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Medusa Asyncore patch
by Matthew T. Kromer 12 Dec '01

12 Dec '01

People having problems with medusa on Linux and Solaris (particularly solaris) can try running this patch: http://www.zope.org/Members/matt/patchMedusa-asyncore.py Run it from your Zope root. It will copy asyncore.py from the python lib and patch it using the "patch" command.

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ZBabel Object incompatibility with Zope 2.5 b2
by Joachim Werner 11 Dec '01

11 Dec '01

Hi! This time I need some specialists to help ... Here is some code from ZBabel Objects. ZBabel objects are folders that hold localized versions of anything you want to internationalize and pass getting attributes and calling objects to one of these localized versions depending on your language choice. In Zope 2.4 this works fine. But with Zope 2.5 b2 there are recursion problems: class ZBabelObject(Folder): '''ZBabelObject class ''' ..... def __getattr__(self, name): '''__getattr__(self, name) --> try to get an attribute from the localized object; return attr''' if name[0] != '_' and not self._v_alreadyLooking: try: self._v_alreadyLooking = 1 trueObject = self._getTrueObject() if hasattr(trueObject, name): return Rewrapper((trueObject.getId(), name)) <= HERE THE REWRAPPER IS CALLED # return getattr(trueObject, name) finally: self._v_alreadyLooking = 0 return Base.__getattr__(self, name) Look at the code above: the __getattr__ code calls the Rewrapper to make sure that the object gets the right context. If you replace the line by the commented-out one, the attributes work, but calling the object will not work. E.g., an image width or height will be passed fine, but calling the image will cause an authorization request even for managers. It seems as though __call__ will look for some security assertions via __getattr__ (?), but can't find them due to the missing wrapper. I have no clue. Here is the Rewrapper code: class Rewrapper(Base): def __init__(self, path): self._path = path def __of__(self, parent): ob = parent for p in self._path: ob = getattr(ob, p) <= HERE WE GET A RECURSION ERROR return ob When the code is run unchanged with 2.5, we get an infinite recursion (well, Zope halts it after a few recursions) at the marked line, which is bad. Does anybody have a clue why that happens NOW, and what has change in that respect from 2.4 to 2.5? Maybe there are alternative implementations? The aim is that the localized object just behaves like a normal image, DTML Method, whatever, but actually maps to different contained object versions. BTW: The full code is available here: http://cvs.iuveno-net.de/CVS/cvsweb.cgi/ZBabel/ZBabelObject.py Joachim

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more than one user: zope 'hangs'
by Stephan Herschel 11 Dec '01

11 Dec '01

Hello, We have got a funny problem in Zope: if user A issues a long-running query user B also has to wait in the meantime - zope just waits for A's query to finish. We are using interbase as our database and GV Interbase Database Adapter 0.9.6 on a linux system. In the README it says 'threadsafety ... is set to 1 - threads may share the module but not connections' Somehow i suspect the problem lies there. Can anyone give me a hint on this problem? Thanks in advance, Stephan

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More signal 11 restarts....
by Daniel Duclos 11 Dec '01

11 Dec '01

I have a zope that is dumping signal 11 every 40 minutes or so. I have tried recompile python 2.1.1 with-threads without-pymalloc, recompile Zope with it, recompile ZPAtterns, recompile and instal MYSQL for Python 0.9.1, upgraded to Zope 2.4.3, all this on a Debian Linux box. Nothing changed... still restarting... Anybody, please, has any ideia on this matter? Please, let me know if there's any relevant info that I forgot to mention abot my case! Thanks in advance!! -- daniel lobato duclos -- daniduc(a)hiper.com.br -- http://www.hiperlogica.com.br -----------------------------------------------------------------------------

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recipe for trapping SIGSEGV and SIGILL signals on solaris
by Joseph Wayne Norton 11 Dec '01

