About six months ago, I signed up for a dedicated server with slicebox.net. The servers are hosted at he.net which has a good reputation. And the price at that time was very attractive, $99/month for their 2-processor 64-bit server with centOS. They set up the machine quickly. But from there it just went downhill.
Over the next three months, the server and slicebox's rdns server was subjected to multiple downtimes. I went through setting up a dozen sites and configuring/tuning postfix, contacting mail providers like comcast, aol, yahoo, etc, configuring feedback loops for the email, to resolve the bad IP history and get email properly delivered.
Link-building experts are sometimes confused about the guidelines for links -- supposedly, any link that "is paid" should "be nofollowed" which supposedly indicates that the link should not "pass pagerank". And if you are "caught" by "Google" "buying" or "selling" "reputation" through "links" then you may be penalized by Google in any of a variety of ways, like a pagerank devaluation (for instance).
I have one site which uses PHP sessions identified by browser cookies to store user state information. This allows the application to store a large amount of information efficiently, providing continuity for a complex user session without sacrificing performance, and without using the database. Just reference the session like any other hash, and anything you stored is still there, no matter the complexity of the data type with no serialization required.
I had some trouble installing APC from the published stable and beta versions and from pecl / pear - errors like
error: 'apc_regex' has no member named 'nreg'
I recently had the opportunity to dig into drupal's activemenu module, a seldom-used and not-entirely-functional ajax framework that can be used to build menus/trees on the fly. It provided a good roadmap that I was able to customize to work well for a project I did with rockpeaks.com.
Here's a quick screencast overview of the project and what it entailed:
Well, one of my websites has been successful to the point where I have to start looking into performance issues. It's based on osDate, so most of what I find may be helpful to others using that system. Since osDate uses image processing, mysql and smarty templates, these are the main areas for optimization.
(The following graph from my Google webmaster tools console was added Nov 30, 2009, three weeks after I began working on the optimizations, so you can see that even as my database grows - as it does slowly over time with a larger userbase - my average page load time is vastly improved due to these performance tips)
OsDate has a simple system for allowing only registered, logged-in users view certain pages. These pages (like userpicgallery.php for instance) simply include the file "sessioninc.php" right after setting up the session. Sessioninc.php checks to see whether the user is a registered, logged-in user, and if not, redirects the user to the login page.
I know from google analytics that about 25% of my paid clicks are from return visitors. Drilling deeper, I learned that one visitor from a certain city in California (I know the exact city) has been searching google for one of my most expensive keywords and clicking on my adwords ad, as his way to return to my site. OK, once or twice, that's great. But this man visited fifty times in one week. I guess he likes my filipina dating site, Christian Filipina. Hey Google, please give me some control to limit the number of repeat visits!
I've recently been learning about video chat for one of my sites. Although Adobe is in the process of making p2p video chat widely available, by making it (RTMFP/Stratus) part of the nearly-ubiquitous Flash 10 standard (see adobe developer portal), it appears there are no good solutions for peer-to-peer video chat yet, so I'm now in the process of setting up a chat server on my dedicated centos linux box, and associated chat software to run it.
I'm working with one site that is struggling with mail being rejected outright by other mail servers and sent to the spam box. Over the past month, I've fixed a few errors in the MIME formats, contacted rejecting domains (aol, live, yahoo, etc), all of which has increased slightly the success rate on mail delivery. But not enough. So the next step has been to setup the signature pages so that the site can sign mail and no spammers can take advantage of the good reputation the site builds. This is no guarantee, of course, but it's the next logical thing to try.