Thread: Support for Slony 2.0?
Hi, I want to know if we still want to support Slony. I was working on fixing an issue with our support of Slony till I finally understood we don't have any support of Slony 2.0. I remember that some of us wanted to get rid of our Slony support. I'm all to keep it. I think this is the kind of things that makes pgAdmin special. So, I'm ready to work on this: make sure Slony 1.2 is still supported and add support for 2.0. But before working on this, I want to make sure this won't be a useless effort. So I guess I would like to have a final decision on this. Do we decide to drop Slony support in 1.14, or do we decide that I can work on it, fix it, add support for 2.0, etc.? -- Guillaume http://www.postgresql.fr http://dalibo.com
On Wed, Jan 19, 2011 at 21:19, Guillaume Lelarge <guillaume@lelarge.info> wrote: > Hi, > > I want to know if we still want to support Slony. I was working on > fixing an issue with our support of Slony till I finally understood we > don't have any support of Slony 2.0. > > I remember that some of us wanted to get rid of our Slony support. I'm > all to keep it. I think this is the kind of things that makes pgAdmin > special. Do you know anybody who actually use it? :-) I'm +1 for keeping it as long as it doesn't take a lot of work to maintain it, but if it does I htink that time is better spent elsewhere. But in the end, it's up to whomever wants to spend the time. If it's not actually *broken* now, that means it didn't really require much maintenance before, because I don't recall seeing a lot of "fix slony support" commits. Oh, and if we're doing much work on it, how about renaming it from "Replication" to "slony replication" or such? So people won't confuse it with streaming replication which is what most people will think we mean with "replication" in the future, I think. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/
Le 19/01/2011 21:36, Magnus Hagander a écrit : > On Wed, Jan 19, 2011 at 21:19, Guillaume Lelarge <guillaume@lelarge.info> wrote: >> Hi, >> >> I want to know if we still want to support Slony. I was working on >> fixing an issue with our support of Slony till I finally understood we >> don't have any support of Slony 2.0. >> >> I remember that some of us wanted to get rid of our Slony support. I'm >> all to keep it. I think this is the kind of things that makes pgAdmin >> special. > > Do you know anybody who actually use it? :-) > I know at least two that complained about it not being 2.0 aware. Not sure they use it really, but the big error message we have is not good. One easy way to fix 1.12 is to add a "We don't support Slony 2.0." message when one clicks on the replication node, and to stop showing nodes below it. But we need something for 1.14 or later: either get rid of all, or support all. > I'm +1 for keeping it as long as it doesn't take a lot of work to > maintain it, but if it does I htink that time is better spent > elsewhere. But in the end, it's up to whomever wants to spend the > time. If it's not actually *broken* now, that means it didn't really > require much maintenance before, because I don't recall seeing a lot > of "fix slony support" commits. > I think Slony 1.2 is working. At least, I haven't seen any bug reports. Slony 2.0 doesn't. > Oh, and if we're doing much work on it, how about renaming it from > "Replication" to "slony replication" or such? So people won't confuse > it with streaming replication which is what most people will think we > mean with "replication" in the future, I think. > You mean when 9.2 or 9.3 will be released? when we'll have all those admin and monitoring capacities? :-D yeah, I know, you're doing quite a lof of great stuff to make that happen now (now like "in 9.1"). Well, actually, I do believe this isn't the end of Slony. Not now, not tomorrow, not still in two years from now. To answer the question, yeah, we could rename it till we need it for another kind of replication (the streaming one for instance). -- Guillaume http://www.postgresql.fr http://dalibo.com
