HTTP protocol is connection-less and only the client can request information from a server. In any case, a server can contact a client… HTTP is purely half-duplex. Furthermore, a server can answer only one time to a client request.
Some websites or web applications require the server to update client from time to time. There were a few ways to do so: - the client request the server at a regular interval to check if there is a new information available - the client send a request to the server and the server answers as soon as he has an information to provide to the client (also known as long time polling)
But those methods have many drawbacks due to HTTP limitation. So a new protocol has been designed: websockets, which allows a 2 ways communication (full duplex) between a client and a server, over a single TCP connection. Furthermore, websockets re-use the HTTP connection it was initialized on, which means it uses the standard TCP port.
Via Nicolas Weil, Srdjan Strbanovic
Working with HTTP from the command-line is a valuable skill for HTTP architects and API designers to have. The cURL library and curl command give you the ability to design a Request, put it on the pipe, and explore the Response. The downside to the power of curlis how much breadth its options cover. Running curl --help spits out 150 different flags and options. This article demonstrates nine basic, real-world applications of curl.
In this tutorial we’ll use the httpkit echo service as our end point. The echo server’s Response is a JSON representation of the HTTP request it receives.
Pushing out incremental changes to a service-oriented cluster can be tricky, especially when changes span multiple services. Introducing seaport, a service registry written in node.js based on semvers.
With seaport, services are brought up with a name@version string and other processes can connect to services that match a name@semver pattern.
Ember Data is a peristence layer for Ember.Js. Unlike Ember, which currently has a candidate for a 1.0 release, Ember Data is still very much a work in progress. This has been a source of confusion for people who are learning Ember, as the two frameworks are complimentary but currently exist in different realms of stability.
Ember Data has ambitious goals, and it has come a long way in the last year. If you’re the kind of programmer who loves working on upcoming stuff, you might find it exhilarating. On the other hand, it is completely understandable if you’d want to avoid it. Deprecations and changing APIs can be frustrating and time consuming.
One thing that is not always clear to people starting with Ember is that Ember works perfectly well without Ember Data! Trust me on this: Discourse doesn’t use Ember Data for peristence and it’s working quite well. Moreover, using AJAX with Ember is something that is not difficult to do.
What you don’t know can hurt you, especially when you convince yourself that you do know it.
Many Agile teams—I believe it’s most Agile teams—get some improvement from applying Agile values, principles, and practices.
These teams do a better job of predicting when they’ll be done, and a better job of being done at the time they predict. They break requirements down into a backlog, they estimate how long items will take, and they burn through that backlog pretty well. Usually by the predicted end of the project, they’re closer to done than they used to be before they went Agile.
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