I am really torn between two different stacks with which to build a large application. One the one hand there is this option:
Node.js
express
coffee script
coffeekup
mongoose/mongodb
or
presistencejs/mysql
Play Framework w/ Scala
Anorm w/ mysql
or mongodb
The node.js path is appealing to me because i can write all of the server side code, views and client side code in coffeescript, which i already know. If i go down this road i am still not 100% sure which db path i would take. mongoose makes storing data quick and easy, but the lack of true relationships might be more difficult to work with given the data model i have in mind (very SQLish).
The Play Framework path is also appealing because i know the framework well when using Java, but i don't know much about Scala, so there would be a hit to productivity as i work through learning that language. The Anorm database access layer is appealing because i can write the SQL by hand which i would prefer, and have the results mapped to objects automatically, which saves a lot of effort.
I keep leaning towards node.js, but i'm not sold on the best db access layer to use. Anyone have any experience with any of this and can share some insight?
The stack you choose should depend upon the needs of your application. Let's look at Play vs. Node for their strengths:
Node
Real-time applications (chat, feeds)
Event-driven architecture
Can perform client-server duties (e.g. serve files), but not well-suited for this
Database management, testing tools, etc, available as additional packages
Play!
Client-server applications (website, services)
Share-nothing architecture
Can perform real-time duties (e.g. Websockets), but not well-suited for this
Database management (including migrations!), testing tools, etc, built into core
If your application more closely matches a traditional web-based model, Play is probably your best choice. If you need immediate feedback and real-time dynamic messaging, Node is the better choice.
For large traditional applications, seriously consider the Play! Framework because of the built-in unit and functional testing along with database migrations. If incorporated into the development process, these go a long way toward an end product that works as expected and is stable and error-free.
There are 10 major categories you should consider when comparing web frameworks:
Learn: getting started, ramp up, overall learning curve.
Develop: routing, templates, i18n, forms, json, xml, data store access, real time web.
Test: unit tests, functional tests, integration tests, test coverage.
Secure: CSRF, XSS, code injection, headers, authentication, security advisories.
Build: compile, run tests, preprocess static content (sass/less/CoffeScript), package.
Deploy: hosting, monitoring, configuration.
Debug: step by step debugger, profilers, logging,
Scale: throughput, latency, concurrency.
Maintain: code reuse, stability, maturity, type safety, IDEs.
Share: open source activity, mailing lists, popularity, plugins, commercial support, jobs.
Check out my talk Node.js vs Play Framework for a detailed breakdown of how these two frameworks compare across these 10 dimensions.
Related
I'm a backend developer with background of Java and Python. I've started with Flutter 3 months ago. I find Dart an easy language to learn and fun to write code in. Google did a good job there.
What is challenging for me is figuring out best practices when working with flutter. The official documentation (docs.flutter.dev) is good and it's also interesting to look at the Dart code powering the framework. But I haven't seen a resource that goes over best practices for design/architecture of a Flutter application.
In particular, I'm interested in how to maintain separation of concerns between Database , Domain and Presentation layers.
I'm using Firebase Store for my (realtime) database. The API provides the data in the form of a JSON object (Map). This is fine, but I want to translate this into my own domain model instances (for data validation, enrichment and enforcing other business rules). What I don't know is how to bridge the gap between database and UI (Widgets). I want to keep a Clean Architecture, and would like to learn how to do this correctly. I should also add that I don't have prior experience with Asynchronous code, which seems to be an important skill to gain.
I've experimented in using InheritedWidgets to try and expose my data to the UI/Presentation layer as model instances, without the UI knowing about the specifics of the database, but ran into difficulties because I don't understand the Flutter framework and Dart async programming very well. I also know there are frameworks like Bloc that are supposed to solve data/state management issues. But as much as possible I want to stick to the basics before I start using more elaborate and heavier tools.
What recommended resources are out there that I'm missing, that could help me become a better Dart/Flutter developer?
I'm interested in creating a web application and I've just done some research on the what makes a good web server. I've search through the facebook, twitter and foursquare. They share what software they used to build their infrastructure.
For me, some of the software used are new. I'd like to ask some questions here.
why create a back end server, isn't a web server running PHP is enough? Why use java/scala for backend? Do we really need RPC framework such as thrift/protocol buffer? What is that RPC framework used for? Is it used for communication between frontend and backend servers?
