October 1999 - Zope - Zope lists

Getting the / (root) id/name
by Edward Muller 28 Oct '99

28 Oct '99

How do I get the / (root) id/name? I want to use it with <dtml-tree>......... ---------------------------------------------------------------- Edward Muller / Firm Wide Architecture - Systems Architect Paine Webber - 1000 Harbor Blvd. 5th Floor - Weehawken, NJ 07087 201-352-0190 - 201-272-7002 (fax) - emuller(a)painewebber.com <mailto:emuller@painewebber.com> ----------------------------------------------------------------

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Zope Cacheability
by Garth T Kidd 28 Oct '99

28 Oct '99

I think I've figured out why www.zope.org is so slow, and it's got nothing to do with the hardware or running the mailing list on the server itself. Quite simply, www.zope.org is doing anywhere up to seven times as much work as it needs to do. If you want the world's proxy servers to co-operate with your site to reduce the load on your servers, and want to be able to front-end your servers with reverse proxy caches to *really* take the load off your servers, you need to generate headers which tell them when they need to check back to see whether your object has been modified and -- for when they check -- when the object they're requesting was last modified. I spotted www.zope.org's problem whilst using it as an example site to check that a proxy I was installing was working properly. The log file was full of misses, even upon reloads. Checking later with Mark Nottingham's cacheability checker (written in Python) told the whole story: http://www.ircache.net/cgi-bin/cacheability.py The home page itself will always be stale. That's arguably okay because it's so dynamic, but we could give ourselves pretty good dynamism and still avoid a lot of needless hits if we whack an "expires in ten minutes" header item in there. If we're waiting for a team to approve a news item, we can wait another ten minutes for the page to expire out of everyone's caches. More subtle thinking on this is below. The following images referenced by the home page are completely non-cacheable: Images/blue-rounder1.gif Images/blue-rounder2.gif Images/redhat.gif Images/apache.gif Images/python.gif Images/spacer.gif (hit more than once) SpotLightOn/garage So, every time you hit www.zope.org, your browser probably makes a good seven needless requests. That makes you wait, and needlessly loads down the server. It's not just the main page, though. Every page you hit has at least the first five of those. No wonder the server is crawling! The only good ews is that Images/zpowered.jpg is cacheable. It was last modified about ten weeks ago, according to the server. Proxies will have to check back to find out whether or not it has been updated, but at least the server can just tell them it hasn't instead of sending them the whole image again, like the others. Adding an expiry tag to this would help, too. Why zpowered.jpg is cacheable but none of the others are is beyond me. Whatever's going on, though, we should fix it. There's no reason those guys can't be sending an accurate Last-modified and a reasonable Expires (say, an hour or a day in the future -- how often are you going to change 'em?). --- It's also fun to hit http://sqiushdot.org/ with the cacheability checker. We have to suffer a redirect to get to the actual content, which wastes a hit. Neither the redirect or its destination are cacheable. Most of Squishdot's images are cacheable -- they issue Last-Modified headers -- but will be checked once per page view by any vigilant cache. The non-vigilant ones will probably use the "if it's been around this long it'll be around a quarter again as long" kludge. A good reason to whack an explicit Expires header in is that you get to over-ride that. Result: vigilant proxies lay off, and non-vigilant proxies pay more attention. What more could you want? Squishdot uses http://nedstat.tripod.com/ as an access counter. Sprung! Ironically, the only image that is cacheable on www.zope.org -- the Powered By Zope logo -- is uncacheable on Squishdot. D'oh! --- Once I've got access to the guts of a public Zope server (should be less than a week) I'm going to start drilling into Zope cacheability and figuring out how easy it is to fix. I strongly suspect the answer is going to be "not very hard at all", except perhaps for the mucking around deeper in Zope's internals required to get Last-Modified answers without rendering an object (see below). The goal is simple: figure out what modifications can be made to Zope's basic items so that they're at least reasonably cacheable. The best reference for figuring out what headers we want to generate is probably Mark's Caching Tutorial for Web Authors and Webmasters: http://www.mnot.net/cache_docs/ ... and as well as patching Zope up, we can ask Mark to update his document to add Zope to the list of potentially cache-friendly live content engines. :) As well as tackling the images, which is the easiest Big Win, we could hack some code together to figure out when a page last mutated enough to be considered "modified". For the www.zope.org front page, that's probably when the last news item was approved or the last spotlight was added, whichever was more recent. This hack can't be more than a few lines of code, right? I'm thinking along the lines of a last_modified DTML method which returns the time the object was created unless an "always_stale" property is true. For bonus points, we could use a dependency_list property to have last_modified check the objects we depend on (the list of recent news items, for example) automatically. As I mentioned above, Zope will still end up rendering the entire object if we generate the header items using <dtml-call>. If we want an improvement there, we need to dip deeper into Zope's guts. We'll need some Serious Zope Talent to intervene, there. :) Any volunteers? Regards, Garth.

