Re: PostgreSQL + Replicator developer meeting 10/28

On Tue, 28 Oct 2008 19:46:42 +0200
Hannu Krosing <hannu(at)2ndQuadrant(dot)com> wrote:

> > The current topics are:
> >
> > * New MCP architecture
>
> What's new ?
>
> I have some doubts about the current architecture based on my reading
> of replicator wiki, but would like to learn about the "new"
> architecture before spending too much time in studying the "old" one.

The two obvious problems with the existing MCP architecture is:

1. Single point of failure
2. Portability

The new architecture is set to remove both of those. The short version
is the MCP will be moved into the backend. Thus:

Master->MCP|Slave ->Slave1
->Slave2
->Slave3

The process being, Master sends data to MCP|Slave, MCP|Slave writes it
to disk (optionally restores it) and then forwards it to 1,2,3 who then
receive the data, write it to disk and then restore it.

If master dies, you can promote to any of the slaves and the left over
slaves will connect to the promoted slave and begin receiving updates.

If the MCP|Slave dies a new Slave can begin the MCP|Slave process.

Alvaro or Alexey can speak more technically about implementation than I
can.

>
> > * DDL Replication
>
> Is it there alread, or is it just a planned feature ?

Planned feature.

>
> * How hard would it be to extract DDL replication part and use it as
> basis for DDL after trigger support for use in trigger based
> replication/auditing like Slony ann pgQ/Londiste ?

Hmm I am not sure. We are pretty deep into the core and only use
triggers for GRANT/REVOKE/CREATE ROLE .

Sincerely,

Joshua D. Drake

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