❑ Memcache::connect bool Memcache::connect ( string host [, int port [, int timeout]] ) This method creates and opens a connection to a memcached server running on host. The port parameter specifies the TCP port used by memcached, the default being 11211, and timeout specifies how long to wait when attempting to connect before returning FALSE. Returns true on success, FALSE on failure. ❑ Memcache::decrement int Memcache::decrement ( string key [, int value] ) ❑ When storing a simple numeric value in the memory cache, you can actually use the decre- ment() method to decrease the value matching key by the provided value. If no decrement value is specified, the cached value is decremented by 1. This method returns FALSE on failure, or the item’s new value upon success. ❑ Memcache::delete bool Memcache::delete (string key [, int timeout] ) This method deletes the item identified by key from the memory cache. Providing a value for timeout causes the item to be deleted after the provided number of seconds. Returns FALSE on failure, and TRUE on success. ❑ Memcache::flush bool Memcache::flush ( void ) This method tells memcached to immediately set the expiration on all items in the cache. Once this method is called, any item in the cache can be overwritten by new keys, but the memory is not released until that happens. This method returns TRUE on success, or FALSE on failure. ❑ Memcache::get string Memcache::get ( string key ) string Memcache::get ( array keys ) This method retrieves an item or items stored in the memory cache, matching the given key or array of keys. It returns either a string or array on success, depending on how many keys were provided to match against, and FALSE if no keys are found matching the input parameters. ❑ Memcache::getStats array Memcache::getStats ( void ) This returns an array containing various bits of information regarding the status of the memory cache, such as current and total connections, number of cached items, and server uptime. ❑ Memcache::getVersion string Memcache::getVersion ( void ) This returns a simple string with the version number of the memcached server, or FALSE if an error occurs. 302 Chapter 12 15_59723x ch12.qxd 10/31/05 6:38 PM Page 302 ❑ Memcache::increment int Memcache::increment ( string key [, int value] ) Like the decrement() method, increment() allows you to easily change a simple numeric value directly in the memory cache— in this case, incrementing the stored variable by value, or 1 if no value is provided. Returns the new value on success, or FALSE on failure. ❑ Memcache::pconnect bool Memcache::pconnect ( string host [, int port [, int timeout]] ) This method creates and opens a persistent connection to the memcached server, similar to a MySQL persistent connection. The parameters are the same as connect(): host specifies the memcached server hostname or IP address, port specifies the listening port for memcached, and timeout specifies the connection timeout period. ❑ Memcache::replace bool Memcache::replace ( string key, mixed var [, int flag [, int expire]] ) This searches through the cached objects for an item matching key, and if found, replaces it with the value var. Like add() and set(), replace() can supply a flag to request compres- sion when storing the value, and also give an optional expiration time for the new value. This method returns TRUE on success, FALSE on failure. ❑ Memcache::set bool Memcache::set (string key, mixed var [, int flag [, int expire]] ) This stores the value var in the memory cache, even if there is a preexisting item matching key. Arguments are identical to those of add() and replace(). Returns TRUE on success, FALSE on failure. You can use these methods in a similar manner as the MySQLi methods— you connect to the memcached server, process data in and out of the cache, and then disconnect. The following simple example stores a Circle object in the memory cache: <?php class Circle { public $radius; public function area() { return pi() * pow($this->radius, 2); } } $memc = new Memcache(); $memc->connect(‘10.0.0.20’, 11211); $c = new Circle(); 303 Caching Engines 15_59723x ch12.qxd 10/31/05 6:38 PM Page 303 $c->radius = 15; $memc->set(‘circle1’, $c); $stats = $memc->getStats(); $memc->close(); print_r($stats); ?