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RE: [Zope] Are there any Tutorials?
by Michel Pelletier 27 Oct '99

27 Oct '99

> -----Original Message----- > From: Jose de Leon [mailto:jadiel@thevision.net] > Sent: Wednesday, October 27, 1999 6:21 PM > To: zope(a)zope.org > Subject: [Zope] Are there any Tutorials? > > > This type of software is new to me and fascinating. I'm > having a hard time > changing my paradigm. > > Are there any other tutorials to help someone get started > besides the basic > one that comes with Zope when you install it? There are a staggering amount of how-tos on the Zope site (76!). Most of them written by community members. Granted, some of them are not written in the clearest english, but all of them provide a pretty usefull thing or two. Some of them go way indepth, some of them are even funny. Alas, i don't doubt some of them have an error or two in them. The coolest thing is that most of them are written from the perspective of experience. They're like 76 diary entries of various community members. Due to their number, your best tool here is the zope's site advanced search page: http://www.zope.org/SiteIndex/searchForm Here, you can, for example, select 'How-To' as your meta_type (if you don't select one, you'll search everything), and type what your serching for. Or don't type anything and see them all. -Michel

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Are there any Tutorials?
by Jose de Leon 27 Oct '99

27 Oct '99

This type of software is new to me and fascinating. I'm having a hard time changing my paradigm. Are there any other tutorials to help someone get started besides the basic one that comes with Zope when you install it? Thanks, Jose

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running ./start doesn't go into background
by Geoff Nordli 27 Oct '99

27 Oct '99

I started zope using the "./start" command. It starts everything, but doesn't go into the background. Is that normal. should I start it like: "./start &" to put it into the background. I also have two "z2.py -D" processes running one has UID of nobody, and the other has UID of root. I would think there should only be one, and it should have the UID of nobody. thanks, Geoff Nordli

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Imorting Dynamic Pic into Zope
by Stephan Richter 27 Oct '99

27 Oct '99

hello everyone, I hav a problem: I am generating with PIL or GD an image using an external method. The picture gets saved on the local File System. How can I import the picture into Zope, so I can display it. (Note: The picture has a short lifetime and it is not necessary to add it to the ZODB.) Thanks, Stephan -- Stephan Richter iXL - Software Designer and Engineer CBU - Physics, Computer Science and Chemistry Student

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SmartWorker
by Oleg Broytmann 27 Oct '99

27 Oct '99

Hi! While browsing the Web, just found Yet Another Web Application Development Platform. Now it is SmartWorker, and it is based on Perl: http://www.smartworker.org/ License will change in near future for (I think) more open. Web Developmnet Platforms? Aren't there a little too many of them? :) Oleg. ---- Oleg Broytmann Foundation for Effective Policies phd(a)phd.russ.ru Programmers don't die, they just GOSUB without RETURN.

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Re: [Zope] RE: SQL connection needed
by Thomas B. Passin 27 Oct '99

27 Oct '99

Try renaming the file to ZODBC-3.1.0b2-win32.x86.gz, then unzipping. It contains a tar file. With Winzip, it will then untar the tar file. With something else, you may have to unzip the tar file, then untar it separately. You may have to tell the unzipping program what the right file extension is. Tell it tar. The tar file contains everything. You untar it into the Zope directory, and you are supposed to get a new directory called Zodbcda under the lib/python directory. The files go into that directory. I just went through this, and it worked for me. Thomas Passin >BUT, there is no "ZODBCDA.tgx" file. The only file that comes with the ODBC >download (a gz file) is "ZODBC-3.1.0b2-win32.x86" there is no extension. >When I extract this file to the Zope folder I do not see ZODBCDA on the >products list on the control panel. > >Any assistance would be GREATLY appreciated >

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Zope Front door thoughts
by Jason Cunliffe 27 Oct '99

