August 1999 - Zope-Dev

2nd of back-to-back communications with Zope hanging?
by Marc.Conley＠mapics.com 16 Aug '99

16 Aug '99

I am using 2.0.0b1. I am interested in whether or not anyone else is having a problem with two back-to-back communications with Zope hanging for a period of time but ultimately working? I am opening a URL on a Java client using UrlConnection which is requesting that Zope run an external method. The purpose of the external method is to create a folder and add a property to the folder. After I get the result back from the above external method, I immediately open another Url from the Java client which calls another external method which requests the information that was added (the folder's property). When I open these Url's back-to-back, I finally get the response I am looking for after about 30 seconds. If I put a 1/2 second delay before opening the 2nd Url, it eliminates the problem--I get the response immediately. But, this is a bandaid for some kind of problem. Can anyone explain what I am experiencing here--have you had similar problems? Or even better, is this something that has been fixed recently. Overall, 2.0.0b1 is stable, etc. for what I am doing, so I was trying to wait until the final general release 2.0 comes out to switch. Thanks for any help/tips/explanations you may have!

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Zope transactions and DAs
by Ross J. Reedstrom 16 Aug '99

16 Aug '99

Hey Zopeists - I spent some time this weekend testing the ZPyGreSQLDA with Zope2 beta4. I seem to have it working reasonably well now, but there are two issues I want to take up with those with more experience on the guts of the new TM machinery than me (I guess that means DC folks, primarily). First, observed behavior: My test system: Linux 2.2.10 Zope 2.0.0b4 (Linux x86 binary release: i.e. with it's own python) Python 1.5.2 PostgreSQL 6.4.2 and 6.5.0 My tests consist of creating a ZPyGreSQL connection, and two Z SQL methods, one valid (it's: SELECT * FROM pg_tables) and one invalid (SELECT * FROM no_such_table). Then, with the backend db running with a moderate level of logging, I use the manage_test interfaces on the Z SQL objects, and follow what's going on in the PostgreSQL logs. First, on startup, Zope2 opens 2 connections to the backend DB. This seems to relate to the number of active threads, since in later tests, I got more and more connections being created. This is fine, except only one connection is killed when you close the Zope DB Connection object. The rest hang around until the Zope process exits. Is there something I'm supposed to do in the DA to manage the connection pool? Second, I'm not happy with how the TM machinery is interacting with my DA. At first, with a fresh connection, when I use a ZSQL method, what I see is that Zope calls the _begin(), query(), and _finish() methods in my DA. However, as soon as there's been an error on a given db connection (like calling a ZSQL method with syntax errors), Zope only calls query(). I handle the rollback of the backend inside the query method: is that correct? Is there some what to get Zope to keep using the _begin and _finish calls? Lastly, I'm seeing some hanging in the Zope process, which I'd normally attribute to me not knowing what I'm doing in my DA code, but may relate to the lockups others have been reporting. What I see is occasionally, when I hit the 'Submit Query' button in the manage_test interface, the HTTP request get sent, then nothing happens. If I hit it again, I get an immediate response. If I do this enough times, quickly enough, I sometimes get a new connection to the DB backend, which hangs around until Zope quits. Well, that's about it for now. If anyone wants to tryout my code, it's at http://wallace.ece.rice.edu/ZPyGreSQLDA-0.3-rjr2.tar.gz DC folk, you can also find it in the obvious place, where the ZDP people would look. Ross -- Ross J. Reedstrom, Ph.D., <reedstrm(a)rice.edu> NSBRI Research Scientist/Programmer Computer and Information Technology Institute Rice University, 6100 S. Main St., Houston, TX 77005

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form action in specific context
by Martijn Faassen 16 Aug '99

16 Aug '99

Hi everybody, I'm trying to find the best way to describe this problem. I'm dealing with XML Document, but this could just occur if I have a folder subfolders and some documents inside. What I have is set of DTML methods that render the contents of an XML Document to an XML page. It does this by going into the XML tree (which you can see as a folder tree), and because through acquisition the right DTML method to render a specific element (or type of folder) is known at that element too, I simply call that method on that element to render. I do stuff somewhat like this: DTML Method render_foo: <h2><dtml-var title></h2> <dtml-with bar> <dtml-var render_bar> </dtml-with> DTML method render_bar: <form action="form_response"> .. </form> <p><dtml-var whateverproperty></p> Basically, I just call different render_* DTML methods on subtrees, which exist because of acquisition. This all works well, and my HTML gets rendered. But as you see, I included a form in render_bar. But then, on the rendered page, when I submit the form, what is called by the form is *not* a DTML method on the 'current' branch of the tree, but a DTML method at the folder where the XML document resides. This is understandable, but not what I want; I want to call a DTML method in the tree (that should be there because of acquisition), because otherwise the DTML method will not have the right context. In the example I'd like to call form_response in the context of the object that is rendered by render_bar. So somehow I will need to do something with this: <form action="????">. What should I put in the action attribute? An alternative would be to use hyperlinks, and a 'href'. But how do I know what URL to call? The 'URL' Zope variable isn't helpful, as it gives the URL of the root. I want the URL of the current object that is rendered. I'm afraid this all sounds terribly confusing. If so, please let me know and ask questions, so I can clarify. Regards, Martijn

