On Mon, Mar 24, 2008 at 12:18 PM, Luis Lavena <<a href="mailto:luislavena@gmail.com">luislavena@gmail.com</a>> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div class="Ih2E3d">On Mon, Mar 24, 2008 at 3:58 PM, Scott Windsor <<a href="mailto:swindsor@gmail.com">swindsor@gmail.com</a>> wrote:<br>
<br>
<br>
</div>You're using *RMagick*, not ImageMagick directly. If you used the<br>
later (via system calls) there will no be memory leakage you can worry<br>
about.</blockquote><div><br>You're correct - I'm using 'RMagick' - and it uses a large amount of memory. But that's not really the overall point. My overall point is how to properly handle a rails app that uses a great deal of memory during each request. I'm pretty sure this happens in other rails applications that don't happen to use 'RMagick'.<br>
<br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>Moving from FastCGi to Mongrel will also require you monitor your<br>
cluster processes with external tools, since you're suing things that<br>
leak too much memory like RMagick and requires restart of the process.<br>
</blockquote><div><br>Yes, although all monitoring will be able to do is kill off a mis-behaved application. I'd much rather run garbage collection rather than kill of my application. <br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
To make it clear: the memory leaked by RMagick cannot be recovered<br>
with garbage collection mechanism. I tried that several times but in<br>
the long run, required to restart and hunt down all the zombies<br>
processes left by Apache.<br>
<div class="Ih2E3d"></div></blockquote><div class="Ih2E3d"><br>So far, running the GC under fastcgi has given me pretty good results. The zombing issue with fast cgi is a known issue with mod_fastcgi and I'm pretty sure unrelated to RMagick or garbage collection.<br>
<br>
</div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Can you tell me how you addressed the "schedule" of the garbage<br>
collection execution on your previous scenario? AFAIK most of the<br>
frameworks or servers don't impose to the user how often GC should be<br>
performed.<br>
<div class="Ih2E3d"></div></blockquote><div class="Ih2E3d"><br>In the previous scenario I was using fast_cgi with rails. In my previous reply I provided a link to the rails fastcgi dispatcher.<br><a href="http://dev.rubyonrails.org/browser/trunk/railties/dispatches/dispatch.fcgi">http://dev.rubyonrails.org/browser/trunk/railties/dispatches/dispatch.fcgi</a><br>
<br>In addtion, in other languages and other language web frameworks there are provisions to control garbage collection (for languages that have garbage collections, of course).<br> <br>
</div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">I'll bet is rails specific, or you should take a look at the fcgi ruby<br>
extension, since it is responsible, ruby-side, of bridging both<br>
worlds.<br>
</blockquote><div><br>This is done in the Rails FastCGI dispatcher. I believe that the equivalent of this in Mongrel is the Mongrel Rails dispatcher. Since the Mongrel Rails dispatcher is distributed as a part of Mongrel, I'd say this code is owned by Mongrel, which bridges these two worlds when using mongrel as a webserver.<br>
</div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>
On a personal note, I believe is not responsibility of Mongrel, as a<br>
webserver, take care of the garbage collection and leakage issues of<br>
the Vm on which your application runs. In any case, the GC of the VM<br>
(MRI Ruby) should be enhanced to work better with heavy load and long<br>
running environments.<br>
<font color="#888888"></font></blockquote><div> <br>Ruby provides an API to access and call the Garbage Collector. This provides ruby application developers the ability to control when the garbage collection is run because in some cases, there may be an application-specific reason to prevent or explicity run the GC. Web servers are a good example of these applications where state may help determine a better time to run the GC. As you're serving each request, you're generally allocating a number of objects, then rendering output, then moving on to the next request. <br>
<br>By limiting the GC to run in between requests rather than during requests you are trading request time for latency between requests. This is a trade-off that I think web application developers should deciede, but by no means should this be a default or silver bullet for all. My position is that this just be an option within Mongrel as a web server.<br>
<br>- scott <br></div></div><br>