On Wed, Jan 19, 2011 at 22:17, Guillaume Lelarge <guillaume@lelarge.info> wrote: > Le 19/01/2011 21:36, Magnus Hagander a écrit : >> On Wed, Jan 19, 2011 at 21:19, Guillaume Lelarge <guillaume@lelarge.info> wrote: >>> Hi, >>> >>> I want to know if we still want to support Slony. I was working on >>> fixing an issue with our support of Slony till I finally understood we >>> don't have any support of Slony 2.0. >>> >>> I remember that some of us wanted to get rid of our Slony support. I'm >>> all to keep it. I think this is the kind of things that makes pgAdmin >>> special. >> >> Do you know anybody who actually use it? :-) >> > > I know at least two that complained about it not being 2.0 aware. Not > sure they use it really, but the big error message we have is not good. :-) True. > One easy way to fix 1.12 is to add a "We don't support Slony 2.0." > message when one clicks on the replication node, and to stop showing > nodes below it. Well, for backport, that seems reasonable. > But we need something for 1.14 or later: either get rid of all, or > support all. Agreed. >> I'm +1 for keeping it as long as it doesn't take a lot of work to >> maintain it, but if it does I htink that time is better spent >> elsewhere. But in the end, it's up to whomever wants to spend the >> time. If it's not actually *broken* now, that means it didn't really >> require much maintenance before, because I don't recall seeing a lot >> of "fix slony support" commits. >> > > I think Slony 1.2 is working. At least, I haven't seen any bug reports. > Slony 2.0 doesn't. Ok. >> Oh, and if we're doing much work on it, how about renaming it from >> "Replication" to "slony replication" or such? So people won't confuse >> it with streaming replication which is what most people will think we >> mean with "replication" in the future, I think. >> > > You mean when 9.2 or 9.3 will be released? when we'll have all those > admin and monitoring capacities? :-D yeah, I know, you're doing quite a > lof of great stuff to make that happen now (now like "in 9.1"). Well, > actually, I do believe this isn't the end of Slony. Not now, not > tomorrow, not still in two years from now. No, I mean *today*. Given that a lot of people have said "9.0 is the replicatoin release", people are probably already reacting to it. > To answer the question, yeah, we could rename it till we need it for > another kind of replication (the streaming one for instance). I think we should rename it even if we don't have another option - simply because *postgresql* has another option. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/
On Wed, Jan 19, 2011 at 8:19 PM, Guillaume Lelarge <guillaume@lelarge.info> wrote: > Hi, > > I want to know if we still want to support Slony. I was working on > fixing an issue with our support of Slony till I finally understood we > don't have any support of Slony 2.0. That's not correct - it certainly was working as Sachin made changes to support 2.0, eg: http://git.postgresql.org/gitweb?p=pgadmin3.git;a=commitdiff;h=0edc75af62a223d5a015c81de7d1ebeea3d7ccd3 -- Dave Page Blog: http://pgsnake.blogspot.com Twitter: @pgsnake EnterpriseDB UK: http://www.enterprisedb.com The Enterprise PostgreSQL Company
Le 19/01/2011 22:26, Dave Page a écrit : > On Wed, Jan 19, 2011 at 8:19 PM, Guillaume Lelarge > <guillaume@lelarge.info> wrote: >> Hi, >> >> I want to know if we still want to support Slony. I was working on >> fixing an issue with our support of Slony till I finally understood we >> don't have any support of Slony 2.0. > > That's not correct - it certainly was working as Sachin made changes > to support 2.0, eg: > > http://git.postgresql.org/gitweb?p=pgadmin3.git;a=commitdiff;h=0edc75af62a223d5a015c81de7d1ebeea3d7ccd3 > Oops, yeah, you're right. Sorry. So we have at least two bugs on 2.0. -- Guillaume http://www.postgresql.fr http://dalibo.com
On Wed, 2011-01-19 at 21:19 +0100, Guillaume Lelarge wrote: <snip> > But before working on this, I want to make sure this won't be a > useless effort. So I guess I would like to have a final decision on > this. Do we decide to drop Slony support in 1.14, or do we decide that > I can work on it, fix it, add support for 2.0, etc.? <Talk is cheap for me. All I can do is testing.> ...from a PoV of a user or a DBA from field, we need a real GUI that helps people to setup a Slony-I cluster easily -- or say, as easy as possible. So, if it is not too much effort, I'd say we need to support Slony. Cheers, -- Devrim GÜNDÜZ PostgreSQL Danışmanı/Consultant, Red Hat Certified Engineer PostgreSQL RPM Repository: http://yum.pgrpms.org Community: devrim~PostgreSQL.org, devrim.gunduz~linux.org.tr http://www.gunduz.org Twitter: http://twitter.com/devrimgunduz
