The other question that''s been bugging me that I''m hoping someone has already thought about is how to describe inter-host dependencies. We have a few examples of situations where we need puppet to be aware of the state of other machines in the cluster: 1) Load balanced servers - it would be nice if we could write rules that will only allow puppet to change the state of one of the real servers at a time 2) Dependent services - we have service that run on different hosts, which need to be started up in a particular order (eg the master database needs to be running before the middleware application tries to start). The two problems seem to be quite similar, there are probably other real world examples where this type of capability would be useful. Does puppet understand this concept at the moment? Bernard. -- Bernard Gardner Spry Business Technology Solutions Pty. Ltd. http://www.sprybts.com/ PO Box 860, Strawberry Hills, NSW 2012, AUSTRALIA _______________________________________________ Puppet-users mailing list Puppet-users@madstop.com https://mail.madstop.com/mailman/listinfo/puppet-users
On Sep 11, 2007, at 4:20 AM, Bernard Gardner wrote:> The other question that''s been bugging me that I''m hoping someone > has already thought about is how to describe inter-host dependencies. > > We have a few examples of situations where we need puppet to be > aware of the state of other machines in the cluster: > 1) Load balanced servers - it would be nice if we could write rules > that will only allow puppet to change the state of one of the real > servers at a time > 2) Dependent services - we have service that run on different > hosts, which need to be started up in a particular order (eg the > master database needs to be running before the middleware > application tries to start). > > The two problems seem to be quite similar, there are probably other > real world examples where this type of capability would be useful. > > Does puppet understand this concept at the moment?Puppet currently has no concept of inter-host dependencies, and I''ve no idea how to even do it, much less when it will arrive. I''m definitely open to ideas, though. :) -- America believes in education: the average professor earns more money in a year than a professional athlete earns in a whole week. -- Evan Esar --------------------------------------------------------------------- Luke Kanies | http://reductivelabs.com | http://madstop.com
On Tue, Sep 11, 2007 at 07:20:28PM +1000, Bernard Gardner wrote:> We have a few examples of situations where we need puppet to be aware > of the state of other machines in the cluster: > 1) Load balanced servers - it would be nice if we could write rules > that will only allow puppet to change the state of one of the real > servers at a time > 2) Dependent services - we have service that run on different hosts, > which need to be started up in a particular order (eg the master > database needs to be running before the middleware application tries > to start). > > The two problems seem to be quite similar, there are probably other > real world examples where this type of capability would be useful. > > Does puppet understand this concept at the moment?Yes, although it''s quite broken at the moment. See the discussion on exported resources on this list over the last couple of days. The usual term for the functionality is "export/collect" if you want to search the wiki. - Matt -- And Jesus said unto them, "And whom do you say that I am?" They replied, "You are the eschatological manifestation of the ground of our being, the ontological foundation of the context of our very selfhood revealed." And Jesus replied, "What?" -- Seen on the ''net