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Problem with distributing ZClasses
by Josh Zeidner 16 Aug '99

16 Aug '99

Has the distribution mechanism been tested for ZClasses? I am having trouble getting this product to work on other peoples systems. -Josh Z _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com

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ZCatalog peculiarities?
by Phillip J. Eby 16 Aug '99

16 Aug '99

I've been spelunking through the ZCatalog source this morning, and there are a couple of things I don't understand, that look to me like memory leaks and other problems. First, in Catalog.py, it seems like virtually every method of the Catalog class calls self.useBrains(). useBrains() creates a new class each time it's called, and then deliberately creates a circular reference in that class, such that it can't be deleted. Finally, the logic of where useBrains() is called, is such that it will be called once for every item retrieved from every search done on the catalog. Thus, every record should end up as an instance of a different class, specifically created for that record. This has me baffled, because I can't see why that would be something useful. Am I missing something really deep here, or is it just a bug? It would seem to me that there should be something like "_v_brains_inuse =_v_brains" at the end of the useBrains() method, so that at the beginning you can check for whether "brains is _v_brains_inuse" and skip creating a new class, etc. once the brains are initialized. The next thing I've noticed, is that Catalog.py imports from Query, but then never actually uses anything from it. Oh, sure, there's an orify() function that does stuff, and a query_map local variable set up in searchResults() that references orify, but query_map never gets used. (And ZCatalog.py makes up another copy of the same query_map object and passes it in, but that never gets used either.) I even dug down to Index.py and TextIndex.py to make sure query_map wasn't used down at that level, and then I realized that query_map wasn't part of the namespace being passed down there anyway. This all looks like some sort of vestigial leftovers, perhaps during porting from ZTables...? The third thing I saw, is that there are lots of constructs of the form: if something in somethingelse.keys(): where the object 'somethingelse' appears to have a perfectly good has_key() method available. Again, is there some sort of deep Zen here, like trying to force index pages to be loaded, or...? I mean, it seems like this would be much less efficient than just hitting the has_key() methods. Last, and definitely least, I notice that useBrains() uses a loop to create scopy, when "scopy=self.schema.copy()" would suffice. That wouldn't be anything worth 'fixing', except considering how often that code would appear to be being called. I'm really tempted to run something through the debugger or profiler just to see if I'm totally off base on how often useBrains() is getting called. But I thought I'd run this by the experts, since if y'all did this stuff on purpose, you'd be able to tell me. :) Oh, one other thing. Not a bug, but a feature... It seems to me that if you are searching a ZCatalog on index 'foo', it looks possible to do something like: Catalog(foo=['bar','baz'],foo_usage='range:min:max') And receive records with values of foo ranging from 'bar' to 'baz'. Is this a supported, intended feature, or...? Just wondering.

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Re: [Zope] Alpha of ODP Viewer product
by Michel Pelletier 16 Aug '99

16 Aug '99

"Andrew M. Kuchling" wrote: > > Maik Roeder writes: > >What do you mean by "get the *real* XML dumps into Zope" ? > > Various pieces don't expect to handle 45Mb of input data. For > example, ZPublisher.Client handles file uploads by reading all the > data into memory, and it dies; pcgi-wrapper tries to read all of stdin > and also dies, etc. I'm trying to do it from the monitor_client with > the following incantation: > > import Zope ; a=Zope.app() > a.manage_addProduct['XMLDocument'].add(a, > id='s1', title='Structure', > file=open('structure.rdf', 'r') ) > > I haven't made this work yet, and suspect this is also choking > somewhere along the way. Anyone from Digicool ever tried to shovel > this much data into an XMLDocument? > Sub transactions can help in this particular case, I believe. A quick glance at the XMLDocument code looks like it doesn't use subtransactions like File objects do (see lib/python/OFS/Image.py manage_addFile method). I could be wrong, but it looks like a pretty simple change. Amos? -Michel > -- > A.M. Kuchling http://starship.python.net/crew/amk/ > A slovenly action repeated thrice has become a habit. > -- Robertson Davies, _Leaven of Malice_ > > _______________________________________________ > Zope maillist - Zope(a)zope.org > http://www.zope.org/mailman/listinfo/zope > > (To receive general Zope announcements, see: > http://www.zope.org/mailman/listinfo/zope-announce > > For developer-specific issues, zope-dev(a)zope.org - > http://www.zope.org/mailman/listinfo/zope-dev )

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Calendar TAG Error : Unrecognized timezone
by kentsin 14 Aug '99

14 Aug '99

I encount the following error when using calendar tag : Error Type: DateTimeError Error Value: Unrecognized timezone The code is  <h1>Testing</h1>     The system is in win98 with time zone set to GMT+08:00 Beijing, Chongqing, Hong Kong, Urumqi

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Re: [Zope-dev] Trying to design a PythonMethod Product
by Christopher Petrilli 13 Aug '99

