On Wed, Apr 11, 2012 at 3:31 PM, 乔志强 <qiaozhiqiang@xxxxxxxxxxxxxxxx> wrote: > So in sync streaming replication, if master delete WAL before sent to the only standby, all transaction will fail forever, > "the master tries to avoid a PANIC error rather than termination of replication." but in sync replication, termination of replication is THE bigger PANIC error. I see your point. When there are backends waiting for replication, the WAL files which the standby might not have received yet must not be removed. If they are removed, replication keeps failing forever because required WAL files don't exist in the master, and then waiting backends will never be released unless replication mode is changed to async. This should be avoided. To fix this issue, we should prevent the master from deleting the WAL files including the minimum waiting LSN or bigger ones. I'll think more and implement the patch. Regards, -- Fujii Masao -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
