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2014, Tuesday November 18

HTTP remote access for SynDB SQL execution

For mORMot, we developed a fully feature direct access layer to any RDBMS, implemented in the SynDB.pas unit.

You can use those SynDB classes to execute any SQL statement, without any link to the framework ORM.
At reading, the resulting performance is much higher than using the standard TDataSet component, which is in fact a true performance bottleneck.
It has genuine features, like column access via late-binding, an innovative ISQLDBRows interface, and ability to directly access the low-level binary buffers of the database clients.

We just added a nice feature to those classes: the ability to access remotely, via plain HTTP, to any SynDB supported database!

Continue reading...

2014, Saturday August 16

Will WebSocket replace HTTP? Does it scale?

You certainly noticed that WebSocket is the current trendy flavor for any modern web framework.
But does it scale? Would it replace HTTP/REST?
There is a feature request ticket about them for mORMot, so here are some thoughts - matter of debate, of course!
I started all this by answering a StackOverflow question, in which the actual answers were not accurate enough, to my opinion.

From my point of view, Websocket - as a protocol - is some kind of monster.

You start a HTTP stateless connection, then switch to WebSocket mode which releases the TCP/IP dual-direction layer, then you may switch later on back to HTTP...
It reminds me some kind of monstrosity, just like encapsulating everything over HTTP, using XML messages... Just to bypass the security barriers... Just breaking the OSI layered model...
It reminds me the fact that our mobile phone data providers do not use broadcasting for streaming audio and video, but regular Internet HTTP servers, so the mobile phone data bandwidth is just wasted when a sport event occurs: every single smart phone has its own connection to the server, and the same video is transmitted in parallel, saturating the single communication channel... Smart phones are not so smart, aren't they?

WebSocket sounds like a clever way to circumvent a limitation...
But why not use a dedicated layer?
I hope HTTP 2.0 would allow pushing information from the server, as part of the standard... and in one decade, we probably will see WebSocket as a deprecated technology.
You have been warned. Do not invest too much in WebSockets..

OK. Back to our existential questions...
First of all, does the WebSocket protocol scale?
Today, any modern single server is able to server millions of clients at once.
Its HTTP server software has just to be is Event-Driven (IOCP) oriented (we are not in the old Apache's one connection = one thread/process equation any more).
Even the HTTP server built in Windows (http.sys - which is used in mORMot) is IOCP oriented and very efficient (running in kernel mode).
From this point of view, there won't be a lot of difference at scaling between WebSocket and a regular HTTP connection. One TCP/IP connection uses a little resource (much less than a thread), and modern OS are optimized for handling a lot of concurrent connections: WebSocket and HTTP are just OSI 7 application layer protocols, inheriting from this TCP/IP specifications.

But, from experiment, I've seen two main problems with WebSocket:

  1. It does not support CDN;
  2. It has potential security issues.

Continue reading...

2014, Monday August 11

Cross-Platform mORMot Clients - Smart Mobile Studio

Current version of the main framework units target only Win32 and Win64 systems.

It allows to make easy self-hosting of mORMot servers for local business applications in any corporation, or pay cheap hosting in the Cloud, since mORMot CPU and RAM expectations are much lower than a regular IIS-WCF-MSSQL-.Net stack.
But in a Service-Oriented Architecture (SOA), you would probably need to create clients for platforms outside the Windows world, especially mobile devices.

A set of cross-platform client units is therefore available in the CrossPlatform sub-folder of the source code repository. It allows writing any client in modern object pascal language, for:

  • Any version of Delphi, on any platform (Mac OSX, or any mobile supported devices);
  • FreePascal Compiler 2.7.1;
  • Smart Mobile Studio 2.1, to create AJAX or mobile applications (via PhoneGap, if needed).

This series of articles will introduce you to mORMot's Cross-Platform abilities:

Any feedback is welcome in our forum, as usual!

Continue reading...

Cross-Platform mORMot Clients - Delphi / FreePascal

Current version of the main framework units target only Win32 and Win64 systems.

It allows to make easy self-hosting of mORMot servers for local business applications in any corporation, or pay cheap hosting in the Cloud, since mORMot CPU and RAM expectations are much lower than a regular IIS-WCF-MSSQL-.Net stack.
But in a Service-Oriented Architecture (SOA), you would probably need to create clients for platforms outside the Windows world, especially mobile devices.

