ThinkPHP /dev/blog - PHP

An introduction to Hadoop

nospam@example.com (Thomas Steur) — Wed, 21 Jul 2010 11:13:00 +0200

What is Hadoop?

Apache Hadoop is a Java-Framework for large-scale distributed batch processing infrastructure which runs on standard computers. The biggest advantage is the ability to scale to hundreds or thousands of computers. Hadoop is designed to efficiently distribute and handle large amounts of work across a set of machines. When I speak of very large amounts of data, in this case I mean hundreds of Giga-, Tera- or Peta-Bytes. There is not enough space for such an amount of data on a single node. Therefore, there is a separate "Hadoop Distributed File Systems (HDFS)" which splits data into many smaller parts and distributes each part redundantly across multiple nodes. Hadoop can handle lower amounts of data and is even able to run on a single computer, but it is not particularly efficient because of the resulting overhead. There are better alternatives like Gearman in such a case.

A Hadoop-Cluster often consists of thousands of nodes whereof errors are a daily occurrence. Therefore, it has a high degree of fault tolerance to correct failures as quickly and as automatically as possible.
Continue reading "An introduction to Hadoop"

Import and export data using PHPExcel

nospam@example.com (Daniel Schlichtholz) — Thu, 15 Jul 2010 10:36:00 +0200

A few weeks ago I had to read and write Excel files of the format BIFF8 (Excel 97), because the customer did not accept the workaround of exporting data to CSV. PEAR's Spreadsheet_Excel_Writer combined with the project Spreadsheet_Excel_Reader on SourceForge was a good helper in the past - but only for BIFF5. BIFF8 support in spreadsheet excel writer has been a problem for a long time, and according to the authors, is still somewhat kludgy in the current version. So I needed an alternative.
After a short research I stumbled upon PHPExcel which supports reading and writing of many formats in one API. It is released under the GNU Lesser General Public License which gives you the freedom to use it in commercial applications. Output and input formats are not limited to Excel files. This article gives you a short overview about what you can do with it and demonstrates the basic usage.
Continue reading "Import and export data using PHPExcel"

Facebook Open Graph

nospam@example.com (Daniel Prokscha) — Mon, 21 Jun 2010 11:45:00 +0200

During its developer conferene f8 on the 21st of April, Facebook presented Open Graph. But what is it exactly and what can I, as a webmaster, do with it? This and more will be clarified in this article (read german version).

Continue reading "Facebook Open Graph"

Profiling best practices: Benchmarking and optimizing real-world scenarios in a business context

nospam@example.com (Thomas Bley) — Wed, 16 Jun 2010 13:28:09 +0200

Over the years, PHP has evolved from a script language to a programming language used in big applications with high-level architectures. As the most popular language for web applications, PHP is very fast, robust and stable by default. Coming from tiny scripts, PHP is used in large-scale web applications nowadays. In terms of business context, we need to focus on these three key factors:

Scalability
Responsiveness
Resource misusage

Continue reading "Profiling best practices: Benchmarking and optimizing real-world scenarios in a business context"

Study about relevance of business goals in PHP software architecture

nospam@example.com (Björn Schotte) — Thu, 27 May 2010 12:58:17 +0200

PHP software developers and system integrators actually play an important role in running the world's largest web infrastructures. From Facebook, Gruner & Jahr, Kabel Deutschland and Lufthansa to a diversity of corporations, they all trust PHP and the respective systems built with it. It is not questionable that these systems provide a solid software architecture. The point of interest is how these architectures are aligned to the fast pace of changing business goals, which categories of business goals are considered during architecture creation and which means are utilised in projects.

Periklis Tsirakidis, Software Developer at Mayflower and Johann-Peter Hartmann, CTO at Mayflower, created a study around a survey with more than 150 respondants from the PHP community and professional PHP ISVs. They did not only have a look at the usage of patterns like MVC, but also at the relevance of TCO-driven business goals and future trends on tool usage in architecture creation.

