On Fri, Jan 10, 2014 at 03:27:10PM -0800, Josh Berkus wrote: > On 01/10/2014 01:49 PM, Andres Freund wrote: > > On 2014-01-10 10:59:23 -0800, Joshua D. Drake wrote: > >> > >> On 01/10/2014 07:47 AM, Bruce Momjian wrote: > >> > >>> I know there was a desire to remove this TODO item, but I think we have > >>> brought up enough new issues that we can keep it to see if we can come > >>> up with a solution. I have added a link to this discussion on the TODO > >>> item. > >>> > >>> I think we will need at least four new GUC variables: > >>> > >>> * timeout control for degraded mode > >>> * command to run during switch to degraded mode > >>> * command to run during switch from degraded mode > >>> * read-only variable to report degraded mode > > I would argue that we don't need the first. We just want a command to > switch synchronous/degraded, and a variable (or function) to report on > degraded mode. If we have those things, then it becomes completely > possible to have an external monitoring framework, which is capable of > answering questions like "is the replica down or just slow?", control > degrade. > > Oh, wait! We DO have such a command. It's called ALTER SYSTEM SET! > Recently committed. So this is really a solvable issue if one is > willing to use an external utility.
How would that work? Would it be a tool in contrib? There already is a timeout, so if a tool checked more frequently than the timeout, it should work. The durable notification of the admin would happen in the tool, right? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
