[Zope] Performance related to content loops/depth

[Jens Vagelpohl]

it looks like the site developers used relative links in their pages, 
which can lead to this problem. using absolute links prevents it.

jens


On Thursday, June 6, 2002, at 01:04 , Granzow, Doug (NCI) wrote:

> Bear with me, I'm a sysadmin, not a developer.
>
> I'm maintaining a Zope 2.5.1 server with Python 2.1.3 on Solaris 7.  We
> recently upgraded from Zope 2.3.1.  I'm seeing a problem where,
> occasionally, a bot will come along to index our site and suddenly Zope
> stops responding to all requests.  It looks like what is happening is that
> the bot finds a loop in the content where each time you click on a link, 
> you
> are returned to the same page, but the URL has one more level of depth.  
> For
> example, I see requests in the log file for things like this:
>
> siteroot/info/catalog/catalog/catalog/catalog/catalog/catalog/catalog/catalo
> g/catalog/catalog/catalog/catalog/catalog/catalog/catalog
>
> When a bot hits this it keeps going deeper and deeper until we deny access
> to the bot.  When I request a URL like that in my browser, even just one
> time, Python's CPU usage shoots to near 100%, and stays there for several
> seconds.  If I keep clicking on the link to go deeper, it doesn't take 
> long
> for it to effectively become a denial of service attack, because the
> processing time required to process each request seems to grow more and 
> more
> as you go deeper.
>
> Is there any way to stop this from happening?  Obviously we want to remove
> loops like this from the content, but as I said, I'm the sysadmin, not the
> developer.
>
> Any input is appreciated!
>
>