The 24-page long study (English) is available for free after registration at our website and will be delivered as PDF via e-mail. (Please don't mind the form is currently in German, the study itself is in English language)

For German readers: German IT news portal heise.de had a deeper look at the study upfront.

PHProjekt V6 kicks out of the door on March 18th

nospam@example.com (Björn Schotte) — Wed, 10 Mar 2010 18:21:01 +0100

PHProjekt V6, our little ~~beast~~bee and Open Source project management software, kicks out of the door on March 18th as GA. It's a complete rewrite (and thus, a major version update was needed) with Zend Framework and dojo and now licensed under LGPL (earlier versions were licensed under GPL). You may ask what you want to do until March 18th? Well, besides eating popcorn for Film@11:

follow the little bee @phprojekt6
get social with PHProjekt at its Facebook fanpage
visit the PHProjekt blog for regular updates
check out the code at github
want to talk to the developers or contribute? /join #phprojekt on freenode (irc.freenode.org)
... and, finally, try out the demo at p6.phprojekt.com

The bee is watching you!

A comet over PHProjekt 6

nospam@example.com (Martin Ruprecht) — Thu, 04 Mar 2010 12:59:37 +0100

So far PHProjekt 6 (P6, see http://phprojekt.com) is already enhanced with nice AJAX workflows and snappy user-experience. Nevertheless, we discussed a way to provide synchronous communication and direct information within the application.

Everybody knows GoogleMail with its easy to use frontend. Maybe you use it for your daily work. In GoogleMail, there is no need to refresh the page to receive a new mail, Google informs you automatically whenever a new mail is available. But how is this possible? The answer to this question is really simple: The server triggers a signal informing that a new mail is available. This technology is called Comet and describes a way how the server communicates with the client [see http://en.wikipedia.org/wiki/Comet_(programming) ].

Is there a way to use Comet for P6? As P6 works with a lot of users, it is important for me as a user to be informed when somebody has changed something in my projects or has added an urgent todo. The list where a notification could be triggered is long, but at the moment, only email notifications are sent immediately. So, what we need in P6 are real-time notifications. With real-time notifications, for example, every time somebody changes something in my project, I receive a message in form of a highlighted info box. This looks like a typical use case for using Comet. And yes, Comet would be great for realizing this kind of real-time notification! But since the users love the handy system requirements (Apache Server and MySQL) and the ease of installation, something different is needed than a real Comet architecture, because all the Comet magic is based on a so called application server, e.g. Jetty, Persevere. Therefore, I decide to implement another (Comet-) technology, called Long Polling. You can find the name AJAX Polling for this technology, too.

The technology behind Long Polling is to open a connection from the client to the server and not to close this connection immediately. Ok, that´s fine, but how to open a connection and "hold" it? Opening a connection to the server is easy, a simple AJAX will do the trick. P6 uses the Dojo Toolkit for all its AJAX, so in this case I used the Dojo.xhrPost.

        dojo.xhrPost({
            url:   myUrl,
            error: function(error, handle) {
                handleError(myUrl, error);
            },
            load: function(response) {
                if (false != response.data) {
                    showToaster(response.data);
                }
            },
            handleAs: 'json'
        });

Since the HTTP protocoll is connection-based, at the server-side, a process is also needed that holds the connection and does not return . So, what I do to hold this connection open is to set a simple timeout during the execution of the server-side script, in my case I use sleep(). This is the basic idea of long polling, but the gimmick of this approach is to return earlier if something happens on the server-side. In other words, I open a connection to the server and check whether there are any changes, if not, the connection stays open for the maximum polling time. If yes, the response will be returned to the client immediately.

