March 2002 - Zope - Zope lists

RE: [Zope] Creating a file in the filesystem?
by abg＠comco-inc.com 04 Mar '02

04 Mar '02

1) Install LocalFS (http://www.zope.org/Members/jfarr/Products/LocalFS) 2) Create the following External Method (call it addLocalFSFolder): from OFS.Folder import Folder def addLocalFSFolder(self, id): ob = Folder() ob.id = id self._setObject(id, ob) 3) Call it from DTML like so: <dtml-call "addLocalFSFolder(myLocalFS, myFolderName)"> This works for creating folders. Should be easy enough to modify to create files. Aaron > -----Original Message----- > From: j2 [mailto:spamfilter2@mupp.net] > Sent: Monday, March 04, 2002 12:06 PM > To: zope(a)zope.org > Subject: [Zope] Creating a file in the filesystem? > > > I would like to create a semaphore file in the filesystem > (/tmp/restart > maybe?) and then poll that file from a cron job to see if a > certain daemon > should be restarted. But, how on earth do one create such an object? > > > _______________________________________________ > Zope maillist - Zope(a)zope.org > http://lists.zope.org/mailman/listinfo/zope > ** No cross posts or HTML encoding! ** > (Related lists - > http://lists.zope.org/mailman/listinfo/zope-announce > http://lists.zope.org/mailman/listinfo/zope-dev ) >

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zope-client.py: XML-RPC && WxPython
by Thomas Guettler 04 Mar '02

04 Mar '02

Hi! I patched ZopeClient.py from Amos Latteier. You can now edit Python-Scripts, too. zope-client.py lets you access zope with a native GUI (wxPython) via XML-RPC. It is more an example than an useful programm. If your interested you can get it from http://guettli.sf.net thomas -- Thomas Guettler <guettli(a)thomas-guettler.de> http://www.thomas-guettler.de

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RE: [Zope] The Principles of Designing a Heavy Load Site with Zop e
by sean.upton＠uniontrib.com 04 Mar '02

