General architecture for backend? - rest

We are trying to be forward looking in our architecture choice on some of the new systems we are designing. Pretty much we want to architecture back end system that no matter what interface we decide to use (WinForms, Silverlight, MVC, Webforms, WPF, IOS (IPad/Iphone), ect...) which i believe just screams REST. Our organization generally will only use Microsoft APIs but since i have no idea when WCF-Web-Api will be released and we want to get started soon it looks like we have no other choice.
We want to take baby steps here to increase the chances of buy off. So we don't want to have to set up another server with IIS.
In the foreseeable future we will only be using WinForms & WebForms. What i was thinking we could use Nancy on the local machine but communicate with it in a RESTFul way. That way in the future it should be as simple as setting up a server and redirecting all the clients to that server rather than locally.
I've never used either NancyFX or OpenRasta, but, from what ive heard, it sounded like a good fit.
So the questions are:
Is the way i'm thinking on approaching this a good approach
Does it sound like NancyFX or OpenRasta would be a better fit?
Any reason why we should wait for WCF-Web-API and if so does anyone have an approx release date.

OpenRasta was built for resource-oriented scenarios. You can achieve the same thing with any other frameworks (with more or less pain). OpenRasta gives you a fully-composited, IoC friendly environment that completely decouples handlers and whatever renders them (which makes it different from MVC frameworks like nancy and MVC).
I'd add that we have a very strong community, a stable codebase and we've been in this for quite a few years, we're building 2.1 and 3.0 and our featureset is still above and beyond what you can get from most other systems. Compare this to most of the frameworks you've highlighted, where none have reached 1.0.
Professional support is also available, if that's a deciding factor for your company.
But to answer your question fully, depending on your scenario and what you want to achieve, you can make anything fits, given enough work. I'd suggest reformulating your question in terms of architecture rather than in terms of frameworks.

Related

Risk evaluation for framework selection

I'm planning on starting a new project, and am evaluating various web frameworks. There is one that I'm seriously considering, but I worry about its lasting power.
When choosing a web framework, what should I look for when deciding what to go with?
Here's what I have noticed with the framework I'm looking at:
Small community. There are only a few messages on the users list each day
No news on the "news" page since the previous release, over 6 months ago
No svn commits in the last 30 days
Good documentation, but wiki not updated since previous release
Most recent release still not in a maven repository
It is not the officially sanctioned Java EE framework, but I've seen several people mention it as a good solution in answers to various questions on Stack Overflow.
I'm not going to say which framework I'm looking at, because I don't want this to get into a framework war. I want to know what other aspects of the project I should look at in my evaluation of risk. This should apply to other areas besides just Java EE web, like ORM, etc.
I'll say that so-called "dead" projects are not that great a danger as long as the project itself is solid and you like it. The thing is that if the library or framework already does everything you can think you want, then it's not such a big deal. If you get a stable project up and running then you should be done thinking about the framework (done!) and focus only on your webapp. You shouldn't be required to update the framework itself with the latest release every month.
Personally, I think the most important point is that you find one that is intuitive to your project. What makes the most sense? MVC? Should each element in the URL be a separate object? How would interactivity (AJAX) work? It makes no sense to pick something just because it's an "industry standard" or because it's used by a lot of big-name sites. Maybe they chose it for needs entirely different from yours. Read the tutorials for each framework and be critical. If it doesn't gel with your way of thinking, or you have seen it done more elegantly, then move on. What you are considering here is the design and good design is tantamount for staying flexible and scalable. There's hundreds of web frameworks out there, old and new, in every language. You're bound to find half a dozen that works just the way you want to think in your project.
Points I consider mandatory:
Extensible through plug-ins: check if there's already plug-ins for various middleware tasks such as memcache, gzip, OpenID, AJAX goodness, etc.
Simplicity and modularity: the more complex, the steeper the learning curve and the less you can trust its stability; the more "locked" to specific technologies, the higher the chances that you'll end up with a chain around your ankle.
Database agnostic: can you use sqlite3 for development and then switch to your production DB by changing a single line of code or configuration?
Platform agnostic: can you run it on Apache, lighttpd, etc.? Could you port it to run in a cloud?
Template agnostic: can you switch out the template system? Let's say you hire dedicated designers and they really want to go with something else.
Documentation: I am not that strict if it's open-source, but there would need to be enough official documentation to enable me to fully understand how to write my own plug-ins, for example. Also look to see if there's source code of working sites using the same framework.
License and source code: do you have access to the source code and are you allowed to modify it? Consider if you can use it commercially! (Even if you have no current plans to do that currently.)
All in all: flexibility. If I am satisfied with all four points, I'm pretty much done. Notice how I didn't have anything about "deadness" in there? If the core design is good and there's easily installable plug-ins for doing every web-dev 3.0-beta buzzword thing you want to do, then I don't care if the last SVN commit was in 2006.
Here are the things I look for in a framework before I decide to use it for a production environment project:
Plenty of well laid out and written documentation. Bad documentation just means I'm wasting time trying to find how everything works. This is OK if I am playing around with some cool new micro framework or something else, but not when it's for a client.
A decently sized community so that you can ask questions, etc. A fun and active IRC channel is a big plus.
Constant iteration of the product. Are bugs being closed or opened on a daily/weekly basis? Probably a good sign.
I can go through the code of the framework and understand what's going on. Good framework code means that the projects longterm life has a better chance of success.
I enjoy working with it. If I play with it for a few hours and it's the worst time of my life, I sure as hell won't be using it for a client.
I can go on, but those are some primary ones off the top of my head.
Besides looking at the framework, you also need to consider a lot of things about yourself (and any other team members) when evaluating the risks:
If the framework is a new, immature, "bleeding-edge" framework, are you going to be willing and able to debug it and fix or work around whatever problems you encounter?
If there is a small community, you'll have to do a lot of this debugging and diagnosis yourself. Will you have time to do that and still meet whatever deadlines you may have?
Have you looked at the framework yourself to determine how good it is, or are you willing to rely on what others say about it? Why do you trust their judgment?
Why do you want to use this rather than the "officially sanctioned Java EE framework"? Is it a pragmatic reason, or just a desire to try something new?
If problems with the framework cause you to miss deadlines or deliver a poor product, how will you talk about it with your boss or customer?
All the signs you've cited could be bad news for your framework choice.
Another thing that I look for are books available at Amazon and such. If there's good documentation available, it means that authors believe it has traction and you'll be able to find users that know it.
The only saving grace I can think of is relative maturity. If the framework or open source component is mature, there's a chance that it does the job as written and doesn't require further extension.
There should still be a bug tracker with some evidence of activity, because no software is without bugs (except for mine). But it need not be a gusher of requests in that case.

