What is HTTP/2?

HTTP/2 is an extended version of HTTP communication protocol after HTTP/1.1. Targets of the improvement are:

Faster communication (50% improvement)
Better utilization of available network capacity
Keep existing application with the older version (HTTP/1.1) running (no changes required)

How those targets can be achieved? There are several technical aspects:

Applying header field compression
Allowing multiple concurrent exchanges on the same connection (allowing interleaving request & response)
No change in core concepts of HTTP such as method, status codes, URIs, and headers.

HTTP/2 adds a binary framing layer in HTTP protocol that dictates how messages are encapsulated and transferred. There are several terms in HTTP/2 protocol:

Stream. It is a bidirectional flow of bytes that can contain one or more messages.
Frame. It is the smallest unit of messages in the stream. It has a header that contains the identity to which the stream belongs. Frame can contain encoded header data or payload data of a request or response message.
Message. It is a resembled-form of one or more frames. It is mapped to request or response messages.

Because a single connection can have multiple related streams, there is a stream prioritization scheme. If a stream is required by other streams, this stream is prioritized for using available resources first. If two streams have no dependency or have the same dependency, They are prioritized proportionally by their weights.

HTTP/2 also provides building blocks for allowing client/server to implement stream or connection-level flow control. Without flow control, as a sender can send multiple streams continuously, it can flood the receiver. The receiver can advertise information about the flow control window which is exchanged in SETTINGS frame. When a DATA frame is received by a receiver, WINDOW_UPDATE frame is sent by the receiver.

Another good thing about HTTP/2 is its capability for a server to push data to a client. It is initiated by the server by sending PUSH_PROMISE frames.

Comments

Rangkaian Sensor Infrared dengan Photo Dioda

Keunggulan photodioda dibandingkan LDR adalah photodioda lebih tidak rentan terhadap noise karena hanya menerima sinar infrared, sedangkan LDR menerima seluruh cahaya yang ada termasuk infrared. Rangkaian yang akan kita gunakan adalah seperti gambar di bawah ini. Pada saat intensitas Infrared yang diterima Photodiode besar maka tahanan Photodiode menjadi kecil, sedangkan jika intensitas Infrared yang diterima Photodiode kecil maka tahanan yang dimiliki photodiode besar. Jika tahanan photodiode kecil maka tegangan V- akan kecil . Misal tahanan photodiode mengecil menjadi 10kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 10 / (10+10) x Vcc V- = (1/2) x 5 Volt V- = 2.5 Volt Sedangkan jika tahanan photodiode besar maka tegangan V- akan besar (mendekati nilai Vcc). Misal tahanan photodiode menjadi 150kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 150 / (150+10) x Vcc V- = (150/160) x 5

Configuring Swap Memory on Ubuntu Using Ansible

If we maintain a Linux machine with a low memory capacity while we are required to run an application with high memory consumption, enabling swap memory is an option. Ansible can be utilized as a helper tool to automate the creation of swap memory. A swap file can be allocated in the available storage of the machine. The swap file then can be assigned as a swap memory. Firstly, we should prepare the inventory file. The following snippet is an example, you must provide your own configuration. [server] 192.168.1.2 [server:vars] ansible_user=root ansible_ssh_private_key_file=~/.ssh/id_rsa Secondly, we need to prepare the task file that contains not only the tasks but also some variables and connection information. For instance, we set /swapfile as the name of our swap file. We also set the swap memory size to 2GB and the swappiness level to 60. - hosts: server become: true vars: swap_vars: size: 2G swappiness: 60 For simplicity, we only check the exi

Beautiful Rain (JDorama)

Saya selalu tertarik dengan film-film inspirasional, baik movie atau pun serial drama. Akhir-akhir ini saya tertarik untuk menonton drama serial jepang. Saya googling dengan keyword "inspirational japan dorama" kemudian saya dapati sejumlah review beberapa film bagus dari sejumlah netizen. Salah satu yang kemudian saya tonton adalah Beautiful Rain . Setiap episode film ini selalu membuat saya sangat terharu sampai meneteskan air mata. :' Yah, ini mungkin saja karena saya yang terlalu melankolis. Hahaha. Ini sedikit review dari saya tentang film ini.

API Gateway Using KrakenD

The increasing demands of users for high-quality web services create the need to integrate various technologies into our application. This will cause the code base to grow larger, making maintenance more difficult over time. A microservices approach offers a solution, where the application is built by combining multiple smaller services, each with a distinct function. For example, one service handles authentication, another manages business functions, another maintains file uploads, and so on. These services communicate and integrate through a common channel. On the client side, users don't need to understand how the application is built or how it functions internally. They simply send a request to a single endpoint, and processes like authentication, caching, or database querying happen seamlessly. This is where an API gateway is effective. It handles user requests and directs them to the appropriate handler. There are several tools available for building an API gateway, su

Deliver SaaS According Twelve-Factor App

If you haven't heard of the twelve-factor app , it gives us a recommendation or a methodology for developing SaaS or web apps structured into twelve items. The recommendation has some connections with microservice architecture and cloud-native environments which become more popular today. We can learn the details on its website . In this post, we will do a quick review of the twelve points. One Codebase Multiple Deployment We should maintain only one codebase for our application even though the application may be deployed into multiple environments like development, staging, and production. Having multiple codebases will lead to any kinds of complicated issues. Explicitly State Dependencies All the dependencies for running our application should be stated in the project itself. Many programming languages have a kind of file that maintains a list of the dependencies like package.json in Node.js. We should also be aware of the dependencies related to the pla

Manage Kubernetes Cluster using Rancher

Recently, I sought a simpler method to deploy and maintain Kubernetes clusters across various cloud providers. The goal was to use it for development purposes with the ability to manage the infrastructure and costs effortlessly. After exploring several options, I decided to experiment with Rancher. Rancher offers a comprehensive software stack for teams implementing container technology. It tackles both the operational and security hurdles associated with managing numerous Kubernetes clusters. Additionally, it equips DevOps teams with integrated tools essential for managing containerized workloads. Rancher also offers an open-source version, allowing free deployment within one's infrastructure. The Rancher platform can be deployed either as a Docker container or within a Kubernetes cluster utilizing the K3s engine. We can read the documentation on how to install Rancher on K3s using Helm . Rancher itself enables the creation and provisioning of Kubernetes clusters and

LUKI NOTES

Search This Blog