13 Aug '99

>> Look at the expression machinery, it would be insane to duplicate security >> already implemented, and frustrating to have two separate "paradigms" for >> managing security. > > Surely! This consists of DT_Util, VSEval, and gparser, yes? As far as I > can tell, these perform two tasks; They screen out restricted names and > guard selected operations. You folks may want to seriously consider > replacing gparser with something using bytecodehacks; Walking an AST is > terribly opaque and complex compared to manipulating an EditableCode object. > That's how I'm doing things, anyway, and I'll do my best to use the > information and guard functions in DT_Util directly. Hmm. For that matter, > I may try to generalize enough to offer a plug-in replacement for VSEval. I would be curious of the performance difference as well. We wrote our stuff LONG before anyone had developed anything better, and it was heavily optimized. Even a 5-10% performance hit is probably unacceptable in DTML, given it needs to be faster as it is, and adding additional overhead is silly. It would have to benefit Zope at some level above just making it more "obvious" how an AST is walked... 99.999999999% of users will never see it, nor should they want to. >> Actually, we talked about just limiting the "instruction counter" so that >> you could catch anything that was taking an excessively long period of > time >> to execute. Say 1M byte-codes? This avoids having to worry about >> individual flow constructs. > > Sounds great! How? :-) I'll have to look, but I recall Jim explaining a way to do this, so I'm sure it's possible. >> > 7. Either disallow "global", or redirect access to globals into a > controlled >> > namespace. >> >> Look at management of namespaces in expressions. > > This part is proving to be fairly deep. DTML objects require a client and > mapping to operate on. I want PythonMethods to be a*lot* like External > Methods, with any number of parameters (including zero) and the option to > pass '_' or 'REQUEST' explicitly. Under this regime, global names can't > refer to Zope namespace contents; So far, I've got them accessing a volatile > private namespace. Hehehe, namespaces are *very* deep indeed, and are one of the difficulties in doing things that people think should be "easy". Our goal was NOT to make "External Methods" internal, but rather to allow more complex Python expression web enabled. The former is a very dangerous path to walk down from a security perspective. In fact, in our "image" it wouldn't even have a "def" statement, nor could you define classes, etc., it was simply for encapsulating more complex logic. > This has led me to extend my original idea. I *really* dislike requiring a > separate Zope object for every method in a module of external methods, and I > think it would be even more annoying when the actual code is web-managed. > Now I'm thinking of creating a PythonModule product, which could define and > expose any number of functions and classes. These would act like methods of > the PythonModule. Perhaps defining an object named 'default' (or > 'index_html'? <bleah>) would allow the PM to be called/rendered directly. > Now, all the objects in the PM would have a meaningful shared global > namespace, just as if they were in a regular Python module. I disagree strongly here. An "method" is an object, and it might reside in a container (which one might call a Module), but modules are namespaces, not objects in the sense that you're using them. I think your goals, while admirable, are substantially large enough in scope to mire down the implementation with additional chrome that may or may not be useful. I'd recommend getting something very basic done before attempting the Holy Grail. I very much think you should use the existing machinery, rather than designing your own new... it's just more variables to examine when trying to understand the isolation mechanisms. Chris -- | Christopher Petrilli Python Powered Digital Creations, Inc. | petrilli(a)digicool.com http://www.digicool.com

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exception under load
by Robin Becker 13 Aug '99

13 Aug '99

I see this now and then with loaded CVS Zope 1999-08-13T16:56:52 ERROR(200) ZServer uncaptured python exception, closing chan nel <zhttp_channel connected 127.0.0.1:1680 at 1ee89a0 channel#: 854 requests:1> (exceptions.AttributeError:'int' object has no attribute 'send' [C:\Python\deve l\Zope\ZServer\medusa\asyncore.py|poll|64] [C:\Python\devel\Zope\ZServer\medusa\ asyncore.py|handle_write_event|298] [C:\Python\devel\ZOPE\ZServer\medusa\asyncha t.py|handle_write|144] [C:\Python\devel\ZOPE\ZServer\medusa\asynchat.py|initiate _send|211] [C:\Python\devel\Zope\ZServer\medusa\http_server.py|send|394] [C:\Pyt hon\devel\Zope\ZServer\medusa\asyncore.py|send|231] [<string>|send|1]) -- Robin Becker

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Re: [Zope-dev] Zope scheduler any one.
by Josh Zeidner 13 Aug '99

13 Aug '99

You could write a simple system script to contact a URL inside sope fairly easily. -Josh Z >From: Robin Becker <robin(a)jessikat.demon.co.uk> >To: zope-dev(a)zope.org >Subject: [Zope-dev] Zope scheduler any one. >Date: Fri, 13 Aug 1999 10:46:27 +0100 > >Any plans for a Zope scheduler ie a means of getting certain things done >periodically. I would like to pack the database automatically fairly >regularly, and periodically remove certain user folders and the like. >-- >Robin Becker > >_______________________________________________ >Zope-Dev maillist - Zope-Dev(a)zope.org >http://www.zope.org/mailman/listinfo/zope-dev > >(To receive general Zope announcements, see: >http://www.zope.org/mailman/listinfo/zope-announce > >For non-developer, user-level issues, >zope(a)zope.org, http://www.zope.org/mailman/listinfo/zope ) _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com

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