Re: [Zope-dev] Is there an alternative to zdaemon?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 23 Dec 2006, at 14:53, Jim Fulton wrote: > I don't think it ever caused anyone any headache apart from maybe working around different ways in which forking/daemonizing is handled on some platforms (OS X comes to mind). Any software we own is an inherent liability. Of course, hopefully, most things we own provide enough benefits to overcome this inherent liability. I agree that there may not be alternatives compelling enough to justify a change. To be honest, I'm coming across many situations where maintenance and upgrade issues make me wish the original developers had reinvented a couple wheels instead of relying on third party packages. Even if they work fine right now you'll have the risk of incompatibilities or lack of reaction when it comes to fixing bugs that make your life harder down the line. zdaemon is a little different of course, it's a "standalone" functionality in a way. It's not some Zope product that other packages rely on. jens -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.5 (Darwin) iD8DBQFFjTzTRAx5nvEhZLIRAlQGAJ9CJkklU/H9cyn+ayTPWQDjm8zOUQCggj9p zaBUE/Pze8m+cEr2P6ghUxk= =PLqx -END PGP SIGNATURE- ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Is there an alternative to zdaemon?
Jens Vagelpohl wrote: ... So with all that said, what's the use case for switching zdaemon out for something else? Not owning it. :) > What other functionalities are *you* looking for? Ditto. > I don't think it ever caused anyone any headache apart from maybe working around different ways in which forking/daemonizing is handled on some platforms (OS X comes to mind). Any software we own is an inherent liability. Of course, hopefully, most things we own provide enough benefits to overcome this inherent liability. I agree that there may not be alternatives compelling enough to justify a change. Jim -- Jim Fulton mailto:[EMAIL PROTECTED] Python Powered! CTO (540) 361-1714http://www.python.org Zope Corporation http://www.zope.com http://www.zope.org ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Is there an alternative to zdaemon?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 23 Dec 2006, at 14:23, Jim Fulton wrote: zdaemon is an interesting case because it is s non-zope and (mostly) non-python specific. I must say that it amazes me that there isn't an established alternative out there. When people start talking about such functionalities I only ever see Daemontools mentioned. I never used it, but from your description it seems to have some shortcomings. One point in zdaemon's favor that I forgot about in my original analysis is that it has a (also undocumented) subclassing API that allows applications to add new commands. We certainly leverage this to provide the debug and run commands. supervisor2 looks very cool. But it is also "ours" in some sense. It also is much bigger than zdaemon. It looks like like something that people will often choose over zdaemon. zdaemon is still attractive to me over supervisor2 because it is smaller, less ambitious and I already understand it. :) And, of course, there are the good backward compatibility arguments that you make. So with all that said, what's the use case for switching zdaemon out for something else? What other functionalities are *you* looking for? I don't think it ever caused anyone any headache apart from maybe working around different ways in which forking/daemonizing is handled on some platforms (OS X comes to mind). jens -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.5 (Darwin) iD8DBQFFjTGMRAx5nvEhZLIRAt3TAKCCeKr94fU3Vp9wkyhYDCOLmZpGpgCdFjau HeEVqYANXGEMMfmmdbhmvRw= =jy2/ -END PGP SIGNATURE- ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Is there an alternative to zdaemon?
Andreas Jung wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 - --On 22. Dezember 2006 15:55:48 -0500 Jim Fulton <[EMAIL PROTECTED]> wrote: It has 2 major disadvantages: - It is ours. :) We are bearing the burden of maintaining it. This is offset by the fact that it hasn't required much maintenance. ..which is actually a sign of "it-just-works". - It is largely undocumented. This makes it much harder to use than it needs to be. It also makes it under appreciated. I made a start at fixing this yesterday: http://svn.zope.org/zdaemon/trunk/src/zdaemon/README.txt?view=auto It isn't very hard to use, so documenting it isn't really all that hard. ...which is almost True for a lot of parts of the Zope 2 core :-) I wonder if we should be using some other daemon manager. Arguably, there's no reason for the Zope project to maintain one if something is available that does what we need. I think (meanwhile) that this is not enough to justify the replacement of a component. Replacing a Zope 2 component always caused some pain. So as a rule for replacing something in the Zope 2 core we consider those rules: - the replacement solves existing functional problems - it adds major functional benefits - no issues with backward compatibility, well tested etc. For the Zope 2 core we must be very careful about changing stuff. Stability and backward compatibility are much, much more important for the end-user than satisfying our replace-all-with-something-better drive :-) Don't get me wrong but we've done some minor mistakes with replacing stuff in the past and because of that I became a bit conservative about changing things. Of course I am only speaking for the Zope 2 core. I feel the same need for conservatism. These are all good arguments. A strong counter force is that we seem to have more on our plate than we can handle. We either need to get more people helping, or we need