Simon Riggs wrote: > On Fri, 2011-02-18 at 21:39 -0500, Bruce Momjian wrote: > > Simon Riggs wrote: > > > Most parameters are set on the primary. Set > > > > > > primary: synchronous_standby_names = 'node1, node2, node3' > > > > > > which means that whichever of those standbys connect first will > > > become the main synchronous standby. Servers arriving later will > > > be potential standbys (standby standbys doesn't sound right...). > > > synchronous_standby_names can change at reload. > > > > > > Currently, the standby_name is the application_name parameter > > > set in the primary_conninfo. > > > > > > When we set this for a client, or in postgresql.conf > > > > > > primary: synchronous_replication = on > > > > > > then we will wait at commit until the synchronous standby has > > > reached the WAL location of our commit point. > > > > > > If the current synchronous standby dies then one of the other standbys > > > will take over. (I think it would be a great idea to make the > > > list a priority order, but I haven't had time to code that). > > > > > > If none of the standbys are available, then we don't wait at all > > > if allow_standalone_primary is set. > > > allow_standalone_primary can change at reload. > > > > Are we going to allow a command to be run when these things happen, like > > archive_command does, or is that something for 9.2? > > Not really sure which events you're speaking of, sorry. As I write, I > don't see a place or a reason to run a command, but that might change > with a longer explanation of what you're thinking. I wouldn't rule out > adding something like that in this release, but I'm not around for the > next week to add it.
Sorry. I was thinking of allowing a command to alert an administrator when we switch standby machines, or if we can't do synchronous standby any longer. I assume we put a message in the logs, and the admin could have a script that monitors that, but I thought a pager-like command would be helpful, though I don't think we do that in any other case, so maybe it is overkill. These are all optional ideas. Also, I like that you are using application name here. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
