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MountedFileStorage 0.02 now available.
by Anthony Baxter 11 Jun '00

11 Jun '00

MountedFileStorage 0.02 is now available. Changes in Release 0.02: New help files. You can now use MountedFileStorage to create new ZODB files. Nitty-gritty is in the SubApplication.py file - quite possibly useful to people doing other sorts of mounted storages. Note the patch in no_repeat_metatypes.patch - not essential, but will stop your 'add' menus getting bloated to hell. README follows: MountedFileStorage, 0.02. Ok, so the DC guys have been talking about allowing multiple ZODB support, but I couldn't see a way to use it. A bit of trawling through the CVS and I found the guts of a MountedItem object which has now been removed. Using that as inspiration and a source of pointers, I've bolted together a really simple Product for mounting multiple ZODB files onto a Zope installation. You should also check out the "MountedDatabases":http://www.zope.org/Members/jim/ZODB/MountedDatabases section of the ZODB Wiki. First of all, you need to be running a really really recent "CVS":http://www.zope.org/Resources/CVS version of Zope. 2.2alpha1 isn't good enough. Then install this product (it unpacks in lib/python/Products/MountedFileStorage). Sample usage: Select 'Mounted FileStorage' from the product add list. For 'file' put nifty.fs. Leave 'path' blank, and put 'nifty' as the id, click 'create'. You've now got an empty ZODB installed. _WARNING_: This is really really untested stuff. It Works For Me. Not To Be Taken Internally. Do Not Come Crying To Me If It Breaks Your Zope Install. If you want to play with this stuff, you really should back up your Data.fs _first_. For more info, see the online Help. In particular, check out the known bugs and problems section. Security Issues: There probably are some. I've no idea what they might be. The product makes a really simple-minded effort to not allow badness through (any filename with a '/' or '\' in it). Don't give access to the permission 'Mount FileStorages' to anyone that you don't trust, though. Note that this includes anyone with Manager role on the system. Note also, though that you can only mount existing files that are in var/. Anthony Baxter <anthony(a)interlink.com.au>, Sun Jun 11 17:38:20 EST 2000

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Re: [Zope] load-balancing recommendations ? (configuration and hardware)
by Anthony Baxter 11 Jun '00

11 Jun '00

>>> chas wrote > I've often heard about the infinite-scalability that will > be created by something like ZEO and I've always wondered > about one thing : how is the load-balancing being done ? There's a number of approaches you can take here: 1. Buy something - a cisco localdirector, an arrowpoint (also now owned by cisco), or similar. This is the approach we take - in a past life I've seen an LD get the absolute crap kicked out of it and it just kept working (it was in front of some _large_ proxy caches). www.cisco.com www.arrowpoint.com 2. Software - there's linux virtual server, there's eddieware, there's probably a bunch of commercial packages as well, although I don't know why you'd bother... www.linuxvirtualserver.org www.eddieware.org Which of these solutions you go for largely depends on your budget - the first set of options are probably more robust and flexible, but the latter is definately going to be cheaper :) Anthony -- Anthony Baxter <anthony(a)interlink.com.au> It's never too late to have a happy childhood.

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Re: dtml-tree with data from multiple tables
by Lance Kurisaki 11 Jun '00

11 Jun '00

>>I'd like to generate a tree with data from different >>SQL tables depending on the tree level. In other >>words, the first level data comes from one table, >>second level comes from another. >> >>How can the branches_expr expression determine what >>the current tree level is? Can I pass a parameter to >>let me know the current level? I tried the following, >>but it didn't work... >> >> <dtml-tree id=name branches_expr="child_lookup(_['tree-level'])"> > > >I think Anthony baxter's "Some neat tricks with dtml->tree" <url: >http://www.zope.org/Members/anthony/tree-coding->tricks > will help you out That How-To uses the same SQL table to define children at all levels of the tree. How can I use different tables at different levels? Am I able to determine the current level in my child_lookup() method? Thanks, Lance __________________________________________________ Do You Yahoo!? Yahoo! Photos -- now, 100 FREE prints! http://photos.yahoo.com

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Zope w/ FreeBSD 4.
by Jason C. Leach 10 Jun '00

10 Jun '00

hi, I would do with a hand getting zope working w/ FreeBSD 4. I make it by going to the /usr/ports, and why I try and start it with './start' I get the errors at the end of this msg. Also, Zope seems to have installed the SSL mod for Apache. Do I need to make any modificatons to get that working or does the install script do it all. I see I have a apache.conf.Zope-Changes and am wondering if I need to add them by hand? Thanks, J. su-2.03# cd /usr/local/www/Zope-2.1.6/ su-2.03# ls LICENSE.txt access start w_pcgi.pyc zpasswd.py README.txt doc stop wo_pcgi.py zpasswd.pyc ZServer inst utilities wo_pcgi.pyc Zope.cgi lib var z2.py Zope.cgi.orig pcgi w_pcgi.py z2.pyc su-2.03# ./start Traceback (innermost last): File "/usr/local/www/Zope-2.1.6/z2.py", line 493, in ? logger_object=lg) File "/usr/local/www/Zope-2.1.6/ZServer/medusa/http_server.py", line 552, in __init__ self.bind ((ip, port)) File "/usr/local/www/Zope-2.1.6/ZServer/medusa/asyncore.py", line 205, in bind return self.socket.bind (addr) socket.error: servname not supported for ai_socktype su-2.03#

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Exceptions and XMPRPC
by Peter Kropf 10 Jun '00