to do less. Something to keep in mind is that many people who help now actually want and deserver to be able to do new things too. :) zdaemon is an interesting case because it is s non-zope and (mostly) non-python specific. I must say that it amazes me that there isn't an established alternative out there. One point in zdaemon's favor that I forgot about in my original analysis is that it has a (also undocumented) subclassing API that allows applications to add new commands. We certainly leverage this to provide the debug and run commands. supervisor2 looks very cool. But it is also "ours" in some sense. It also is much bigger than zdaemon. It looks like like something that people will often choose over zdaemon. zdaemon is still attractive to me over supervisor2 because it is smaller, less ambitious and I already understand it. :) And, of course, there are the good backward compatibility arguments that you make. Jim -- Jim Fulton mailto:[EMAIL PROTECTED] Python Powered! CTO (540) 361-1714http://www.python.org Zope Corporation http://www.zope.com http://www.zope.org ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Is there an alternative to zdaemon?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 - --On 22. Dezember 2006 15:55:48 -0500 Jim Fulton <[EMAIL PROTECTED]> wrote: > > It has 2 major disadvantages: > > - It is ours. :) We are bearing the burden of maintaining it. >This is offset by the fact that it hasn't required much maintenance. ..which is actually a sign of "it-just-works". > > - It is largely undocumented. This makes it much harder to use than it >needs to be. It also makes it under appreciated. I made a start at >fixing this yesterday: > > http://svn.zope.org/zdaemon/trunk/src/zdaemon/README.txt?view=auto > > It isn't very hard to use, so documenting it isn't really all that hard. ...which is almost True for a lot of parts of the Zope 2 core :-) > > I wonder if we should be using some other daemon manager. Arguably, > there's > no reason for the Zope project to maintain one if something is available > that does what we need. I think (meanwhile) that this is not enough to justify the replacement of a component. Replacing a Zope 2 component always caused some pain. So as a rule for replacing something in the Zope 2 core we consider those rules: - the replacement solves existing functional problems - it adds major functional benefits - no issues with backward compatibility, well tested etc. For the Zope 2 core we must be very careful about changing stuff. Stability and backward compatibility are much, much more important for the end-user than satisfying our replace-all-with-something-better drive :-) Don't get me wrong but we've done some minor mistakes with replacing stuff in the past and because of that I became a bit conservative about changing things. Of course I am only speaking for the Zope 2 core. Andreas -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (Darwin) iD8DBQFFjLuICJIWIbr9KYwRAgsRAJ9p3Td7KOmKzHzLn89nnQpSdYMtnwCcDyDR iKgZV5H76vnCpjqO3Mccrv4= =DYYW -END PGP SIGNATURE- ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
[Zope-dev] Is there an alternative to zdaemon?
Yesterday I started working on some updates to zdaemon. zdaemon is pretty cool. It is a Unix-only tool that: - Turns an arbitrary program into a fairly well-behaved daemon - Provides management of an applications output as a log file. - Provides start, stop and restart commands for starting or stopping applications. - Provides a status command for finding out if an app is running. - Provides a kill command for sending an app a signal (e.g. for log rotation). - Automatically restarts applications that exit abnormally, with a fairly reasonable approach for limiting restart attempts in case something is failing on startup. - Provides a number of useful configuration settings that can be managed using a clean (ZConfig-based) log file. It is written in Python, but it can control any program. We're using it to control spread, which is a C program. spread comes with it's own Red Hat startup script, but spread fails to detach from the controlling terminal. zdaemon makes it behave properly and provides a startup script that will work on any Unix-like system. It has 2 major disadvantages: - It is ours. :) We are bearing the burden of maintaining it. This is offset by the fact that it hasn't required much maintenance. - It is largely undocumented. This makes it much harder to use than it needs to be. It also makes it under appreciated. I made a start at fixing this yesterday: http://svn.zope.org/zdaemon/trunk/src/zdaemon/README.txt?view=auto It isn't very hard to use, so documenting it isn't really all that hard. I wonder if we should be using some other daemon manager. Arguably, there's no reason for the Zope project to maintain one if something is available that does what we need. Does anyone know of something that does what zdaemon does? daemontools seems somewhat close: http://cr.yp.to/daemontools.html Going from the documentation, it doesn't seem to be as clever about application restart. The documentation says nothing about distinguishing between normal and abnormal restarts or avoiding useless restarts when there are start-up errors. If we do continue to maintain zdaemon, we really should publicize it more widely, both to get credit and to get more people interested in maintaining it. Because I want the enhancements I'm making for another project I'm working on, I'm going to proceed with them for now. Thoughts? Jim -- Jim Fulton mailto:[EMAIL PROTECTED] Python Powered! CTO (540) 361-1714http://www.python.org Zope Corporation http://www.zope.com http://www.zope.org ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
