Обсуждение: More Slony questions
Hello again Dave et al., I'm still playing at intervals with setting up Slony-I replication via pgAdmin, and have a couple more questions - (i) When you add nodes to a Slony cluster, does pgAdmin automagically register a slon service (I'm on Windows) and also run the "slon -addengine" command that's required on Windows to add a node? I ask this because, after creating a Slony cluster with two nodes, I see a service "Slony-I" in Windows' "Services" list which I don't recall seeing there before (though that's not to say that it wasn't!) and wondered if pgAdmin had done it. To add to my confusion about the service, the command-line reported in the service properties is: C:\Program Files\PostgreSQL\8.2\bin\slon.exe -service The -service switch is one which doesn't appear in the usage list given by "slon --help". What does it do, or where can I find out more? (ii) What exactly is the "Admin node" in a cluster's properties in pgAdmin? - Is it simply a node in the cluster against which one would execute slonik scripts, if doing things by hand? Is it required? Also, when looking at the properties of the cluster via the "Replication" treeview node of the master (source) database, the admin node is listed as the slave (target) node; but when looking at the properties of the same cluster via the slave database, the "Admin node" field says "None". Please help me make sense of all this! Thanks...! Ray. --------------------------------------------------------------- Raymond O'Donnell, Director of Music, Galway Cathedral, Ireland rod@iol.ie ---------------------------------------------------------------
Raymond O'Donnell wrote: > Hello again Dave et al., > > I'm still playing at intervals with setting up Slony-I replication via > pgAdmin, and have a couple more questions - Ah, congratulations - you've now used pgAdmin's Slony support more than I have :-p > (i) When you add nodes to a Slony cluster, does pgAdmin automagically > register a slon service (I'm on Windows) and also run the "slon > -addengine" command that's required on Windows to add a node? I ask this > because, after creating a Slony cluster with two nodes, I see a service > "Slony-I" in Windows' "Services" list which I don't recall seeing there > before (though that's not to say that it wasn't!) and wondered if > pgAdmin had done it. No, it doesn't. pgInstaller would have done it when you installed PostgreSQL + Slony. > To add to my confusion about the service, the command-line reported in > the service properties is: > > C:\Program Files\PostgreSQL\8.2\bin\slon.exe -service > > The -service switch is one which doesn't appear in the usage list given > by "slon --help". What does it do, or where can I find out more? It starts slon.exe in service mode. That should only happen when it's started by the Service Control Manager which is why it's undocumented. > (ii) What exactly is the "Admin node" in a cluster's properties in > pgAdmin? - Is it simply a node in the cluster against which one would > execute slonik scripts, if doing things by hand? Is it required? It's a pseudo node that pgAdmin manages the cluster from. It is required, unless you use Slonik only. > Also, when looking at the properties of the cluster via the > "Replication" treeview node of the master (source) database, the admin > node is listed as the slave (target) node; but when looking at the > properties of the same cluster via the slave database, the "Admin node" > field says "None". Please help me make sense of all this! To be honest I struggle with it myself. I'd just ignore that detail for now and satisfy yourself with the fact that I hope to simplify things in future versions :-) Regards, Dave
Dave Page wrote: > Ah, congratulations - you've now used pgAdmin's Slony support more than > I have :-p That's *really* reassuring! :-P > No, it doesn't. pgInstaller would have done it when you installed > PostgreSQL + Slony. OK, so having created the cluster, nodes and subscriptions in pgAdmin, do I now go and run the "slon -addengine" commands for each node in the cluster? And if so, should this be done *before* I add the subscription(s)? I should add that I've tried this already, and though Slony seems to be running and adding messages to the event log, nothing seems to be getting replicated! I'll mess around with it a bit more later on today. I'm looking at all this because I've to write a manual for a small installation I set up recently, and while it'll almost certainly be me who maintains it for the foreseeable future I have to allow for others - mostly non-technical - looking after it also. I'm a relative newcomer to Slony and have been using slonik, but I thought pgAdmin might offer an easier route for others. Thanks for all the help, Ray. --------------------------------------------------------------- Raymond O'Donnell, Director of Music, Galway Cathedral, Ireland rod@iol.ie ---------------------------------------------------------------
Raymond O'Donnell wrote: > Dave Page wrote: > >> Ah, congratulations - you've now used pgAdmin's Slony support more than >> I have :-p > > That's *really* reassuring! :-P Just telling it like it is :-) >> No, it doesn't. pgInstaller would have done it when you installed >> PostgreSQL + Slony. > > OK, so having created the cluster, nodes and subscriptions in pgAdmin, > do I now go and run the "slon -addengine" commands for each node in the > cluster? And if so, should this be done *before* I add the subscription(s)? Sort out slon first, then subscribe iirc. Way back when we'd just finished the windows port of Slony, Rob Treat blogged some setup notes which may help you: http://people.planetpostgresql.org/xzilla/index.php?/archives/200-Alpha-testing-Slony-on-win32-Crib-Notes.html > I should add that I've tried this already, and though Slony seems to be > running and adding messages to the event log, nothing seems to be > getting replicated! I'll mess around with it a bit more later on today. > > I'm looking at all this because I've to write a manual for a small > installation I set up recently, and while it'll almost certainly be me > who maintains it for the foreseeable future I have to allow for others - > mostly non-technical - looking after it also. I'm a relative newcomer to > Slony and have been using slonik, but I thought pgAdmin might offer an > easier route for others. pgAdmin makes things nice and graphical, but doesn't really help simplify the concepts unfortunately. I will be working on that at some point, probably not for this release cycle though (this is a 6 month one, instead of the normal 12 though so it's not too bad!) Regards, Dave.