04 Mar '02

I'm chime in with some of my thoughts and questions... Storage: why not something like logical volume management and a LV group over a handful of DAS devices; seems cheaper than one big array? I would think 5 TB is doable on a 2-box cluster with 4-6 midrange DAS units connected on dual-bus SCSI or Fibre per box, at likely less than $250,000 if you shop for some bargains... Then again, size may not be as much of an issue as load? Load balancing: L4 switch (or LVS?) in front of a group of Squid boxes in front of a decent sized ZEO cluster. Most L4 switches will do DSR/OPR (direct-send or out-of-path return) instead of proxy mode, sending packets directly from the balanced servers to the requesting client, but this packet rewriting technique means that load-balancer cannot detect whether or not the node its sending packets to is up, since it can't get a response, so you usually have to use IP-takeover based clustering (Linux FailSafe or Heartbeat) to takeover a dead proxy/caching server. In theory, this approach would eliminate a single load-balancer as a bottleneck because it becomes a packet pusher and not a brokering proxy, which would make something like this ideal for directing traffic to multiple proxy servers under a high load... Price tag: 20,000 for 2x L4 switches, 20,000 for 4 decent Proxy boxes to run Squid. Caching/Proxying: in response to the original post, I would think it would make more sense to bypass Apache altogether and proxy to ZServer (with ICP patches) directly from a competent load-balancing, ICP-capable, caching proxy like Squid. If nothing else, have Squid cache the page elements (all static pages, images, client-loaded javascript source files) that can be cached to alleviate some stress on your Zope server and allow you to still keep things relatively simple. Then again, I've never tried Apache+PCGI with Zope... Rendering: my question is when does a ZEO connection, for ODB-stored content become the bottleneck? I realize using a replicated RDB solves this problem to some extent for those using ONLY relational data for content in their apps, but I'm personally more curious about intensive use of ZODB. There are issues of bandwidth to and processing power of a ZSS. Can ZEO (yet) support using ClientStorage on an intermediary ZSS to use client caching in a hierarchy of ZSS boxes? I know that this wasn't technically possible a while back, at least from what I remember reading on the ZODB-dev list, and I wonder if it would actually yield better performance in most real world scenarios? Page Impressions & Rendering: I'm looking for an example of how Zope would handle under extreme dynamic loads with a fairly straightforward example...For a single Zope server (direct to ZServer), what kind of numbers (Req/sec) would it be reasonable to assume that you could serve for a otherwise static page that used a dtml-method that rendered results from a Catalog query returning a dozen results (assuming direct reads from metadata tables - no getObject() calls) on new-fast hardware (say, an Athlon 1.6GHz + lots of DDR using FileStorage on a striped volume on fast disks)? Could a single box like this sustain 25-30Rec/sec in ideal conditions, assuming a very aggressive use of aggregated HTTP keepalive connections was put in front of it via proxy? Personally, what I would like to be able to do is eventually be able to serve 100 simple and uncached Req/Sec along these lines from a 4-5 node cluster of ZEO Clients on 2CPU Athlon MP boxes running 2 Zope+ClientStorage instances each, with load distributed via Squid+ICP (assuming that these requests were always a cache MISS in Squid)... Sean -----Original Message----- From: Matthew T. Kromer [mailto:matt@zope.com] Sent: Monday, March 04, 2002 7:49 AM To: zope(a)zope.org Cc: iap(a)y2fun.com Subject: Re: [Zope] The Principles of Designing a Heavy Load Site with Zope I think there are some fundamental misunderstandings going on here, but I thought it would be interesting to try to respond anyway. iap(a)y2fun.com wrote: > Hi, > > This issue has been discussed again and again, > > I would like to clarify my idea and your comments will be very > appreciated. > > Suppose we want to provide a server which is: > > 1) Hosting 1,000,000 members' profile. Each member's disk quota is 5MB. > > Which means we need at least 5,000GB (5 TeraGB) disk space. > > 2) Assume the concurrent accessing to a URL is 1000 request/per second > > 3) Assume all the requests retrieve dynamic content. > > 4) We want to leverage the power of Zope which means all the pages > should be > > rendered by zope. > Having 5 TB of disk space usually means some very high-powered RAID gear; my personal favorite is the EMC Symmetrix units; I think you would probably want at least two of those to provide your coverage. Estimated cost for this is about $5,000,000 (but *very* dependant on EMC's pricing strategies). You could get by for less, by distributing each disk with each CPU (the breadrack approach.) 1000 requests/second isnt terribly high; Zope installations have done 400/sec with no problem. However, these are in situations where Zope is being heavily cached; less than 10% of the requests are actually being rendered by Zope. So, if you wanted no caching (ala everything is completely dynamic content), my estimate is you would need something like 100 1Ghz Intel Pentium III class machines to perform that amount of dynamic rendering. If each of those machines had a 50 GB disk drive, you'd theoretically have your 5TB of disk space. At a rough commercial cost of $4,000 per unit (probably a bit high), that's only $400,000. As a practical matter, you'd then need some pretty hefty load balancing servers; at least two, possibly more. However, that begs the question of how you organize that much disk space. It's not an easy task. Whether or not you use an RDBMS is irrelevant until you can work out a strategy for using the disk space scattered amongst all of those machines. * * * Now, if you forget for a moment about requiring each page to be dynamically rendered each time it is viewed, and you set aside the storage questions, you could estimate that, with a 90% caching rate, you could serve 1000 requests/sec with only about 14 machines (10 renderers, 2 cache servers, and two load balancers). Estimated cost for that is $56,000. What is most unrealistic about this scenario is your assumptions about the member base, and its ratio to expected activity. One million users may only generate 1,000 requests/sec, but they certainly could generate a lot more. In fact, a critical strategy for large systems like this is anticipating for "peak demand" events. Lets say you send an e-mail out to all million people, telling them to log in and check out a particular URL. That timed event will generate a demand curve that is not evenly distributed over time; in fact, it is usually very front-loaded. Within about 5 minutes, more than 10% of the user base will respond. This is a raw rate of about 333 requests/sec, but that prprobably esumes that the single URL is the only thing they load; usually, a page contains images and other content (style sheets etc) which also much be fetched. Pages with a high art content can have 25 elements or more on them. That pushes the request rate up to 8333 requests/sec; way out of the 1000 request/sec bound. > The priciples I would like to verify are: > > 1) Some database (RDBMS) should be used instead of FileStorage for ZODB. > > 2) The ZEO should be used for constructing a cluster computing. > > 3) The Apache should be the front end instead of ZServer. > > 4) The PCGI should be the connection between Apache and Zope. > > 5) I shouldn't create static instance into the ZODB but query the > > external database. > > 6) The "Cache" of zope is useless since all the responses are dynamic > rendered. > > By the way, how much will this kind of system costs, regardless the > hardware? > > Iap, Singuan > -- Matt Kromer Zope Corporation http://www.zope.com/ _______________________________________________ Zope maillist - Zope(a)zope.org http://lists.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope-dev )