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2011/1/20 Devrim GÜNDÜZ <devrim@gunduz.org>: > ...from a PoV of a user or a DBA from field, we need a real GUI that > helps people to setup a Slony-I cluster easily -- or say, as easy as > possible. I'm just not sure that PgAdmin actually makes setting up a Slony-I cluster easier than writing a Slonik script. It probably makes maintaining an existing cluster easier though. -- Regards, Peter Geoghegan
On Thu, 2011-01-20 at 18:37 +0000, Peter Geoghegan wrote: > > > ...from a PoV of a user or a DBA from field, we need a real GUI that > > helps people to setup a Slony-I cluster easily -- or say, as easy as > > possible. > > I'm just not sure that PgAdmin actually makes setting up a Slony-I > cluster easier than writing a Slonik script. It probably makes > maintaining an existing cluster easier though. I pretty much agree with you -- but not all people can use cli, or can maintain Slony-I using altperl tools. -- Devrim GÜNDÜZ PostgreSQL Danışmanı/Consultant, Red Hat Certified Engineer PostgreSQL RPM Repository: http://yum.pgrpms.org Community: devrim~PostgreSQL.org, devrim.gunduz~linux.org.tr http://www.gunduz.org Twitter: http://twitter.com/devrimgunduz
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2011/1/20 Devrim GÜNDÜZ <devrim@gunduz.org>: > I pretty much agree with you -- but not all people can use cli, or can > maintain Slony-I using altperl tools. I use the command line for lots of things, but I also find GUI tools like PgAdmin useful. For example, I have a strong preference for developing Postgres functions using PgAdmin. I think that I have a rather balanced view. I also think that the ability to organise things in a slonik script in a way that makes sense for you (ordering things in a domain specific, logical manner with plenty of comments) is just easier than doing it the PgAdmin way for any person, not just a person who has a general preference for using command line tools. If you don't agree with this, try managing Slony replication for more than 2 or 3 nodes using PgAdmin. -- Regards, Peter Geoghegan
Le 20/01/2011 19:39, Devrim GÜNDÜZ a écrit : > On Thu, 2011-01-20 at 18:37 +0000, Peter Geoghegan wrote: >> >>> ...from a PoV of a user or a DBA from field, we need a real GUI that >>> helps people to setup a Slony-I cluster easily -- or say, as easy as >>> possible. >> >> I'm just not sure that PgAdmin actually makes setting up a Slony-I >> cluster easier than writing a Slonik script. It probably makes >> maintaining an existing cluster easier though. > > I pretty much agree with you -- but not all people can use cli, or can > maintain Slony-I using altperl tools. Maybe they could if they would. But most of them don't want to use a CLI tool. And there are probably many things to do to make it look better on pgAdmin. I never used the replication part of pgAdmin till this week. I had a look at it and it's really interesting. -- Guillaume http://www.postgresql.fr http://dalibo.com
Why don't we have a wizard-type facility to generate a Slonik script, rather than calling the "bare-metal" functions ourselves? That could potentially be much more useful. The reason that the existing facilities are a bit of a chore to use when you get past a couple of nodes is that paths and listens have to be individually managed, and the number involved increases quadratically with respect to the number of nodes. In other words, it's a GUI analogue of writing a Slonik script, as opposed to a higher level facility that usefully abstracts details away. I could imagine this really helping with complicated Slony setups involving daisy-chaining. -- Regards, Peter Geoghegan
Le 20/01/2011 20:15, Peter Geoghegan a écrit : > Why don't we have a wizard-type facility to generate a Slonik script, > rather than calling the "bare-metal" functions ourselves? That could > potentially be much more useful. The reason that the existing > facilities are a bit of a chore to use when you get past a couple of > nodes is that paths and listens have to be individually managed, and > the number involved increases quadratically with respect to the number > of nodes. In other words, it's a GUI analogue of writing a Slonik > script, as opposed to a higher level facility that usefully abstracts > details away. > > I could imagine this really helping with complicated Slony setups > involving daisy-chaining. > We don't do wizards. Moreover, I'm not sure this would be really useful. But if you want to work on it, yes, go ahead. And we'll see how it goes. -- Guillaume http://www.postgresql.fr http://dalibo.com