> If you run this script, it will print an array containing the statistics of the memory cache at that time. If it’s the first time you run the script, or first time memcached is used on your server, your curr_items value should be 1, reflecting the newly added Circle object: Array ( [pid] => 1379 [uptime] => 4148 [time] => 1124758570 [version] => 1.1.12 [rusage_user] => 0.030000 [rusage_system] => 0.010000 [curr_items] => 1 [total_items] => 8 [bytes] => 77 [curr_connections] => 1 [total_connections] => 9 [connection_structures] => 2 [cmd_get] => 0 [cmd_set] => 8 [get_hits] => 0 [get_misses] => 0 [bytes_read] => 605 [bytes_written] => 1856 [limit_maxbytes] => 134217728 ) Removing memcached Like the other DSO caching solutions, you can quickly disable memcache functionality by commenting- out or removing the appropriate lines from php.ini and restarting Apache. At that point you can delete memcache.so from your PHP extensions directory, and the memcached daemon from the system binary folder (wherever it was installed to earlier, most likely /usr/local/bin or /usr/bin). Using Different Caching Engines Together Now at this point, the gears might be turning in your head, and you start to wonder, “What happens if I used more than one caching engine simultaneously?” Well, as you might suspect, a proper choice of complimentary solutions can slightly increase performance, but there are certain combinations that won’t do you any good. 304 Chapter 12 15_59723x ch12.qxd 10/31/05 6:38 PM Page 304 JPCache and memcached can play well with others, but APC, eAccelerator, and the Zend Optimizer are somewhat mutually exclusive. While they might load together just fine, and not throw any errors when executing a PHP script, there’s little to no reason to use a combination of opcode caches. All three in some way or another provide roughly the same functionality, so using multiple opcode caches will only result in the system being as fast as the slowest cache. Try to pick just one opcode caching solution, and try combining it with memcached and JPCache. Throw your preferred content-compression solution into the mix— the built-in content compression in JPCache is still too buggy — and you’ve got a lean and mean combined-cache serving machine. Choosing Your Caching Engine So which caching solution is right for you? Perhaps it’s best for you to first evaluate the needs of your sys- tem, and look for any places that are currently or will soon be a bottleneck. If you’re struggling with heavy classes and objects zinging around your scripts, or frequently pull a large amount of repetitive data from your database, memcached will be your best bet for some performance improvements. If your website code generates relatively static pages—you’re not using excessive user personalization or other highly dynamic elements — you should consider using JPCache. If the data layer is not really your bottleneck, but your PHP code could use some general performance tweaks, one of the opcode caching engines will help you out. If you’re unsure which optimizer/cache to use, a safe bet would be APC. What it may lack in the low-level engine boost or optimization that Zend Optimizer may deliver, it makes up for by being highly customizable, and well-supported — it is after all, part of the PECL repository. Summary Regardless of which caching solution you choose, any of the systems discussed in this chapter have the potential to drastically increase the performance of your LAMP setup. With the proper care and configu- ration, your caching solution will allow you to serve a greater number of users concurrently, and help ward off any possible DOS or Slashdot Effect you may encounter some day. 305 Caching Engines 15_59723x ch12.qxd 10/31/05 6:38 PM Page 305 15_59723x ch12.qxd 10/31/05 6:38 PM Page 306 Content Management Systems A Content Management System (CMS) assists a software or Web developer in organizing and facil- itating any collaborative process and its final outcome. The term “content management” loosely refers to not only the checking in and out of files, but also the generalized sharing of information, such as common calendars, wikis, and the like. The earliest Content Management Systems emerged around 1975 when mainframes and electronic publishing required really began to catch on. These earliest versions were basically nothing more than general repositories that enabled multiple users to participate in the same project. As computer systems became more and more complex, the need to effectively manage content also becomes more complex. As the Internet came to fruition, so did the wave of CMSs. Now there are more CMSs than you can shake a stick at. The goal of this chapter is to try and wade through all the muck to help you define whether you need a CMS, which variety of CMS is right for your project, and how you can use a CMS to improve your efficiency. Types of CMSs CMSs come in all shapes and sizes, and can basically manage anything being worked on by a team of individuals. From managing simple static website content, to allowing collaborative documen- tation across the Internet (wiki), CMSs perform many functions. CMS packages can generally be classified into two categories: Enterprise CMSs and Web CMSs. Enterprise CMSs These high-powered software packages are usually comprehensive solutions, delivering effective content management for use on an enterprise, or corporate level. They are designed to help a cor- poration become more efficient and cost-effective, and increase accuracy and functionality, while decreasing human error and customer response times. 