A set of cross-platform client units is therefore available in the CrossPlatform sub-folder of the source code repository. It allows writing any client in modern object pascal language, for:

  • Any version of Delphi, on any platform (Mac OSX, or any mobile supported devices);
  • FreePascal Compiler 2.7.1;
  • Smart Mobile Studio 2.1, to create AJAX or mobile applications (via PhoneGap, if needed).

This series of articles will introduce you to mORMot's Cross-Platform abilities:

Any feedback is welcome in our forum, as usual!

Continue reading...

Cross-Platform mORMot Clients - Generating Code Wrappers

Current version of the main framework units target only Win32 and Win64 systems.

It allows to make easy self-hosting of mORMot servers for local business applications in any corporation, or pay cheap hosting in the Cloud, since mORMot CPU and RAM expectations are much lower than a regular IIS-WCF-MSSQL-.Net stack.
But in a Service-Oriented Architecture (SOA), you would probably need to create clients for platforms outside the Windows world, especially mobile devices.

A set of cross-platform client units is therefore available in the CrossPlatform sub-folder of the source code repository. It allows writing any client in modern object pascal language, for:

  • Any version of Delphi, on any platform (Mac OSX, or any mobile supported devices);
  • FreePascal Compiler 2.7.1;
  • Smart Mobile Studio 2.1, to create AJAX or mobile applications (via PhoneGap, if needed).

This series of articles will introduce you to mORMot's Cross-Platform abilities:

Any feedback is welcome in our forum, as usual!

Continue reading...

Cross-Platform mORMot Clients - Units and Platforms

Current version of the main framework units target only Win32 and Win64 systems.

It allows to make easy self-hosting of mORMot servers for local business applications in any corporation, or pay cheap hosting in the Cloud, since mORMot CPU and RAM expectations are much lower than a regular IIS-WCF-MSSQL-.Net stack.
But in a Service-Oriented Architecture (SOA), you would probably need to create clients for platforms outside the Windows world, especially mobile devices.

A set of cross-platform client units is therefore available in the CrossPlatform sub-folder of the source code repository. It allows writing any client in modern object pascal language, for:

  • Any version of Delphi, on any platform (Mac OSX, or any mobile supported devices);
  • FreePascal Compiler 2.7.1;
  • Smart Mobile Studio 2.1, to create AJAX or mobile applications (via PhoneGap, if needed).

This series of articles will introduce you to mORMot's Cross-Platform abilities:

Any feedback is welcome in our forum, as usual!

Continue reading...

2014, Friday January 10

RESTful mORMot

Our Synopse mORMot Framework was designed in accordance with Fielding's REST architectural style without using HTTP and without interacting with the World Wide Web.
Such Systems which follow REST principles are often referred to as "RESTful".

Optionally, the Framework is able to serve standard HTTP/1.1 pages over the Internet (by using the mORMotHttpClient / mORMotHttpServer units and the TSQLHttpServer and TSQLHttpClient classes), in an embedded low resource and fast HTTP server.

Continue reading...

REpresentational State Transfer (REST)

Representational state transfer (REST) is a style of software architecture for distributed hypermedia systems such as the World Wide Web.
As such, it is not just a method for building "web services". The terms "representational state transfer" and "REST" were introduced in 2000 in the doctoral dissertation of Roy Fielding, one of the principal authors of the Hypertext Transfer Protocol (HTTP) specification, on which the whole Internet rely.

 

There are 5 basic fundamentals of web which are leveraged to create REST services:

  1. Everything is a Resource;
  2. Every Resource is Identified by a Unique Identifier;
  3. Use Simple and Uniform Interfaces;
  4. Communication is Done by Representation;
  5. Every Request is Stateless.

Continue reading...

2014, Sunday January 5

AES encryption over HTTP

In addition to regular HTTPS flow encryption, which is not easy to setup due to the needed certificates, mORMot proposes a proprietary encryption scheme. It is based on SHA-256 and AES-256/CTR algorithms, so is known to be secure.

You do not need to setup anything on the server or the client configuration, just run the TSQLHttpClient and TSQLHttpServer classes with the corresponding parameters.

Continue reading...

2013, Thursday September 19

FreePascal Lazarus and Android Native Controls

We all know that the first Delphi for Android was just released...

I just found out an amazing alternative, using native Android controls, and FPC/Lazarus as compiler and IDE.

