Getting up to speed on current web service design practices - rest

I'm admittedly unsure whether this post falls within the scope of acceptable SO questions. If not, please advise whether I might be able to adjust it to fit or if perhaps there might be a more appropriate site for it.
I'm a WinForms guy, but I've got a new project where I'm going to be making web service calls for a Point of Sale system. I've read about how CRUD operations are handled in RESTful environments where GET/PUT/POST/etc represent their respective CRUD counterpart. However I've just started working on a project where I need to submit my requirements to a developer who'll be developing a web api for me to use but he tells me that this isn't how the big boys do it.
Instead of making web requests to create a transaction followed by requests to add items to the transaction in the object based approach I'm accustomed to, I will instead use a service based approach to just make a 'prepare' checkout call in order to see the subtotal, tax, total, etc. for the transaction with the items I currently have on it. Then when I'm ready to actually process the transaction I'll make a call to 'complete' checkout.
I quoted a couple words above because I'm curious whether these are common terms that everyone uses or just ones that he happened to choose to explain the process to me. And my question is, where might I go to get up to speed on the way the 'big boys' like Google and Amazon design their APIs? I'm not the one implementing the API, but there seems to be a little bit of an impedance mismatch in regard to how I'm trying to communicate what I need and the way the developer is expecting to hear my requirements.

Not sure wrt the specifics of your application though your general understanding seems ik. There are always corner cases that test the born though.
I would heed that you listen to your dev team on how things should be imolemented and just provide the "what's" (requirements). They should be trusted to know best practice and your company's own interpretation and standards (right or wrong). If they don't give you your requirement (ease-of-use or can't be easily reusable with expanded requirements) then you can review why with an architect or dev mgr.
However, if you are interested and want to debate and perhaps understand, check out Atlassian's best practice here: https://developer.atlassian.com/plugins/servlet/mobile#content/view/4915226.
FYI: Atlassian make really leading dev tools in use in v.large companies. Note also that this best-practices is as a part of refactoring meaning they've been through the mill and know what worked and what hasn't).
FYI2 (edit): Reading between the lines of your question, I think your dev is basically instructing you specifically on how transactions are managed within ReST. That is, you don't typically begin, add, end. Instead, everything that is transactional is rolled within a transaction wrapper and POSTed to the server as a single transaction.

Related

BMC Remedy 9.1 REST API front end performance impacts

I understand this is a loaded question, however I am going to try my luck to see if anyone has info/documentation that I have been unable to locate thus far. Perhaps someone with a better understanding of REST API functionality could point me in the correct direction.
In looking to deploy Remedy 9.1, I am being told REST API will be disabled due to performance concerns of the front end application itself (web interface). I am trying to find out if there is any quality control or prioritization that occurs on the backend that would mitigate this concern.
I understand that there are some obvious savings in not having to dynamically render a webpage or engage the front end virtually at all when making a REST API call, so when pulling data its more lean 1 to 1 to use REST. However if someone where to be reckless with a REST API call, is the ARServer at all equipped to manage this request by assigning it low priority, or would it simply take down the whole system?
In a perfect world I would love if someone could point me to some specific documentation that has something close to a definitive answer either way.
Thanks for any help anyone may be able to send my way.
Deploy a server group, keep one server for the front end and one for the back end. Only make calls to the 'back end' server.
I think the bigger issue that is being avoided is that there are kinds of places for bottlenecks. If they are concerned about that, what guardrails do they have in place to protect from an overloaded database? Or a table lock? The REST API is just another client. There is only so much you can do to protect the system. Since it is another client, it has all the protections at the app level that exist for every other client. Indexing, requiring search criteria, threading, and other performance tactics will help regardless of the client.
RCJ has a good point in that you can dedicate servers in the server group (or even outside of it) to accommodate their needs. But you will always go back to the central database as the ultimate risk.

Which server setup would be easiest to send a photo/text from an iOS app (swift) to a place where I can download/access them?