11 Dec '01

Hello. We are facing zope restarts on the solaris 5.6 platform with zope 2.4.3 and python 2.1.1. I put together a script based some information on an old posting to the apache mailing list. The following shell/perl script allows one to get a core file from a dying zope child process and also allow the zope to restart without any side effects. The script .... #!/bin/sh PATH=$PATH:/usr/local/bin export PATH cd /tmp for PID in `ps -u zfs -f -o pid,comm,args | fgrep z2.py | cut -d' ' -f1` do export PID truss -f -l -t\!all -S SIGSEGV,SIGILL -p $PID 2>&1 \ | perl -pe 'system("gcore $ENV{'PID'} && sleep 5 && kill -9 $ENV{'PID'}"), exit($ENV{'PID'}) if /(SIGSEGV|SIGILL)/;' & done Step 1: modify script to match your environment. Step 2: execute script Step 3: wait for core file to be dumped in /tmp. Step 4: analyze with gdb where $PID is the pid of the dumped process #bash gdb /path/to/bin/python /tmp/core.$PID #0 0xef5b9810 in _lwp_sema_wait () (gdb) where #0 0xef5b9810 in _lwp_sema_wait () #1 0xef647ea0 in _park () #2 0xef647b84 in _swtch () #3 0xef6468a4 in cond_wait () #4 0xef6467c8 in _ti_pthread_cond_wait () #5 0x50220 in PyThread_acquire_lock (lock=0xd9d878, waitflag=1) at Python/thread_pthread.h:313 #6 0x51f18 in lock_PyThread_acquire_lock (self=0xda39b8, args=0x0) at ./Modules/threadmodule.c:67 #7 0x35db4 in fast_cfunction (func=0xda39b8, pp_stack=0xed40f828, na=0) at Python/ceval.c:2994 #8 0x33ca0 in eval_code2 (co=0x267848, globals=0x51ec4, locals=0x0, args=0x0, argcount=0, kws=0x0, kwcount=0, defs=0x0, defcount=0, closure=0x0) at Python/ceval.c:1951 : : It seems that we are facing trouble due to the thread library on solaris (unless the truss command has introduced a side-effect). Anyone else facing similiar troubles? .... or maybe I should post this to a python mailing list. - joe

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How makesetup deals with Zope ?
by Pascal Samuzeau 11 Dec '01

11 Dec '01

Hi, Next week I've tried to install the ParsedXML, under my Zope. Unfortunately, the installation failed. After some hours of hard worker, I've only change the permission of the makesetup file with : chmod 644 /usr/local/zope/Zope-2.4.3-linux2-x86/lib/python2.1/config/makesetup So, I have 2 questions about it 1-- Even I thought to see what makesetup is doing for and what it is doing, is there anybody to explain me in more details, for my personal knowledge ? 2-- In fact, the real question of this mail. The makesetup file should'nt installed with the "x" bit on, when we installed Zope ? Sincerily PS -------------------------------------------------- Oreka ! Nous sommes l'internet moins cher ! Surfez 25% moins cher avec http://www.oreka.com

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My thoughts on the development process
by Martijn Faassen 10 Dec '01

10 Dec '01

Hi there, I've read parts of the open letter threads just now. There's a lot of talk about how if only we have better tools the whole process will go better and Zope will get more contributors. That's a typical hacker response, and I do this myself as well. Throwing more technology at a problem doesn't always make a problem go away. And though technological solutions to social problems are nice if you can have them, and we should look for them, they don't always work. I'm not convinced more technology will make the dead fish problem go away. I think the contributing process is in fact too heavyweight. It should be easier for people to get in drastic changes to Zope. The only way for people to take more responsibility if they can actually have it. Only a few people will take it, but that's more than what is possible now, with possibly the single exception of my taking responsibility for ParsedXML. And until recently I was still in the position of doubting whether I really had it formally, not just de-facto. I kept asking for approval and guidelines from the official maintainers, but they were too busy (no blame to them), so I went on anyway and did a release eventually. I dread having to go through the fishbowl to add in my 'node path' implementation to ParsedXML. I've done the design work, I've implemented most of it, and I feel I'd have mostly wasted time writing a fishbowl proposal. I hadn't even explored the problem enough to be able to do that. I needed to prototype it to understand it. I've discussed some issues with people locally and and on the Zope-XML mailing list. And I'll probably release a version in a few days. Perhaps adding Formulator to the Zope core would be nice eventually. But going through the fishbowl bureaucracy would take forever. I only have so much time to spend on it, and I'd rather spend time improving the product itself. And now look at how the Zope core is actually being developed. Sure, there's lots of stuff in the fishbowl about what the Zope future should be like. Plenty of stuff, though some stuff is rather hard to find. But I have a lot of praise for what the Zope Corp people have accomplished it it; it's a lot better than having no such thing at all, even if it's only used as a notification service in part. The main thinking about the directions of Zope is not done in the fishbowl or on the lists, it's in the minds of the talented people at Zope Corp and in the brainstorm sessions they hold together. That's the natural way people work. I work that way too. Such a process can occur on mailing lists as well, but it's very hard to break into it. I've tried several times. I'll keep trying as I'm convinced it's possible, but it takes a lot of persistence. Time will tell. On the Zope-XML list I just post regular updates about my thinking to encourage discussion, and sometimes that works. So what am I trying to get at with this mail? One thing is that the process is too heavy-weight right now. The other thing is that the core coders at Zope Corp are in a position nobody else is in, and that should change. They are the only ones that can get around the fishbowl if they so desire. They can use the fishbowl in effect as a notification service. Not that they want to; I don't doubt their good intentions for one minute. But I want to be able to use it like that too when I need to. Others should be able to as well. I think I and a few other contributors are slowly getting to that position, but it happens too slowly and takes way too much persistence now. So let's trade in some risks to the Zope core development (rash action and messed up stuff happening once every while), in exchange for a lot more active contributors. Regards, Martijn