Is WebService the next Big thing?

I was today trying to figure out on working with WebService and found many articles really gospel over the Web Service and its effectiveness in the Market share.
My Questions are:
For a Complex project of critical data, is it better to opt for WebService?
What Makes WebService different from other way of fetching the data?
The answer is... it depends. Web services are not really the next Big thing, they have been a Huge Thing for years now. In business applications, web services allow a big level of interoperability and capabilities never seen before.
They help integration with legacy systems, cooperation between distinct departments, defining loosely coupled interfaces and such. You should read some about Service-oriented architecture.
If all you need is a PHP application that handles data from a single database, you might not need web services at all. If you are designing a solution that revolves around multiple data sources, with complex security involved, multiple languages and/or multiple applications, then web services become essential.
SOAP is a protocol; if working with PHP, you'll need to check out the PHP: SOAP guide to understand how it works. For every language (almost), there are existing APIs to develop web services. Anyhow you might want to check RESTful web services instead of SOAP-based ones, they are generally simpler to implement/understand. But that's another debate ;-).
Cheers.
That mostly depends on the definition of "big thing".
My experience with the WS stack and SOAP and all the acronym soup is that it takes an awful lot of workforce to deploy it. The status of the frameworks is complex, and definitely not something a hobbyist can put to work in a couple of afternoons. We have seen how many things on the net became the next big thing just because they were easy. Easy to understand, easy to interact with, easy in technology. Wikipedia, twitter, digg, youtube are internet big things, and they are, from the interaction point of view, light years away from SOAP/WS based interaction. They are KISS: simple and stupid. A whole horizontal market was opened just because of their simplicity. Even multiprocessing platforms like BOINC don't use anything near the WS stack, but they are the core of many high-throughput efforts.
Now, if you have to deal with complex multi-host transactions, authentication, credential delegation, caching... WS is there. It's the target that makes the need: banks, flight reservation, stuff like this. but they won't impact the common programmer. They require too much energy and too many different competences at once to become something usable for a horizontal market of developers.
Also, I am a REST person. I never advocated SOAP with much emphasis, but there was nothing else and it was a better evolution over XMLRPC (which, if you have to perform dumb RPC, IMHO it's still a good choice). Now I changed my mind. You mostly have resources on the web, and you interact with them with HTTP methods. SOAP is nothing but RPC on hypersteroids. No, REST is not the solution that replaces WS. At all. it's simply easier to use and to debug, albeit more difficult to design (you have to think in terms of resources instead of method calls). It's KISS. That's why it has more chances for success on the horizontal market.
It depends.
Web services can be useful if you need to expose the data across security boundaries, where a direct connection to an RDBMS would be a bad idea.
Popular method for implementing web services nowdays is to use RESTful API (eg. via Ajax/JSON). It's already "next big thing" – almost every major player has been offering it for years. Google, Flickr, Twitter, you name it.
The big advantage is that they help to implement an API layer.
If you implement your solution using a "bus" where the web services sit, it opens up your product to a far greater range of users and moves away from being a proprietary product.
It also enables people to interface using a wide range of solutions e.g web service clients can be implemented using command line, Jsp, Java, Asp, .NET, PHP etc.
They also enable code re-use e.g. if you implement GetClientDetails (ID) as a web service for one user, when the next group comes along wanting the same thing, all you have to do is give them the WSDL and they are away.

