Re: serverlog rotation/functions

Path withdrawn by author.

---------------------------------------------------------------------------

Andreas Pflug wrote:
> Updated version.
>
> Only timestamp of fresh logfile in shared mem, with sanity checks.
> On SIGHUP, timestamp is checked if rotation was issued, as well as
> changed log_filename setting from postgresql.conf.
>
> Regards,
> Andreas
>
>
>

> Index: src/backend/postmaster/postmaster.c
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/backend/postmaster/postmaster.c,v
> retrieving revision 1.405
> diff -u -r1.405 postmaster.c
> --- src/backend/postmaster/postmaster.c 24 Jun 2004 21:02:55 -0000 1.405
> +++ src/backend/postmaster/postmaster.c 6 Jul 2004 22:12:22 -0000
> @@ -729,6 +729,11 @@
> reset_shared(PostPortNumber);
>
> /*
> + * Opens alternate log file
> + */
> + LogFileInit();
> +
> + /*
> * Estimate number of openable files. This must happen after setting
> * up semaphores, because on some platforms semaphores count as open
> * files.
> Index: src/backend/utils/adt/misc.c
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/adt/misc.c,v
> retrieving revision 1.35
> diff -u -r1.35 misc.c
> --- src/backend/utils/adt/misc.c 2 Jul 2004 18:59:22 -0000 1.35
> +++ src/backend/utils/adt/misc.c 6 Jul 2004 22:12:34 -0000
> @@ -202,3 +202,137 @@
> FreeDir(fctx->dirdesc);
> SRF_RETURN_DONE(funcctx);
> }
> +
> +
> +extern FILE *logfile; // in elog.c
> +#define MAXLOGFILECHUNK 50000
> +
> +static char *absClusterPath(text *arg)
> +{
> + char *filename;
> +
> + if (is_absolute_path(VARDATA(arg)))
> + filename=VARDATA(arg);
> + else
> + {
> + filename = palloc(strlen(DataDir)+VARSIZE(arg)+2);
> + sprintf(filename, "%s/%s", DataDir, VARDATA(arg));
> + }
> + return filename;
> +}
> +
> +
> +Datum pg_logfile_get(PG_FUNCTION_ARGS)
> +{
> + size_t size=MAXLOGFILECHUNK;
> + char *buf=0;
> + size_t nbytes;
> + FILE *f;
> +
> + if (!PG_ARGISNULL(0))
> + size = PG_GETARG_INT32(0);
> + if (size > MAXLOGFILECHUNK)
> + {
> + size = MAXLOGFILECHUNK;
> + ereport(WARNING,
> + (errcode(ERRCODE_OUT_OF_MEMORY),
> + errmsg("Maximum size is %d.", size)));
> + }
> +
> + if (PG_ARGISNULL(2))
> + f = logfile;
> + else
> + {
> + /* explicitely named logfile */
> + char *filename = absClusterPath(PG_GETARG_TEXT_P(2));
> + f = fopen(filename, "r");
> + if (!f)
> + {
> + ereport(WARNING,
> + (errcode_for_file_access(),
> + errmsg("file not found %s", filename)));
> + PG_RETURN_NULL();
> + }
> + }
> +
> + if (f)
> + {
> +
> + if (PG_ARGISNULL(1))
> + fseek(f, -size, SEEK_END);
> + else
> + {
> + long pos = PG_GETARG_INT32(1);
> + if (pos >= 0)
> + fseek(f, pos, SEEK_SET);
> + else
> + fseek(f, pos, SEEK_END);
> + }
> + buf = palloc(size+1);
