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RemObjects Remoting SDK?

June 3, 2019 Leave a comment

Reading this you could be forgiven for thinking that I must promote RemObjects products, It’s my job now right? Well yes, but also no.

dataabstract-illustration-rework-ro-1100The thing is, I’m really not “traveling salesman” material by any stretch of the imagination. My tolerance for bullshit is ridiculously low, and being practical of nature I loath fancy products that cost a fortune yet deliver nothing but superficial fluff.

The reasons I went to work at RemObjects are many, but most of all it’s because I have been an avid supporter of their products since they launched. I have used and seen their products in action under intense pressure, and I have come to put some faith in their solutions.

Trying to describe what it’s like to write servers that should handle thousands of active user “with or without” RemObjects Remoting SDK is exhausting, because you end up sounding like a fanatic. Having said that, I feel comfortable talking about the products because I speak from experience.

I will try to outline some of the benefits here, but you really should check it out yourself. You can download a trial directly here: https://www.remotingsdk.com/ro/

Remoting framework, what’s that?

RemObjects Remoting framework (or “RemObjects SDK” as it was called earlier) is a framework for writing large-scale RPC (remote procedure call) servers and services. Unlike the typical solutions available for Delphi and C++ builder, including those from Embarcadero I might add, RemObjects¬†framework stands out because it distinguishes between transport, host and message-format – and above all, it’s sheer quality and ease of use.

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RemObjects Remoting SDK ships with a rich selection of channels and message formats

This separation between transport, host and message-format makes a lot of sense, because the parameters and data involved in calling a server-method, shouldn’t really be affected by how it got there.

And this is where the fun begins because the framework offers you a great deal of different server types (channels) and you can put together some interesting combinations by just dragging and dropping components.

How about JSON over email? Or XML over pipes?

The whole idea here is that you don’t have to just work with one standard (and pay through the nose for the privilege). You can mix and match from a rich palette of transport mediums and message-formats and instead focus on your job; to deliver a kick-ass product.

And should you need something special that isn’t covered by the existing components, inheriting out your own channel or message classes is likewise a breeze. For example, Andre Mussche have some additional components on GitHub that adds a WebSocket server and client. So there is a lot of room for expanding and building on the foundation provided by RemObjects.

And this is where RemObjects has the biggest edge (imho), namely that their solutions shaves weeks if not months off your development time. And the central aspect of that is their integrated service designer.

Integration into the Delphi IDE

Dropping components on a form is all good and well, but the moment you start coding services that deploy complex data-types (records or structures) the amount of boilerplate code can become overwhelming.

The whole point of a remoting framework is that it should expose your services to the world. Someone working in .net or Java on the other side of the planet should be able to connect, consume and invoke your services. And for that to happen every minute detail of your service has to follow standards.

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The RemObjects Service Builder integrates directly into the Delphi IDE

When you install RemObjects SDK, it also integrates into the Delphi IDE. And one of the features it integrates is a complete, separate service designer. The designer can also be used outside of the Delphi IDE, but I cannot underline enough how handy it is to be able to design your services visually, right there and then, in the Delphi IDE.

This designer doesn’t just help you design your service description (RemObjects has their own RODL file-format, which is a bit like a Microsoft WSDL file),¬†the core purpose is to auto-generate all the boilerplate code for you — directly into your Delphi project (!)

So instead of you having to spend a week typing boilerplate code for your killer solution, you get to focus on implementing the actual methods (which is what you are supposed to be doing in the first place).

DLL services, code re-use and multi-tenancy

The idea of multi-tenancy is an interesting one. One that I talked about with regards to Rad-Server both in Oslo and London before christmas. But Rad-Server is not the only system that allows for multi-tenancy. I was doing multi-tenancy with RemObjects SDK some 14 years ago (if not earlier).

Remember how I said the framework distinguishes between transport, message and host? That last bit, namely host, is going to change how you write applications.

When you install the framework, it registers a series of custom project types inside the Delphi IDE. So if you want to create a brand new RemObjects SDK server project, you can just do that via the ordinary File->New->Other menu option.

One of the project types is called a DLL Server. Which literally means you get to isolate a whole service library inside a single DLL file! You can then load in this DLL file and call the functions from other projects. And that is, ultimately, the fundamental principle for multi-tenancy.

And no, you don’t have to compile your project with external packages for this to work. The term “dll-server” can also be a bit confusing, because we are not compiling a network server into a DLL file, we are placing the code for a service into a DLL file. I used this project type to isolate common code, so I wouldn’t have to copy unit-files all over the place when delivering the same functionality.

It’s also a great way to save money. Don’t want to pay for that new upgrade? Happy with the database components you have? Isolate them in a DLL-Server and continue to use the code from your new Delphi edition. I have Delphi XE3 Database components running inside a RemObjects DLL-Server that I use from Delphi XE 10.3.

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DLL server is awesome and elegantly solves real-life problems out of the box

In my example I was doing business-logic for our biggest customers. Each of them used the same database, but they way they registered data was different. The company I worked for had bought up these projects (and thus their customers with them), and in order to keep the customers happy we couldn’t force them to re-code their systems to match ours. So we had to come up with a way to upgrade our technology without forcing a change on them.

The first thing I did was to create a “DLL server” that dealt with the database. It exposed methods like openTable(), createInvoice(), getInvoiceById() and so on. All the functions I would need to work with the data without getting my fingers dirty with SQL outside the DLL. So all the nitty gritty of SQL components, queries and whatnot was neatly isolated in that DLL file.

I then created separate DLL-Server projects for each customer, implemented their service interfaces identical to their older API. These DLL’s directly referenced the database library for authentication and doing the actual work.

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When integrated with the IDE, you are greeted with a nice welcome window when you start Delphi. Here you can open examples or check out the documentation

Finally, I wrapped it all up in a traditional Windows system service, which contained two different server-channels and the message formats they needed. When the service was started it would simply load in the DLL’s and manually register their services and types with the central channel — and voila, it worked like a charm!

Rock solid

Some 10 years after I delivered the RemObjects based solution outlined above, I got a call from my old employer. They had been victim of a devastating cyber attack. I got a bit anxious as he went on and on about damages and costs, fearing that I had somehow contributed to the situation.

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But it turned out he called to congratulate me! Out of all the services in their server-park, mine were the only ones left standing when the dust settled.

The RemObjects payload balancer had correctly dealt with both DDOS and brute force attacks, and the hackers were left wanting at the gates.