Mmm. Fat finger.. At Fri, 26 Jun 2020 16:14:38 +0900 (JST), Kyotaro Horiguchi <horikyota....@gmail.com> wrote in > Hello. > > If we are going to dive so close to server shutdown, we can just > utilize the restart-after-crash path, which we can assume to work > reliably. The attached is a quite rough sketch, hijacking smart > shutdown path for a convenience, of that but seems working. "pg_ctl > -m s -W stop" lets server demote. > > > I hadn't time to investigate Robert's concern about shared memory for > > snapshot > > during recovery. > > The patch does all required clenaup of resources including shared
The path does all required clenaup of.. > memory, I believe. It's enough if we don't need to keep any resources > alive? > > > The patch doesn't deal with prepared xact yet. Testing > > "start->demote->promote" > > raise an assert if some prepared xact exist. I suppose I will rollback them > > during demote in next patch version. > > > > I'm not sure how to divide this patch in multiple small independent steps. I > > suppose I can split it like: > > > > 1. add demote checkpoint > > 2. support demote: mostly postmaster, startup/xlog and checkpointer related > > code > > 3. cli using pg_ctl demote > > > > ...But I'm not sure it worth it. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
