This might be due to a configuration incompatibility with the Cache Manager stuff (for example, ZClass methods can't be cached). As a result, you may need to cache the pages manually by using a reverse caching proxy and Expires/Last-Modified headers as I described. I realize that needing to go in and tweak your configuration is not something you want to have to do while your site is getting hammered, but there's probably not much of a choice. That said, it's likely that the emergency will be over with before you get a working configuration up, which is of course frustrating. Hopefully, at some point we'll have a pretty and comprehensive set of step-by-step documents describing specifically how to set Zope up for high load. In the meantime, the rule of thumb is "always cache as much as possible"; the corollary is "always test your cache hit rate before putting something into production". You'll probably want to do both before you get Slashdotted the next time. ----- Original Message ----- From: "Michael Fraase" <mfraase@farces.com> To: "'Chris McDonough'" <chrism@zope.com>; <zope@zope.org> Sent: Tuesday, November 20, 2001 2:22 PM Subject: RE: [Zope] Urgent help needed: Zope falls over under moderate load
They just don't show up in the list of cacheable items.
-- Michael Fraase ARTS & FARCES LLC mfraase@farces.com www.farces.com PGP Fingerprint: 3D85 F3F4 9E65 4949 176A 260C CB47 190D C864 9A96
-----Original Message----- From: Chris McDonough [mailto:chrism@zope.com] Sent: Tuesday, November 20, 2001 12:45 PM To: mfraase@farces.com; zope@zope.org Subject: Re: [Zope] Urgent help needed: Zope falls over under moderate load
Are the pages uncacheable because they're restricted by security or for another reason?
----- Original Message ----- From: "Michael Fraase" <mfraase@farces.com> To: "'Chris McDonough'" <chrism@zope.com>; <zope@zope.org> Sent: Tuesday, November 20, 2001 1:14 PM Subject: RE: [Zope] Urgent help needed: Zope falls over under moderate load
Thanks Chris,
I've cached what I can find. The only page that's cacheable is index_html; the pages being hit are another layer deeper in the hierarchy. I've also cached all of the page elements (images, header, footer) I could find.
-- Michael Fraase ARTS & FARCES LLC mfraase@farces.com www.farces.com PGP Fingerprint: 3D85 F3F4 9E65 4949 176A 260C CB47 190D C864 9A96
-----Original Message----- From: Chris McDonough [mailto:chrism@zope.com] Sent: Tuesday, November 20, 2001 12:11 PM To: mfraase@farces.com; zope@zope.org Subject: Re: [Zope] Urgent help needed: Zope falls over under moderate load
Your clients maybe *should* laugh at you if you're not doing any caching. ;-)
To cache, you have two options.
Use Zope's RAM Cache Manager to do caching. As a result, the pages you choose to cache will be cached in RAM and won't be regenerated on each request.
- OR -
Use a caching web server in front of Zope to bear the brunt of the load in conjunction with (perhaps) the HTTP Accelerated Cache Manager stuff in Zope. In this case, your web server (or proxy) keeps a copy of a pregenerated page and serves it out to requestors instead of continually asking Zope to regenerate it.
One of these is going to be necessary for any sort of high-traffic site. Zope can't keep up when it needs to dynamically generate content; you need to help it out by doing some kind of caching.
If you don't or can't use Cache Managers, but you still want to use an HTTP caching proxy in front of your Zope site, you'll need to make each of the pages you want to cache has an "Expires" and "Last Modified" header. You may do this by using RESPONSE.setHeader if you're not using a cache manager. If you're behind Apache, you can use mod_proxy with caching turned on.
See http://www.zope.org/SiteIndex/search?text_content=caching for more information.
I've also found the document about mod_perl and headers at http://perl.apache.org/guide/correct_headers.html helpful... there are lots of other nuggets in that document as well.
HTH,
- C
----- Original Message ----- From: "Michael Fraase" <mfraase@farces.com> To: <zope@zope.org> Sent: Tuesday, November 20, 2001 12:39 PM Subject: [Zope] Urgent help needed: Zope falls over under moderate load
So yesterday my site got slashdotted. Zope fell over within minutes. A day later it's still falling over within an hour or so.
I have 512Kb DSL (the outbound channel is 512Kb; the inbound channel is 768Kb). I figured that bandwidth would be saturated or that Windows 2000 Pro would melt long before Zope would fail, but that has proven not to be the case.
Here's the particulars of my installation:
Pentium III 850MHz with 768Mb RAM MS Windows 2000 Pro with current patches and service packs Zope 2.4.3 running as a service Squishdot 1.3.0 512Kb bandwidth
Here's the registry start parameters:
"C:\PROGRA~1\FARCES~1\bin\python.exe" "C:\PROGRA~1\FARCES~1\z2.py" -S -w80 -W9800
I don't know what the -S is; -w80 sets the port Zope's web server listens on; and -W9800 sets the WebDAV port.
Zope just shuts down and closes port 80 on what seems to be very moderate load. We're talking a peak of less than 60,000 hits, a peak of 125Mb bandwidth usage, just over 58,000 page views, and a peak of 4013 visitors.
What I've been doing is to manually stop the Zope service and restart it, but that's ridiculous. At this rate, clients are going to laugh at me when I suggest using Zope for a web project.
Anyone have any ideas? I'm digestified, so please cc me in any response.
Thanks kindly.
-- Michael Fraase ARTS & FARCES LLC mfraase@farces.com www.farces.com PGP Fingerprint: 3D85 F3F4 9E65 4949 176A 260C CB47 190D C864 9A96
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