Re: Kludge in pg_standby.c

no. I have been without a working win32 build environment for a while. Working on fixing that right now..

/Magnus

> ------- Original Message -------
> From: Bruce Momjian <bruce(at)momjian(dot)us>
> To: Gregory Stark <stark(at)enterprisedb(dot)com>, Magnus Hagander <magnus(at)hagander(dot)net>
> Sent: 08-04-07, 1:54:37
> Subject: Re: [HACKERS] Kludge in pg_standby.c
>
> Magnus, have you looked at this yet?
>
> ---------------------------------------------------------------------------
>
> Gregory Stark wrote:
> >
> > There's a suspicious ifdef in pg_standby for WIN32 which smells like a kludge
> > added to work around a Windows problem which makes it work but at great
> > expense:
> >
> > #ifdef WIN32
> > /*
> > * Windows reports that the file has the right number of bytes
> > * even though the file is still being copied and cannot be
> > * opened by pg_standby yet. So we wait for sleeptime secs
> > * before attempting to restore. If that is not enough, we
> > * will rely on the retry/holdoff mechanism.
> > */
> > pg_usleep(sleeptime * 1000000L);
> > #endif
> >
> > This happens before we return *any* WAL file to be processed. That means it
> > slows down the processing of any file by 1s. On a server which has fallen
> > behind this means it can't process files as quickly as it can copy them, it's
> > limited to at most 1/s.
> >
> > I think it wouldn't be hard to do this properly. We can try to open the file,
> > handle the expected Windows error by sleeping for 1s and repeating until we
> > can successfully open it. Something like (untested):
> >
> > bool success = false;
> > int fd, tries = 10;
> > while (--tries) {
> > fd = open(WALFilePath, O_RDONLY);
> > if (fd >= 0) {
> > close(fd);
> > success = true;
> > break;
> > } else if (errno == EWINDOWSBLOWS) {
> > usleep(1000000);
> > } else {
> > perror("pg_standby open:");
> > exit(2);
> > }
> > }
> > if (!success) {
> > fprintf(stderr, "pg_standby: couldn't open file \"%s\" due to \"%s\",
> > WALFilePath, strerror(EWINDOWSBLOWS));
> > exit(2);
> > }
> >
> >
> > --
> > Gregory Stark
> > EnterpriseDB http://www.enterprisedb.com
> > Ask me about EnterpriseDB's RemoteDBA services!
> >
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> --
> Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
> EnterpriseDB http://enterprisedb.com
>
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>