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Creating a file in the filesystem?
by j2 04 Mar '02

04 Mar '02

I would like to create a semaphore file in the filesystem (/tmp/restart maybe?) and then poll that file from a cron job to see if a certain daemon should be restarted. But, how on earth do one create such an object?

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Re: [Zope] Users more information
by Oliver Erlewein 04 Mar '02

04 Mar '02

Hi Antonio I'm having the same problem. I don't want to switch to one of the cookie-based products but would like to save the last login time. I have an additional object per user but whenever a value in an object changes it makes a copy for undo. This'll blast your Data.fs pretty soon. Other options are a flatfile which is accessed py a Python-script or a Database like MySQL (looks a little like overkill ;) ). At the moment I preffer the flatfile (like some pagecounters for Zope) but I'm still pondering over how to improve on performance... Maybe somebody has such a Pythonscript already?? Oliver Erlewein -- GMX - Die Kommunikationsplattform im Internet. http://www.gmx.net

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ZMySQLDA 2.0.8 and MySQL-python-0.9.0
by sbergmann＠weblog.de 04 Mar '02

04 Mar '02

Hi! Does somebody know if it´s possible to change the default values for the "Advanced Options" in ZMySQLDA? The Default is "Maximum rows to retrieve: 1000" "Maximum results to cache: 100". If I have a big table and want to select more then 1000 rows I always have to change the value after creating a new ZSQLMethod. When I forget these the results are not valid. I tried to to find the Values in the sourcecode but didn´t find. Bye Steffen

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<form action=SCRIPT(paramaters) ..>
by chrisf 04 Mar '02

04 Mar '02

How do I code the following <form action=SCRIPT(paramaters) ...> </form> Sound trivial, and silly but I can not seem to figure out the syntax. Chris

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Barnes & Nobles Putting Zope Books in the wrong place! !!!!!
by James Johnson 04 Mar '02

04 Mar '02

I tend to agree, but sometimes mistakes work out to be blessings in disguise. As a network professional it's been nearly impossible to convince some other professionals the merits of Zope. Now as the original poster said. "The Web app section is huge" The networking professional is overwhelmed with so many choices. I'm asking the community is that not sweet marketing? I bet you more professionals will look at the book if it's the only Web app server in the networking section. Let's not get lost in the sea of "Web Application" marketing power-houses. While zope is an application server. It can also be called a networking system, because I can use it to connect people and resources together. My main point is I don't think they have enough money at DC to pay B&N for such exclusive placement. If you can't find Zope in any section you can always ask for help finding the right section. What we want are the people who never heard of Zope but maybe "Web Application". If I had a choice it would be both sections, but if I had to choose it would be the networking section.... Somebody wants it noticed! With this knowledge I think we stand an even better chance targeting the network professional on the merits and usage of Zope. Developers are important, but zope needs to make more headway with networking professionals. This might be the perfect time to illustrate the main differences between Zope and other "Web App Servers" That's why its confusing and should belong in both sections ;-) Imho, -James p.s. I know at first it seems wrong to leave an Web application product out of that section if you can't have both sections. My thoughts are that a developer will eventually find the software and tools needed to get the job done. The network pro may not ever look at the same section. but if each and every network pro is exposed to Zope when they are seeking knowledge in their profession, that is power just in being able to hear one say "I've heard of it". That's exactly some of the things I've been dreaming of to happen. > In retail, product placement is often key to whether or not something > is sold; this should interest authors and publishers. I agree that > this is a mismatch. > From: Robert Geiger [mailto:rgeiger@bellsouth.net] > Sent: Monday, March 04, 2002 7:14 AM > To: zope(a)zope.org > Subject: [Zope] Barnes & Nobles Putting Zope Books in the wrong > place!!!!!! > > > I don't know who knows anybody at B&N, but maybe the authors of the > ZOPE related books can all call the booksellers and get them to put > the Zope books in the correct section! > > Currently, B&N keeps the ZOPE books in the Networking systems section, > a hodge podge of books that have absolutely nothing to do with Web App > development. > > I brought this to the attention of the section manager, and, although > he agreed with me, he told me there are other people higher up the > food chain that decide these things, and that he could not move them. > The computer inventory system would have to tell him where to put the > books. > > There is a Web Development section, and a Languages section. Either > one would be more apropos for Zope books. > > The Python section has grown considerably, and if placed in the > language section, would be within a shelf of the well-browsed python > language books. > > The Web development section is fairly huge, and mostly related to > various ASP, PHP, and other tools, and, given it's size, would be > harder to stand out in, although it would be a more apropriate > section. On the plus side, being > > at the END of a section (Z) is a good thing. > > So, after having to browse EVERY section at B&N, and finding Zope in > the 'wrong' one, I'd like it to be easier for EVERYONE to find these > books. > > Enough said, just wanting to let somebody know. I tried, now it's the > communities turn! >

