From 8bed238c871fae205c5c6615f3b9ab8a039359e2 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 24 Aug 2009 20:08:32 +0000 Subject: [PATCH] Try to make silent_mode behave somewhat reasonably. Instead of sending stdout/stderr to /dev/null after forking away from the terminal, send them to postmaster.log within the data directory. Since this opens the door to indefinite logfile bloat, recommend even more strongly that log output be redirected when using silent_mode. Move the postmaster's initial calls of load_hba() and load_ident() down to after we have started the log collector, if we are going to. This is so that errors reported by them will appear in the "usual" place. Reclassify silent_mode as a LOGGING_WHERE, not LOGGING_WHEN, parameter, since it's got absolutely nothing to do with the latter category. In passing, fix some obsolete references to -S ... this option hasn't had that switch letter for a long time. Back-patch to 8.4, since as of 8.4 load_hba() and load_ident() are more picky (and thus more likely to fail) than they used to be. This entire change was driven by a complaint about those errors disappearing into the bit bucket. --- doc/src/sgml/config.sgml | 54 ++++++---- src/backend/postmaster/postmaster.c | 101 +++++++++++++----- src/backend/utils/misc/guc.c | 4 +- src/backend/utils/misc/postgresql.conf.sample | 8 +- 4 files changed, 111 insertions(+), 56 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 2b34921e70..7a44f074a8 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1,4 +1,4 @@ - + Server Configuration @@ -2588,7 +2588,37 @@ local0.* /var/log/postgresql - + + + silent_mode (boolean) + + silent_mode configuration parameter + + + + Runs the server silently. If this parameter is set, the server + will automatically run in background and disassociate from the + controlling terminal. + This parameter can only be set at server start. + + + + + When this parameter is set, + the server's standard output and standard error are redirected + to the file postmaster.log within the data directory. + There is no provision for rotating this file, so it will grow + indefinitely unless server log output is redirected elsewhere + by other settings. It is recommended that log_destination + be set to syslog or that logging_collector be + enabled when using this option. Even with those measures, errors + reported early during startup may appear in + postmaster.log rather than the normal log destination. + + + + + @@ -2722,26 +2752,6 @@ local0.* /var/log/postgresql - - silent_mode (boolean) - - silent_mode configuration parameter - - - - Runs the server silently. If this parameter is set, the server - will automatically run in background and any controlling - terminals are disassociated. - The server's standard output and standard error are redirected - to /dev/null, so any messages sent to them will be lost. - Unless syslog logging is selected or - logging_collector is enabled, using this parameter - is discouraged because it makes it impossible to see error messages. - This parameter can only be set at server start. - - - - diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index cabd61fc0f..7c96d978a0 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -37,7 +37,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.589 2009/08/24 18:09:37 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.590 2009/08/24 20:08:32 tgl Exp $ * * NOTES * @@ -191,7 +191,7 @@ static int SendStop = false; /* still more option variables */ bool EnableSSL = false; -bool SilentMode = false; /* silent mode (-S) */ +bool SilentMode = false; /* silent_mode */ int PreAuthDelay = 0; int AuthenticationTimeout = 60; @@ -744,7 +744,7 @@ PostmasterMain(int argc, char *argv[]) } /* - * Fork away from controlling terminal, if -S specified. + * Fork away from controlling terminal, if silent_mode specified. * * Must do this before we grab any interlock files, else the interlocks * will show the wrong PID. @@ -894,20 +894,6 @@ PostmasterMain(int argc, char *argv[]) */ set_max_safe_fds(); - /* - * Load configuration files for client authentication. - */ - if (!load_hba()) - { - /* - * It makes no sense continue if we fail to load the HBA file, since - * there is no way to connect to the database in this case. - */ - ereport(FATAL, - (errmsg("could not load pg_hba.conf"))); - } - load_ident(); - /* * Initialize the list of active backends. */ @@ -1023,6 +1009,20 @@ PostmasterMain(int argc, char *argv[]) */ autovac_init(); + /* + * Load configuration files for client