It creates small .apk file: only 180 KB, from my tests!

It makes use of direct LCL access of Android native controls, so it is a great sample.

Continue reading...

2013, Tuesday September 10

Thread-safety of mORMot

We tried to make mORMot at the same time fast and safe, and able to scale with the best possible performance on the hardware it runs on.
Multi-threading is the key to better usage of modern multi-core CPUs, and also client responsiveness.

As a result, on the Server side, our framework was designed to be thread-safe.

On typical production use, the mORMot HTTP server will run on its own optimized thread pool, then call the TSQLRestServer.URI method. This method is therefore expected to be thread-safe, e.g. from the TSQLHttpServer. Request method. Thanks to the RESTful approach of our framework, this method is the only one which is expected to be thread-safe, since it is the single entry point of the whole server. This KISS design ensure better test coverage.

Let us see now how this works, and publish some benchmarks to test how efficient it has been implemented.

Continue reading...

2013, Wednesday September 4

HTTPS communication in mORMot

In mORMot, the http.sys kernel mode server can be defined to serve HTTPS secure content.

Yes, mORMots do like sophistication:

When the aUseSSL boolean parameter is set for TSQLHttpServer.Create() constructor, the SSL layer will be enabled within http.sys.
Note that useHttpSocket kind of server does not offer SSL encryption yet.

We will now define the steps needed to set up a HTTPS server in mORMot.

Continue reading...

2013, Thursday July 4

Let mORmot's applications be even more responsive

In mORmot applications, all the client communication is executed by default in the current thread, i.e. the main thread for a typical GUI application.
This may become an issue in some reported environments.

Since all communication is performed in blocking mode, if the remote request takes long to process (due to a bad/slow network, or a long server-side action), the application may become unresponsive, from the end-user experience.
Even Windows may be complaining about a "non responsive application", and may propose to kill the process, which is far away from an expected behavior.

In order to properly interacts with the user, a OnIdle property has been defined in TSQLRestClientURI, and will change the way communication is handled.
If a callback event is defined, all client communication will be processed in a background thread, and the current thread (probably the main UI thread) will wait for the request to be performed in the background, running the OnIdle callback in loop in the while.

Continue reading...

2013, Wednesday April 24

mORMots know how to swim like fishes

Another great video by warleyalex.

This time, a full FishFacts demo in AJAX, using mORMot and its SQLite3 ORM as server.

See it on YouTube!

Feedback is welcome on our forum.

Update:

I've just uploaded the corresponding source code to our repository.
See sample 19 - AJAX ExtJS FishFacts.
You need to download the corresponding DB file to run the sample.
Enjoy!

2013, Tuesday April 2

Two videos about EXTjs client of mORMot server

Two nice videos, posted by a framework user.

The first one presents a remote RESTful access of a SQLite3 database, hosted by a mORMot server:

After one post in the forum, warleyalex was able to easily add remote filtering of the request:

In addition to the previous video about security (by which the mORMot authentication model seems much more secure than DataSnap's), this is a very nice demo!
Thanks a lot, warleyalex for the feedback and information!

2013, Sunday February 17

Interface-based service sample: remote SQL access

You will find in the SQLite3\Sample\16 - Execute SQL via services folder of mORMot source code a Client-Server sample able to access any external database via JSON and HTTP.
It is a good demonstration of how to use an interface-based service between a client and a server.
It will also show how our SynDB classes have a quite abstract design, and are easy to work with, whatever database provider you need to use.

The corresponding service contract has been defined:

  TRemoteSQLEngine = (rseOleDB, rseODBC, rseOracle, rseSQlite3, rseJet, rseMSSQL);

IRemoteSQL = interface(IInvokable) ['{9A60C8ED-CEB2-4E09-87D4-4A16F496E5FE}'] procedure Connect(aEngine: TRemoteSQLEngine; const aServerName, aDatabaseName, aUserID, aPassWord: RawUTF8); function GetTableNames: TRawUTF8DynArray; function Execute(const aSQL: RawUTF8; aExpectResults, aExpanded: Boolean): RawJSON; end;

Purpose of this service is:
- To Connect() to external databases, given the parameters of a standard TSQLDBConnectionProperties. Create() constructor;
- Retrieve all table names of this external database as a list;
- Execute any SQL statement, returning the content as JSON array, ready to be consumed by AJAX applications (if aExpanded is true), or a Delphi client (e.g. via a TSQLTableJSON and the mORMotUI unit).

