March 2000 - Zope - Zope lists

thanks
by Jonathan Park 06 Mar '00

06 Mar '00

Thank you, very much! -Jon

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Starting Zope automatically on bootup (QUEST)
by Oscar Picasso 06 Mar '00

06 Mar '00

Hi, I'm running Zope 2.1.14 on Redhat Linux 6.1. I would like it to start automatically when the computer boots. I'm looking for a workable rc script for this configuration. I tried the script found on the How-to: Installing and Upgrading Zope 2.X. On start up the computer displays the messages "Sarting Zope2 service: ". However it doesn't go further and I have to reboot my computer. Thanks in advance. Here is the script I used. Thanks in advance. ################################################### #! /bin/sh # # processname: zope2 # Source function library. .. /etc/rc.d/init.d/functions # Get config. .. /etc/sysconfig/network # Check that networking is up. if [ ${NETWORKING} = "no" ] then exit 0 fi # See how we were called. case "$1" in start) echo -n "Starting Zope2 service: " daemon /usr/local/zope/zope214/start ;; stop) echo -n "Stopping Zope2 service: " /usr/local/zope/zope214/stop ;; restart|reload) $0 stop $0 start ;; *) echo "Usage: zope {start|stop|restart}" exit 1 esac exit ##############################

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Comparing "unsized objects" and strings
by Christian Selig 06 Mar '00

06 Mar '00

Hello all, I have a little problem. I know where it is, but not how to solve it :-) I have a DTML document: ---snip <dtml-in "externalMeth(p)"> <dtml-var aid>  </dtml-in> ---snap Okay, no problem so far. But when I want to compare the value to a parameter I have given to the document via a <FORM>: ---snip <dtml-in "externalMeth(p)"> <dtml-var aid>  <dtml-if "aid == param"> Hi there! </dtml-if> ---snap The expression evaluates always to false. I have traced the problem back with an external method ("<dtml-if "equals(aid, param)">"). When trying the "len" function on both variables, "param" is not a problem (it's a string from the the <FORM>), but "aid" complains that it was an "unsized object". How do I compare them? Thanks in advance Christian -- \|/ ____ \|/ http://www.bnv-bamberg.de/home/sledge/ (Home) "@'/ ,. \'@" http://linux.bnv-bamberg.de/ (LUG Bamberg) /_| \__/ |_\ http://miranda.sourceforge.net/ (Miranda Project) \__U_/ http://fsub.schule.de/ (Linux for Schools)

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Newbie Question regarding MYSQL and Zope
by CURTIS David 06 Mar '00

06 Mar '00

Hi, What versions of Zope (probably 2.1.4) and what versions of MySQL work together? I have tried unsuccessfully to get MySQL to work with the the MySQLDA using the latest stuff.

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RE: [Zope] even more tree problems
by Brian Lloyd 06 Mar '00

06 Mar '00

> The problem no is getting the URL's of objects inside > tree code - absolute preferred but relative would do > if it was all that would work. Tried all the solutions > in the ObjectURLs howto but none of them work. Any > attempt to generate an absolute url gets the local > name bit loses the path to the object. > > Code below > ---------- > where it says > <A HREF="&dtml-URL1;/silly" TARGET="ltscmain"> > > I need to get a url for current object. > Logically, I need the equivalent of > > "&dtml-url-<dtml-var id>>" > > How can I do this? If I'm understanding the problem correctly, try: <dtml-var tree-item-url> Hope this helps! Brian Lloyd brian(a)digicool.com Software Engineer 540.371.6909 Digital Creations http://www.digicool.com

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Help! Python?
by Tom Deprez 06 Mar '00

06 Mar '00

Hi, I'm still strugling with the manage_afterAdd method. Since Zope always tells -at the line CatalogAware.manage_afterAdd- the object CatalogAware doesn't exists, I'm now trying to import the CatalogAwareness.py file. So far, so good, it now imports the CatalogAwareness file. However, I still get this stupid message the object CatalogAware doesn't exists, etc... This is driving me crazy! Somebody an idea? Tom.

