12 дек. 2014 г., в 16:46, Heikki Linnakangas <hlinnakan...@vmware.com> написал(а):
> There have been a few threads on the behavior of WAL archiving, after a > standby server is promoted [1] [2]. In short, it doesn't work as you might > expect. The standby will start archiving after it's promoted, but it will not > archive files that were replicated from the old master via streaming > replication. If those files were not already archived in the master before > the promotion, they are not archived at all. That's not good if you wanted to > restore from a base backup + the WAL archive later. > > The basic setup is a master server, a standby, a WAL archive that's shared by > both, and streaming replication between the master and standby. This should > be a very common setup in the field, so how are people doing it in practice? > Just live with the wisk that you might miss some files in the archive if you > promote? Don't even realize there's a problem? Something else? Yes, I do live like that (with streaming replication and shared archive between master and replicas) and don’t even realize there’s a problem :( And I think I’m not the only one. Maybe at least a note should be added to the documentation? > > And how would we like it to work? > > There was some discussion in August on enabling WAL archiving in the standby, > always [3]. That's a related idea, but it assumes that you have a separate > archive in the master and the standby. The problem at promotion happens when > you have a shared archive between the master and standby. AFAIK most people use the scheme with shared archive. > > [1] > http://www.postgresql.org/message-id/CAHGQGwHVYqbX=a+zo+avfbvhlgoypo9g_qdkbabexgxbvgd...@mail.gmail.com > > [2] http://www.postgresql.org/message-id/20140904175036.310c6466@erg > > [3] > http://www.postgresql.org/message-id/CAHGQGwHNMs-syU=mevsesthna+exd9pfo_ohhfpjcwovayr...@mail.gmail.com. > > - Heikki > > > -- > Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-hackers -- Vladimir
