Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> writes: > BTW, there's a bunch of replication related stuff that we should work to > close, that are IMHO more important than synchronous replication. Like > making the standby follow timeline changes, to make failovers smoother, and > the facility to stream a base-backup over the wire. I wish someone worked on > those...
So, we've been talking about base backup streaming at conferences and we have a working prototype. We even have a needed piece of it in core now, that's the pg_read_binary_file() function. What we still miss is an overall design and some integration effort. Let's design first. I propose the following new pg_ctl command to initiate the cloning: pg_ctl clone [-D datadir] [-s on|off] [-t filename] "primary_conninfo" As far as user are concerned, that would be the only novelty. Once that command is finished (successfully) they would edit postgresql.conf and start the service as usual. A basic recovery.conf file is created with the given options, standby_mode is driven by -s and defaults to off, and trigger_file defaults to being omitted and is given by -t. Of course the primary_conninfo given on the command line is what ends up into the recovery.conf file. That alone would allow for making base backups for recovery purposes and for standby preparing. To support for this new tool, the simplest would be to just copy what I've been doing in the prototype, that is run a query to get the primary file listing (per tablespace, not done in the prototype) then get their bytea content over the wire. That means there's no further backend support code to write. https://github.com/dimitri/pg_basebackup We could prefer to have a backend function prepare a tar archive and stream it using the COPY protocol, with some compression support, but that's more complex to code now and to parallelize down the road. Regards, -- Dimitri Fontaine http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
