[Zope] Re: Zope 2.9 Product Refreshing
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dieter Maurer wrote: ... You have that point-of-failure anyway if you are using the RAM-based sessions provided by Zope's core sessioning. If availability is important to you, then you *need* to be using ZEO and a load balancer, at which point you also have to look at a more scalable / available sessioning solution. We are using ZEO, a load balancer and nevertheless have sessions in RAM. True, it is less safe than with persistent sessions -- but it is also more efficient. We do this by ensuring that independent of the load balancer's choice a request for a given session goes to that Zope instance that has this session. Then you have the problem the orignal poster was trying to avoid: you can't restart an appserver without losing session data for some users. Externalizing the session storage removes the appserver as a point-of-failure for user sessions. Tres. - -- === Tres Seaver +1 202-558-7113 [EMAIL PROTECTED] Palladion Software Excellence by Designhttp://palladion.com -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.2.2 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFE2iTZ+gerLs4ltQ4RAn3HAKDNYodL3ENdV/jrQZhmEEtMkIQnbwCfbT+5 xH3krOiXo7KRd5G+DiEp92I= =WLfz -END 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 )
[Zope] Re: Zope 2.9 Product Refreshing
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 James Davies wrote: This isn't really a solution. Clients will still lose session data, which is unacceptable. -James. On Monday 07 August 2006 22:15, Reinoud van Leeuwen wrote: On Mon, Aug 07, 2006 at 10:12:42PM +1000, James Davies wrote: We have Zeo, but running a seperate instance of zope for each site is still too much (We probably host around 50 sites at the moment, and growing. The only economical way to do this is to put multiple sites in one zope instance). Still you can shutdown 1 ZEO client; update products there and start it up again... There will be some performance degradation but the sites stay up... (and I hope you've got enough ZEO clients so that bringing 1 down will not cause severe problems...) You have that point-of-failure anyway if you are using the RAM-based sessions provided by Zope's core sessioning. If availability is important to you, then you *need* to be using ZEO and a load balancer, at which point you also have to look at a more scalable / available sessioning solution. There are a couple of alternatives out there: - SQL-based session implementaitons (including some which will drop into your application seamlessly), e.g.: http://www.zope.org/Members/anthony/software/SQLSession (really old, might need some tweaking). - A memcached-based solutions, e.g.: http://agendaless.com/Members/tseaver/software/mcdutils/ Refresh is dangerous because it mostly works, and because when it breaks, the breakage surfaces as heisenbugs. I therefore have a rule about supporting folks who use refresh: if they can't reproduce the problem with refresh disabled, I can't help them. Tres. - -- === Tres Seaver +1 202-558-7113 [EMAIL PROTECTED] Palladion Software Excellence by Designhttp://palladion.com -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.2.2 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFE2Lqw+gerLs4ltQ4RAv6bAKCr7ooZQq0ZEYoxw3J6uq9bKrgGOACgp5is cmP3uyTUBCOMk8Mv0Xk24R8= =a6Ui -END 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 )
[Zope] Re: Zope 2.9 Product Refreshing
Andreas Jung wrote: James Davies wrote: Another major issue I've discovered is Zope hosting. We reguarly deploy custom sites on shared zope environments, and having to restart an entire server just to update one product severely breaks our uptime guarentee. Refresh only works in debug-mode. You want to tell us that you are running a production site in debug-mode? Since when does refresh only work in debug mode? Admittedly we are still on Zope 2.7.x, but it works in non-debug mode for me. When I need to update skin folders on our production server then I do that by forcing the skin product to refresh. For other products I restart the servers, but as Reinoud points out if you have multiple ZEO clients that doesn't result in any downtime (we currently have 6 ZEO clients) although it will result in a slower response for the first few hits after the restart. ___ 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: Zope 2.9 Product Refreshing
--On 7. August 2006 12:42:38 + Duncan Booth [EMAIL PROTECTED] wrote: Andreas Jung wrote: James Davies wrote: Another major issue I've discovered is Zope hosting. We reguarly deploy custom sites on shared zope environments, and having to restart an entire server just to update one product severely breaks our uptime guarentee. Refresh only works in debug-mode. You want to tell us that you are running a production site in debug-mode? Since when does refresh only work in debug mode? Admittedly we are still on Zope 2.7.x, but it works in non-debug mode for me. Possibly I haven't used Refresh since Zope 2.7 :-) I considered it always to be a hack and it raised more problems than it solved. -aj pgpuLRRQR3Tis.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 )