On Thu, Oct 27, 2011 at 10:12, Fujii Masao <masao.fu...@gmail.com> wrote: > On Thu, Oct 27, 2011 at 4:49 PM, Magnus Hagander <mag...@hagander.net> wrote: >> On Thu, Oct 27, 2011 at 09:46, Fujii Masao <masao.fu...@gmail.com> wrote: >>> On Thu, Oct 27, 2011 at 4:40 PM, Magnus Hagander <mag...@hagander.net> >>> wrote: >>>> On Thu, Oct 27, 2011 at 09:29, Fujii Masao <masao.fu...@gmail.com> wrote: >>>>> On Thu, Oct 27, 2011 at 3:29 AM, Magnus Hagander <mag...@hagander.net> >>>>> wrote: >>>>>> I've applied this version with a few more minor changes that Heikki >>>>>> found. >>>>> >>>>> Cool! >>>>> >>>>> When I tried pg_receivexlog and checked the contents of streamed WAL file >>>>> by >>>>> xlogdump, I found that recent WAL records that walsender has already sent >>>>> don't >>>>> exist in that WAL file. I expected that pg_receivexlog writes the >>>>> streamed WAL >>>>> records to the disk as soon as possible, but it doesn't. Is this >>>>> intentional? Or bug? >>>>> Am I missing something? >>>> >>>> It writes it to disk as soon as possible, but doesn't fsync() until >>>> the end of each segment. Are you by any chance looking at the file >>>> while it's running? >>> >>> No. I looked at that file after shutting down the master server. >> >> Ugh, in that case something is certainly wrong. There is nothing but >> setting up some offset values between PQgetCopyData() and write()... > > When end-of-copy stream is found or an error happens, pg_receivexlog > exits without flushing outstanding WAL records. Which seems to cause > the problem I reported.
Not sure I follow. When we arrive at PQgetCopyData() there should be nothing buffered, and if the end of stream happens there it returns -1, and we exit, no? So where is the data that's lost? I do realize we don't actually fsync() and close() in this case - is that what you are referring to? But the data should already have been write()d, so it should still be there, no? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