Should I Use a Framework While Learning Web Development

I realize that this may be subjective but I truly need an answer to this and I can't seem to find anything close enough to it in the rest of the Forum. I have read some folks say that the framework (any MVC framework) can obscure too many things while others say that it can promote good practices. I realize that frameworks are great for a certain level of programmer but what about individuals starting out? Should one just focus on the language or learn them together?
I think web development is way more than anyone grasps when they first start getting into it! Read this and know that it is all optional...but required to be really good at what you do.
I suggest that you spend time learning your language first. I would suggest learning C# simply because it is vastly more marketable and it is usually directly supported in most of MS products. By learning C# - programming in ASP.NET, console apps, servers, services, desktop apps, etc. will all be within your reach. You can program for most of the MS products as well as on many Linux type platforms.
Once you have this down then you can move to programming for the web as programming for the web has some intricacies that most other environments don't have. Concepts such as sessions, caching, state management, cross site scripting, styling, client side vs server side programming, browser support, how HTTP works, get vs post, how a form works, cookies, etc. are all at the top of the list of things to learn separately not to mention learning the ASP.NET base frameworks and namespaces.
Once you have the programming language down and then the concepts of web programming I suggest that you pause and learn database design. Don't worry about performance just yet...try to first learn good design. Performance will come next. A good start for you is Access (blasphemy I know). It is easy for a beginner to work with. And it translates into a more robust platform such as SQL Server easily. Learn at the very least some SQL...but I suggest that you learn as much as your stomach can handle. I heard someone say that SQL is like the assembly language of the database. The number one thing that slows an application to a halt is piss poor database design and poor queries. Once you have this knowledge - stuff it away in the back of your mind and take a look at a good ORM. NHybernate is probably best at the moment but is more complex that the basic learner needs. For that reason I currently suggest getting LINQ to SQL up and running as it is SUPER EASY to work with. Then look at Entity Framework (although I still think it sucks...and you should wait till EF 2.0...ERRRRR...now 4.0 released with .net 4.0). Then NHybernate.
Now is the time to start to understand the infrastructure that is required by web development. You may bump your head against this as you learn some of the web programming stuff. But you need to understand the basics of DNS, IIS, load balancers, sticky routing, round robin, clustering, fault tolerance, server hardware setup, web farms, cache farms (MemCached Win32, Velocity), SMTP, MSMQ, database mail queuing, etc. Many people may say you don't need this. That there will be some knowledgeable network admin to help you out here. However they generally know things that impact them...not you. The more you know here the more valuable you will be to the company that hires you.
Now you can get into the details of best practices and design patterns. Learn about the basics such as repository pattern, factory pattern, facade pattern, model view presenter pattern, model view controller pattern, observer pattern, and various other things. Follow Martin Fowler and others for suggestions here. Take a look at concepts such as inversion of control, dependency injection, SOLID principle, DRY, FIT, test driven design, and domain driven design, etc. Learn as much as you can here before moving to the next step.
NOW you can think about frameworks! Start by creating a basic application with ASP Classic (comes with IIS for free!). This will give you a flavor of a no frills web development environment. Take a look at ASP.NET web forms (briefly) to see how MS attempted to make things easier by hiding all the complex stuff (which you now know how to manage on your own from your readings of the above materials!!!). Now you no longer need ASP.NET Web Forms. Move immediately to ASP.NET MVC. The MVC framwork gives you all the power you need to create a good easily manageable web application. If you build something really big no framework for pure web development may be able to deal with what you need. However MVC is way more extensible for such UBER custom scenarios.
Now that you have made it through the journey to ASP.NET MVC you can take a look at things such as Microsofts Enterprise Application Blocks (such as they use at MySpace). Take a look at Elmah error logging (a must have). Look at how to build a custom SiteMapProvider for your MVC site. If you need to get into searching stuff understand Lucene.NET.
And if you made it this far...you are ready to figure out the rest on your own as it comes up! Have fun. There is a lot of room in this space for a person with some understanding of all of the above concepts.
You'll be using SOME sort of framework. The question is, what level do you want to learn at?
You'll probably not care to learn about asynchronous I/O and mutlithreaded vs. select/poll styles of web servers.
So then, your language of choice is going to provide a layer atop this, the languages preferred "web interface" API. For Java it's Servlets, the lowest level you'd typically code at for server side web applications.
You should find what this "lower level" layer is in your language and learn the API at least. You should know basic HTTP like status codes, cookies, redirects, POST vs GET, URL encoding, and possibly what some of the more important headers do.
You'll then come to appreciate what these higher level frameworks bring to the table, and be better able to evaluate what is the appropriate level of abstraction for your needs/project.
Web development requires a certain degree of organization, since it relies so much on separation of concerns. The browser, for example, is designed to display data and interact with the user. It is not designed to lookup data from a database, or perform analysis. Consequently, a web development framework can help provide services that are needed to make the browser experience a practical one.
