RE: [Zope-dev] RE: [ZODB-Dev] [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss

2004-06-27 Thread Tim Peters
[sathya] so can we safely assume that zeo does not mix the asyncore implementation with forks or threads and hence does not suffer from the child concurrently operating on sockets along with parent syndrome that dieter is experiencing ? appreciate any clarifications. It's normal for a ZEO

[Zope-dev] Re: CatalogBrains since Zope2.7.1b1

2004-06-27 Thread Santi Camps
Optional arguments will still allow untrusted code to bypass security checks. Yes, that's true. Here are three solutions to this, two of which do not involve catalog changes: - Use a proxy role on the script that invokes getObject which grants the permissions needed. - Use

Re: [Zope-dev] RE: [ZODB-Dev] [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss:MAYBE NOT

2004-06-27 Thread sathya
hello tim, thanks for the clarification below and also the pointers to the posix behaviour of fork. The Warning about Zope/ZEO clients in the subject line certainly caused some alarm bells to go off. I am assuming now that dieters description below of using forks does not gel with the ZOPE/ZEO

[Zope-dev] Re: [Warning] Zope/ZEO clients: subprocesses can lead to non-deterministic message loss

2004-06-27 Thread Dieter Maurer
ATTENTION: Crosspost -- Reply-To set to '[EMAIL PROTECTED]' On Friday, I reported a bug that can cause non-deterministic message loss and duplication of messages in forking applications with an asyncore mainloop thread. Unfortunately, the proposed workararound does not work for various reasons

[Zope-dev] Re: [Plone-users] Re: [ZODB-Dev] [Warning] Zope/ZEO clients: subprocesses can lead to non-deterministic message loss

2004-06-27 Thread Dieter Maurer
Paul Winkler wrote at 2004-6-25 17:41 -0400: On Fri, Jun 25, 2004 at 07:23:19PM +0200, Dieter Maurer wrote: ATTENTION: Crosspost -- Reply-To set to '[EMAIL PROTECTED]' Today, I hit a nasty error. The error affects applications under Unix (and maybe Windows) which * use an asyncore

RE: [Zope-dev] RE: [ZODB-Dev] [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss

2004-06-27 Thread Dieter Maurer
Tim Peters wrote at 2004-6-27 04:46 -0400: ... [Dieter] When a process forks the complete state, including file descriptors, threads and memory state is copied and the new process executes in this copied state. We now have 2 asyncore threads waiting for the same events. A problem is

Re: RE: [Zope-dev] RE: [ZODB-Dev] [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss

2004-06-27 Thread Tim Peters
[Dieter Maurer] The problem occured in a ZEO client which called asyncore.poll in the forked subprocess. This poll deterministically stole ZEO server invalidation messages from the parent. I'm sorry, but this is still too vague to guess what happened. - Which operating system was in use? -

[Zope-dev] [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss: would like to duplicate this

2004-06-27 Thread sathya
Tim Peters wrote: just to add my 2 cents I have been looking at zserver code, the only time fork or system (which i presume invokes execve ) calls are used are at startup to either a) run a cmdline b) daemonize heres a snip from strace output strace -o strace.txt -f -e trace=fork,execve ./runzope

Re: [Zope-dev] [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss:MAYBE NOT

2004-06-27 Thread Tim Peters
[sathya] thanks for the clarification below and also the pointers to the posix behaviour of fork. The Warning about Zope/ZEO clients in the subject line certainly caused some alarm bells to go off. I am assuming now that dieters description below of using forks does not gel with the ZOPE/ZEO

[Zope-dev] Re: [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss: would like to duplicate this

2004-06-27 Thread Tim Peters
[sathya] ... The zeoclient causes threads to be created but there are no forks or system calls as far as I can tell (or strace for that matter) Can you please point out where in the zeo code does forking occur ? I will try and duplicate this condition. ZEO and ZEO never fork -- they wouldn't

Re: [Zope-dev] Re: [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss: ONLY IF YOUR APP CODE FORKS

2004-06-27 Thread sathya
tim thanks for confirming it. Wont loose sleep over it now. I did not mean to sound like questioning anybodys track record. Since we have ZEO clusters in production it raised alarm bells thats all. Its good to know the problem MAY occur only if u fork in your own app code and the core zeo/zope

Re: [Zope-dev] Re: [Warning] Zope/ZEO clients: subprocesses can lead tonon-deterministic message loss: ONLY IF YOUR APP CODE FORKS

2004-06-27 Thread Tim Peters
[sathya] tim thanks for confirming it. Wont loose sleep over it now. I did not mean to sound like questioning anybodys track record. No, it didn't sound like you were. I mentioned that Dieter has an excellent track record because *I'm* giving him a hard time here wink. I'm sure he's seeing

[Zope-dev] Dare To get A m[o]rtgage

2004-06-27 Thread Bill Hanks
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