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Help Please
by Jonathan Park 06 Mar '00

06 Mar '00

I'm very new to zope and I was wondering how I can reference a property that is in a subfolder. ex: there is a folder called "main" inside the "main" there is a folder called "sub" and I create a property called "message" is there a way for me to call to that property outside of that folder. Any help would be greatly appreciated. Thanks -Jon

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Registering just an icon not constructor
by Shalabh Chaturvedi 06 Mar '00

06 Mar '00

In my python product I have a class (IssueFollowup), which I don't want to register using registerClass because I want instances to be added only through instances of another class (Issue). I have the necessary code in class Issue that creates and adds objects of class IssueFollowup to the folder in context. 1. Is this ok ? (Seems to work but are there any possible pitfalls) 2. IssueFollowup objects appear in the Contents tab but without any icons. How can I register an icon without having IssueFollowup pollute the drop down list ? Thanks, Shalabh

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RE: [Zope] Zope and remote caches.
by Martijn Pieters 06 Mar '00

06 Mar '00

From: jiva(a)devware.com [mailto:jiva@devware.com] > So, if I am grokking the whole zope thang properly here, then > theoretically, when I imbed objects within my zope documents, I > shouldn't hardcode in specific urls to them. Instead, I should treat > them almost as if they are always in the current directory, even if > they are a couple of folders up. This way, if I want to override some > behavior in the future, I just copy the object down into the current > folder and edit it. I notice however, that if I do this, it plays > hell with browser caching because the browser winds up pulling things > from different places all the time even if it's actually winding up > pulling the same document down. How do other people deal with this? Use the absolute_url() method on the objects. That way, your generated HTML will contain absolute URLs to the objects, that are the same across different Folders in your site even when the object is acquired from elsewhere. Overriding as you described will still work the same, the URLs will reflect the change accordingly. Syntax variations (as always from the top of my head, not tested, YMMV): <dtml-var "object.absolute_url()"> <dtml-var object url> &dtml.url-object; The last notation is especially useful in HTML tag attributes, as it won't break WYSIWYG HTML editors: <a href="&dtml.url-object;">Go to object</a> -- Martijn Pieters, Software Engineer | Digital Creations http://www.digicool.com | Creators of Zope http://www.zope.org | mailto:mj@digicool.com ICQ: 4532236 | PGP: http://wwwkeys.nl.pgp.net:11371/pks/lookup?op=get&search=0xA8A32149 -------------------------------------------

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RE: [Zope] Scalability bombing missions
by Paul Everitt 06 Mar '00