The nice thing about employing a platform is that it will provide core components essential to the making of any web application that you won't (and shouldn't) have to think about, such as user membership, for example. Many of the design decisions and deep thinking about how to implement these services has already been done for you, freeing you to focus on what you actually want you application to do.
Of the available frameworks, I find that frameworks that implement the MVC (model-view-controller) pattern are very practical. They clearly organize different functions of web development, while giving you full control over the markup presented to the browser.
All that said, you will need some fundamental skills to fully realize web development, such as HTML, CSS, and a core programming language for the actual underlying program, whether you use a platform or not.
I don't think I agree with the Andrew. I don't think learning C is a pre requisite for web development. In fact, learning something like Javascript, Action-script or PHP is often easier due in large part to the vast numbers of sites and tutorials available, and are enough to expose you to the fundamentals of pretty much every programing language. Variable, Conditions, Loops and OOP. I just think learning C# introduces a lot of learning that isn't really relevant to web development such as pointers and memory management.
As for wether you should learn a framework first? Definitely not. Never ever. You need to be able to stand on your own two feet first and be comfortable with HTML/CSS, Server Side Scripting (PHP/ASP/Python/Ruby whatever) and love it or loathe it, but you're going to have to have a decent understanding of Flash and Action-script.
The order in which you learn these is entirely up to you. But my learning plan would go like this...
Start with HTML. It takes about half an hour to get the basics (it's made up of tags with attributes, end of lesson 1) and it's good to get it out of the way first.
Then start leaning CSS. You'll get the basics again, very quickly. But CSS is a minefield so expect to spend the rest of your life figuring it out.
Next up Action-script. Most people wouldn't agree with me, but bear with me. HTML and CSS aren't programming languages. Action-script is. And learning a programing language for the first time is difficult and tedious. The advantage Action-script has over most other languages is that the results are very visual. It's enjoyable to work with and you can sit back and take pride in your accomplishments at regular intervals. This isn't possible with server-side scripting languages or Javascript and there's a whole host of stuff you need to learn to get server side scripting up and running. You can't build space invaders in with PHP for example.
I've changed my thinking here. I would encourage beginners to ignore ActionScript and focus on Javascript. I still believe that being able to see stuff on screen quickly is a good motivator, but I would encourage people to look at canvas tag tutorials and frameworks. Javascript has come a long way since 2009, and is now the lingua franca of programming, so it's incredibly useful. My initial point about HTML and CSS not being programming languages still stands.
Then, you can start with your server side language. At the same time, you're going to have to figure out the database stuff. I recommend PHP and MySQL because it's free.
Again, I've changed my thinking here. I would encourage beginners to use Javascript on the backend (Node.js), and split their database learning between relational databases and noSql solutions such as Mongo.
Then.... learn your framework. Or better yet, roll your own. That's what I've been doing and it's supercharged my learning.
If you're getting into web development, You HAVE to know how those building blocks work. You don't have to be an expert in all the areas, but you should try to become an expert in at least one of them. If you start learning a framework before you get the fundamentals you'll be in a sticky middle ground where you don't understand why things don't work which will infuriate you, and anyone who has to work with you.
you should learn how to use framework because it would be helpfull for u in the future also it is easier to learn.
MVC will help you a lot .. trust me ... i was developing web project not using mvc and it is like mess ... (in the past there are no well know mvc and i never heard about it)
Short version: yes, and then some.
FWIW : This more generic answer may be of use to someone out there.
What: Frameworks take out tedium of using boiler-plate code again and again. They hide complexity and design issues under wizards and conventions. They also use special libraries, design patterns etc. in ways that are far from obvious to a beginner.
So using a framework is good for getting things done without knowing exactly how - like using an ATM without knowing the internals. You just add your code bits in certain places and things 'just work'.
HTML > CSS > Ruby > SQL > Rails/Javascript framework > Libraries would make for a good learning track. Rest you learn as you go along by being curious, hanging out on forums or as extended learning as need arises.
HOW: The problem starts the minute you step outside simple text-book examples (i.e. when you try to get it to do something even a bit different).
Decoding cryptic error messages when it seems like you've done everything right but things still don't work. Searching on error strings in forums may help out. Or just re-starting from scratch.
Reading up articles and books, videos, trial-and-error, hard-work, search-engines, stackoverflow/forums, local gurus, design articles, using libraries, source-code browsing are a good way to climb the learning curve gently and on a requirement basis.
Working-against-the-framework is the number one problem for beginners. Understanding what the framework expects is key to avoiding white-hair in this phase. Having enough insight to manually do what the framework automates may help reduce this second-guessing effort.
WHY: For more advanced debugging/design, it's good to know what the framework is doing under the hood esp. when things don't work as you planned. Initially you can take the help of local-gurus or forum gurus who've already done the hard work. Later as you go deeper you can take on more of that role. For example there's a "rebuilding rails" book which looks under the hood of Ruby on Rails.
Note: Some of the tips are oriented towards Ruby/Rails but you can easily substitute your favourite language/framework instead.

