On Thu, Jul 12, 2012 at 8:39 PM, Magnus Hagander <mag...@hagander.net> wrote: > On Tue, Jul 10, 2012 at 7:03 PM, Fujii Masao <masao.fu...@gmail.com> wrote: >> On Tue, Jul 10, 2012 at 3:23 AM, Fujii Masao <masao.fu...@gmail.com> wrote: >>> Hi, >>> >>> I found several problems in pg_receivexlog, e.g., memory leaks, >>> file-descripter leaks, ..etc. The attached patch fixes these problems. >>> >>> ISTM there are still some other problems in pg_receivexlog, so I'll >>> read it deeply later. >> >> While pg_basebackup background process is streaming WAL records, >> if its replication connection is terminated (e.g., walsender in the server >> is accidentally terminated by SIGTERM signal), pg_basebackup ends >> up failing to include all required WAL files in the backup. The problem >> is that, in this case, pg_basebackup doesn't emit any error message at all. >> So an user might misunderstand that a base backup has been successfully >> taken even though it doesn't include all required WAL files. > > Ouch. That is definitely a bug if it behaves that way. > > >> To fix this problem, I think that, when the replication connection is >> terminated, ReceiveXlogStream() should check whether we've already >> reached the stop point by calling stream_stop() before returning TRUE. >> If we've not yet (this means that we've not received all required WAL >> files yet), ReceiveXlogStream() should return FALSE and >> pg_basebackup should emit an error message. Comments? > > Doesn't it already return false because it detects the error of the > connection? What's the codepath where we end up returning true even > though we had a connection failure? Shouldn't that end up under the > "could not read copy data" branch, which already returns false?
You're right. If the error is detected, that function always returns false and the error message is emitted (but I think that current error message "pg_basebackup: child process exited with error 1" is confusing....), so it's OK. But if walsender in the server is terminated by SIGTERM, no error is detected and pg_basebackup background process gets out of the loop in ReceiveXlogStream() and returns true. Regards, -- Fujii Masao -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