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Python Conference News
by Joya Subudhi 10 Dec '01

10 Dec '01

Python 10 Conference News Tim Berners-Lee, Director of the World Wide Web Consortium, and Andrew Koenig, Principal Research Staff Member at AT&T Shannon Laboratory, will give the keynote addresses. Tim Berners-Lee will speak on "Webizing Python" and Andrew Koenig will discuss "Notes from a Polygot Outsider." The entire program of the Refereed Paper Track is complete. You can view the titles and authors of all the presentations within each session and check out nominations for the Best Paper Award on the Python 10 Web site. The Tutorials Day program is also complete. Silver Sponsors of Python 10 are: Hostway Corporation: http://www.hostway.com and New Riders Publishing: http://www.newriders.com Registration for Python 10 is open. Save with early bird registration rates when you register online before January 7, 2002. To register and for conference details, visit: http://www.python10.org The Tenth International Python Conference February 4th through February 7th The Hilton Alexandria Mark Center Alexandria, Virginia

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100k+ objects, or...Improving Performance of BTreeFolder...
by sean.upton＠uniontrib.com 10 Dec '01

10 Dec '01

Interesting FYI for those looking to support lots of cataloged objects in ZODB and Zope (Chris W., et al)... I'm working on a project to put ~350k Cataloged objects (customer database) in a single BTreeFolder-derived container; these objects are 'proxy' objects which each expose a single record in a relational dataset, and allow about 8 fields to be indexed (2 of which, TextIndexes). Some informal stress tests using 100k+ _Cataloged_ objects in a BTreeFolder in Zope 2.3.3 on my PIII/500/256mb laptop are proving to be successful, but not without some stubborn investigation and a few caveats. BTreeFolder, using ObjectManager APIs, frankly, just won't scale for bulk-adds of objects to folders. I was adding CatalogAware objects to my folder (including index_object()). After waiting for bulk-add processes to finish after running for 2 days, I killed Zope and started trying to optimize, figuring that the problem was related to Catalog and my own RDB access code, and got nowhere (well, I tuned my app, bu this didn't solve my problem), then went to #zope, got a few ideas, and ended up with the conclusion that my problem was not Catalog-related, but related to BTreeFolder; I initially thought it was a problem with the C-Based generic BTree implementation scaling well past 10k objects, but felt I couldn't point the finger at that before some more basic stuff was ruled out. The easiest thing to do in this case, was to figure out what was heavily accessing the BTree via its dictionary-like interface, and the thought occurred to me that there might be multiple has_key checks, security stuff, and the like called by ObjectManager._setObject(), and I was right. I figured a switch to use the simple BasicBTreeFolder._setOb() for my stress tests might reveal an increase in speed, and... ...it works, acceptably, no less, on my slow laptop for 100,000 objects. It took ~50 minutes to do this on meager hardware with a 4200 RPM ide disk, and I figure a bulk add process like this on fast, new hardware (i.e. something with upwards of 22k pystones and lots of RAM) with a dedicated server for my RDB, would likely take 1/5th this time, or about 10 minutes (by increasing both MySQL performance, and Zope performance); combine this with ZEO and have a dedicated node do this, and I think this is a small amount of proof of Zope's ability to scale to many objects. (See my caveats at the bottom of this message, though). After days of frustration, I'm actually impressed by what I found: My data-access APIs are very computationally expensive, since they establish a MySQLdb cursor object for each call and execute a query; these data access methods used in bulk adding 100k objects after using _setOb() during Cataloging via index_object() (the transaction done all in memory for now, but likely moved to subtransactions soon to support up to 4x that data). So far, the moral of the story: use _setOb(), not _setObject() for this many objects! I haven't seen any material documenting anything like this for BTreeFolder, so I figured I would share with zope-dev what I found in the hopes that developers creating products with BTreeFolder and/or future implementations of BTreeFolder might take this into account, in docs, if nothing else. Caveats: - I'm using FileStorage and an old version of Zope (2.3.3). I can't say how this will perform with Python 2.1/Zope 2.