16_59723x ch13.qxd 10/31/05 6:39 PM Page 307 They can integrate corporate functions such as shipping and delivery systems, invoicing, employee and human resource issues, customer relations, and document management and transactional (sales) sys- tems. Enterprise CMSs bring data management down to the user level so many users can add their indi- vidual piece to a very large integrated pie. Software companies deploying these complex systems pride themselves on offering highly customized company-wide solutions, and the software usually comes with a relatively hefty price tag. Web CMS/Portals Web CMS packages are mostly created for use on the web. They can incorporate numerous functions, or have one specific function they are centered around. They allow users to update portions of a common Web site or collaborate in a website “community.” Web CMSs can make a developer’s life easy by bring- ing functionality to a website quickly and easily, and allowing a lead developer to include others in site development and maintenance without fear of straying from the standards. Open source Web CMS packages will be the focus of this chapter, in particular the PHP/MySQL packages. A subset of the Web CMS category is groupware. This type of package runs over an intranet or over the Internet and is designed to allow collaboration between users, presumably working for the same company, working on the same projects. They typically offer features such as project management, file checking in and out, calendar systems, email, and internal forums. Open Source Web CMS Packages Common functions of a Web CMS include: ❑ Static web page updates: Updates content without altering look and feel of site. ❑ Weblogs (blogs): Online journals. ❑ Wiki: Collaborative documentation projects. ❑ Publications: Posting and organization of news articles. ❑ Managed learning environments: Web-based learning. ❑ Transactional CMS: E-commerce functions. ❑ Image and file galleries: Compilation of images or files for public use. ❑ Forums: Bulletin board systems fostering discussions between users. ❑ Chat rooms: Real-time chatting between users. ❑ RSS feeds: Allows users to download content. ❑ Polls: Allows users to vote on a topic. ❑ Calendar systems: Web-based multi-user calendars. There are numerous other functions that could be considered underneath the CMS realm, but these are the major ones and the ones on which this chapter focuses. First, take a look at some of the more comprehensive open source CMS packages. 308 Chapter 13 16_59723x ch13.qxd 10/31/05 6:39 PM Page 308 All-Inclusive Web CMSs Like fancy tropical resorts that wrap up your vacation all into one nice neat package, these comprehen- sive Web CMSs can do as little or as much as you like. The following sections introduce you to some of the more popular packages available, although a myriad of these can be found on websites such as http://www.sourceforge.net. This text does not go into detail about installation on these packages, as you’ve probably had some experience in this department in the past. However, if there are any special considerations regarding installation, they will be duly noted. As well, you need to have all aspects of the LAMP system working properly before installing these packages. Most all-inclusive Web CMSs have common functionality such as changing user permissions, modifying site layout, changing server settings, and so on. One thing that should be mentioned is that there is a lack of transactional CMS interfaces (shopping carts for e-commerce) with many of the so-called compre- hensive CMS packages available. ExponentCMS ExponentCMS is available at http://www.exponentcms.org. At the time of this writing, the most cur- rent version is 0.96.3, and is what this section is based on. On the Exponent/Sourceforge interface at http://sourceforge.net/projects/exponent/, you can find links to screenshots, documentation, contributions, and the standard Sourceforge information. Installation Notes Installation is relatively simple, and the only thing you need to know before installation is that you will need to create a database. This applies to both remote and local installations. You will also need to have a user and password set up, as you will be asked to supply all that information during the installation process. General Overview/Default Installation Installing this CMS gives you several features that are “active” by default. These are: ❑ Address Book: Organizes contact information. ❑ Admin Control Panel: Easy-to-use interface for administering the site. ❑ Calendar System: Keeps track of events with different views. ❑ Contact Form: Allows visitors to the site to contact you. ❑ Image Manager: Works with other modules to manage images on the site. ❑ Preview Link: Lets those working on the site preview their work. ❑ Private Messaging Center: Allows users to send emails or private messages to one another. ❑ Resource Manager: Organizes and displays uploaded files. ❑ Text Module: Displays text and keeps track of revisions. ❑ Weblog/Online Journal Manager: Organizes blog entries. 