December 1999 - Zope

Ever seen this problem?
by Eric W. Sink 13 Dec '99

13 Dec '99

We have been chasing a problem with our Zope server. Comments from others here on the mailing list have given me the impression that others might be facing the same quandry. Basically, the problem is that Zope intermittently "hangs". When I say "hangs", what I mean is: 1. It stops serving web requests. When attempting to access Zope via HTTP, the tcp connection succeeds, but nothing is every returned. 2. We cannot get in through the monitor_client 3. Zope appears to be using no CPU time. 'ps' reports that there are several Python processes associated with Zope, but none of them are doing anything. 4. Since HTTP does not work at all, access to /manage or /manage_debug doesn't get anywhere. 5. The only remedy which has worked is to kill the Zope server and restart it. 6. netstat does *not* report any unusual number of sockets owned by python Zope processes. 7. The size of the Python Zope processes does not seem unusual. Last time I checked, they were all around 13M each. We run Zope 2.1.0 final, the version compiled by Digital Creations, downloaded from their site. The same problem existed on 2.1.0b2 and the 2.0 series. The problem is not specifically reproduceable. There is no sequence of steps which causes Zope to hang in the manner described. Nonetheless, it happens. Sometimes it happens a lot. Sometimes it happens infrequently. We run ZServer as our web server. We have never tried running Zope behind Apache. (Should we?) Our machine is a dual-PIII 550 with 512MB of RAM. The operating system is Debian 2.1 (potato). The problem has appeared under other configurations, but we have not tried Zope under any other version of Linux. Virtually nothing else ever runs on this machine, other than Zope. The machine is sitting on a 10-base-T Ethernet, connected to a T-1 line. This Zope server has never been exposed to anything which I would consider to be a really heavy load. The Zope server in question can be seen at www.sourcegear.com It is [usually] up and running. :-) Suspicions: This seems to happen more often when we are editing things using /manage. But then again, there have been several times when it has hung while nobody was even around. We have tried using wget -r to abuse ZServer in the hopes that we could get it to fail predictably. This worked once, causing a hang after five minutes or so. The next time we tried it, Zope carried on for half an hour under heavy load, with no problems. I don't mind fighting a bug, but I don't enjoy intermittent ones. :-( Sometimes Zope stays up longer than others. We have had situations where it stayed up for three days. And, we have had situations where it stayed up for three minutes. This latter situation *seemed* to be associated with the presence of a robot which was crawling our site. Every time we brought the site back up, the robot would resume, and the site would go back down. Watching the log file caused us to suspect a problem with certain types of acquisition. We had some bad relative URLs in our content which were causing deep recursion. The crawler was happily crunching through everything it could find, and our log file revealed some extremely long URLs. [ We blocked the crawler at our firewall. :-) ] However, we fixed every bad relative URL we could find, and the hangs have continued. Less frequent, I supposed, but they still continue. Our site is not terribly large. We do have quite a few documents, but nothing out of the ordinary. Most or all of our images are PNG. We *do* have a ZCatalog running. We use the Knowledge product. One section of our site is a database front end using ZMySQLDA. However, this part of the site is not currently visible to the rest of the world (at least there is no link to it). We have seen no particular correlation between frequency of access to this section of the site and frequency of "hangs". We tried activating the debug_log once, using instructions obtained from a message posted to this list. Unfortunately, that was the attempt wherein Zope ran for half an hour under heavy load with no problem. Our Data.fs file is 77MB. We have never compacted it. Any advice would be *much* appreciated. We have a new service that we are *almost* ready to deploy, and we really need to resolve this problem before it goes out. Thanks in advance. -- Eric W. Sink, Software Craftsman SourceGear Corporation eric(a)sourcegear.com

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Versions needed?
by Barbara Pfieffer 13 Dec '99

13 Dec '99

I got permission from my web host to install Zope. A couple of questions: They have Solaris 2.7, Zope is for 2.6. Will that make a difference? They have python 1.5.1. Does that make a difference or should I ask them to upgrade to 1.5.2? They will do it, but only if I need it. Thanks Barbara ------------------------------------------------ Make Your Site Sell! Products http://www.myssproducts.com/ Learn How to have a profitable, successful Web Site! FREE Download! -------------------------------------------------

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RE: [Zope] permissions check without triggering login
by Toby Dickenson 13 Dec '99

13 Dec '99

> -----Original Message----- > From: Martijn Faassen [mailto:m.faassen@vet.uu.nl] > Sent: 13 December 1999 14:37 > To: zope(a)zope.org > Subject: Re: [Zope] permissions check without triggering login > > > Steve Spicklemire wrote: > > > Could you set the 'proxy' for that method to have a role > > that can check with impunity? > > Interestingly, this works. You'd think that if I set the proxy to > manager it wouldn't work as I'd wanted, because this proxy > role now has > permissions equal to that of manager, so I still couldn't check if > Anonymous can view. But apparently this isn't the case, and it does > work.. > > Could somebody explain this behavior? AUTHENTICATED_USER doesnt have the permission, the role does.

