September 1999 - Zope-Dev

Parse.
by Juan Javier Carrera Obrero 13 Sep '99

13 Sep '99

Hi ! We are using Zope 2.1.6 for Windows NT Server, and Oracle 8i as RDBMS. When the ZSQL methods are runned, the values of the parameters of the SQL query are remplaced by Zope before sending the query to the Oracle database jet (it does not the "parse"). Thus, if two users runs the same query but with different parameters, it is considered as two different queries because the values of the parameters of the ZSQL method are remplaced firstly. When it is realized by more users with diferent parameters, the Oracle's cache is fulling quickly and it is overing. Do exists any way for sending the query of the ZSQL method and theirs parameters, trying that the values of the parameters was remplaced in the database jet, and no previously. Perhaps, it was a ODBC problem, or the Zope code does not allow it. I do not know it. Any body can help me ? Thanks. JUAN JAVIER CARRERA OBRERO e-mail: jcarrera(a)uco.es

1 0

Re: [Zope-dev] Caching
by Christopher Petrilli 13 Sep '99

13 Sep '99

> In ROXEN (RXML); There is a tag line where by you can cache certain content > within the <CACHE> brackets. Is there something similar within Zope? What has been thought of is doing more "rendered caching" (i.e. cache rendered results, thereby short-circuiting the DTML process). This could be very advantageous, but gets into a lot of issues of management of the cache which is non-trivial (Vignette, one of our competitors that does "consultant-ware" has several patents on it), so... patches accepted. Note that performance will be one of our "watch words" in the coming months. Chris -- | Christopher Petrilli Python Powered Digital Creations, Inc. | petrilli(a)digicool.com http://www.digicool.com

2 1

Caching
by Paul Mokbel 12 Sep '99

12 Sep '99

In ROXEN (RXML); There is a tag line where by you can cache certain content within the <CACHE> brackets. Is there something similar within Zope? This is how it could be implemented: "  ", where foo bar can be an SQL call.. This can be useful for Message Boards as an example. Thanks, /* "There are two major products that came out of Berkeley: LSD and Unix. We don't believe that to be a coincidence. " -BSD fortunes Paul Mokbel */

1 0

Re: [Zope-dev] Using ZODB standalone
by Phillip J. Eby 11 Sep '99

11 Sep '99

At 02:10 PM 9/11/99 -0400, A.M. Kuchling wrote: >I'm experimenting with using ZODB3 to store a tree of objects, but >don't understand what I'm doing. My expectation is that the amount of >memory used should be bounded, because objects should be flushed from >the cache when they haven't been accessed in a while. Instead, the >Python process grows continually. This should be expected, as FileStorage objects keep an index mapping persistent ID's to file seek positions. Even though the cache should be flushed of the objects themselves, the index will grow with each commit of newly created objects. Thus, memory consumption will grow by at least 32 bytes per object, and probably more, since there is overhead for the mapping object itself when it refactors itself as it grows, and it may cause some memory fragmentation as well. This memory size will never be reduced by much (unless objects are deleted and the DB packed) because any process opening the FileStorage will build up the exact same index upon startup. If you plan on having a million-object DB, plan on having 32-64M of RAM available just for OID indexing. It is probably possible to cut this overhead by having FileStorage use a custom-built mapping object written in C specifically designed for FileStorage's needs, but I have not tried anything like this yet.

1 0

Using ZODB standalone
by A.M. Kuchling 11 Sep '99

11 Sep '99

I'm experimenting with using ZODB3 to store a tree of objects, but don't understand what I'm doing. My expectation is that the amount of memory used should be bounded, because objects should be flushed from the cache when they haven't been accessed in a while. Instead, the Python process grows continually. Here's the simple test code I'm playing with: # Open a ZODB; this all seems fine. from ZODB import FileStorage, DB fs = FileStorage.FileStorage('/scratch/mydata.fs') db = DB( fs ) conn = db.open() # Here's my test class -- do I need to do more? import Persistence class myClass(Persistence.Persistent): pass # Create a single root object c = myClass() root = conn.root() root['c'] = c # Loop for a long time, creating new myClass instances and adding them # as an attribute to the last instance. (Perhaps ZODB needs to keep # the whole path from the root object in memory, and this test should # be building a bushy tree instead of a constantly deepening chain?) for i in xrange(100000): c.num = i c.subobject = myClass() c = c.subobject # Do commits every few objects. if (i % 100) == 0: print 'Committing' get_transaction().commit() Do I need to call some method to force a GC of the cache? What am I missing? Incidentally, are Jim's slides from the DCPIGgies meeting available online? I suspect their discussion of ZODB3 (and the slides showing the steps in using it) would be helpful. -- A.M. Kuchling http://starship.python.net/crew/amk/ prompt. n. (Unix) A symbol on the screen indicating which shell is attacking you. -- Stan Kelly-Bootle, _The Computer Contradictionary_

