf * hard nofile 500000 * soft nofile 500000 ignite hard nofile 500000 ignite soft nofile 500000

NTFS Mount read write mode

sudo ntfsfix /dev/sda7 

If you are not able to mount ntfs mount as read write mode use this. Then  mount.

sudo mount --rw --source /dev/sda7 --target /media/ddrive