On Fri, Jun 18, 2010 at 04:33, Takahiro Itagaki <itagaki.takah...@oss.ntt.co.jp> wrote: > Hi, > > We don't have any statistic views for walsenders in SR's master server > in 9.0, but such views would be useful to monitor and manage standby > servers from the master server. I have two ideas for the solution - > adding a new system view or recycling pg_stat_activity: > > 1. Add another system view for walsenders, ex. "pg_stat_replication". > It would show pid, remote host, and sent location for each walsender. > > 2. Make pg_stat_activity to show walsenders. We could use current_query > to display walsender-specific information, like: > =# SELECT * FROM my_stat_activity ; > -[ RECORD 1 ]----+--------------------------------- > datid | 16384 > <snip> > current_query | SELECT * FROM my_stat_activity ; > -[ RECORD 2 ]----+--------------------------------- > datid | 0 > datname | > procpid | 4300 > usesysid | 10 > usename | itagaki > application_name | > client_addr | ::1 > client_port | 37710 > backend_start | 2010-06-16 16:47:35.646486+09 > xact_start | > query_start | > waiting | f > current_query | walsender: sent=0/701AAA8 > > The attached patch is a WIP codes for the case 2, but it might be > better to design management policy via SQL in 9.1 before such detailed > implementation. Comments welcome.
I like version 1 much better. It'll be a lot easier for a management tool to get the data in proper columns and not have to parse it out of an arbitrary string field. The downside is that version 1 will require an initdb, and not version 2, right? In that light, #2 is probably the only one we can do for 9.0 (unless we stumble upon other initdb-forcing changes), so maybe we should do that one as a temporary measure (and if so, note it both in the documentation and code that it's a temporary thing). Wouldn't we also need something similar for the receiving end? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