Really appreciate for those who answer my questions, or if there's some books you would suggest me to read.
Thank you.
It sounds as though you'd like to build a scalable backend infrastructure that ultimately will be used to do the following:
Serve content. This is the web server layer.
Perform some type of back end processing for user requests
coming in from the web server layer and communicate with the data store. Call this the application server layer.
Save session state and user data in a distributed, fault tolerant, eventually consistent key value store.
Also, it sounds as though you want to do this using commodity PC hardware.
This is a tall order.
Foursquare uses Scala with the Lift framework, jetty for their web server. Here's more. And more.
Facebook uses many different technologies. I know that for their data store they use HBase (they were using Cassandra)
Yahoo uses HBase to keep track of user statistics.
Twitter started as a Ruby-backend web site. They moved to Scala. Twitter is incrementally moving from mysql (I assume sharded) to Cassandra using their proprietary incremental database conversion tool.
As far as scaling on the application server and web server end, I know that what really counts is having a language that has the ability to spawn new user processes in user space and a manager process that assigns new worker processes the requests coming in. Think of it as running a very efficient company. The more work you've got coming in, the more people you hire. This is the Actor model. Some languages have actors built in,(erlang) others have actors implemented as frameworks(akka) or libraries (Scala native). Apparently, Scala's native actors are buggy so some people got together and implemented the akka framework for Scala and Java. There's a lot of discussion online regarding actors and which language and libraries one should use. Erlang has a lot going for it out of the box, however, Scala runs in the JVM and allows you to reuse a lot of the existing Java web libraries (which could have some issue if they happen to have static objects declared in them) Erlang has actors and the OTP libraries, but apparently does not have the rich libraries that Java has. So, for me it really boils down to Scala (with akka) or Erlang.
For the web server, with Scala, you can use any java app server. Foursquare uses jetty for most things. It's not written in Scala, but since Scala compiles down to bytecode that runs on the JVM it easily interops with any java app server.
People also say that there aren't that many Erlang programmers and that Erlang is harder to learn (functional programming vs imperative programming) Scala is functional and imperative at the same time (meaning you can do either)
Erlang is functional. Now, functional programming has a lot of things going for it as one expert functional programmer can get a lot more done than an expert imperative programmer. Yahoo stores was originally written and maintained in Lisp (functional language) by one man. On the other hand, imperative programming is easier to learn and used widely in a team setting. Imperative languages are good for some things, functional languages for
others. The right tool for the right job.
Back to the web server discussion, with Erlang, you can use yaws or you can run a framework (Chicago Boss)
Here's more on the Scala vs Erlang debate.
Another link.
More here.
And another.
Another opinion.
On the database end, you have a lot of choices. See here.
You can even eschew the database all-together and save your data in mnesia (Erlang's runtime data store)
My answer is not complete as this topic (scaling app servers, databases and web servers) is very complicated and full of debate. Some frameworks even blur the tiers (web server, application server, database) distinction and integrate a lot of the functionality of these layers within the framework itself.
For example, I encounter a lot of problems developing complex webapp using PHP only. PHP has no threads, php is lacking many good things that has scala, or another good modern language with rich syntax. PHP is slow comparing to compiled JVM language. PHP is less secure in my opinion. It is good to get a bunch of data and render as HTML page, but processing for high load is not its plus. RPC as you suggest serves as communication layer.
I am wondering if it would be possible to develop an enterprise-level web application without the use of a standard MVC structure and application server by carrying the business/flow logic and session data to the client-size Javascript and make it talk to REST data services directly...maybe we could make use of an authorization/authentication layer and a second validation layer sitting on top of the data services. All these services operate on standard HTTP methods, support configurable logging&monitoring, and content or query parameters are all contained in the HTTP request/response body. Static HTML and Javascript are served to the browser and the rest is carried out by Javascript functions talking to the HTTP-based authorization/authentication, validation and then data services. Do you think this kind of an architecture could satisfy enterprise-level web application requirements?
It's possible but unlikely; what are the drivers that suggest this architecture to you? Is it just to be different or are there some specific aspects that this best addresses?
by carrying the business/flow logic
and session data to the client-side
Javascript and make it talk to REST
data services directly
In theory you'd still be able to have an appropriately layered solution (Business Logic (BL) script vs UI focused script) but practically speaking it'd be messy, and you'd lose the ability to physically separate it into different tiers. This could "bite" you at any number of places in the life of the system.