I'm using swift — and the app needs to send a photo and matching text (that a user submits) to a server so that I can download the photo/text.
Would an existing FTP server that I have setup for my website be possible for this application? Or would it make more sense to do something with a web portal?
During my research, I'm finding options like Backendless, Alamofire, Gold Racoon, and various others. They seem like overkill for the simple task I'm looking to accomplish. Is there some minimal service out there that can automate my simple need? If not, which of these options would you recommend for my situation?
Ideally the setup would be free, but I'd be willing to spend up to $100 or $10/month if the service fits.
I'm new to app development so I'm feeling overwhelmed with the options and not sure how to begin researching. I hope beginner questions aren't frowned upon here — I would really appreciate any advise on what I should begin learning to achieve my goal of sending a photo+text from an iOS app to a place where I can access them.
If there are other questions I should be asking to achieve this, please let me know.
For your case there are two main routes to consider
1. BYOS (Bring Your Own Server)
With this option, you are responsible for creating and maintenance of your own server.
Now you can use various services such as Digital Ocean and Amazon for this.
On top of this, you would be responsible for creating your own database and maintaining it as well. Plus, you would need to write server side code along with client side code (the app) in order to instantiate communication between the two.
The advantage of this is that you virtually have control of everything but I think it is pretty clear how painful this task is.
2: BAS (Backend As a Service) Highly recommended
With this route, you simply have to write the app and let another service handle the server side of things. One of the most common ones is Firebase. Most folks including startups go down this route.
There are a bunch of other services out there.
Two Cents:
Whatever option or service you decide to use, I would recommend you make sure that:
a. The service has a good track record.
You do not want something that might end up getting shutdown in the next couple months. I know it is hard to predict this but certain initial guesses/probabilities can be made.
b. Make sure its community is vibrant.
The last thing you as a newbie wants is to be stuck and have no one to help you. Research around and see the different questions people ask and whether or not answers exist.

Does there exist a robust Twilio enabled CMS with subscription management?

I've done quite a bit of searching for a CMS platform or robust framework that will perhaps facilitate the management of signup and subscriptions right of the box with a Twilio tie in.
Thus far I've only been successful at finding how many startups have been funded by the Twilio fund, who's building the nextgen voice enabled app, and various other things of that nature vs any real meat. Seems that there's a dearth of meaningful information without applying a plethora of negative google filters to reduce matches and even then it's still not giving anything real meaningful wrt my search.
So, I'm hoping that someone may have a better eye on the lay of the Twilio landscape as far as already existent systems go that can handle the bulk of needs that exist for a "regular" CMS esque site that needs to also handle subscriptions and e-commerce related tasks.
Hitherto I've just planned to build something out myself, but I wanted to do a sanity check before I spend a lot of time that could perhaps be obviated.
My suggestion would be to find a CMS that does everything you want (except the twilio links), on the platform you want, and then just add the Twilio stuff in. Twilio is simple to use, and should be simple to add-on to most open source CMS's. It'll probably be the easiest part of the project....

How to manage multiple clients with slightly different business rules? [closed]

