The way I think of the Y-valve* is that the stem of the Y is the client - whether the normal fbclient or the Java client or other language specific clients. The connection request goes from the client to a provider. Right now, the providers are Remote (which may be built into the Y-valve) and Engine12. Someone could create a provider that translated Firebird requests to Oracle/PostgreSQL/MySQL or whatever and offer a provider to a different back end. If there's enough demand, Firebird 2.5 could be cut back to be a provider to older versions of Firebird.
So the stem is the client and the branches are the providers. Cheers, Ann * Y-valve is a nautical term. On a boat, the head (toilet) outflow goes through a Y-valve. One leg takes the effluent to a holding tank, the other dumps it overboard. No parallel implied between what goes through the Firebird Y-valve and the nautical term. On Tue, Jun 14, 2016 at 4:46 PM, fabia...@itbizolutions.com.au [firebird-support] <firebird-support@yahoogroups.com> wrote: > > > > Mark > > Thank you, I think I am beggining to understand the concept, so the > provider's have to be combined including ALWAYS Engine12 (the core FB > server procedure/method that really goes to the file on disk and does the > reading and writting to the DB). So the following combinations are valid: > Providers = Remote + Engine12 > Providers = Loopback + Engine12 > Providers = Remote + Loopback + Engine12 (the first two in any orther) > > And any Providers combination excluding Engine12 would not work because it > is not including the component that goes to the DB file and reads/writes > from /to it. > > It seems Engine12 is not the same "type of component" as the other > Providers. In the documentation it is refered as a Y valve, if I understand > it correctly Engine12 is the base of the Y, while the other providers are > the top left and top right of the Y, you can have any top you want, BUT YOU > MUST HAVE the base always, else it does not work, correct? > > > Cheers, > Fabian > > > > ----- Original Message ----- > *From:* Mark Rotteveel m...@lawinegevaar.nl [firebird-support] > <m...@lawinegevaar.nl+[firebird-support]> > *To:* firebird-support@yahoogroups.com > *Sent:* Wednesday, June 15, 2016 5:32 AM > *Subject:* Re: [firebird-support] Engine12 mistery > > On 2016-06-14 19:44, fabia...@itbizolutions.com.au [firebird-support] > wrote: > > My understanding from reading the documentation is: > > > > Provider = Remote means the client is on the network, excluding > > 127.0.0.1 > > Provider = Loopback means the client is actually on the same OS > > instance as the FB3 engine, and it is using the 127.0.0.1 to access > > the database to avoid the "embedded server concept" from answering > > the > > request, as it would capture the DB file and will not allow any other > > clients from remote /network source. > > Engine12 = The local server takes control of the database as if it > > was > > an embedded server, killing all future chance of accessing the DB > > from > > the network, so Engine12 is if I understand correctly the way to talk > > to the DB engine in "exclusive" mode when you want to perform > > maintenance or work on the security database. > > > > Is the above wrong? > > Yes, your understanding is wrong. Engine12 **is** the component that > actually does the work with the database file. The rest is just plumbing > to connect to servers (or make fbclient connect to a local server), > select the right provider, etc. > > As the release notes say: > > http://www.firebirdsql.org/file/documentation/release_notes/html/en/3_0/rnfb30-engine.html > > * Remote (establish network connection) > * Engine12 (main database engine) > * Loopback (force network connection to the local server for <database > name> without an explicit network protocol being supplied). > > There was also talk of providing an 'Engine11' which would essentially > be a Firebird 2.5 you could use to connect to ODS 11.2 and older > database files. > > Your confusion likely stems from the fact that Firebird embedded now is > fbclient + Engine12, as opposed to Firebird server + Engine12 for a > normal database server, while Firebird embedded used to be a separate > DLL/SO. BTW: In normal situations fbclient **does not** have access to > Engine12, so it only behaves as a client library. > > Mark > > > > ------------------------------------ > Posted by: Mark Rotteveel <m...@lawinegevaar.nl> > ------------------------------------ > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > Visit http://www.firebirdsql.org and click the Documentation item > on the main (top) menu. Try FAQ and other links from the left-side menu > there. > > Also search the knowledgebases at > http://www.ibphoenix.com/resources/documents/ > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > ------------------------------------ > > Yahoo Groups Links > > > > > > >