authentication. + */ + if (!load_hba()) + { + /* + * It makes no sense to continue if we fail to load the HBA file, + * since there is no way to connect to the database in this case. + */ + ereport(FATAL, + (errmsg("could not load pg_hba.conf"))); + } + load_ident(); + /* * Remember postmaster startup time */ @@ -1204,15 +1204,46 @@ reg_reply(DNSServiceRegistrationReplyErrorType errorCode, void *context) /* - * Fork away from the controlling terminal (-S option) + * Fork away from the controlling terminal (silent_mode option) + * + * Since this requires disconnecting from stdin/stdout/stderr (in case they're + * linked to the terminal), we re-point stdin to /dev/null and stdout/stderr + * to "postmaster.log" in the data directory, where we're already chdir'd. */ static void pmdaemonize(void) { #ifndef WIN32 - int i; + const char *pmlogname = "postmaster.log"; + int dvnull; + int pmlog; pid_t pid; + int res; + /* + * Make sure we can open the files we're going to redirect to. If this + * fails, we want to complain before disconnecting. Mention the full path + * of the logfile in the error message, even though we address it by + * relative path. + */ + dvnull = open(DEVNULL, O_RDONLY, 0); + if (dvnull < 0) + { + write_stderr("%s: could not open file \"%s\": %s\n", + progname, DEVNULL, strerror(errno)); + ExitPostmaster(1); + } + pmlog = open(pmlogname, O_CREAT | O_WRONLY | O_APPEND, 0600); + if (pmlog < 0) + { + write_stderr("%s: could not open log file \"%s/%s\": %s\n", + progname, DataDir, pmlogname, strerror(errno)); + ExitPostmaster(1); + } + + /* + * Okay to fork. + */ pid = fork_process(); if (pid == (pid_t) -1) { @@ -1231,8 +1262,8 @@ pmdaemonize(void) MyStartTime = time(NULL); /* - * GH: If there's no setsid(), we hopefully don't need silent mode. Until - * there's a better solution. + * Some systems use setsid() to dissociate from the TTY's process group, + * while on others it depends on stdin/stdout/stderr. Do both if possible. */ #ifdef HAVE_SETSID if (setsid() < 0) @@ -1242,14 +1273,26 @@ pmdaemonize(void) ExitPostmaster(1); } #endif - i = open(DEVNULL, O_RDWR, 0); - dup2(i, 0); - dup2(i, 1); - dup2(i, 2); - close(i); + + /* + * Reassociate stdin/stdout/stderr. fork_process() cleared any pending + * output, so this should be safe. The only plausible error is EINTR, + * which just means we should retry. + */ + do { + res = dup2(dvnull, 0); + } while (res < 0 && errno == EINTR); + close(dvnull); + do { + res = dup2(pmlog, 1); + } while (res < 0 && errno == EINTR); + do { + res = dup2(pmlog, 2); + } while (res < 0 && errno == EINTR); + close(pmlog); #else /* WIN32 */ /* not supported */ - elog(FATAL, "SilentMode not supported under WIN32"); + elog(FATAL, "silent_mode is not supported under Windows"); #endif /* WIN32 */ } @@ -3241,8 +3284,8 @@ BackendInitialize(Port *port) if (!load_hba()) { /* - * It makes no sense continue if we fail to load the HBA file, since - * there is no way to connect to the database in this case. + * It makes no sense to continue if we fail to load the HBA file, + * since there is no way to connect to the database in this case. */ ereport(FATAL, (errmsg("could not load pg_hba.conf"))); diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 264b45451a..0fe3b4b98c 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -10,7 +10,7 @@ * Written by Peter Eisentraut . * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.510 2009/08/04 16:08:36 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.511 2009/08/24 20:08:32 tgl Exp $ * *-------------------------------------------------------------------- */ @@ -734,7 +734,7 @@ static struct config_bool ConfigureNamesBool[] = true, NULL, NULL }, { - {"silent_mode", PGC_POSTMASTER, LOGGING_WHEN, + {"silent_mode", PGC_POSTMASTER, LOGGING_WHERE, gettext_noop("Runs the server silently."), gettext_noop("If this parameter is set, the server will automatically run in the " "background and any controlling terminals are dissociated.") diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 41488e264f..c6c02fcd81 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -265,6 +265,11 @@ #syslog_facility = 'LOCAL0' #syslog_ident = 'postgres' +#silent_mode = off # Run server silently. + # DO NOT USE without syslog or + # logging_collector + # (change requires restart) + # - When to Log - @@ -314,9 +319,6 @@ # statements running at least this number # of milliseconds -#silent_mode = off # DO NOT USE without syslog or - # logging_collector - # (change requires restart) # - What to Log -