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We have written a software package for a particular niche industry. This package has been pretty successful, to the extent that we have signed up several different clients in the industry, who use us as a hosted solution provider, and many others are knocking on our doors. If we achieve the kind of success that we're aiming for, we will have literally hundreds of clients, each with their own web site hosted on our servers.
Trouble is, each client comes in with their own little customizations and tweaks that they need for their own local circumstances and conditions, often (but not always) based on local state or even county legislation or bureaucracy. So while probably 90-95% of the system is the same across all clients, we're going to have to build and support these little customizations.
Moreover, the system is still very much a work in progress. There are enhancements and bug fixes happening continually on the core system that need to be applied across all clients.
We are writing code in .NET (ASP, C#), MS-SQL 2005 is our DB server, and we're using SourceGear Vault as our source control system. I have worked with branching in Vault before, and it's great if you only need to keep 2 or 3 branches synchronized - but we're looking at maintaining hundreds of branches, which is just unthinkable.
My question is: How do you recommend we manage all this?
I expect answers will be addressing things like object architecture, web server architecture, source control management, developer teams etc. I have a few ideas of my own, but I have no real experience in managing something like this, and I'd really appreciate hearing from people who have done this sort of thing before.
Thanks!
I would recommend against maintaining separate code branches per customer. This is a nightmare to maintain working code against your Core.
I do recommend you do implement the Strategy Pattern and cover your "customer customizations" with automated tests (e.g. Unit & Functional) whenever you are changing your Core.
UPDATE:
I recommend that before you get too many customers, you need to establish a system of creating and updating each of their websites. How involved you get is going to be balanced by your current revenue stream of course, but you should have an end in mind.
For example, when you just signed up Customer X (hopefully all via the web), their website will be created in XX minutes and send the customer an email stating it's ready.
You definitely want to setup a Continuous Integration (CI) environment. TeamCity is a great tool, and free.
With this in place, you'll be able to check your updates in a staging environment and can then apply those patches across your production instances.
Bottom Line: Once you get over a handful of customers, you need to start thinking about automating your operations and your deployment as yet another application to itself.
UPDATE: This post highlights the negative effects of branching per customer.
Our software has very similar requirements and I've picked up a few things over the years.
First of all, such customizations will cost you both in the short and long-term. If you have control over it, place some checks and balances such that sales & marketing do not over-zealously sell customizations.
I agree with the other posters that say NOT to use source control to manage this. It should be built into the project architecture wherever possible. When I first began working for my current employer, source control was being used for this and it quickly became a nightmare.
We use a separate database for each client, mainly because for many of our clients, the law or the client themselves require it due to privacy concerns, etc...
I would say that the business logic differences have probably been the least difficult part of the experience for us (your mileage may vary depending on the nature of the customizations required). For us, most variations in business logic can be broken down into a set of configuration values which we store in an xml file that is modified upon deployment (if machine specific) or stored in a client-specific folder and kept in source control (explained below). The business logic obtains these values at runtime and adjusts its execution appropriately. You can use this in concert with various strategy and factory patterns as well -- config fields can contain names of strategies etc... . Also, unit testing can be used to verify that you haven't broken things for other clients when you make changes. Currently, adding most new clients to the system involves simply mixing/matching the appropriate config values (as far as business logic is concerned).
More of a problem for us is managing the content of the site itself including the pages/style sheets/text strings/images, all of which our clients often want customized. The current approach that I've taken for this is to create a folder tree for each client that mirrors the main site - this tree is rooted at a folder named "custom" that is located in the main site folder and deployed with the site. Content placed in the client-specific set of folders either overrides or merges with the default content (depending on file type). At runtime the correct file is chosen based on the current context (user, language, etc...). The site can be made to serve multiple clients this way. Efficiency may also be a concern - you can use caching, etc... to make it faster (I use a custom VirtualPathProvider). The largest problem we run into is the burden of visually testing all of these pages when we need to make changes. Basically, to be 100% sure you haven't broken something in a client's custom setup when you have changed a shared stylesheet, image, etc... you would have to visually inspect every single page after any significant design change. I've developed some "feel" over time as to what changes can be comfortably made without breaking things, but it's still not a foolproof system by any means.
In my case I also have no control other than offering my opinion over which visual/code customizations are sold so MANY more of them than I would like have been sold and implemented.
This is not something that you want to solve with source control management, but within the architecture of your application.
I would come up with some sort of plugin like architecture. Which plugins to use for which website would then become a configuration issue and not a source control issue.
This allows you to use branches, etc. for the stuff that they are intended for: parallel development of code between (or maybe even over) releases. Each plugin becomes a seperate project (or subproject) within your source code system. This also allows you to combine all plugins and your main application into one visual studio solution to help with dependency analisys etc.
Loosely coupling the various components in your application is the best way to go.
As mention before, source control does not sound like a good solution for your problem. To me it sounds that is better yo have a single code base using a multi-tenant architecture. This way you get a lot of benefits in terms of managing your application, load on the service, scalability, etc.
Our product using this approach and what we have is some (a lot) of core functionality that is the same for all clients, custom modules that are used by one or more clients and at the core a the "customization" is a simple workflow engine that uses different workflows for different clients, so each clients gets the core functionality, its own workflow(s) and some extended set of modules that are either client specific or generalized for more that one client.
Here's something to get you started on multi-tenancy architecture:
Multi-Tenant Data Architecture
SaaS database tenancy patterns
Without more info, such as types of client specific customization, one can only guess how deep or superficial the changes are. Some simple/standard approaches to consider:
If you can keep a central config specifying the uniqueness from client to client
If you can centralize the business rules to one class or group of classes
If you can store the business rules in the database and pull out based on client
If the business rules can all be DB/SQL based (each client having their own DB
Overall hard coding differences based on client name/id is very problematic, keeping different code bases per client is costly (think of the complete testing/retesting time required for the 90% that doesn't change)...I think more info is required to properly answer (give some specifics)
Layer the application. One of those layers contains customizations and should be able to be pulled out at any time without affect on the rest of the system. Application- and DB-level "triggers" (quoted because they may or many not employ actual DB triggers) that call customer-specific code or are parametrized with customer keys) are very helpful.
Core should never be customized, but you must layer it in somewhere, even if it is simplistic web filtering.
What we have is a a core datbase that has the functionality that all clients get. Then each client has a separate database that contains the customizations for that client. This is expensive in terms of maintenance. The other problem is that when two clients ask for a simliar functionality, it is often done differnetly by the two separate teams. There is currently little done to share custiomizations between clients and make common ones become part of the core application. Each client has their own application portal, so we don't have the worry about a change to one client affecting some other client.
Right now we are looking at changing to a process using a rules engine, but there is some concern that the perfomance won't be there for the number of records we need to be able to process. However, in your circumstances, this might be a viable alternative.
I've used some applications that offered the following customizations:
Web pages were configurable - we could drag fields out of view, position them where we wanted with our own name for the field label.
Add our own views or stored procedures and use them in: data grids (along with an update proc) and reports. Each client would need their own database.
Custom mapping of Excel files to import data into system.
Add our own calculated fields.
Ability to run custom scripts on forms during various events.
Identify our own custom fields.
If you clients are larger companies, you're almost going to need your own SDK, API's, etc.

