Showing posts from February, 2015

HTTP 2 Frame Format

All HTTP 2 frames begin with a fixed 9-octet header followed by a variable- length payload as shown in following Figure. +-----------------------------------------------+ | Length (24) | +---------------+---------------+---------------+ | Type (8) | Flags (8) | +-+-------------+---------------+-------------------------------+ |R| Stream Identifier (31) | +=+=============================================================+ | Frame Payload (0...) ... +---------------------------------------------------------------+  Figure : HTTP 2 Frame Layout So there are total six fields in HTTP 2 frame. Now lets see each field  in detail : Length: The length of the frame payload expressed as an unsigned  24-bit integer. Values greater than 2^14 (16,384) MUST NOT be  sent unless the receiver has set a larger value for  SETTINGS_MAX_FRAME_SIZE.  The 9 octets o

Everything you need to know about HTTP 2

HTTP allows a browser to connect with a Web server to load a pages, same is the case with HTTP 2. As Mark Nottingham , chairman of the IETF working group behind creating the standards,  said on his blog that the HTTP 2 specifications have been formally approved. From here, the specs go through a request for comment phase and then published. So HTTP 2 is out for implementation. See this HTTP 2 implementations. The HTTP standard is getting an overhaul and while faster Web pages are a big win for the first major revision since 1999, better encryption may have a more lasting impact. HTTP 2 is promising faster loading speed. By reading draft of HTTP 2, I have noticed that HTTP 2 standard is based on SPDY , which was introduced by Google and adopted by other browsers (Such Firefox, Chrome). This post will be explaining you, all the required details you need to know about HTTP 2. So lets begin.. What is HTTP 2 ? HTTP 2 is a replacement for how HTTP is expressed “on the wire”. It is not a announced free Internet service for India with Reliance

Happy 🙂 has announced free Internet service for India . Now you can access few websites on Internet for free.  To access Internet for free what you need to do is just get Reliance SIM card (do not activate any data plan), setup connection and start surfing.  Note that if you have Android mobile phone then you need to download app (which is free app) . This service currently only available with Reliance Network because Facebook has tied up only with Reliance Communications to offer free access to Internet . India is the first country in Asia to get the new app . In past four years Facebook has partnered with more than 150 wireless providers to offer free or discounted access to its social network,  but the new app is the first time the company has added services beyond its own website. Following are the websites which you can surf for free :   Bing Search OLX   Aaj Tak  AccuWeather  AP Speaks   Astrology   Babajob  BabyCenter &

Video decryption using caesar cipher - Matlab Tutorial

% code for encryption is available at'encrypted.avi');nFrames=obj.NumberOfFrames;%// Will open an avi file name test.avi in local folderaviobj = avifile('decrypted.avi');%// the quality of this video fileaviobj.Quality = 80;%// compression method. See matlab manual for details.aviobj.COMPRESSION ='None';%%color imagefor k=1:nFrames img=read(obj,k); % figure(1),imshow(img,[]); img_size=size(img); %disp(temp); %image(img); %12X22 %pause(4); img1=zeros(img_size(1),img_size(2),3); for a =1:img_size(1) for b=1:img_size(2) for c=1:img_size(3) img1(a,b,c)= img(a,b,c); end; end; end;

Encrypting webcam-video using caesar cipher - Matlab Tutorial

clc; vid = videoinput('winvideo',1,'YUY2_160x120'); set(vid, 'ReturnedColorSpace', 'rgb'); %vid.LoggingMode = 'disk&memory'; vid.TriggerRepeat = Inf; set(vid,'FramesPerTrigger', 1); start(vid); i=0; auto_compress_count=0; j=0; frame=zeros(); %// Will open an avi file name test.avi in local folder aviobj = avifile('encrypted.avi'); %// the quality of this video file aviobj.Quality = 80; %// compression method. See matlab manual for details. aviobj.COMPRESSION ='None';%%color image try % here condition specifies how many frames to encrypt while j<200 i=i+1; img=getsnapshot(vid); img_size=size(img); %disp(temp); image(img); img1=zeros(img_size(1),img_size(2),3);

Tuning performance of Apache Server

Apache is the most popular and widely used web server.  Apache allows us to run web applications with minimal configuration and easy administration. However for highly data driven applications Apache may go slow, sometimes really very slow. So in this post we are going to see how we can tune the performance of Apache by simply following above listed suggestions: 1. Removing almost all unused modules/ not required modules : Save memory by not loading modules that you do not need, including but not limited to mod_php , mod_ruby , mod_perl , etc. 2. Using mod_disk_cache NOT mod_mem_cache : mod_mem_cache will not share its cache amongst different Apache processes, which results in high memory usage with little performance gain since on an active server, mod_mem_cache will rarely serve the same page twice in the same Apache process. 3. Setup appropriate Expires, Etag, and Cache-Control Headers : to utilize your cache, you must tell it when a file expires, otherwise your client wil