Re: "Hot standby"?

From: Greg Stark <gsstark(at)mit(dot)edu>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Josh Berkus <josh(at)agliodbs(dot)com>, Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov>, Mark Mielke <mark(at)mark(dot)mielke(dot)cc>, Peter Eisentraut <peter_e(at)gmx(dot)net>, Bruce Momjian <bruce(at)momjian(dot)us>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: "Hot standby"?
Date: 2009-08-12 02:00:43
Message-ID: 407d949e0908111900w3de03870h6616e4b43478846c@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

As I see it we potentially have the following modes to deal with:

Archive file mode asynchronous archive
Archive file mode asynchronous standby slave
Streaming mode asynchronous standby slave
Streaming mode synchronous standby slave
Archive file mode asynchronous read-only slave
Streaming mode asynchronous read-only slave
Streaming mode synchronous read-only slave

By "standby slave" I mean a server which is constantly in recovery
mode but isn't open for connections. This is what we (and Oracle) have
been calling a warm standby. By "read-only slave" I mean a server
which is open for connections and can handle read-only queries, which
as I mentioned Oracle calls a hot standby. Note that *all* of these
are "log-based replication".

I'm not actually certain we can handle streaming synchronous mode to a
standby slave. Does the slave need to have connections enabled to
handle feeding wal sync status to the master?

I don't see any particular reason to come up with names for each of
these combination of modes. I'm pretty happy just saying there are
three different configuration options and certain options depend on
other options so only certain combinations are legal.

--
greg

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2009-08-12 02:08:58 Re: pgindent timing (was Re: [COMMITTERS] pgsql: Refactor NUM_cache_remove calls in error report path to a PG_TRY)
Previous Message Tom Lane 2009-08-12 02:00:02 Re: WIP: getting rid of the pg_database flat file