productivity superstar frameworks/tools for side gigs

If you were going to start building web sites as a consulting business on the side -- keeping your day job -- and you also had a toddler and a wife, what frameworks/tools would you pick to save you typing?
Any language.
I'm looking for a productivity superstar stack that won't tie my hands too much when I have to update the site 6 months later, or "evolve" the data model once in production.
It needs to allow me to say "yes" to the client: community features, CMS, security, moderation, AJAX, ...
I would suggest Django. Super simple to get something up and running really quick. You are using Python which has a large library to go with it. For me Ruby on Rails would be a close second.
I'd probably look at DotNetNuke. Its easy to set up (a lot of hosts will do it for you) and easy to use and put together a custom site that business's will be able to maintain in the future.
Its fairly easy to create custom modules that are specific to a business and hundreds of modules for sale (or free) that can be integrated into DNN for special uses.
Take a look at Microsoft's Sharepoint server if you'd like a pre-made framework with many options for plugging in your own code. Sharepoint is kind of a world unto itself but it is a very powerful environment.
Update: I'm surprised to have been voted down on this one. Keep in mind that the questioner specifically requested frameworks that included a CMS. Sharepoint meets this criteria - unlike straight .NET or other web development frameworks.
If you are going to vote the entry down, I think you owe it to the person who asked the question to explain why you don't think he should not even explore it as an option. You could be right - collective wisdom is what voting on SO is all about. But without an explanation, we don't know why you think you are right.
My answers are going to revolve around the .NET stack.
Use Master pages and CSS templates. This makes it so much easier to pop in a new look and feel for your customer.
For sure I'd include the Dynamic Data framework in the .NET world.
Hosting might become an issue for your customer. Questions around managing email addresses, procedures on how to quickly update the website to include the new contact phone number (different for each customer, I'd assume) Consider getting a reseller account on your favorite webhost, and dole out webhosting accounts as appropriate. There are lots of issues around this point. It may turn out to be a nice source of recurring revenue.
Build yourself a few patterns including a database wrapper which would handle all your data calls (i.e. a dll which wraps all your data calls, sets up your ADO.NET objects, runs your sproc calls, and picks up the connstring from app.config or something similar.)
This goes a long way to maintainability as well.
I would recomend going with anything MVC in a language you can undertand! Theres a couple of CMS's in python, php and ruby using that design and well... that allows you to be ready for combat for Ajax and expanding anything very fast.
This is definitely not a question that can be answered.
I prefer asp.net webforms because I think it allows for extremely rapid web app development, but I am sure you will receive recommendations for:
asp.net mvc
Ruby on Rails
PHP and some framework
Python and some framework such as Django
I believe PHP has the most pre-built apps that you can use, though asp.net also has the things you are looking for.
All of these platforms and frameworks can do what you want.
Choose between Rails and Django. They both have different strengths. I like Rails better in general, but Django's admin interface can save you a lot of time when you need it.
There's another factor to take into consideration here: what are you the most familiar with? I believe that some studies have found upwards of a 30% loss of productivity when trying to learn a new language/framework.
Sometimes, there's nothing wrong with just sticking to what you know. But if you're interested in what languages/frameworks to learn, I'll refer you to the other posts because the above was the only thing I really have to add.
I recommend looking into Grails. It uses Groovy which is similiar to Java (so if you know this already you're good to go). Groovy runs on the JVM so you can still use all the great libraries already available for Java. Yet, since it's a dynamic language with a lot of the similar bells and whistles like Ruby you can use closures and that kind of neat stuff when you need/want to. And you're not slowed down by Java's traditonal slow compile-deploy-test development cycle.
Grails is already setup with Hibernate and Spring. You can create CRUD application in practically no-time (pretty much like Rails applications), and at the same time drill down and be able to control every little details since it's built on such proven and well-supported technologies. In addition there's literally hundreds of plugins available that helps you easily set up things like mailing lists, security, AJAX components and so on.
Otherwise, if you want to set up a community site and don't want to code a single line you could always check out ning.com.