A wizard as you suggest has been on my "if only i had the time and energy" todo list for a few years :-) On 1/20/11, Peter Geoghegan <peter.geoghegan86@gmail.com> wrote: > Why don't we have a wizard-type facility to generate a Slonik script, > rather than calling the "bare-metal" functions ourselves? That could > potentially be much more useful. The reason that the existing > facilities are a bit of a chore to use when you get past a couple of > nodes is that paths and listens have to be individually managed, and > the number involved increases quadratically with respect to the number > of nodes. In other words, it's a GUI analogue of writing a Slonik > script, as opposed to a higher level facility that usefully abstracts > details away. > > I could imagine this really helping with complicated Slony setups > involving daisy-chaining. > > -- > Regards, > Peter Geoghegan > > -- > Sent via pgadmin-hackers mailing list (pgadmin-hackers@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgadmin-hackers > -- Dave Page Blog: http://pgsnake.blogspot.com Twitter: @pgsnake EnterpriseDB UK: http://www.enterprisedb.com The Enterprise PostgreSQL Company
On 20 January 2011 21:28, Dave Page <dpage@pgadmin.org> wrote: > A wizard as you suggest has been on my "if only i had the time and > energy" todo list for a few years :-) It's something that I'd like to take a look at, once we finish wx 2.9 support. As I think you'll agree, it's important that the end result is a Slonik script rather than a series of calls to bare metal functions from within PgAdmin. It's useful to produce something that people can generalise from, keep and append (if only with comments). We shouldn't attempt to completely abstract away the details, because that probably isn't going to work. I think that this approach will bring most of the benefits of command line tools, without the same degree of complexity. There's obviously a lot of redundancy within Slonik scripts, where each connection string must appear multiple times and so on. Slonik is a bit of a foot-gun. It was designed to be embedded within other languages for a reason I suppose. Its flexibility and extensibility is more of a hindrance than a help to many users, at least when there isn't some tool that makes it accessible. I think that users are inclined to add nodes and their paths a node at a time, perhaps in some logical domain specific order. As things stand, the user has to navigate the entire set of nodes with the object browser and add listens/paths everywhere when adding each new node. On the other hand, when writing a slonik script, most people will just add nodes one after the other, and append the paths that relate to the node that they are currently storing paths for, without much regard to what node each path will actually reside on. I like to put each node's "store path()"s within a separate, commented block. I also like to order the store path()s within that commented block logically and consistently. I think that the wizard (a term that I'm not fond of, because it's sort of reminiscent of Microsoft Bob or something) should first present the user with the option of generating a script that does a handful of high level things - the single well defined tasks that most Slonik scripts do, such as creating a new cluster while creating a new replication set, adding/removing a new node to/from an existing one or executing a script. I'm pretty sure that it'll be possible to do all of this without storing any additional metadata. -- Regards, Peter Geoghegan
Le 22/01/2011 15:46, Peter Geoghegan a écrit : > On 20 January 2011 21:28, Dave Page <dpage@pgadmin.org> wrote: >> A wizard as you suggest has been on my "if only i had the time and >> energy" todo list for a few years :-) > > It's something that I'd like to take a look at, once we finish wx 2.9 > support. As I think you'll agree, it's important that the end result > is a Slonik script rather than a series of calls to bare metal > functions from within PgAdmin. Actually, I don't. If people are that interested in a Slonik script, they would learn the Slonik language if they want to do a good job. The UI in pgAdmin is a way to skip that part, and this is why it's interesting to keep it. Anyway, I'm not opposed to add this wizard if we still keep the UI we already have. -- Guillaume http://www.postgresql.fr http://dalibo.com