309 Content Management Systems 16_59723x ch13.qxd 10/31/05 6:39 PM Page 309 The “inactive” features (those you can simply turn on) are: ❑ Banner Manager: Manages banner ad campaigns and click-throughs. ❑ Content Rotator: Displays different images or text to the user each time they visit the site. ❑ Flash Animation Manager: Organizes a Flash Animation. ❑ Form Module: Manages any forms on the site. ❑ HTML Template Manager: Manages uploaded HTML templates. ❑ Login Module: Allows users to log in to the site. ❑ Multi-site Manager: Allows you to create and manage other sites. ❑ Navigator: Manages the navigation system. ❑ News Feed System: Organizes and displays news articles. ❑ Search: Allows users to search the site. ❑ UI Switcher: Gives users with the correct permissions the ability to switch from user to administrator. Through the easy-to-use admin Module Manager, you can activate or deactivate any of these modules with the click of a button. Other modules are available for downloading from http://www.sourceforge.net. With the Extension Upload Manager, installing modules is easy; you don’t even need to unzip them. These extensions include: ❑ Article Manager: Organizes and displays articles on the site. ❑ Bulletin Board: Manages site forum. ❑ FAQ: Manages the FAQ section of the site. ❑ Image Gallery: Allows users to rank and view images. ❑ Listing Manager: Organizes and manages listings, such as real estate listings. ❑ Page Displayer: Allows you to upload and display dynamically generated pages (such as PHP). ❑ Slideshow: Manages slideshows on the site. Besides installing, activating, and deactivating site modules, as the site admin you can import data (such as a user list in csv format) through the admin interface. This makes it easy for you to convert from another system or from an internal database. There is the WYSIWYG HTMLArea editor also embedded into the software, making it easy for your authors and contributors to add text. As an admin, you also have control over the HTMLArea toolbar, which lets you determine what text options your users have. Customizing the Default Settings Like most other CMS packages, you can alter user settings in the Admin Control Panel. With Exponent CMS, you can set approval policies based on users and content, although this CMS is module-focused as opposed to user-focused. For example, you could create an approval policy for the Calendar module 310 Chapter 13 16_59723x ch13.qxd 10/31/05 6:39 PM Page 310 only that would require at least two approvals from other admins on the site before requested changes are shown. While you can also assign permissions for a module to a user or group, it is done through each specific module, rather than the user interface. There are no various levels of user access — either a user is an admin or not. Also, while you can view which users have permissions on which module, you cannot see all the modules a single user is responsible for. In addition, Exponent CMS gives you some control over your settings in the Configure Site area of the admin interface. Database Settings You can switch between MySQL and PostgreSQL, and of course alter database name, username, pass- word, port, and any table prefix names. Display Settings/Themes There are several themes pre-packaged with the site, but creating your own theme is easy enough by editing the appropriate files (or creating your own from scratch). Unless you love to reinvent the wheel, our suggestion is to pick the theme that comes closest to the layout you want to go with and edit from there. There is a link at the bottom of each of the sample themes (under the Manage Themes page) that allows you to view the complete file list for that theme, making it easy for you to see which files you need to alter to fit your needs. In this section, you can also change how other contributors to the site are referenced, and how the dates and times are shown to website visitors. General Configuration Settings Under this section, you can customize page titles, meta tags and keywords, and language selection. You can also turn on/off user registration, engage the CAPTCHA (Computer Automated Public Turing Test to Tell Computers and Humans Apart) test to prevent bots from registering, and control session timeouts and SSL settings. SMTP Settings This is the place to set your SMTP ports, username, passwords, authentication methods, and so on. You can also switch to php_mail() function here if you would like. Other Add-Ons Besides activating/deactivating pre-installed modules, and installing new modules made available, there is also a hefty list of other contributions offered up by the masses. This is available through Exponent’s Sourceforge interface site at http://www.sourceforge.net, under the Tracker➪ Contributions section. It includes some pretty helpful add-ons, such as adding horizontal drop-down navigation, so by all means check it out. Changing the Layout and Look of Modules While it’s easy to add and delete modules with ExponentCMS, it is even easier to move them around on the page. Making modules look different from one another proves to be a bit of a challenge, however. 