/*
* pgarch_start
*
* Called from postmaster at startup or after an existing archiver
* died. Attempt to fire up a fresh archiver process.
*
* Returns PID of child process, or 0 if fail.
*
* Note: if fail, we will be called again from the postmaster main loop.
*/
int
pgarch_start(void)
{
time_t curtime;
pid_t pgArchPid;
/*
* Do nothing if no archiver needed
*/
if (!XLogArchivingActive())
return 0;
/*
* Do nothing if too soon since last archiver start. This is a safety
* valve to protect against continuous respawn attempts if the archiver is
* dying immediately at launch. Note that since we will be re-called from
* the postmaster main loop, we will get another chance later.
*/
curtime = time(NULL);
if ((unsigned int) (curtime - last_pgarch_start_time) <
(unsigned int) PGARCH_RESTART_INTERVAL)
return 0;
last_pgarch_start_time = curtime;
#ifdef EXEC_BACKEND
switch ((pgArchPid = pgarch_forkexec()))
#else
switch ((pgArchPid = fork_process()))
#endif
{
case -1:
ereport(LOG,
(errmsg("could not fork archiver: %m")));
return 0;
#ifndef EXEC_BACKEND
case 0:
/* in postmaster child ... */
InitPostmasterChild();
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Drop our connection to postmaster's shared memory, as well */
dsm_detach_all();
PGSharedMemoryDetach();
PgArchiverMain(0, NULL);
break;
#endif
default:
return (int) pgArchPid;
}
/* shouldn't get here */
return 0;
}
/*
* Postmaster subroutine to start a syslogger subprocess.
*/
int
SysLogger_Start(void)
{
pid_t sysloggerPid;
char *filename;
if (!Logging_collector)
return 0;
/*
* If first time through, create the pipe which will receive stderr
* output.
*
* If the syslogger crashes and needs to be restarted, we continue to use
* the same pipe (indeed must do so, since extant backends will be writing
* into that pipe).
*
* This means the postmaster must continue to hold the read end of the
* pipe open, so we can pass it down to the reincarnated syslogger. This
* is a bit klugy but we have little choice.
*/
#ifndef WIN32
if (syslogPipe[0] < 0)
{
if (pipe(syslogPipe) < 0)
ereport(FATAL,
(errcode_for_socket_access(),
(errmsg("could not create pipe for syslog: %m"))));
}
#else
if (!syslogPipe[0])
{
SECURITY_ATTRIBUTES sa;
memset(&sa, 0, sizeof(SECURITY_ATTRIBUTES));
sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.bInheritHandle = TRUE;
if (!CreatePipe(&syslogPipe[0], &syslogPipe[1], &sa, 32768))
ereport(FATAL,
(errcode_for_file_access(),
(errmsg("could not create pipe for syslog: %m"))));
}
#endif
/*
* Create log directory if not present; ignore errors
*/
mkdir(Log_directory, S_IRWXU);
/*
* The initial logfile is created right in the postmaster, to verify that
* the Log_directory is writable. We save the reference time so that the
* syslogger child process can recompute this file name.
*
* It might look a bit strange to re-do this during a syslogger restart,
* but we must do so since the postmaster closed syslogFile after the
* previous fork (and remembering that old file wouldn't be right anyway).
* Note we always append here, we won't overwrite any existing file. This
* is consistent with the normal rules, because by definition this is not
* a time-based rotation.
*/
first_syslogger_file_time = time(NULL);
filename = logfile_getname(first_syslogger_file_time, NULL);
syslogFile = logfile_open(filename, "a", false);
pfree(filename);
#ifdef EXEC_BACKEND
switch ((sysloggerPid = syslogger_forkexec()))
#else
switch ((sysloggerPid = fork_process()))
#endif
{
case -1:
ereport(LOG,
(errmsg("could not fork system logger: %m")));
return 0;
#ifndef EXEC_BACKEND
case 0:
/* in postmaster child ... */
InitPostmasterChild();
/* Close the postmaster's sockets */
ClosePostmasterPorts(true);
/* Drop our connection to postmaster's shared memory, as well */
dsm_detach_all();
PGSharedMemoryDetach();
/* do the work */
SysLoggerMain(0, NULL);
break;
#endif
default:
/* success, in postmaster */
/* now we redirect stderr, if not done already */
if (!redirection_done)
{
#ifdef WIN32
int fd;
#endif
/*
* Leave a breadcrumb trail when redirecting, in case the user
* forgets that redirection is active and looks only at the
* original stderr target file.
*/
ereport(LOG,
(errmsg("redirecting log output to logging collector process"),
errhint("Future log output will appear in directory \"%s\".",
Log_directory)));
#ifndef WIN32
fflush(stdout);
if (dup2(syslogPipe[1], fileno(stdout)) < 0)
ereport(FATAL,
(errcode_for_file_access(),
errmsg("could not redirect stdout: %m")));
fflush(stderr);
if (dup2(syslogPipe[1], fileno(stderr)) < 0)
ereport(FATAL,
(errcode_for_file_access(),
errmsg("could not redirect stderr: %m")));
/* Now we are done with the write end of the pipe. */
close(syslogPipe[1]);
syslogPipe[1] = -1;
#else
/*
* open the pipe in binary mode and make sure stderr is binary
* after it's been dup'ed into, to avoid disturbing the pipe
* chunking protocol.
*/
fflush(stderr);
fd = _open_osfhandle((intptr_t) syslogPipe[1],
_O_APPEND | _O_BINARY);
if (dup2(fd, _fileno(stderr)) < 0)
ereport(FATAL,
(errcode_for_file_access(),
errmsg("could not redirect stderr: %m")));
close(fd);
_setmode(_fileno(stderr), _O_BINARY);
/*
* Now we are done with the write end of the pipe.
* CloseHandle() must not be called because the preceding
* close() closes the underlying handle.
*/
syslogPipe[1] = 0;
#endif
redirection_done = true;
}
/* postmaster will never write the file; close it */
fclose(syslogFile);
syslogFile = NULL;
return (int) sysloggerPid;
}
/* we should never reach here */
return 0;
}