"Enterprise" grade systems are seldom small, I hate to think how much logic you'd be having to send over the wire to support a given action/process.
Putting all the BL into a scripting language ties you to that platform, and platforms change over time. The bad thing about scripts is that whilst they are stable to a degree I'd suggest they are more exposed to change than server-based platforms like Java or .Net. In an enterprise scenario, the servers will have very tight change control and upgrade paths mapped out for them - whereas browsers are much more open to regular change.
There's the issue of compatibility - unless you're tied to a specific browser (to the version level) guaranteeing consistent behavior is going to be harder, and will likely require more development effort. Let's say you deliver the solution successfully; what do you do when the business wants to take advantage of mobile computing - say iPads? Your only option is going to be a browser - you won't be able to take advantage of any of the native advantages of the platform. "The web and browsers" might seem like they'll be around forever - but then I'm guessing that what MainFrame folks said at the time. A server-centered solution is going to give you more life for less expense.
Staffing will be an issue - you'll need very strong JavaScript and server-side developers.
Security: having your core BL out on the client where it's much more exposed sounds very dangerous.
EDIT:
Web Apps can be sow for many reasons - not many of which are reason enough to put all your BL in JavaScript on the client. Building apps for performance is a whole field of endeavor on its own - I suggest you get more familiar with Architecting and implementing for performance before you write off n-tier web apps altogether :)
Regarding keeping your layers separated: there are different ways of doing this but it boils down to abstraction - and more correctly to keeping good design principles in mind; if you haven't heard of SOLID that would be a good place to start. In terms of implementation start reading up on Dependency Inversion (FYI - self-promotion, the articles mine and is .Net focused, but you should have no problem tracking down Java-based ones too).
Update: This question was inspired by my larger quest for mapping ontologically the whole software systems architecture enchilada. I've written a blog post about it, and hopefully it will help clarify what I'm after.
Many, many, many frameworks and stacks that's event-driven have too much variation for my little head to get around. Is there somewhere some resources that defines the outline of a reasonable Application Event Model, what events there are, and what triggers are most common?
I've got my own framework with a plugin and event-driven architecture, but I want to open-source it, and as such would like to make it closer to some common ground as not to alienate people.
So to clarify; this is for an application, meaning setting up the environment, the dependencies, the data sources (like databases), and being a MVC framework setting up the model, the view, launching controllers / actions, and in the GUI various stages of the interface (header, content, columns, etc.).
Ideas? Thoughts? Pointers? (And I've made it language and platform neutral at this point)
I read your blog entry, which btw I found an extremely interesting read, but... this question does not seem to reflect the broadness of the issue you are presenting there.
What you are after is very abstract and theoretical. What I mean to say is that if you tie any of those ideas to actual technology you will find yourself 'stuck' with it. This is why many of us are reluctant to use any framework. Especially the 'relabeled' products suddenly claiming to conform to the trend. We choose mainly on the basis of what appears to be needed to reach a predetermined result.
Frameworks (or tools in general) that target the application architecture domain distinguish themselves primarily by the amount of responsibility they are designed to take on. Spring for example only deals with the concept of decoupling and is therefore easily adopted and useable in many situations. The quality of any framework is expressed in terms of how well the designers of such frameworks were able to keep their products within the boundaries of that responsibility. Some front-to-end products will do exactly the opposite, code generators being among the 'worst' of them.
To answer your question at the top of this page, I do not think there is a framework that does what you want at this time and I do not think there is a single model of how applications (should) work. Keep in mind though that the application architecture domain deals with technology more than it does with concepts. In other words: If it works and meets the requirements, then you're pretty much done.
That said, you might find something of value in agent-based systems.
Heh. Most developers pick the major framework they like the tools for and stick with it. That's usually the winning strategy. I sympathize with your desire not to marry a single vendor.
Keep in mind however, that in developing your own framework, you're going to end up tied to a single vendor anyway. :-)
Is there somewhere some resources that defines the outline of a reasonable
Application Event Model, what events there are, and what triggers are most common?
I don't think so.
From what I see, there are two kinds of models out there: those with a real framework with which you can make a working data entry dialog, and abstract meta-meta-models that are optimized for modeling themselves.
Try surveying a few current frameworks that have good documentation online and cross-reference the major terminology in a spreadsheet. It's an interesting exercise.