This diagram shows the basic workflow, and the lines below show the possible solution in PHP:

        $counter  = 0;
        $maxLoops = 4;
        $data     = array();

        while ($counter != $maxLoops) {
            $counter++;
            $data = $this->getMessage($userId); // get data from database
            if (false === empty($data)) {
                return $data; // there is something new, return immediately
            }
            sleep(5); // nothing is new, sleep for 5 sec.
        }

        return $data; // return the empty array

For P6 this means that I always save the following: the person who triggers an event, the event itself (e.g. somebody adds a new note), the item, the project, the creation time, the time until this message is valid, and the persons who should receive a frontend message from the database. The long polling loop checks whether there is anything new. If yes, it returns the data. If not, the polling loop starts again. Every event is saved in the database for a maximum of two minutes, except events in the future. Itis real-time so itis possible to miss a message ;-)

One word about the Dojo Toolkit. The AJAX API of Dojo provides several functions to communicate with the server. The easiest way is to use dojo.xhrGet or dojo.xhrPost. I decided to use the Post version. Although the function has a property setTimeout, which allows you to set the time to wait for a response from the server, this is not needed, because of the sleep loops at the server side.

Now, lets look at the downsides of the long polling approach. Yes, I partly agree with everybody who says that the permanent polling to the server causes massive traffic and server load, especially with an increasing number of users. But in the special case of P6 this is OK, because the number of users is manageable and in most cases, P6 runs in a local network. In addition, the frontend messages are configurable, You can set the polling loop and the number of requests to the database.

Considering all the facts and keeping in mind that P6 is designed to be a lightweight open source groupware, I am positive to say that the Long Polling technology is the right choice for P6.

Strategische Vorgehensmodelle für Web Security Vortrag@Mayflower-München

nospam@example.com (Maria Lekkou) — Tue, 02 Mar 2010 11:39:00 +0100

Achtung! Neuer Termin: 04. März 2010

Am kommenden Donnerstag, den 04.03.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in München statt (Mannhardtstraße 6, S-Bahn Isartor).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Strategische Vorgehensmodelle für Web Security".

Web Security rückt zunehmend in den Mittelpunkt aktueller Businessanwendungen. Dabei gibt es einige strategische Vorgehensmodelle, wie Web Security für Lösungen in Unternehmen realisiert werden kann. Johann-Peter Hartmann gibt einen Überblick.

Die "Donnerstags-Vorträge" werden sowohl in München als auch in Würzburg gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!

Foto: ntr23 (flickr)

Mobile Apps mit PhoneGap, Vortrag@Mayflower-Würzburg

nospam@example.com (Andreas Ganje) — Sun, 21 Feb 2010 20:16:02 +0100

Am kommenden Donnerstag, den 25.02.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in Würzburg statt (Pleichertorstrasse 2, 97070 Würzburg, Straßenbahn und die Haltestelle Congress Centrum).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Mobile Apps mit PhoneGap".

Thorsten Rinne zeigt, wie man mit Webtechnologien (Html, Css, JavaScript) mobile Apps für iPhone, Android, Blackberry und Co. entwickeln kann und weist auf die Unterschiede zwischen PhoneGap, Titanium Developer und anderen ähnlichen Plattformen hin.

Die "Donnerstags-Vorträge" werden sowohl in Würzburg als auch in München gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!

Größere KartenansichtMobile Apps mit PhoneGap, Vortrag@Mayflower-Würzburg

Mobile Apps: Welches SDK ist das Richtige für mich? Vortrag@Mayflower-München

nospam@example.com (Maria Lekkou) — Tue, 16 Feb 2010 09:52:29 +0100

Am kommenden Donnerstag, den 18.02.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in München statt (Mannhardtstraße 6, S-Bahn Isartor).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Mobile Apps: Welches SDK ist das Richtige für mich?".

Tobias Schlüter geht in seinem Vortrag auf die verschiedenen mobilen Plattformen (Android, Symbian, iPhone OS usw.) ein und beschreibt, wie man mit Cross-Plattform-SDKs eine App für mehrere Plattformen schreiben kann.

Die "Donnerstags-Vorträge" werden sowohl in München als auch in Würzburg gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!

Developing PHP Internals on Windows, Vortrag@Mayflower-Würzburg

nospam@example.com (Andreas Ganje) — Sun, 14 Feb 2010 19:45:40 +0100

Am kommenden Donnerstag, den 18.02.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in Würzburg statt (Pleichertorstrasse 2, 97070 Würzburg, Straßenbahn und die Haltestelle Congress Centrum).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Developing PHP Internals on Windows".