> + nbytes = fread(buf, 1, size, f);
> + buf[nbytes] = 0;
> +
> + fseek(f, 0, SEEK_END);
> +
> + if (!PG_ARGISNULL(2))
> + fclose(f);
> + }
> +
> + if (buf)
> + PG_RETURN_CSTRING(buf);
> + else
> + PG_RETURN_NULL();
> +}
> +
> +
> +Datum pg_logfile_length(PG_FUNCTION_ARGS)
> +{
> + if (PG_ARGISNULL(0))
> + {
> + if (logfile)
> + {
> + fflush(logfile);
> + PG_RETURN_INT32(ftell(logfile));
> + }
> + }
> + else
> + {
> + struct stat fst;
> + fst.st_size=0;
> + stat(absClusterPath(PG_GETARG_TEXT_P(0)), &fst);
> +
> + PG_RETURN_INT32(fst.st_size);
> + }
> + PG_RETURN_INT32(0);
> +}
> +
> +
> +Datum pg_logfile_name(PG_FUNCTION_ARGS)
> +{
> + char *filename=LogFileName();
> + if (filename)
> + {
> + if (strncmp(filename, DataDir, strlen(DataDir)))
> + PG_RETURN_CSTRING(filename);
> + else
> + PG_RETURN_CSTRING(filename+strlen(DataDir)+1);
> + }
> + PG_RETURN_NULL();
> +}
> +
> +
> +Datum pg_logfile_rotate(PG_FUNCTION_ARGS)
> +{
> + char *renamedFile = LogFileRotate();
> +
> + if (renamedFile)
> + {
> + if (strncmp(renamedFile, DataDir, strlen(DataDir)))
> + PG_RETURN_CSTRING(renamedFile);
> + else
> + PG_RETURN_CSTRING(renamedFile+strlen(DataDir)+1);
> + }
> + else
> + PG_RETURN_NULL();
> +}
> +
> Index: src/backend/utils/error/elog.c
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/error/elog.c,v
> retrieving revision 1.142
> diff -u -r1.142 elog.c
> --- src/backend/utils/error/elog.c 24 Jun 2004 21:03:13 -0000 1.142
> +++ src/backend/utils/error/elog.c 6 Jul 2004 22:12:37 -0000
> @@ -63,7 +63,6 @@
> #include "utils/memutils.h"
> #include "utils/guc.h"
>
> -
> /* Global variables */
> ErrorContextCallback *error_context_stack = NULL;
>
> @@ -71,9 +70,17 @@
> PGErrorVerbosity Log_error_verbosity = PGERROR_VERBOSE;
> char *Log_line_prefix = NULL; /* format for extra log line info */
> unsigned int Log_destination = LOG_DESTINATION_STDERR;
> +char *Log_filename = NULL;
>
> bool in_fatal_exit = false;
>
> +FILE *logfile = NULL; /* the logfile we're writing to */
> +static char logfileName[MAXPGPATH]; /* current filename */
> +static pg_time_t logfileTimestamp=0; /* logfile version this backend is currently using */
> +
> +static pg_time_t *globalLogfileTimestamp = NULL; /* logfile version the backend should be using (shared mem) */
> +
> +
> #ifdef HAVE_SYSLOG
> char *Syslog_facility; /* openlog() parameters */
> char *Syslog_ident;
> @@ -140,6 +147,9 @@
> static const char *error_severity(int elevel);
> static void append_with_tabs(StringInfo buf, const char *str);
>
> +static char *logfile_getname(pg_time_t timestamp);
> +static void logfile_reopen(void);
> +
>
> /*
> * errstart --- begin an error-reporting cycle
> @@ -931,11 +941,181 @@
> /*
> * And let errfinish() finish up.
