Binary Search for Javascript Arrays
If you need to search through a large array, or you search arrays frequently in your Javascript code, or if you do both, chances are a binary search will give you better performance than a linear search (read: for loop). One caveat, however, is that binary search algorithms only work on sorted arrays. Here is a binary search function I sometimes use in my code:
A Better HAProxy Health Check For Dynamic Websites
Nobody wants their website to go down, or worse, for users to notice the site is down. Because of this most larger websites will run on multiple servers to provide some level of high availability. In a multi-server architecture there is typically a load balancer (or cluster of load balancers) to distribute the load among a pool of web servers. When a server goes down it’s taken out of the pool until it is once again ready to handle requests. HAProxy (a software load balancer) has the ability to perform this task by doing periodic health checks on all the servers in a cluster. The default settings, though, could give false positives in some cases, and thus create a bad user experience by allowing ill application servers to continue receiving requests.
Recursive Find and Replace With grep and Perl
I thought it might be a nice idea to start posting useful little commands and bits of code every now and then–ones I’ve found to be particularly useful. So here’s the first one, recursive find and replace. A masterfully crafted regular expression paired with this command can save you hours of tedious work.
Taking The Pain Out Of Domain Hunting
Coming up with a suitable name for a business, product, or website is something I do on a fairly regular basis. In brainstorming a name I often make lists of words I’d like to use, like adjectives and nouns than relate the product. Then I start combining the words to create a unique name and check to see if the related domain is taken or not. The problem is that even though I may have come up with a name I really like, if the domain name is taken, it isn’t worth keeping.
High Performance Comet on a Shoestring
I’ve had my eye on the advances that are being made in the Comet arena for a while now, but it was only this past weekend that I finally sat down and used it for a project. In doing so, there was a particular configuration problem I needed to address, and that was…uh, addressing.
Introducing Comet to an existing architecture assumes there is already a web server in the neighborhood, and that it is, in one way or another, receiving traffic from port 80. Due to the fact that many site visitors will likely be positioned behind a firewall unwilling to accept connections on ports other than 80 or 443, we also need to get our Comet server running on port 80 as well. This normally wouldn’t be much of a problem at all, unless you don’t want to fork over the money for an extra IP address. I don’t & I didn’t. So let me show you how I did so.
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About
Sean Murphy is a freelance web application developer currently living near Orlando, FL. Aside from building his own applications and contributing to open source projects, he works with clients to provide top-notch consulting & development expertise.
