Tom doesn't like returning the server's logfile using a pgsql function
unless logfile rotation is implemented, so here it is.
This proposal doesn't include a daemon that triggers pg_logfile_rotate when appropriate (timestamp and/or length dependent), pg_autovacuum might be a good place to do that.
I'd also like to see a table pg_logfile which contains all logfile names, to be able to access older logfiles.
Comments?
Regards, Andreas
Index: doc/src/sgml/func.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql-server/doc/src/sgml/func.sgml,v
retrieving revision 1.206
diff -u -r1.206 func.sgml
--- doc/src/sgml/func.sgml 2 Jun 2004 21:34:49 -0000 1.206
+++ doc/src/sgml/func.sgml 13 Jun 2004 15:57:06 -0000
@@ -7308,6 +7308,80 @@
columns do not have OIDs of their own.
</para>
+ <indexterm zone="functions-misc">
+ <primary>pg_logfile_get</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_logfile_length</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_logfile_name</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_logfile_rotate</primary>
+ </indexterm>
+ <para>
+ The functions shown in <xref linkend="functions-misc-logfile">
+ deal with the server log file if configured with log_destination
+ <quote>file</quote>.
+ </para>
+
+ <table id="functions-misc-logfile">
+ <title>Server Logfile Functions</title>
+ <tgroup cols="3">
+ <thead>
+ <row><entry>Name</entry> <entry>Return Type</entry>
<entry>Description</entry></row>
+ </thead>
+
+ <tbody>
+ <row>
+
<entry><literal><function>pg_logfile_get</function>(<parameter>size_int4</parameter>,
+
<parameter>offset_int4</parameter>,<parameter>filename_text</parameter>)</literal></entry>
+ <entry><type>cstring</type></entry>
+ <entry>get a part of the current server log file</entry>
+ </row>
+ <row>
+
<entry><literal><function>pg_logfile_length</function>(<paramater>filename_text</parameter>)</literal></entry>
+ <entry><type>int4</type></entry>
+ <entry>return the current length of the server log file</entry>
+ </row>
+ <row>
+ <entry><literal><function>pg_logfile_rotate</function>()</literal></entry>
+ <entry><type>cstring</type></entry>
+ <entry>rotates the server log file and returns the new log file
+ name</entry>
+ </row>
+ <row>
+ <entry><literal><function>pg_logfile_name</function>()</literal></entry>
+ <entry><type>cstring</type></entry>
+ <entry>returns the current server log file name</entry>
+ </row>
+ <row>
+ <entry><literal><function>pg_logfile_rotate</function>()</literal></entry>
+ <entry><type>cstring</type></entry>
+ <entry>rotates the server log file and returns the previous log file
+ name</entry>
+ </row>
+ </tbody>
+</tgroup>
+</table>
+<para>
+The <function>pg_logfile_get</function> function will return the
+ contents of the current server log file, limited by the size
+ parameter. If size is NULL, a server internal limit (currently
+ 50000) is applied. The position parameter specifies the
+ starting position of the server log chunk to be returned. A
+ positive number or 0 will be counted from the start of the file,
+ a negative number from the end; if NULL, -size is assumed
+ (i.e. the tail of the log file).
+</para>
+<para>
+Both <function>pg_logfile_get</function> and
+ <function>pg_logfile_length</function> have a filename
+ parameter which may specify the logfile to examine or the
+ current logfile if NULL.
+</para>
+
</sect1>
<sect1 id="functions-array">
Index: doc/src/sgml/runtime.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql-server/doc/src/sgml/runtime.sgml,v
retrieving revision 1.266
diff -u -r1.266 runtime.sgml
--- doc/src/sgml/runtime.sgml 10 Jun 2004 22:26:17 -0000 1.266
+++ doc/src/sgml/runtime.sgml 13 Jun 2004 15:57:17 -0000
@@ -1721,14 +1721,25 @@
<listitem>
<para>
<productname>PostgreSQL</productname> supports several methods
- for loggning, including <systemitem>stderr</systemitem> and
- <systemitem>syslog</systemitem>. On Windows,
- <systemitem>eventlog</systemitem> is also supported. Set this
+ for logging, including <systemitem>stderr</systemitem>,
+ <systemitem>file></systemitem> and <systemitem>syslog</systemitem>.
+ On Windows, <systemitem>eventlog</systemitem> is also supported. Set this
option to a list of desired log destinations separated by a
comma. The default is to log to <systemitem>stderr</systemitem>
only. This option must be set at server start.
</para>
</listitem>
+ </varlistentry>
+
+ <varlistentry id="guc-syslog-facility" xreflabel="log_filename">
+ <term><varname>log_filename</varname> (<type>string</type>)</term>
+ <listitem>
+ <para>
+ This option sets the target filename for the log destination
+ <quote>file</quote> option. It may be specified as absolute
+ path or relative to the <application>cluster directory</application>.