> */
> +
> errfinish(0);
> }
>
>
> /*
> + * Initialize shared mem for logfile rotation
> + */
> +
> +void
> +LogFileInit(void)
> +{
> + if (!globalLogfileTimestamp && Log_filename && (Log_destination & LOG_DESTINATION_FILE))
> + {
> + /* allocate logfile version shared memory segment for rotation signaling */
> + globalLogfileTimestamp = ShmemAlloc(sizeof(pg_time_t));
> + if (!globalLogfileTimestamp)
> + {
> + ereport(FATAL,
> + (errcode(ERRCODE_OUT_OF_MEMORY),
> + errmsg("Out of shared memory")));
> + return;
> + }
> +
> + *globalLogfileTimestamp = time(NULL);
> +
> + /* open logfile after we successfully initialized */
> + logfile_reopen();
> + }
> +}
> +
> +
> +/*
> + * Rotate log file
> + */
> +char *
> +LogFileRotate(void)
> +{
> + char *filename;
> + char *oldFilename;
> + pg_time_t now;
> +
> + if (!globalLogfileTimestamp || !logfileName || !(Log_destination & LOG_DESTINATION_FILE))
> + return NULL;
> +
> + now = time(NULL);
> +
> + filename = logfile_getname(now);
> + if (!filename)
> + return NULL;
> +
> + if (!strcmp(filename, logfileName))
> + {
> + ereport(ERROR,
> + (errcode(ERRCODE_CONFIG_FILE_ERROR),
> + errmsg("Log_filename not suitable for rotation.")));
> + return NULL;
> + }
> +
> + oldFilename = pstrdup(logfileName);
> + *globalLogfileTimestamp = now;
> +
> + ereport(NOTICE,
> + (errcode(ERRCODE_WARNING),
> + errmsg("Opened new log file %s; previous logfile %s", filename, oldFilename)));
> +
> + return oldFilename;
> +}
> +
> +
> +/*
> + * return current log file name
> + */
> +char*
> +LogFileName(void)
> +{
> + if (logfileName)
> + return pstrdup(logfileName);
> + return NULL;
> +}
> +
> +
> +/*
> + * check if logfile has to be reopened
> + * if called from ProcessConfigFile after SIGHUP, also check for filename template change
> + */
> +void LogFileCheckReopen(bool fromSIGHUP)
> +{
> + if (globalLogfileTimestamp)
> + {
> + if (*globalLogfileTimestamp != logfileTimestamp)
> + {
> + /* sanity check: if it's in the future, shmem probably corrupted */
> + pg_time_t now=time(NULL);
> + if (*globalLogfileTimestamp > now)
> + *globalLogfileTimestamp = now;
> +
> + logfile_reopen();
> + }
> + else if (fromSIGHUP)
> + {
> + char *filename = logfile_getname(logfileTimestamp);
> + if (filename && strcmp(filename, logfileName))
> + {
> + /* template for logfile was changed */
> + logfile_reopen();
> + pfree(filename);
> + }
> + }
> + }
> +}
> +
> +
> +/*
> + * creates logfile name using timestamp information
> + */
> +static char*
> +logfile_getname(pg_time_t timestamp)
> +{
> + char *filetemplate;
> + char *filename;
> +
> + if (is_absolute_path(Log_filename))
> + filetemplate = pstrdup(Log_filename);
> + else
> + {
> + filetemplate = palloc(strlen(DataDir) + strlen(Log_filename) + 2);
> + sprintf(filetemplate, "%s/%s", DataDir, Log_filename);
> + }
> + filename = palloc(MAXPGPATH);
> + pg_strftime(filename, MAXPGPATH, filetemplate, pg_localtime(&timestamp));
> +
> + pfree(filetemplate);
> +
> + return filename;
> +}
> +
> +
> +/*
> + * reopen log file.