I'd have a look at Spring for Java, and the XT Framework Spring module (http://springmodules.dev.java.net/docs/reference/0.9/html/xt.html), which apparently supports event-driven architecture, as starting points. Spring has an MVC framework (inc. convention-based routing to controllers), db configuration (for Hibernate, particularly), plus full dependency injection support. There's also a mechanism in Spring for modularising your web apps, called Spring Slices. And it can be integrated with Jersey for building RESTful apps.
(Unfortunately, I tried to provide links to everything, but this place only lets new users post a single link. So you'll have to do some googling :) )
Scaffolding, what is it? Is it a Rails-only thing?
Scaffolding generally refers to a quickly set up skeleton for an app. It's not rails-only since other platforms have it as well. It's also not generally meant to be a "final" system; merely the first, smallest way to do it.
From Wikipedia:
Scaffolding is a meta-programming
method of building database-backed
software applications. It is a
technique supported by some
model-view-controller frameworks, in
which the programmer may write a
specification that describes how the
application database may be used. The
compiler uses this specification to
generate code that the application can
use to create, read, update and delete
database entries, effectively treating
the template as a "scaffold" on which
to build a more powerful application.
Just like a real scaffolding in a building construction site, scaffolding gives you some kind of a (fast, simplified, temporary) structure for your project, on which you can rely to build the real project.
It can be (and is today) used to describe many things - from abstracting DB layers, to web apps folder structures, and to generating and managing project dependencies .
It is not something that is specific to any language / technology, just like the term skeleton or boilerplate is platform agnostic.
It is just a term borrowed from real scaffolding (like mentioned above).
You build some fast, simplified, (sometimes external, sometimes temporary) structure that will help you to build the real, more complex, finalized structure under, above, inside or outside of that temporary structure .
.. And just like the real scaffolding, the scaffolding structure is meant to support the building process of the project, rather than the project itself (with some exceptions).
Scafolding is usually some type of code generation where you point it at a database, and the technology creates basic CRUD (create, read, update, delete) screens.
I believe that Wikipedia and some answers here provides a narrow and restricted view. Scaffolding is not just for CRUD operations on top of a database. Scaffolding has a broader objective to give you a skeleton app for any kind of technology.
Yeoman is a modern and useful tool for scaffolding. Using their own words:
The web's scaffolding tool for modern webapps
What's Yeoman?
Yeoman helps you to kickstart new projects, prescribing best practices
and tools to help you stay productive.
To do so, we provide a generator ecosystem. A generator is basically a
plugin that can be run with the yo command to scaffold complete
projects or useful parts.
Through our official Generators, we promote the "Yeoman workflow".
This workflow is a robust and opinionated client-side stack,
comprising tools and frameworks that can help developers quickly build
beautiful web applications. We take care of providing everything
needed to get started without any of the normal headaches associated
with a manual setup.
With a modular architecture that can scale out of the box, we leverage
the success and lessons learned from several open-source communities
to ensure the stack developers use is as intelligent as possible.
As firm believers in good documentation and well thought out build
processes, Yeoman includes support for linting, testing, minification
and much more, so developers can focus on solutions rather than
worrying about the little things.
That's it. Use scaffolding to create a quick-start application to work as an example or the foundation of your solution. It makes you productive faster them building things from scratch.
It is not a rails only term although I think it originated there (at least that is where I first heard it.)
Scaffolding is a framework that allows you to do basic CRUD operations against your database with little or no code. Generally, you then go through and add the code to manage the data the way you want replacing the scaffolding. It is generally only intended to get you up and running quickly.
No it is used in other technologies also such as ASP.NET MVC
it creates a basic layout from some predefined code which programmers uses in almost every project , Eg: for database data access it can make a crud method for create, read, update, delete operations
OR you might use it to create layout for your View/Html Code
Scaffolding is writing any piece of code that would not be part of the business logic but would help in unit testing and integration testing.
This is a software engineering term and not bound to any framework or programming language.
No, scaffolding is not the term for the specific platform, however many know this term in the context of Ruby on Rails or .NET
There are also plenty of tools that perform javascript scaffolding:
divjoy.com
flatlogic.com
scaffoldhub.com
yeoman.io
Those tools are also known as code-generators
Scaffolding is the term used when you don't want to create all parts of the structure such as models, views, etc. and want to generate them all in one go. A lot of frameworks use this technique, I studied about it while doing odoo but most of the references given were to ruby on rails :)