06 Mar '00

Hi Jimmie and Patrick. Jimmie wrote: > It was never my intention to imply that throwing $$$dollars at DC was > required to improve scalability. What I said was based on > perception of > such requirement. I'll admit "currently" Zope does not scale > as well or > as elegantly as I would like. A statement I was making was that "if" I > (or anyone) "believed" that scalability == $$$dollars, I would rather > give to DC than Oracle. I believe Larry is doing all right on his own. > :) I want a jet fighter too (sniff). :^) > I find Oracle pricing obscene. For the kind of $dollars it Architectures like Oracle with Vignette running atop it are very capital-intensive. Something that startup dot coms don't have a lot of. When you've spent all your budget on licenses, and _then_ you start writing your application... > would take to > license Oracle I would rather see what DC could do with the additional > employees on beefing up Zope/ZODBs concurrency/scalabilities. > There is a > thread on the WebDB forum about a group of people talking > about putting > together a co-op to buy an Oracle license based on Oracles "unit" > pricing scheme for a moderately powered single processor Intel machine > it was going to run about $20,000. You would have to > renegotiate if your > site got busy and you added a processor. Yuck! Yes, it's a shame, because this model introduces yet another way where you have to partition your "cloud". It shouldn't matter what processor or network gets added to your website "cloud". Just keep throwing capacity into the cloud. Existing scalability architectures have such a schism along the three-tier boundaries that it takes wizards to implement and operate them. Making them, obviously, brittle and prone to problems. > I believe Zope's scalability issues will be solved over time > regardless > of external $dollars. I believe more $dollars could speed up the > process, however it will still take some time. Currently ZEO is an > option but I don't know how well understood it is by the community. It will certainly take some time. But obvious things can be solved as a higher priority. Since scalability means different things to different people, though, there isn't One Answer. > Scalability Now can still be a sticky wicket. > > Future things on Zope's side: > 1. Moore's law. > 2. Advances in Python and it's performance. > a. Python becomes fully multi-threaded, multi-processorable. > b. Stackless Python gets adopted and performance improves. > c. Viper I don't feel that advances in Python are absolutely required. Apache doesn't have a threaded model (before v2), and if Zope could dish out requests like Apache 1.x, everybody would be awfully happy. :^) This begs the question: how fast is fast enough? These stupid PCWeek tests, that give MTS a higher performance score than WebObjects because it claims to do 4,000 requests/sec vs. 2,000 requests/sec, are just ridiculous. At 150 requests/sec, you're talking about the top one percent of websites on the Web. The other worry is that these super-freaky Python advances will require cooperation from the app developers to keep the train on the tracks. > 3. Advances in Zope, it's architecture and performance. > a. Sam Rushing works miracles on Medusa/Zserver using Stackless > Python and Continuations. Again, I'm not so sure this is the big answer. I don't think there's a lot of evidence that Medusa/ZServer is the primary bottleneck. > b. Zope does process pooling with each process on a different > processor. ZEO? Yep, this is ultimately an attractive architecture. Particularly when you pour all three tiers (presentation, logic, data) into it, you get a single facility for scaling and distributing all three. > c. ZODB does multiple data.fs's based on user design based on url > path directories Right, though I'd encourage you to instead speak in terms of the goal, rather than the solution. Is the goal here to solve the 2Gb problem on Linux/x86, to "limit corruption", or is it to do resource accounting on a per user basis? As Jim has pointed out, if your goal is the latter, you won't get there -- user data can still appear in global things like catalogs. Jim's counterproposal, which he claims is easier than doing accounting across separate Data.fs files, is to finish putting accounting hooks into the object database. Whenever a user exceeded their capacity (no matter where the object), an exception would be raised. This would probably require that people be able to do their own packing. I gotta admit, I'm awfully intrigued by this. It is the kind of thing that is _seriously_ compelling vs. other architectures, where you have to keep on-disk quotas for presentation and logic, and in-RDBMS quotas for data. Still, the point is, make sure you speak in terms of goals first. > allowing different Zope processes on different processors to > handle their respective dir. > > It would be nice if some C/Python programming guru/genius would solve > Python's global threadlock issues where Python would scale on > multiprocessor machines. This would potentially render scalability a Doubt it. There's still so much more, such as data scalability (vs. raw performance). As for the latter, we at DC _still_ need to make raw performance go up. Personally, I think a very smart caching system (where subtemplates are pre-rendered in ZServer and know when the objects they depend on have changed) is a huge win for a significant portion of high-load situations. > moot point. The geniuses at AOLserver rewrote the threading of the > built-in Tcl interpreter so that it would be multi-threaded and work > properly with their nice multi-threaded webserver. Tcl's standard > threading I don't think (I could be wrong) is as nice as Python's. Right. Does this, though, limit them on the platforms you run on because of assumptions in the threading model? > If I had Oracle kind of money to throw around I would like to see > Python's thread issue resolved where Python becomes fully > multi-processorable. That would transparently scale Zope and benefit > other Python user's as well. It would enable Python/Zope to embed well > and play nice in multi-threaded webservers like AOLserver and others. > IIRC Apache 2.0 will be multi-threaded. If Python scaled on > multi-processors even a little guy could put together a dual-celery > machine a serve a nice site. Right. But again, this begs the question: what is a "nice site"? What if the goal of a "nice site" could be met w/out the disruption of rearchitecting Python? Is a "nice site" 100K hits/day? A million hits/day? Ten million hits/day? This steps into the next part of the problem. To date, few in the Zope community has been willing to publish any numbers for highly-traffic'd sites, despite pleas even from our board chairman. Perhaps that means there aren't really any sites where Zope's limit has been reached? Probably not. But why are people so reticent to go on the record with their hit logs? But it _does_ mean that, until folks are willing to come forward and provide numbers and test conditions, that we'll be working without a map. > I agree wholeheartedly with you that there should be a concerted > coordinated effort between DC and the community to improve scalability > by allowing people to throw hardware at it. That was the primary issue > causing me to wander the websphere looking at options. I've > learned some > things in the search, but I always looked back at Zope, even tho' my > wife liked Enhydra's logo, she thinks the otter is cute. > Zope's current > logo is much nicer than the Purple and Gold. :) > > If ZEO currently scales well, then DC needs some testimonials on their > website. Right. > There definitely needs to be some documentation best ways to... > As you said, there is a consistent recurring thread of is > ZServer alone > or ZServer behind Apache better. > Should I use a RDBMS or ZODB. Right. > Some of us have no legacy issues. From scratch what's the best way to > design... Ditto. > I agree the solving of Performance/Scalability and > Documentation issues > would definitely help convert lookers into believers. That's a good way to phrase it. --Paul

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