[4/5]. I imagine that one would want to pack the storage between full rebuilds or have very, very fast storage hardware. - Catalog searches without any limiting queries to indexes will simply be too slow for practical use with this many objects, so they need to be forbidden with a permission to prevent accidental over-utilization of system resources or DOS-style attacks. Otherwise, Catalog searches on my slow hard drive seem acceptable. - I'm not too concerned with BTreeFolder __getattr__() performance penalties, though I modified BTreeFolder.__getattr__ just in case to remove the 'if tree and tree.has_key(name)', replacing with try/except; I'm not sure if this helps/hinders, because my stress-test code uses _getOb() instead. - objectIds() doesn't work; or, more accurately, at first glance, <dtml-var "_.len(objectIds())"> doesn't work; I haven't tested anything else. I would like to find out why this is, and fix it. I suppose that there is something done in ObjectManager that BTreeFolder's simple _setOb() doesn't do. If anyone wants to help me figure out the obvious here, I'd appreciate it. ;) - I don't think un-indexed access of records is likely to be very practical with this many, esp. if things like objectIds() are broken, which increases the value of Catalog, and I think that what my experiences here with this project are showing is that Catalog indexing isn't as expensive/slow as I initially thought it would be. That said, I'm sure there can be improvements in Catalog as often is discussed here recently, but for now, I think I'm happy. :) - I Haven't compared these results with OFS.Folder.Folder yet. I'm too lazy/busy to comparison test. - I'm relatively sure that, in my app, the text index BTrees in the Catalog are very 'bushy' (more so than normal) because I am indexing people's full names, and street addresses, which means there are less common words than indexing, say, an every-day document. - Also, I want to make it clear that if I had a data access API that needed more than simple information about my datasets (i.e. I was trying to do reporting on patterns, like CRM-ish types of applications), I would likely wrap a function around indexes done in the RDB, not in Catalog. My requires no reporting functionality, and thus really needs no indexes, other than for finding a record for customer service purposes and account validation purposes. The reason, however, that I chose ZCatalog was for full text indexing that I could control/hack/customize easily. My slightly uninformed belief now is that for big datasets or "enterprise" applications (whatever that means), I would use a hybrid set of (faster) indexes using the RDB's indexes where appropriate (heavily queried fields), and ZCatalog for TextIndexes (convenient). I'm sure inevitable improvements to ZCatalog (there seems to be community interest in such) will help here. - I wonder if "directory-storage" combined with ReiserFS might make for an interesting future ZODB choice for this sort of app. Sean ========================= Sean Upton Senior Programmer/Analyst SignOnSanDiego.com The San Diego Union-Tribune 619.718.5241 sean.upton(a)uniontrib.com =========================

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Re: [Zope-dev] zope collector is broken
by Ken Manheimer 10 Dec '01

10 Dec '01

I'm sorry, i'm unable to reprovoke the problem! Is there anything unusual about how you were submitting? Did you try more than once, to see if the problem is consistent? On Fri, 07 Dec 2001 11:43:52 -0500, Chris Deckard wrote: > I tried submitting a new issue to the Zope collector at 11:42AM > EST. Here's the traceback and error message: > > Zope Error > Zope has encountered an error while publishing this resource. > > Error Type: WorkflowException Error Value: No workflow > provides the "request" action. > [...] > WorkflowException: (see above) -- Ken klm(a)zope.com

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