> + */
> +static void
> +logfile_reopen(void)
> +{
> + if (logfile)
> + {
> + fclose(logfile);
> + logfile = NULL;
> + }
> +
> + if ((Log_destination & LOG_DESTINATION_FILE) && globalLogfileTimestamp)
> + {
> + char *fn;
> +
> + logfileTimestamp = *globalLogfileTimestamp;
> +
> + fn=logfile_getname(logfileTimestamp);
> +
> + if (fn)
> + {
> + logfile = fopen(fn, "a+");
> +
> + if (!logfile)
> + ereport(ERROR,
> + (errcode_for_file_access(),
> + errmsg("failed to open log file %s", fn)));
> +
> + strcpy(logfileName, fn);
> + pfree(fn);
> + }
> + }
> +}
> +
> +
> +/*
> * Initialization of error output file
> */
> void
> @@ -1455,6 +1635,20 @@
> if ((Log_destination & LOG_DESTINATION_STDERR) || whereToSendOutput == Debug)
> {
> fprintf(stderr, "%s", buf.data);
> + }
> +
> + /* Write to file, if enabled */
> + if (logfile && (Log_destination & LOG_DESTINATION_FILE))
> + {
> + /* check if logfile changed */
> + LogFileCheckReopen(false);
> +
> + if (logfile)
> + {
> + fseek(logfile, 0, SEEK_END);
> + fprintf(logfile, "%s", buf.data);
> + fflush(logfile);
> + }
> }
>
> pfree(buf.data);
> Index: src/backend/utils/misc/guc-file.l
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/misc/guc-file.l,v
> retrieving revision 1.22
> diff -u -r1.22 guc-file.l
> --- src/backend/utils/misc/guc-file.l 26 May 2004 15:07:38 -0000 1.22
> +++ src/backend/utils/misc/guc-file.l 6 Jul 2004 22:12:38 -0000
> @@ -276,6 +276,9 @@
> set_config_option(item->name, item->value, context,
> PGC_S_FILE, false, true);
>
> + if (context == PGC_SIGHUP)
> + LogFileCheckReopen(true);
> +
> cleanup_exit:
> free_name_value_list(head);
> return;
> Index: src/backend/utils/misc/guc.c
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/misc/guc.c,v
> retrieving revision 1.213
> diff -u -r1.213 guc.c
> --- src/backend/utils/misc/guc.c 5 Jul 2004 23:14:14 -0000 1.213
> +++ src/backend/utils/misc/guc.c 6 Jul 2004 22:12:46 -0000
> @@ -76,6 +76,8 @@
> static const char *assign_log_destination(const char *value,
> bool doit, GucSource source);
>
> +extern char *Log_filename;
> +
> #ifdef HAVE_SYSLOG
> extern char *Syslog_facility;
> extern char *Syslog_ident;
> @@ -1606,13 +1608,23 @@
> {
> {"log_destination", PGC_POSTMASTER, LOGGING_WHERE,
> gettext_noop("Sets the target for log output."),
> - gettext_noop("Valid values are combinations of stderr, syslog "
> + gettext_noop("Valid values are combinations of stderr, file, syslog "
> "and eventlog, depending on platform."),
> GUC_LIST_INPUT
> },
> &log_destination_string,
> "stderr", assign_log_destination, NULL
> },
> + {
> + {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
> + gettext_noop("Sets the target filename for log output."),
> + gettext_noop("May be specified as relative to the cluster directory "
> + "or as absolute path."),
> + GUC_LIST_INPUT | GUC_REPORT
> + },
> + &Log_filename,
> + "postgresql.log.%Y-%m-%d_%H%M%S", NULL, NULL
> + },
>
> #ifdef HAVE_SYSLOG
> {
> @@ -5033,6 +5045,8 @@
>
> if (pg_strcasecmp(tok,"stderr") == 0)
> newlogdest |= LOG_DESTINATION_STDERR;
> + else if (pg_strcasecmp(tok,"file") == 0)
> + newlogdest |= LOG_DESTINATION_FILE;
> #ifdef HAVE_SYSLOG
> else if (pg_strcasecmp(tok,"syslog") == 0)
> newlogdest |= LOG_DESTINATION_SYSLOG;
> Index: src/backend/utils/misc/postgresql.conf.sample
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/misc/postgresql.conf.sample,v
> retrieving revision 1.113
> diff -u -r1.113 postgresql.conf.sample
> --- src/backend/utils/misc/postgresql.conf.sample 7 Apr 2004 05:05:50 -0000 1.113
> +++ src/backend/utils/misc/postgresql.conf.sample 6 Jul 2004 22:12:47 -0000
> @@ -147,9 +147,12 @@
>
> # - Where to Log -
>
> -#log_destination = 'stderr' # Valid values are combinations of stderr,
> +#log_destination = 'stderr' # Valid values are combinations of stderr, file,
> # syslog and eventlog, depending on
> # platform.
