Re: [Zope] resolving conflict errors
Thanks, I'll take a look. I don't have much faith in getting to do it with the live system, but maybe I can find a way to get some sort of testbed. On Sun, 11 Dec 2005, Michael Dunstan wrote: > On 12/11/05, Dennis Allison <[EMAIL PROTECTED]> wrote: > > > > Good idea, but it is hard to do in a production environment with a "never > > lose data" model. > > Have a go at recreating the problems you are seeing on a development > host. SessionRig can be used to mount a brute force attack of the > session machinery. You'll need to tune that somewhat to your > particular application. > > http://cvs.zope.org/Packages/SessionRig > > michael > -- ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] resolving conflict errors
On 12/11/05, Dennis Allison <[EMAIL PROTECTED]> wrote: > > Good idea, but it is hard to do in a production environment with a "never > lose data" model. Have a go at recreating the problems you are seeing on a development host. SessionRig can be used to mount a brute force attack of the session machinery. You'll need to tune that somewhat to your particular application. http://cvs.zope.org/Packages/SessionRig michael ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] resolving conflict errors
Good idea, but it is hard to do in a production environment with a "never lose data" model. I have suspected the p_resolve_conflict which is clearly wrong for our model and am in the process of trying to rewrite it to take advantage of the semantics of sessions as we use them. The problem I am tracking manifests itself as KeyErrors in the session data structure. The session structure is used pretty much out of the box. Reading is done any which way (e.g, REQUEST['SESSION'][key]) but writing always uses a copy out of the session object, an update of the session object, and the a replacement of the session object back into REQUEST. The session data we lose are generally strings, for example, a user_id. For example, we can set the user_id into the session to a value, and then later, when we reference the session variable, we get a KeyError. While there is no direct causal tie, we suspect this is related to an intervening conflict error. Occasionally the entire SESSION data container disappears. At other times, we get a KeyError exceptions for one or more session variables. I have been trying to understand in detail the management of the session variables. I can see how accesses are managed in ZPublisher/HTTPRequest, but I am still unsure of how that session data is maintained persistent and how session data can generate read-read conflicts. I'll try your suggestion. I also plan to monitor session variable access to determine whether the SESSION data whether a KeyError signals that all session variables are missing or whether only a few are missing. On Sun, 11 Dec 2005, Michael Dunstan wrote: > On 12/9/05, Dennis Allison <[EMAIL PROTECTED]> wrote: > > The problem I am trying to resolve appears to be load related. The > > observed symptom is that (some) session variables spontaneously disappear. > > There appears to be some connection to conflicts, but the exact mechanism > > and the relationship is not yet clear. > > A small possibility is that you are being bitten by the DWIM'ly nature > of TransientObjects conflict resolution where the last modified state > is chosen over the others. If you think this is biting you then try > commenting out _p_resolveConflict of TransientObject. That's bound to > increase the rate of conflict errors but should provide you with a > consistent session state. Perhaps useful as a debugging step. > > michael > -- ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] resolving conflict errors
On 12/9/05, Dennis Allison <[EMAIL PROTECTED]> wrote: > The problem I am trying to resolve appears to be load related. The > observed symptom is that (some) session variables spontaneously disappear. > There appears to be some connection to conflicts, but the exact mechanism > and the relationship is not yet clear. A small possibility is that you are being bitten by the DWIM'ly nature of TransientObjects conflict resolution where the last modified state is chosen over the others. If you think this is biting you then try commenting out _p_resolveConflict of TransientObject. That's bound to increase the rate of conflict errors but should provide you with a consistent session state. Perhaps useful as a debugging step. michael ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
[Zope] First International Workshop on Free/Open Source EIS/ERP