How to write a spec for a website

As I'm starting to develop for the web, I'm noticing that having a document between the client and myself that clearly lays out what they want would be very helpful for both parties. After reading some of Joel's advice, doing anything without a spec is a headache, unless of course your billing hourly ;)
In those that have had experience,
what is a good way to extract all
the information possible from the
client about what they want their
website to do and how it looks? Good
ways to avoid feature creep?
What web specific requirements
should I be aware of? (graphic
design perhaps)
What do you use to write your specs in?
Any thing else one should know?
Thanks!
Ps: to "StackOverflow Purists" , if my question sucks, i'm open to feed back on how to improve it rather than votes down and "your question sucks" comments
Depends on the goal of the web-site. If it is a site to market a new product being released by the client, it is easier to narrow down the spec, if it's a general site, then it's a lot of back and forth.
Outline the following:
What is the goal of the site / re-design.
What is the expected raise in customer base?
What is the customer retainment goal?
What is the target demographic?
Outline from the start all the interactive elements - flash / movies / games.
Outline the IA, sit down with the client and outline all the sections they want. Think up of how to organize it and bring it back to them.
Get all changes in writing.
Do all spec preparation before starting development to avoid last minute changes.
Some general pointers
Be polite, but don't be too easy-going. If the client is asking for something impossible, let them know that in a polite way. Don't say YOU can't do it, say it is not possible to accomplish that in the allotted time and budget.
Avoid making comparisons between your ideas and big name company websites. Don't say your search function will be like Google, because you set a certain kind of standard for your program that the user is used to.
Follow standards in whatever area of work you are. This will make sure that the code is not only easy to maintain later but also avoid the chances of bugs.
Stress accessibility to yourself and the client, it is a big a thing.
More stuff:
Do not be afraid to voice your opinion. Of course, the client has the money and the decision at hand whether to work with you - so be polite. But don't be a push-over, you have been in the industry and you know how it works, so let them know what will work and what won't.
If the client stumbles on your technical explanations, don't assume they are stupid, they are just in another industry.
Steer the client away from cliches and buzz words. Avoid throwing words like 'ajax' and 'web 2.0' around, unless you have the exact functionality in mind.
Make sure to plan everything before you start work as I have said above. If the site is interactive, you have to make sure everything meshes together. When the site is thought up piece by piece, trust me it is noticeable.
One piece of advice that I've seen in many software design situations (not just web site design) relates to user expectations. Some people manage them well by giving the user something to see, while making sure that the user doesn't believe that the thing they're seeing can actually work.
Paper prototyping can help a lot for this type of situation: http://en.wikipedia.org/wiki/Paper_prototyping
I'm with the paper prototyping, but use iplotz.com for it, which is working out fine so far from us.
It makes you think about how the application should work in more detail, and thus makes it less likely to miss out on certain things you need to build, and it makes it much easier to explain to the client what you are thinking of.
You can also ask the client to use iplotz to explain the demands to you, or cooperate in it.
I also found looking for client questionnaires on google a good idea to help generate some more ideas:
Google: web client questionnaire,
There are dozens of pdfs and other forms to learn from