> +#log_filename = 'postgresql.log.%Y-%m-%d_%H%M%S' # filename if
> + # 'file' log_destination is used.
> +
> #syslog_facility = 'LOCAL0'
> #syslog_ident = 'postgres'
>
> Index: src/include/catalog/pg_proc.h
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/include/catalog/pg_proc.h,v
> retrieving revision 1.341
> diff -u -r1.341 pg_proc.h
> --- src/include/catalog/pg_proc.h 2 Jul 2004 22:49:48 -0000 1.341
> +++ src/include/catalog/pg_proc.h 6 Jul 2004 22:13:02 -0000
> @@ -3595,6 +3595,14 @@
> DATA(insert OID = 2556 ( pg_tablespace_databases PGNSP PGUID 12 f f t t s 1 26 "26" _null_ pg_tablespace_databases - _null_));
> DESCR("returns database oids in a tablespace");
>
> +DATA(insert OID = 2557( pg_logfile_get PGNSP PGUID 12 f f f f v 3 2275 "23 23 25" _null_ pg_logfile_get - _null_ ));
> +DESCR("return log file contents");
> +DATA(insert OID = 2558( pg_logfile_length PGNSP PGUID 12 f f f f v 1 23 "25" _null_ pg_logfile_length - _null_ ));
> +DESCR("name of log file");
> +DATA(insert OID = 2559( pg_logfile_name PGNSP PGUID 12 f f f f v 0 2275 "" _null_ pg_logfile_name - _null_ ));
> +DESCR("length of log file");
> +DATA(insert OID = 2560( pg_logfile_rotate PGNSP PGUID 12 f f f f v 0 2275 "" _null_ pg_logfile_rotate - _null_ ));
> +DESCR("rotate log file");
>
> /*
> * Symbolic values for provolatile column: these indicate whether the result
> Index: src/include/utils/builtins.h
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/include/utils/builtins.h,v
> retrieving revision 1.245
> diff -u -r1.245 builtins.h
> --- src/include/utils/builtins.h 2 Jul 2004 18:59:25 -0000 1.245
> +++ src/include/utils/builtins.h 6 Jul 2004 22:13:05 -0000
> @@ -358,6 +358,11 @@
> extern Datum pg_cancel_backend(PG_FUNCTION_ARGS);
> extern Datum pg_tablespace_databases(PG_FUNCTION_ARGS);
>
> +extern Datum pg_logfile_get(PG_FUNCTION_ARGS);
> +extern Datum pg_logfile_length(PG_FUNCTION_ARGS);
> +extern Datum pg_logfile_name(PG_FUNCTION_ARGS);
> +extern Datum pg_logfile_rotate(PG_FUNCTION_ARGS);
> +
> /* not_in.c */
> extern Datum int4notin(PG_FUNCTION_ARGS);
> extern Datum oidnotin(PG_FUNCTION_ARGS);
> Index: src/include/utils/elog.h
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/include/utils/elog.h,v
> retrieving revision 1.69
> diff -u -r1.69 elog.h
> --- src/include/utils/elog.h 24 Jun 2004 21:03:42 -0000 1.69
> +++ src/include/utils/elog.h 6 Jul 2004 22:13:05 -0000
> @@ -182,10 +182,14 @@
> #define LOG_DESTINATION_STDERR 1
> #define LOG_DESTINATION_SYSLOG 2
> #define LOG_DESTINATION_EVENTLOG 4
> +#define LOG_DESTINATION_FILE 8
>
> /* Other exported functions */
> extern void DebugFileOpen(void);
> -
> +extern void LogFileInit(void);
> +extern void LogFileCheckReopen(bool fromSIGHUP);
> +extern char *LogFileRotate(void);
> +extern char *LogFileName(void);
> /*
> * Write errors to stderr (or by equal means when stderr is
> * not available). Used before ereport/elog can be used

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073