Dear Colleague, as the First International Workshop on Free/Open Source EIS/ERP organizer, I would like to invite you to submit a paper to it. This event is the first one, of international dimension, dedicated to free/open source EIS/ERP and will be held in parallel to the IFIP TC8 International Conference on Research and Practical Issues of Enterprise Information Systems 2006 (CONFENIS 2006). We expect papers from both academicians and practitioners, in all subjects related to Enterprise Information Systems and Enterprise Resources Planning. Authors that do not focus their work specifically in free/open source software can submit to Confenis 2006. Elsevier will publish proceedings of both events and best papers will be also published by top ranking IEEE and ACM periodicals. More information is available at http://www.confenis.org. About the IFIP: The IFIP (International Federation for Information Processing) was created in 1960 under the auspicious of UNESCO; it aggregates the main computer societies worldwide, including the ACM and IEEE. It is responsible for the realization of top ranking conferences like IFIP/W3C/ACM International World Wide Web Conference and IEEE/ACM/IFIP International Conference on Hardware/Software Codesign & System Synthesis. More information about IFIP is available at http://www.ifip.or.at/ About the IFIP TC8: The IFIP Technical Committee 8 Information Systems is divided in many subcommittees, each one for a specific IS area: · WG 8.1 Design and Evaluation of Information Systems · WG 8.2 Interaction of Information Systems and the Organization · WG 8.3 Decision Support Systems · WG 8.4 E-Business: Multi-disciplinary research and practice · WG 8.5 Information Systems in Public Administration · WG 8.6 Transfer and Diffusion of Information Technology · WG 8.8 Smart Cards At http://ifiptc8.itu.dk/ more information can be found about the IFIP TC8. Please forward this message and CFPs to other EIS/ERP researchers and practitioners. Best regards, -- Prof. Rogério Atem de Carvalho, D.Sc. Gerente de Pesquisa / Research Manager CEFET Campos ___ ''O remetente desta mensagem é o responsável pelo seu conteúdo e endereçamento. A utilização deste meio para fins que não aqueles dispostos na Portaria nº 267, de 20 de outubro de 2003 da Direção Geral do CEFET CAMPOS, é passível das sanções cabíveis, dispostas nas normas internas para utilização de correio eletrônico e acesso à Internet.'' ___ Servidor de E-mail CEFET Campos ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] Re: why will FastCGI not be supported in the Future.
... > The funny thing is - performance isnt really the pro of > fcgi over http. Its really more about transporting header > and environment data from zope to apache, which is ^^ actually I meant apache to zope. I go and get some coffee... Tino ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] Re: why will FastCGI not be supported in the Future.
Am Mittwoch, den 07.12.2005, 09:39 + schrieb Chris Withers: > Dieter Maurer wrote: > > The original poster explained his wish to retain FCGI: > > > > It reuses an existing connection between Apache and Zope > > while (he thinks and I might believe it) the recommended > > "mod_proxy" way each time opens a new connection. > > > > Thus, FastCGI might be more efficient. > > Show me some evidence proving that fcgi or mod_proxy is the significant > limiting performance factor in a setup involving zope and I'll take this > seriously ;-) The funny thing is - performance isnt really the pro of fcgi over http. Its really more about transporting header and environment data from zope to apache, which is kinda limited with mod_proxy. (Think alternative authentication, ssl ) Tino. ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] Hooks for methods other than GET/POST on port 80?
--On 10. Dezember 2005 10:36:16 +0200 Roman Susi <[EMAIL PROTECTED]> wrote: Not sure if filesystem based products qualify, but its like saying that ´is it operating system problem or stupid application code which brings OS down'. One misbehaving code should not bring down the whole framework, IMHO. Tell me any application or framewokr that you can't bring down with stupid code :-) In this point Zope is neither better nor worse than any other system. -aj pgprpdIj93fHy.pgp Description: PGP signature ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] Hooks for methods other than GET/POST on port 80?
Andreas Jung wrote: > > > --On 9. Dezember 2005 15:33:38 +0200 Roman Susi <[EMAIL PROTECTED]> wrote: > >> >> Hi! >> >> I've found the reason for original bug I hit. The recursion was in my >> code (and gone away after I corrected it). However, the bug I reported to >> Zope.org is still there. >> I think its a bug to freeze the whole server by maximum-recursion-reached >> error in a product... > > > There is always a chance to bring Zope down by writing bad code. But I > still do not understand if this is really a Zope problem or just an > example of stupid code. Not sure if filesystem based products qualify, but its like saying that ´is it operating system problem or stupid application code which brings OS down'. One misbehaving code should not bring down the whole framework, IMHO. > > -aj Regards, Roman ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