27 Oct '99

Message: 28 [snip] > I'd like to suggest we should all, as a community, take a fresh look at > the front door on the Zope web site and suggest improvements to make > sure that new prospective users can get an *immediate* grasp of Zope's > unique "selling" propositions. This is a very, very important thread to me. I'm looking for two things: o What questions should the Zope.org home page, and pages one click away, answer? o What are some effective ways to answer those questions? --Paul hmmm...jumping in here... In the zope lightbulb department, I detect two main cognitive problems and several syntactic/presentation ones: 1. zope = zen object publishing environment. You have to do it to get it. And the more you do the more you get it.. This makes it difficult to explain because there is a dynamic process implicit in re-use, development, adaptation etc. But most textual presentations, no matter how lucid they are, do not capture or convey very well the dynamic nature of either the problem or the solution. Anyone who has been there, done that for a while (even a very short while) 'gets' something others don't because they have an built up an experience of the way in which these tools can help one _think differently about the problem, and also they know the momentum gained from _working with them. It is not just faster to do stuff this way, it is better smarter nicer. Quality of life issue in a sense. 2. Relativistics - As I see it the nature of zope is that object structures work in two directions by hierarchical ordering and by acquisition. I find the term 'Acquisition' is both annoying an misleading name. the The word implies some commercial exchange, but if I have understood it correctly, the metaphor is much closer to the idea of genetics and how genetic traits are affecting by the dynamic conditions of the environment. That the context of some zope DTML code can change its _behavior_ I belive is the key, but on the surface [read FRONT page} this is not so evident. Because zope depends upon a relativistic object model it makes it hard to explain unless one has some experience. The nature of all relativistic explanations is that they depend upon dynamic subjective personal point of view - To take a favorite example of mine - giving someone precise coordinates or a map with a red line showing the route options. As opposed to telling them: " go down the street and then turn left after the traffic lights. .. When you get the bend in the road, cross over and ask anyone there which is the zope.org cafe..." Both approaches are valuable., The overview and the headsup relative model. The web and the web object model is tantalizingly relativistic. There is no map yet and perhaps never could be. Yet zope zen says if the web were built out of these kind of objects it could perhaps map itself. zope objects are like little piece so this maps but as yet there is no map for zope itself... "If you don't know where you are going, you might just end up somewhere else" - Yogi Bera <DTML-PROPOSAL: Make a set of animated zope 'map' to visualize the system and its use.> What would perhaps really help people understand zope is an animated map conveying the relativistic nature as well as the structural and functional key components. the zope.ORG front page is singularly lacking in visual anything. Yes nice simple stripped down functional site, but zope requires a very spatial/logical understanding. And these concepts may be more clearly presented initially using some dynamic spatial metaphors. [hint1: try modelling it on a napkin, and then again with Macromedia Flash] {hint2: try modelling it schematically in Zope but splitting the screen horizontally say with HTML above and DTML below simultaneously or make a simple DTML where a rollover or click() event swaps or expands the DTML to its HTML result. Yes one effective 'message' of the zope.org site is not_hype, not_'flash' but another is that is yet another brillaint tool beloved by cool programmers but which is not exmplainable or presnedtable to non-programmers. You can list features till your are blue in the face, but that won't help some people, especially when ther are soem paradigm dhifts involved. And if they are not programmers, perhaps you need to consider prallel techniques or media to get the message across. Zope is part of the invisble magic of the web. What you see is not what you did WYSINWYD. And there are two audiences or processes - visible and invisible. The relationshuips betwren these needs to be made clearer - by text and by illustration . Q: When the key developers of Zope and its ancestral components were thrashing this stuff out, did they whiteboard or brainstorm on napkins? If so what did they draw? And if they did'nt but you have lunch today, what will you sketch to explain zope? As for the overview, what would the indispensable ZOPE POSTER look like? Perhaps that is a FRONT DOOR ITEM. Perhaps the poster is a sort of flattened all menus exposed type of animated movie. Zope is highly interactive - by design, concept, practice and by result - but there is nothing on the front door which expresses this yet.. Except for the crucial fact this community is very busy learning and doing it! In general the nature between play, learning and design has been officially undermined for many years. OOPS has been threatening to restore respect for these essential creative human actions, but always seems to get bogged down in jargon and technology. Zope is brilliant because it does let one play around with idea, the tools and the structure, learn, and thus iterative design further and better. PATTERNS A potential major breakthrough is this dilemma, has been the rend towards Design Patterns - the adoption by oops programmers of Christopher Alexander's inspiring architectural philosophy. In fact Zope DTML has the beginnings of a very friendly design pattern language. I can easily imagine a ground breaking book on 'Creative Problem Solving and Design Patterns Zope'. Hope something here makes sense to you. Best wishes - Jason Cunliffe ------------------------------------------------- Jason Cunliffe <jasonic(a)nomadicsltd.com> NOMADICS.STUDIO(Design Director) Geo-Digital Arts and Technology Le Vieux Moulin, Route de Mons 83440 SEILLANS, FRANCE Tel: +33 (0)4 94.76.98.72 Fax: +33 (0)4 94.76.97.77

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RE: SQL connection needed
by Sean Kelley 27 Oct '99

27 Oct '99

My situation: > I am trying to find out what Zope is all about and trying to > make a simple > database query from MS > SQL 6.5 (or anything else if I knew how). When I go to add > SQL method it > tells me I need an > SQL connection. I downloaded: ZODBC Database Adapter 3.1.0b2 > (Development) and b1 > and put then both in the site folder and the Zserver folder > and restarted > the Zserver (I am on > windows 98) > I still cannot add the SQL method. Is there another product > I should be > using? I am fairly green > with SQL (I just write SQL based reports in reporting software) THEN I tried the following after these instructions were provided: o reintall Zope o extract ZODBCDA to into the root of the Zope installation (i.e., if you installed ZOpe into c:\zope then extract the ZODBCDA.tgx file into c:\zope. o visit the Zope control panel and see if ZODBCDA shows up as a product. BUT, there is no "ZODBCDA.tgx" file. The only file that comes with the ODBC download (a gz file) is "ZODBC-3.1.0b2-win32.x86" there is no extension. When I extract this file to the Zope folder I do not see ZODBCDA on the products list on the control panel. Any assistance would be GREATLY appreciated

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