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Zope message error
by Miguel Rodríguez 04 Mar '02

04 Mar '02

When I try to install zope 2.5.0 I get the following error: Permission denied: '/usr/local/zope/var/Z2.pid' I'm executing install as root in a RedHat 7.2 system. Any idea?? **************************** DISCLAIMER ****************************** This message is intended exclusively for the named person. It may contain confidential, propietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it an notify the sender. Your must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of 'CÁTENON'. Please note that internet e-mail neither guarantees the confidentiality nor the proper receipt of the message sent. If the addressee of this message does not consent to the use of internet e-mail, please communicate it to us immediately. *************************** AVISO LEGAL ***************************** Este mensaje es solamente para la persona a la que va dirigido. Puede contener información confidencial o legalmente protegida. No hay renuncia a la confidencialidad o privilegio por cualquier transmisión mala/ errónea. Si usted ha recibido este mensaje por error, le rogamos que borre de su sistema inmediatamente el mensaje así como todas sus copias, destruya todas las copias del mismo de su disco duro y notifique al remitente. No debe, directa o indirectamente, usar, revelar, distribuir, imprimir o copiar ninguna de las partes de este mensaje si no es usted el destinatario. Cualquier opinión expresada en este mensaje proviene del remitente, excepto cuando el mensaje establezca lo contrario y el remitente esté autorizado para establecer que dichas opiniones provienen de 'CÁTENON'. Nótese que el correo electrónico vía Internet no permite asegurar ni la confidencialidad de los mensajes que se transmiten ni la correcta recepción de los mismos. En el caso de que el destinatario de este mensaje no consintiera la utilización del correo electrónico vía Internet, rogamos lo ponga en nuestro conocimiento de manera inmediata. ************************************************************************

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Re: [ZOPE] Forum like www.zope-forum.de ?
by BZ 04 Mar '02

04 Mar '02

What ever it is... it can be done with ZUBB. :) http://www.zope.org/Members/BwanaZulia/ZUBB/ BZ On Mon, 04 Mar 2002 20:40:42 +0100, Andreas Heckel <andreas(a)easyleading.org> wrote : > there is no DENIC entry for zope-forum.de ;-) > -- > _______________________________________________________________________ > Andreas Heckel andreas(a)easyleading.org > LINUX is like a wigwam...no gates...no windows and an apache inside ;-) > > _______________________________________________ > Zope maillist - Zope(a)zope.org > http://lists.zope.org/mailman/listinfo/zope > ** No cross posts or HTML encoding! ** > (Related lists - > http://lists.zope.org/mailman/listinfo/zope-announce > http://lists.zope.org/mailman/listinfo/zope-dev ) > > >

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