1 0

unpiclkleable errors
by Robin Becker 11 Sep '99

11 Sep '99

After doing a large number of rather weird hacks to my setup to try and get some java going I now find that I'm getting the following error message every time I load the main manage 1999-09-11T16:30:29 ERROR(200) ZODB Couldn't unnpickle '\000\000\000\000\000\000\004z' I have no idea what I could have done to bring this upon myself. -- Robin Becker

1 1

Zope hacking help
by Lalo Martins 11 Sep '99

11 Sep '99

One day of hacking Zope made my head dizzy :-( pdb was no help, neither grepping for everything I could think of. And so many components to check... ZServer, medusa, ZPublisher, aaagh! Can someone help me to the point where Zope decides what object to serve, based on the URL, and the point where this object is processed (eg, if it's DTML)? []s, |alo +---- -- I am Lalo of deB-org. You will be freed. Resistance is futile. http://www.webcom.com/lalo mailto:lalo@webcom.com pgp key in the web page Debian GNU/Linux -- http://www.debian.org

3 2

Bug with External Methods/Pluggable Brains and Products
by David White 10 Sep '99

10 Sep '99

Hi, I've been playing around a bit lately with using pluggable brains for SQL methods from within a Python Product I'm working on. In the Content Managers Guide there's a section which discusses the use of External Methods and Pluggable Brains with Products and gives the following (shortened) descriptions: >For example, suppose an external method or brain is defined using the file name >foobar.util, then Zope will attempt to load the method or class files from the following >files, in this order: > 1.lib/python/Products/foobar/Extensions/util.py > 2.Extensions/foobar.util.py > 3.Extensions/util.py I tried this out within a SQL method that I created by enteing in a module name like this: 'myProduct.myModule'. I also entered the right mix-in class name which was in the module 'myModule. I already had created a Python Zope Product which resided in INSTANCE_HOME/lib/python/Products/myProduct and I also created an 'Extensions' sub-directory in this Product directory. So based on what the documentation said I thought I had set this up properly, but when I tried to edit the 'Advanced' tab of the SQL method it kept telling me that it couldn't find the module 'myProduct.myModule'. I looked in the App.Extensions.py source and (I think) tracked it down to the following bit of code (line 152): sw=path_split(path_split(SOFTWARE_HOME)[0])[0] for home in (INSTANCE_HOME, sw): #rest of loop... On my machine INSTANCE_HOME=/local/app/Zope and SOFTWARE_HOME=/local/app/Zope/lib/python So why does that first line effectively truncate the last two directories off of SOFTWARE_HOME, effectively making it equivalent to INSTANCE_HOME??? When I comment out that first line and change the second to: for home in (SOFTWARE_HOME, INSTANCE_HOME): #rest of loop things work as stated in the documentation. In any event I think I've found a bug here, either in the code above or in the documentation in the Content Managers Guide. Also I did try to see if this was in the Collector, and I did see an entry which may have been related to this, but it was still 'under review' so I could not view it to make sure. So if someone could shed some light on this bug(?) that would be great. Dave -- ---------------------------------------------------- David R. White Raytheon Electronic Systems Process Support (508) 440-2087 528 Boston Post Rd. Sudbury, MA 01776 davew(a)ed.ray.com ----------------------------------------------------

1 0

Re: [Zope-dev] Multiple inheritance woes
by Rik Hoekstra 10 Sep '99

10 Sep '99

> Hmm.. I know this is a python question, but DejaNews nor the Python website > give me the answers I am looking for: > > I define a baseclass derived from CatalogAware and DTMLMethod: > > class Base(CatalogAware, DTMLMethod): > def index_object(self): > # check a few things I want to know about > # before indexing, maybe even not allowing > # the indexing > CatalogAware.index_object(self) > > A shot in the dark: Shouldn't this be CatalogAware().index_object(self)? At least this explicitly instanciates CatalogAware and stops raising TypeErrors. But I'm not sure this completely solves your problem Rik > Then I define a bunch of classes based on this base class: > > class A(Base): > pass > > class B(Base): > pass > > etc. > > Now, if I do the following: > > a=A() > a.index_object() > > I get a TypeError: > unbound method must be called with class instance 1st argument > > Now, I have seen all sorts of messages relating this error, but none of > them seem to relate to my problem... > > self in Vase.index_object _is_ a class instance, a step-by-step debug > proves this. The python interpreter just won't accept it =(. > > -- > Martijn Pieters, Web Developer > | Antraciet http://www.antraciet.nl > | Tel: +31-35-7502100 Fax: +31-35-7502111 > | mailto:mj@antraciet.nl http://www.antraciet.nl/~mj > | PGP: http://wwwkeys.nl.pgp.net:11371/pks/lookup?op=get&search=0xA8A32149 > ------------------------------------------ > > _______________________________________________ > 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 )

3 3

Zope 2 import
by Anderson Ami 10 Sep '99

10 Sep '99

dear friends I have a problem and I need your help. I installed the Zope 2 and I have an aplication in my old Zope (1.10.3) with the ZODBC 3. I try import the folder that I exported of old Zope, but I can't, why ? thanks anderson ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

2 1