Pierre Joye zeigt wie man Extensions für PHP in Windows entwickeln kann (development environment setup, configuration, compiling php, extensions writting, debugging, testing usw.)

Die "Donnerstags-Vorträge" werden sowohl in Würzburg als auch in München gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!

Größere Kartenansicht

Praktische Anwendung von MySQLDumper, Vortrag@Mayflower-Würzburg

nospam@example.com (Andreas Ganje) — Tue, 09 Feb 2010 20:48:15 +0100

Am kommenden Donnerstag, den 11.02.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in Würzburg statt (Pleichertorstrasse 2, 97070 Würzburg, Straßenbahn und die Haltestelle Congress Centrum).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Praktische Anwendung von MySQLDumper".

Intelligentes Backup-Management bei MySQL-Datenbanken? Kein Problem, denn mit dem MySQLDumper kann jeder Sicherungskopien seiner wichtiger Datenbestände erstellen - und bei Bedarf auch kinderleicht wieder herstellen. Daniel Schlichtholz zeigt wie MySQLDumper einem das Leben erleichtert. Frei nach dem Motto: back it up the easy way...

Die "Donnerstags-Vorträge" werden sowohl in Würzburg als auch in München gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!

Größere Kartenansicht

Continuous Integration und Cruise Control im Projekteinsatz -> Vortrag@Mayflower-München

nospam@example.com (Maria Lekkou) — Mon, 08 Feb 2010 23:35:00 +0100

Am kommenden Donnerstag, den 11.02.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in München statt (Mannhardtstraße 6, S-Bahn Isartor).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Continuous Integration und Cruise Control im Projekteinsatz"

Sebastian Springer zeigt wie man Continuous Integration in PHP-basierten Entwicklungsprozessen einsetzen kann, insbesondere mit dem CruiseControl Framework.

Die "Donnerstags-Vorträge" werden sowohl in München als auch in Würzburg gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!

Live exploiting aus Angreifersicht (XSS / CSRF), Vortrag@Mayflower-Würzburg

nospam@example.com (Andreas Ganje) — Sun, 31 Jan 2010 20:45:00 +0100

Am kommenden Donnerstag, den 04.02.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in Würzburg statt (Pleichertorstrasse 2, 97070 Würzburg, Straßenbahn und die Haltestelle Congress Centrum).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Live exploiting aus Angreifersicht (XSS / CSRF)".

Anhand von interaktiven Beispielen erklärt Frank Ruske die Sicherheitsprobleme XSS (Cross-Site Scripting) & CSRF (Cross-Site Request Forgery). Welche Gefahren gibt es und wie werden diese Lücken ausgenutzt - ist das zentrale Thema dieses Vortrages?.

Die "Donnerstags-Vorträge" werden sowohl in Würzburg als auch in München gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!

Größere Kartenansicht

Mobile Apps mit PhoneGap -> Vortrag@Mayflower-München

nospam@example.com (Maria Lekkou) — Sun, 31 Jan 2010 19:28:01 +0100

Am kommenden Donnerstag, den 04.02.2010 findet wieder ein öffentlicher Vortrag im Mayflower Büro in München statt (Mannhardtstraße 6, S-Bahn Isartor).
Beginn ist um 18:00 Uhr, Thema des Vortrags ist "Mobile Apps mit PhoneGap".

Thorsten Rinne zeigt, wie man mit Webtechnologien (Html, Css, JavaScript) mobile Apps für iPhone, Android, Blackberry und Co. entwickeln kann und weist auf die Unterschiede zwischen PhoneGap, Titanium Developer und anderen ähnlichen Plattformen hin.

Die "Donnerstags-Vorträge" werden sowohl in München als auch in Würzburg gehalten. Bei Interesse einfach das Blog beobachten, um auf dem Laufenden zu bleiben!
Wir freuen uns auf viele Teilnehmer!