I am thinking of refactoring my admin website for golf databases, which currently uses the traditional CRUD architecture.
Is CQRS/Event Sourcing a good model for admin-type websites? It doesn't generate many interesting events, at most it will probably just have CourseCreated, CourseUpdated, and CourseDeleted events.
Most CQRS/Event tutorials/examples that I have seen seems to be more suitable for consumer type websites like Online Shopping cart, Ticket booking system, Restaurant order system, etc.
For Admin-type websites, are we just better off with CRUD, or does CQRS/ES have more to offer?
If most of the events you can think of contain the words Created, Updated, or Deleted then you probably don't need event sourcing. ES is not meant to be a substitute for a CRUD site.
Related
I am trying to shift towards serverless architecture when it comes to building REST API. I came from Ruby on Rails background.
I have successfully understood and adapted services such as Api Gateway, Cognito, RDS and Lambda functions, however I am struggling with putting it all together in optimal way.
My case is the following. I have a simple user based platform when there are multiple resources related to application members say blog application.
I have used Cognito for the sake of authentication and Aurora as the database service for keeping thing like articles and likes..
Since the database and Cognito user pool are decoupled, it is hard for me to do things like:
Fetching users that liked particular article
Fetching users comments
It seems problematic for me because I need to pass some unique Cognito user identifier (retrieved during authorization phase in API gateway) to lambda function which will then save the database record with an external reference to this user. On the other hand, If I were to fetch particular users, firstly I must fetch their identifiers from my relation database and then request users details from Cognito user pool..I lack some standard ways of accessing current user in my lambda functions as well as mechanisms for easily associating databse record with that user..
I have not found some convincing recommended patterns for designing such applications even though it seems like a very common problem and I am having hard time struggling if my approach is correct..
I would appreciate some comments on what are some patterns to consider when designing simple user based platform and what are the pitfalls of my solution. Any articles and examples will also be very helpfull.
Thanks in advance.
These sound like standard problems associated with distributed, indpependent, databases. You can no longer delegate all relationships to the database and get a result aggregating them in some way. You have to do the work yourself by calling one database, then the other.
For a case like this:
Fetching users that liked particular article
You would look up the "likes" database to determine user IDs of those who liked it, then look up the "users" database to determine user details such as name and avatar.
Most patterns follow standard database advice, e.g. in the above example, you could follow the performance-oriented pattern of de-normalising - store user data such as name and avatar against each "like", as long as you feel the extra storage and burden of keeping it consistent is justified by the reduction in queries (probably too many Likes to justify this).
Another important practice is using bulk queries to avoid N+1 queries. This is what Rails does with the includes syntax, but you may have to do it yourself here. In my example, it should only take two queries because the second query should get all required user data in one go, by querying for users matching the list of user IDs.
Finally, I'd suggest you try to abstract things. This kind of code gets messy fast, so be sure to build a well-encapsulated data layer that isolates application code from dealing with the mess of multiple databases.
At Withlocals.com we offer activities such as tours, and home-dinners organised by hosts, to our guests. Some have actual dates at which they are available, but many are always available on request.
Hosts how offer their services occasionally can be easily seen as Performers hosting Events, however hosts that offer their services on request (I feel) are more like products.
The part after booking is easy, emails and pages can describe bookings, reservations, etc. But I am still not quite certain which Schema type to use Products or Events?
You could use Offer in both cases, and only associate an Event (or one of its sub-types, e.g., FoodEvent) if you know a specific date.
The offers property allows to reference an Offer from an Event.
There are a ton of online CMS services out there. And a ton of (new) backend-as-a-service products too. But I can't seem to find what I am looking for.
I am building an app for a client. The app contains data about shops, products, and more. The client must be able to update this data (and not just one person: each shop manager needs to be able to log in and edit the data for their own shop). And of course the app must be able to access this data.
Client edits data online
This has to be extremely user-friendly and completely online. I don't want to sell my client something where they need to install stuff on their server. I don't want to sell them something that's accessible online but looks like phpMyAdmin.
I want a shop owner to be able to go to a webpage, log in, and then see a pretty UI where they can edit the data for their shop. The back-end needs to have a pretty front-end that's auto-generated for whatever data this particular shop owner is allowed to edit.
So there are two bits: storing data in the cloud in such a way that it can be accessed by the app (which I am building with Titanium), and allowing the client to log into the backend and edit the data in a non-tech, user-friendly way.