Of course, this service will be define as sicClientDriven mode, that is, the framework will be able to manage a client-driven TSQLDBProperties instance life time.

Benefit of this service is that no database connection is required on the client side: a regular HTTP connection is enough.
No need to install nor configure any database provider, and full SQL access to the remote databases.

Due to our optimized JSON serialization, it will probably be faster to work with such plain HTTP / JSON services, instead of a database connection through a VPN. In fact, database connections are made to work on a local network, and do not like high-latency connections, which are typical on the Internet.

Continue reading...

2012, Monday December 31

Enhance existing projects with mORMot

Even if mORMot will be more easily used in a project designed from scratch, it fits very well the purpose of evolving any existing Delphi project, or even creating the server side part of an AJAX application. 

One benefit of such a framework is to facilitate the transition from a Client-Server architecture to a N-Tier layered pattern.

Continue reading...

2012, Friday November 23

Speed comparison between WCF, Java, DataSnap and mORMot

Roberto Scheinders wrote a nice blog post about performance and stability of DataSnap XE3, compared with mORMot and some other available frameworks.

Compared frameworks were:

  • DataSnap (Delphi)
  • mORMot (Delphi)
  • ASP.NET WCF
  • Jersey/Grizzly (Java)
  • Node.JS (JavaScript)

In short, DataSnap was slow and not stable (concurrent test was crashing the application), whereas mORMot was very stable, very fast (faster than any other in concurrent mode), and used much less memory.

Continue reading...

2012, Thursday September 6

Roadmap: interface-based callbacks for Event Collaboration

On the mORMot roadmap, we added a new upcoming feature, to implement one-way callbacks from the server.
That is, add transparent "push" mode to our Service Oriented Architecture framework.

Aim is to implement notification events triggered from the server side, very easily from Delphi code, even over a single HTTP connection - for instance, WCF does not allow this: it will need a dual binding, so will need to open a firewall port and such.

It will be the ground of an Event Collaboration stack included within mORMot, in a KISS way.
Event Collaboration is really a very interesting pattern, and even if not all your application domain should be written using it, some part may definitively benefit from it.
The publish / subscribe pattern provides greater network scalability and a more dynamic SOA implementation: for instance, you can add listeners to your main system events (even third-party developed), without touching your main server.
Or it could be the root of the Event Sourcing part of your business domain: since callbacks can also be executed on the server side (without communication), they can be used to easily add nice features like: complete rebuild, data consolidation (and CQRS), temporal query, event replay, logging, audit, backup, replication.

Continue reading...

2012, Monday September 3

Client-Server allowed back to XE3 pro

The attempt to restrict the XE3 professional license did evolve into an amazing discussion in Embarcadero forums, and Delphi-related blogs.

David I announced the (reverted) EULA for Delphi Pro. Remote database access is again possible, with terms similar to Delphi Xe2.
You can check the Software License and Support Terms (EULA) for RAD Studio XE3 products.

This is good news, but also the opportunity to check the definitive terms.

In short, with the XE3 pro license, you have a deployment restrictive clause:

  • You can use DBExpress components and units only locally;
  • You can use DataSnap features only locally (it means that you can prototype using DataSnap, but are not allowed to deploy or redistribute DataSnap).

If you want to use those two features on Client-Server, you would need to buy a Client/Server Pack license:

If licensee has purchased a Client/Server Pack, the Licensee of RAD Studio, Delphi, or C++Builder XE3 Professional Edition (“Product”) may deploy that portion of the Product identified as "dbExpress" and dbExpress enterprise database drivers, in executable form only, to enable client server database access. Embarcadero may deliver the Product identified as “Enterprise,” however Licensee is licensed to use only the “Professional” edition features plus "dbExpress" and the Enterprise dbExpress database drivers in a client/server configuration. Licensee may evaluate the n-Tier DataSnap functionality included in the Enterprise Product delivered, but may not deploy or redistribute DataSnap.

This is now a real opportunity for our Open Source mORMot framework.
With a XE3 pro license, and even with a XE3 starter license, you are able, via our free units and classes:

That is, everything you need to build from a small Client-Server or stand-alone application up to the most scalable Domain-Driven design.

Nice, isn't it?

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