What level of complexity requires a framework?

At what level of complexity is it mandatory to switch to an existing framework for web development?
What measurement of complexity is practical for web development? Code length? Feature list? Database Size?
If you work on several different sites then by using a common framework across all of them you can spend time working on the code rather than trying to remember what is located where and why.
I'd always use a framework of some sort, even if it's your own, as the uniformity will help you structure your project. Unless it's a one page static HTML project.
There is no mandatory limit however.
I don't think there is a level of complexity that necessitates a framework. For me whenever I am writing a dynamic site I immediately consider a framework, and if it will save me time, I use it(it almost always does, and I almost always do).
Consider that the question may be faulty. Many of the most complex websites don't use any popular, preexisting, framework. Google has their own web server and their own custom way of doing things, as does Amazon, and probably lots of other sites.
If a framework makes your task easier, or provides added value, go for it. However, when you get that framework you are tied to a new dependancy. I'm starting to essentially recreate a Joel on Software post, so I will redirect you here for more on adding unneeded dependencies to your code:
http://www.joelonsoftware.com/articles/fog0000000007.html
All factors matter. You should measure how much time you can save using 3rd party framework and compare it to the risks of using other's code
Never "mandatory." Some problems are not well solved by any framework. It would be suggestible to switch to a framework when most of the code you are implementing has already be implemented by the framework in question in a way that suits your particular application. This saves you time, energy, and will most likely be more stable than the fresh code you would have written.
This is really two questions, you realize. :-) The answer to the first one is that it's never mandatory, but honestly, parsing HTML request parameters directly is pretty horrible right from the start. I don't want to do it even once, so I tend to go toward a framework relatively early on.
As far as what measurement is practical, well, what are you worried about? All of the descriptions that you list have value. Database size matters primarily for scaling, in my opinion (you can write a very simple app if you have a very simple schema, even if there are hundreds of thousands of rows in the database). The feature list will probably determine the number and complexity of UI pages, which will in turn help to dictate the code length.
There are frameworks that are there for getting moving very quickly with a simple blog, django or RoR all the way to enterprise full-stack applications Zope. Not to be tied to just the buzz world, you also have ASP.Net and J2EE, etc.
All frameworks and libraries are tools at your disposal. Determine which ones will make your life easier for your given project and use them.
I would say the reverse is true. At some point, your project gets so expansive, that you actually get slowed down by the shortcomings of the framework. For sufficiently large projects you may, in fact, be better off developing your own framework, to meet your own needs. I have seen many times where people were held back in the decisions they could make, or the work they could produce, because they were trying to do something that the framework didn't anticipate. And doing these things that the framework doesn't anticipate can be very troublesome. The nice thing about making your own framework, is that it can evolve with your project, to be a help to you system, instead of a hindrance.
So, to conclude, small projects should be use existing frameworks. Large projects should contain their own framework.