Here's a list of things I tried...
Backend-as-a-service
Services with a great back-end, but without easy auto-generated data editing website:
Appcelerator (Titanium) Cloud Service
Amazon EC2
Stackmob
BackBeam
WebVanta
Parse
API o Mat
ShepHertz Cloud42
Kii
Online CMS
Services that provide a nice way for clients to edit data, but no easy way for apps to connect:
CloudCMS
(and many others I'm sure)
It's insane that no-one seems to be providing the cross-breed of BaaS and online CMS. So many people are building apps for clients, and so many clients are not tech-savvy and are reluctant to get a special server and host database software they don't understand. Why does this not exist? What am I missing?
With apiOmat it's easy to create your own data-editing app for e.g. with JavaScript SDK and HTML. Or you send a feature request so that they build a module for your preferred CMS.
As you mentioned, Cloud CMS is a really good option (disclaimer: I'm one of the founders). The product provides an enterprise content management backend and an API that lets you plug in some really powerful features right into your mobile apps.
This month, we released a brand new user interface which provides much of what you're asking about. Instant forms, document libraries, search and workflow all in one place.
You can check out Cloud CMS here: http://www.cloudcms.com
I completely agree with your assessment particularly with respect to the last mile (getting the final app built). It's kind of the wild west out there and the strong technologies are still proving out.
You mentioned Titanium - that's a good choice. I also quite like the Ionic Framework (http://www.drifty.com/). It's a step in the right direction.
I'm looking for some guidance on my research to building an SaaS. This thread seems to be related, but I'm wondering if this software Rackspace has called rBuilder is what I would be looking for to automate the process of creating an instance of the software with a unique IP address and domain name.
Also, for an application similar to Shopify, does the application work like Facebook where it serves up different information based on the account, or is it better to have separate installs of the software like WordPress, but on a server that you maintain?
IMHO, there are various levels of Multi-tenancy [level1 through level4], among them, the purest form of multi-tenancy [Level4] is to have a single code base to cater to the needs of different customers [tenant's].
In this case, you will be required to maintain all of the configuration metadata within your code base to ensure that each tenant has the capability to customize the application the way they wanted to.
Having a single codebase is very clean, easier to maintain, easy to patch, easy to onboard new customers etc...
Hence, kindly note that you have to decide on the time and expense that you have budgeted for the application that you have planned to as the purest form of multi-tenancy does require some more additional thought process.
You can consult some articles like this and also google on the pros and con's of having the purest form of multi-tenancy vs on-premise model or virtualized model of multi-tenancy.
Also read more from here
In search of a 'Cloud Content Management System' like http://osmek.com/,
I could not find a single other CCMS that does what I want it to do :)
Basically, what I need is content management without a website frontend attached.
Just basic storage of data, documents, images, etc. etc. with a simple API to access, like Osmek. Just NoSQL or SQL based services won't do, because there can be images or documents attached. And, ofcourse, I'd like to have a backend to manage the data (like a typical CMS does) without writing a backend myself (if it's just the service)
Osmek is great, and it works most awesome in conjunction with Actionscript 3, but I'm just looking / searching for alternatives (if there even are any yet).
I need this form of hosted content management for content-manageing a mobile application.
So the question is: Is there anything else out there that does the same as osmek that you know of? OR, how do you manage application specific content?
Thanks!
I'd encourage you to take a look at Cloud CMS (http://www.cloudcms.com).
Cloud CMS is a JSON content management (CMS) platform built on top of MongoDB with a REST API and drivers for a variety of languages. You just drop in a driver and call methods to query, create, update and delete content.
The platform provides everything you need to power the back-end for mobile and HTML5 applications - from managing your content to managing users and groups, credentials, security tokens (OAuth2), Git-like collaborative workspaces, real-time analytics, activities, data transformations and more.
Everything runs in the cloud on an elastic back-end. It's probably more akin to Parse than a traditional CMS. You just make calls to the APIs. We keep the costs low by letting you only pay for what you use (almost like a utility). You just pay for storage and data transfer.
Disclaimer: I'm one of the founders of Cloud CMS. So I'm a pretty lousy reference in terms of its objective value. However, a couple of us worked at traditional "ECM" companies in the past and we think we've built something that puts a genuine beating on those guys.