311 Content Management Systems 16_59723x ch13.qxd 10/31/05 6:39 PM Page 311 [...]... TinyMCE ❑ MySQL, PostgreSQL and SQLite support ❑ Multiuser blogs: One installation of serendipity can serve independent weblogs Summing It Up Serendipity is simple, clean, and solid If you’re looking for a blog that simply does what it’s supposed to do and is very reliable, Serendipity is an excellent choice Wiki Just as programmers, coders, and web developers alike use software to manage development and. .. excellent customizability and functionality It is available at http://www.wordpress.org and the current version at time of this writing is 1.5.11 Installation Notes Installation of this package is incredibly easy and quick to do Prior to installation, make sure you are running PHP 4.1+ and MySQL 3.23.23+ and that you have created your database and username/ password The rest of the documentation you would... workflow processes ❑ Wiki: Collaborative documentation system; also allows authorized users to create and edit content for static HTML pages, and offers a WYSIWYG HTML editor and spell-checker, among other advanced features ❑ Articles: Organizes and manages articles ❑ Blogs: Weblog administration ❑ Directory: Link manager that categorizes links ❑ File Gallery: Organizes and manages uploaded files ❑ FAQs:... with this blogging package such as full standards compliance, ease in upgrading, and the use of the Texturize engine to beautify your text from plain ASCII Summing It Up You will find once you delve into the WordPress package that it is well documented, easy to install, easy to configure and customize, and very functional It also has an excellent support and development community in case you have questions... incredible amount of control, customizability, and functionality In a nutshell, you can dump, restore, and attach files, control database and comment settings, export, configure link formats and set what information is retained for the Wiki documentation (version control, user data, dates, links, status, and more) You can also manage copyright protection, Wiki history, and configure watches Some of the Wiki... contributors, and still foster visitor interactivity, then this might be the CMS for you TikiWiki This software is available at http://www.tikiwiki.org, and the current version available at the time of this writing is 1 .9. 0 Installation Notes If you are using older versions of PHP (older than 4.3) or MySQL (older than 4.0.1), then you will want to pay particular attention to the “Requirements and Setup” documentation,... users so that not all users can publish blog entries, and moderating comments or enabling CAPTCHAs for spam prevention With Serendipity, you can add images to your blog posts, change themes for your site, import and export data, and offer trackback and pingback for others to reference your posts Also akin to Wordpress is the standards compliant code and RSS feeds that can be offered for others Some additional... at the time of writing is 0.10.01, and will be the basis for the discussion here Installation Notes The kind folks at Appalachian State University (the creators of phpWebsite) have set up a command-line installation process that allows you to install directly from the phpWebsite site You can also download the application in sections (core, theme packs, and so on) and install them yourself 315 Chapter... of the site and is broken down into several categories: ❑ ❑ User Info Settings: Allows you to set password and username settings, what default groups users will belong to, avatar settings, blocked usernames (such as “admin”), and alter registration disclaimer ❑ Meta Tags and Footer: Allows you to set meta tag information, such as keywords, description, robots, rating, author, copyright, and the footer... anonymous users, gzip compression, cookie and session info, whether the site is completely down, and customized messages when site is down, IP address, SSL settings, banned IP addresses, and configure cache settings Mail Setup: Allows you to configure mail server settings and mail methods Content Management Systems ❑ Smilies: Controls smilies for the forum, and allows you to create your own ❑ Templates: . become more efficient and cost-effective, and increase accuracy and functionality, while decreasing human error and customer response times. 16_ 597 23x ch13.qxd 10/31/05 6: 39 PM Page 307 They can. portions of a common Web site or collaborate in a website “community.” Web CMSs can make a developer’s life easy by bring- ing functionality to a website quickly and easily, and allowing a lead. in and out, calendar systems, email, and internal forums. Open Source Web CMS Packages Common functions of a Web CMS include: ❑ Static web page updates: Updates content without altering look and