Revserver / Dreamhost question

Michael Kann mikekann at
Fri Aug 13 12:40:58 EDT 2010

Richard and Stephen,

I'm still confused as to the difference between using revServer and using the 3.5 engine. My mental model is that when the apache webserver sees a script with an irev extension it sends it over to the 3.5 engine to parse it. The 3.5 engine sends back some html to push out the door to the browser in Glendale. Apache and the 3.5 engine work together to allow us to use irev scripts. Does the revServer work with Apache to do the same thing?

In short, why RevServer instead of the 3.5 engine?


--- On Fri, 8/13/10, Richard Gaskin <ambassador at> wrote:

From: Richard Gaskin <ambassador at>
Subject: Re: Revserver / Dreamhost question
To: "How to use Revolution" <use-revolution at>
Date: Friday, August 13, 2010, 11:10 AM

stephen barncard wrote:

> 1.  If I want to use my own Revserver instance at Dreamhost, would I have to
> get a 'Personal Server' account?  I understand my shared hosting can't be
> used for this. Has anyone here done this?

Shared hosting should be fine.   Just like the older Rev CGI engine, the only limits you'll run into with RevServer are those imposed by the hosting company for shared accounts, which should be fine for most uses.

Hosts will vary in how they limit resource consumption to prevent a single account from dominating a shared CPU.  For example,, TierraNet, and others limit processes to 30 seconds, while Dreamhost limits them to about 300 aggregate minutes per day.

Which is "better" will depend on your needs (and if you ran a single process for 300 consecutive minutes you'd likely get a letter from Dreamhost asking why you need to do that <g>).  But no matter which specific limits are used by the host, most CGIs will run quite well within them.  Very few customers have run into these limits themselves, and I run a lot of CGIs on TierraNet, Dreamhost, and others and have never come even close them at all.

As many here have noted, 30 seconds is a very long time to run a continuous process.  With my CGIs I target a maximum of 5 seconds and may in some extreme cases tolerate up to 10 seconds if absolutely unavoidable, but even that's too long for my tastes; I can't have the user siting there without feedback for that long.

Looking at resource averages as our guide on this, the Dreamhost support wiki says: "Average shared hosting customers normally use less than 5 CPU minutes per day for their account".  When you consider the popularity of Wordpress, Drupal, Joomla, and other PHP/MySQL-driven systems, that average lends a good perspective of how even complex systems perform under normal loads.

Given the speed of the Rev engine, I'd be surprised if you ever needed more than a second or two to run most things you'd want to do with it on your server.  With the blog, the custom search engine I built for a client, and other relatively processor-intensive tasks, the Rev engine is able to do what I ask of it in a fraction of a second.

But if you ever find that you do need to run unusually lengthy processes, Andre's latest article in the RevUp newsletter covers how to break up a long task into chunks that allow even a shared-hosting account to run long processes without denying performance to other accounts, and will keep your users happy with good responsiveness:


> 2. If I want to use RevServer on multiple domains -  is a  single license
> good for this? Per server, not per domain, right?

My understanding is that it's per server rather than per domain. So if your Dreamhost account has a dozen domains you should be able to use RevServer on all of them, but if you also have hosting on another service you would need an additional license for that other server.

 Richard Gaskin
 Fourth World
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