10 Jun '00

I'm using XMLRPC and Zope for prototyping an application in python. And for the most part, things are VERY easy to accomplish. But I sometimes run into troubles with error handling. It's fairly easy to make a slight mistake in an external python method which takes a fair amount of effort to debug. Or at least for me it's a fair amount. I just might not be using any of the debugging features of Zope. I guess that the heart of my question is this: has anyone done any work to extend the XMLRPC python module and the XMLRPC code in Zope to catch exceptions, convert them to be sent back over the network and then raise them in the scope of the client code? In looking through the XMLRPC code I don't see anything too obvious, but it could just be that I'm getting tired. Thanks! -- Peter Kropf Codesmith VEReCOMM Corp. 2475 Augustine Drive, Suite 102 Santa Clara, CA 95054 408-919-3107; Fax 408-969-0688 peter(a)verecomm.com

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load-balancing recommendations ? (configuration and hardware)
by chas 10 Jun '00

10 Jun '00

Hi Folks, I've often heard about the infinite-scalability that will be created by something like ZEO and I've always wondered about one thing : how is the load-balancing being done ? Just say we have 3 front-line servers (ZSERVER_1, ZSERVER_2 and ZSERVER_3 in the diagram below), each running Zope with identical application logic replicated by ZEO (or simply copied across manually); the front-line servers all use the same database (DB) for storing sessions. Our load-balancer distributes incoming requests between the 3 servers : +---[ZSERVER_1]----+ | | REQUEST-->[LOADBALANCER]----+---[ZSERVER_2]----+------[DB] | | +---[ZSERVER_3]----+ What are people using for the load-balancer (and I'm looking for real load-balancing, not DNS round-robbin) so that the multiple front-line servers appear as one big server... ie. so that they are transparent to the outside world. In particular, so that cookies set by any one of the front line servers will be shared by the others. (ie. they can not have different fully-qualified domain names or else cookies set by one will not be shared by another). Does anybody with experience have any recommendations for the load-balancer ? Thank you very much, chas ps. In the past I've got around this by ensuring that if the very first request from a given browser is dealt with by, say, server silo8.domain.com, then all subsequent requests from that browser are also dealt with by by that server. But that (a) introduces head-aches with application logic and (b) is not good if silo8.domain.com suddenly goes down.

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Traversable DTML methods
by Ian Sparks 10 Jun '00

10 Jun '00

It seems strange to me that SQLMethods are traversable out of the box and "normal" DTML methods are not. It seems to me that traversable DTML methods would be useful (to me this means DTML Methods with parameters). Is this something that might make it into Zope in the future or am I missing something important which means that they simply arn't necessary? - Ian Sparks.

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Problems extracting property type from a ZClass?
by Darran Edmundson 10 Jun '00

10 Jun '00

I'm trying to automatically extract the property names, types and default values from the propertysheet of a class. I'm being foiled by the following bit of strangeness. Consider the following snippet of DTML: <dtml-in "propertyIds()"> <dtml-let pid="_['sequence-item']"> <dtml-var pid> <dtml-var "getProperty(pid)"> <dtml-var "getPropertyType(pid)"><br> </dtml-let> </dtml-in> When run in a "normal" location (ie., outside of the Products hierarchy), it acts as expected giving a list of properties, values *and* their type. E.g., title Zope string selectionChoices ['selection1', 'selection2'] lines date_prop 2000/01/01 date However, wrapped in a <dtml-with "Control_Panel.Products.TestProduct.TestClass.propertysheets.common.properti es"> </dtml-with>, I'm getting the name and value, but not the type, viz. p_string test_string None p_date 2000/01/01 None p_boolean on None p_float 3.1415 None p_int 10023 None p_lines ['line1', 'line2', 'line3'] None p_text this is a test entry of a text box. None p_tokens ['token1,token2,token3'] None p_selection None p_multi_selection None Any ideas? Cheers, Darran.

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ZEO ..again ;)
by Bill Anderson 10 Jun '00

10 Jun '00

OK, after reveiwing the ZEO FAQ, I realized that we seem to be a few weeks behind schedule. Is there any updates on a time frame? I know this would certainly help amk out with his project, and would certainly help me out, even in non-zope apps (I am working on moving a Sybase/Zope setup to straight ZODB with ZEO, but can't get an approval until we at least have an idea of when we can try the code). Half-working code would be fine for me, but last I heard the early-testers indicated it was definitely releasable. :)

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[Ann] Zope 2.1.6: <dtml-in> patch It provides complete batching info at sequence start *and* end It provides complete batching info at sequence start *and* end
by Dieter Maurer 10 Jun '00

10 Jun '00

The Zope 2.1.6 <dtml-in> provides batching information for the previous batch at the start and end of the sequence. Batching information for the following batch, however, is only available at sequence end. This makes it difficult to provide uniform navigation (to previous/next batch) both before and after the sequence. Moreover, if the current batch size is "1" (e.g. size=1), then <dtml-in> provides batch info for the following batch only for the sequence's first element. For all other elements only previous batch information but no following batch information is available. This is a bug. <dtml-in> provides modes "previous" and "next" that do not render the sequence but only provide the respective batching info. The problem with this solution is redundancy: the same parameters must be given to "<dtml-in previous>", "<dtml-in>" and "<dtml-in next>" to obtain reliable information. This is error prone and makes it difficult to separate navigation (for different sequences with different <dtml-in> parameters) in a general navigation method. The patch at URL:http:www.handshake.de/~dieter/pyprojects/zope/dt_in.pat provides uniform batching information both at the start and at the end of the sequence. A batch size of 1 is correctly handled. Dieter

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