Apache

Recently, I have been spending a significant amount of time working on an application which manages the amount of memory assigned to a DreamHost Web VPS. During the time I’ve spent developing this several choices had to be made in what the real goal of the application had to be. When it comes to memory management on a server there are really two goals which don’t always play well together.

Goal One: Save Money

Many people seem to have a belief that just because the site/s are on a VPS, even with memory set as low as possible (300MB of RAM assigned to a machine in the case of a DreamHost VPS), they will have perfect or near perfect uptime. Sadly, this is not the case and often times this misunderstanding/confusion can lead to serious downtime and frustration. Ideally, for people who are trying to have the lowest amount of memory usage possible, a memory management application would realize that there is a need for more memory, calculate an estimated amount of memory needed to handle the increased usage, resize the VPS as closely as possible to that need, then downsize as soon as the memory is no longer needed.

There is one major issue with this scenario:

Creating estimates regarding the amount of memory needed in an environment where usage is constantly changing, is a massive challenge. To be more specific; since the ability to resize a VPS tends to take some time (anywhere from 1-5 minutes), it is possible for memory requirements to have increased during the time that the need was detected and the memory estimate was created. This could create a resize on a VPS with too little memory, causing problems for the website/s on the VPS, as the machine is given too little memory to handle the increased need.

Goal Two: Keep Services Running

If you are on a VPS, chances are you’ve outgrown shared hosting or are looking for more stability and control over the environment your applications run on. If you’ve got a decent understanding of servers, applications, and websites, you may also understand that you need to have enough memory to run all the processes and handle the requests to your sites. Often times simply setting your service to the lowest amount of memory possible is going to be asking for failed script executions and the dreaded 500 error being displayed on your site.

So with this understanding, some people go to the extreme and max out their VPS resources. At DreamHost that means $200 a month for services (4GB worth of RAM) which may not be fully utilized (and most likely are not). So the question here becomes how to balance cost and the need for memory, in order to keep services running without paying the maximum amount at all times.

A Hybrid Memory Manager Focused on Uptime

With these two potential goals in mind, I had decided to mainly focus my attentions on goal two. While I do understand the need to keep price as low as possible, it is my personal belief, gleaned from experience, that a downed website is more damaging to the bottom line than a slightly larger payment for hosting services. So with this in mind, the memory manager was created to focus on uptime, while still saving time and money for those who manually resize throughout the day, and potentially over-allocate memory for their site/s.

All this being said, I am quite excited to be releasing this software soon. The status of this release is currently closed beta. However, if you are interested in testing this on your DreamHost VPS, please contact me. I am looking to increase the pool of Beta testers before the official release.