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How do I call DTML Method which name is stored in a variable
by Carlos Henrique Bauer 13 Dec '99

13 Dec '99

Hi, Thanks to Evan Simpson, I learned a method can be called in the following way: <dtml-var expr="_.render(FetchObj(_.None, _,fetchStr='hie/dee/hoe').id)"> Suppose the name of the method is stored in a variable. How do I invoke the method? -- Carlos Henrique Bauer

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permissions check without triggering login
by Martijn Faassen 13 Dec '99

13 Dec '99

Hi there, I'd like to make a DTML method that produces a list of all subfolders that the user has permission to see; i.e. if Anonymous isn't allowed to 'View' a certain folder I don't want that folder to show up in the list. This howto seemed perfect for my purposes: http://www.zope.org/Documentation/How-To/DetectRoles However, when I actually applied it I ran into a problem I can't seem to get around. I have a folder called 'test1' which has 'Access contents information' and 'View' permission turned off for Anonymous. Now, I have the following dtml_method (in the parent folder of test1): <dtml-if "AUTHENTICATED_USER.has_permission('View', test1)"> Can be viewed! <dtml-else> Can't be viewed! </dtml-if> Unfortunately, when I try this with an anonymous user, this displays the login dialog when executed. I just want to see 'Can't be viewed!'. Is this possible, and if so, how? Regards, Martijn

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a question on external method arguments
by gyst＠nfg.nl 13 Dec '99

13 Dec '99

I'd like to use an external Python method to reference it's caller's object id. Broken down to the simplest example: def testid(self, idref): """test scoping of variables""" return idref which is supposed to return its input argument "idref" unchanged. This works nicely when called from a DTML method, but when I call this external method from a DTML document, something weird happens. DTML source: This is the  Document. My id is reported to be:<dtml-var "testid(id)"> <dtml-let myid=id> but also:<dtml-var "testid(myid)"> </dtml-let> gives the following result: This is the sub1-1 Document. My id is reported to be:<Python Method object at 8451b20> but also:sub1-1 Can anybody explain to me, why I need to copy the "id" variable to a locally scoped "myid" for this to work? And what is the logic that makes the external method return self instead of its input argument? And, of course, I'd like to get to the "id" value through self instead of using an ugly hack like passing an explicit id, which I'm only using for debugging purposes right now. Got to understand where self comes from in an external method, first :-(. :*CU# -- *** Guido A.J. Stevens *** mailto:gyst@nfg.nl *** *** Net Facilities Group *** tel:+31.43.3618933 *** *** http://www.nfg.nl *** fax:+31.43.3560502 ***

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Documents Database and Zope
by Arnaud Lecat 13 Dec '99

13 Dec '99

Is Zope fast enough to / conceived to... store a huge database of files (Word, Excel, etc...) like Lotus for example. I think it's always the same question about Zope scalability... Bye -- >> WinErr: 080 Clavier introuvable - Veuillez appuyer sur n'importe quelle touche pour continuer. << Arnaud LECAT >> Email: lecat(a)hexanet.fr >> WWW page:www.hexanet.fr/~lecat HEXANET >> http://www.hexanet.fr Z.A. Farman sud - 9 rue Roland Coffignot BP 415 - 51689 Reims Cedex 2 - France phone: (33) 03 26 79 30 05 Fax: (33) 03 26 79 30 06

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How to write a product.
by Magnus Heino 13 Dec '99

13 Dec '99

Hi. I want to write a product, like the calendar in MSOutlook. People should be able to add private and public events. Since I have never written a product before, what could be used as a good reference? Seems to me that one should use zclasses, with some logic in python. I had a look at ZDiscussion yesterday, is it doing things the "right" way? /Magnus

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XML-RPC
by Magnus Heino 13 Dec '99

13 Dec '99

Hi. I just read http://www.zope.org/Members/Amos/XML-RPC, but can't get the example to work. If I want to call SiteIndex.search() at www.zope.org with some search-data, and print the answer, how would that be done? /Magnus Heino

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ZDiscussion How does one use this??
by Jochen Haeberle 13 Dec '99

13 Dec '99

Hi, I am new to Zope and am struggling a bit... I downloaded ZDiscussion 0.2.0, extracted it to the correct place and imported the additional zclass (whatever that is, none of the docs explains this). I can add a new ZDiscussion fine, but what than?? It seems like that's an empty folder with some special tabs, but how do I use the discusion??? Furthermore, where is a documentation that tells about that? The ReadMe only covers the DropIn replacment for Confera. Is ZDiscussion just the basis for a product like ZDConfera? If so, where are the features like Preview??? Regards Jochen

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