+ </para>
+ </listitem>
</varlistentry>
<varlistentry id="guc-syslog-facility" xreflabel="syslog_facility">
Index: src/backend/postmaster/postmaster.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/postmaster/postmaster.c,v
retrieving revision 1.403
diff -u -r1.403 postmaster.c
--- src/backend/postmaster/postmaster.c 11 Jun 2004 03:54:43 -0000 1.403
+++ src/backend/postmaster/postmaster.c 13 Jun 2004 15:57:24 -0000
@@ -727,6 +727,11 @@
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/storage/ipc/ipc.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/storage/ipc/ipc.c,v
retrieving revision 1.87
diff -u -r1.87 ipc.c
--- src/backend/storage/ipc/ipc.c 12 Dec 2003 18:45:09 -0000 1.87
+++ src/backend/storage/ipc/ipc.c 13 Jun 2004 15:57:24 -0000
@@ -111,6 +111,8 @@
on_proc_exit_list[on_proc_exit_index].arg);
elog(DEBUG3, "exit(%d)", code);
+
+// LogFileClose();
exit(code);
}
Index: src/backend/utils/adt/misc.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/adt/misc.c,v
retrieving revision 1.34
diff -u -r1.34 misc.c
--- src/backend/utils/adt/misc.c 2 Jun 2004 21:29:29 -0000 1.34
+++ src/backend/utils/adt/misc.c 13 Jun 2004 15:57:30 -0000
@@ -103,3 +103,130 @@
{
PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0),SIGINT));
}
+
+
+
+
+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)
+ 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)
+ PG_RETURN_CSTRING(renamedFile);
+ 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 1.140
diff -u -r1.140 elog.c
--- src/backend/utils/error/elog.c 3 Jun 2004 02:08:04 -0000 1.140
+++ src/backend/utils/error/elog.c 13 Jun 2004 15:57:33 -0000
@@ -63,7 +63,6 @@
#include "utils/memutils.h"
#include "utils/guc.h"
-
/* Global variables */
ErrorContextCallback *error_context_stack = NULL;
@@ -71,9 +70,22 @@
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;
+typedef struct
+{
+ long fileversion;
+ char filename[MAXPGPATH];
+}
+logfileShmemStruct;
+
+FILE *logfile = NULL;
+static long logfileVersion=0;
+static logfileShmemStruct *logfileShmem = NULL;
+
+
#ifdef HAVE_SYSLOG
char *Syslog_facility; /* openlog() parameters */
char *Syslog_ident;
@@ -140,6 +152,9 @@
static const char *error_severity(int elevel);
static void append_with_tabs(StringInfo buf, const char *str);
+static char *logfile_newname(void);
+static void logfile_reopen(void);
+
/*
* errstart --- begin an error-reporting cycle
@@ -931,11 +946,145 @@
/*
* And let errfinish() finish up.
*/
+
errfinish(0);
}
/*
+ * Initialize shared mem for logfile rotation
+ */
+
+void
+LogFileInit(void)
+{
+ if (Log_filename && (Log_destination & LOG_DESTINATION_FILE))
+ {
+ logfileShmem = ShmemAlloc(sizeof(logfileShmemStruct));
+ if (!logfileShmem)
+ {
+ ereport(FATAL,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("Out of shared memory")));
+ return;
+ }
+
+ memset(logfileShmem, 0, sizeof(logfileShmemStruct));
+
+ char *fn = logfile_newname();
+ if (fn)
+ {
+ strcpy(logfileShmem->filename, fn);
+ logfile_reopen();
+ pfree(fn);
+ }
+ }
+}
+
+
+/*
+ * Rotate log file
+ */
+char *
+LogFileRotate(void)
+{
+ char *oldFilename;
+ char *filename;
+
+ if (!logfileShmem || !(Log_destination & LOG_DESTINATION_FILE))
+ return NULL;
+
+ filename = logfile_newname();
+ if (!filename)
+ return NULL;
+
+
+ if (!strcmp(filename, logfileShmem->filename))
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_CONFIG_FILE_ERROR),
+ errmsg("Log_filename not suitable for rotation.")));
+ return NULL;
+ }
+
+ oldFilename = pstrdup(logfileShmem->filename);
+ strcpy(logfileShmem->filename, filename);
+
+ logfileShmem->fileversion++;
+
+ ereport(NOTICE,
+ (errcode(ERRCODE_WARNING),
+ errmsg("Opened new log file %s; previous logfile %s",
logfileShmem->filename, oldFilename)));
+
+ return oldFilename;
+}
+
+
+/*
+ * return current log file name
+ */
+char*
+LogFileName(void)
+{
+ if (logfileShmem)
+ return logfileShmem->filename;
+ return NULL;
+}
+
+
+/*
+ * creates a new logfile name using current timestamp information
+ */
+static char*
+logfile_newname()
+{
+ char *filetemplate;
+ char *filename;
+ pg_time_t now = time(NULL);
+
+ 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(&now));
+
+ pfree(filetemplate);
+
+ return filename;
+}
+
+
+/*
+ * reopen log file.
+ */
+static void
+logfile_reopen(void)
+{
+ if (logfile)
+ {
+ fclose(logfile);
+ logfile = NULL;
+ }
+
+ if ((Log_destination & LOG_DESTINATION_FILE) && logfileShmem)
+ {
+ logfileVersion = logfileShmem->fileversion;
+
+ logfile = fopen(logfileShmem->filename, "a+");
+
+ if (!logfile)
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("failed to open log file %s",
logfileShmem->filename)));
+ }
+}
+
+
+/*
* Initialization of error output file
*/
void
@@ -1445,6 +1594,24 @@
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 */
+ if (logfileShmem && logfileShmem->fileversion != logfileVersion)
+ {
+ logfileVersion = logfileShmem->fileversion;
+ logfile_reopen();
+ }
+
+ if (logfile)
+ {
+ fseek(logfile, 0, SEEK_END);
+ fprintf(logfile, "%s", buf.data);
+ fflush(logfile);
+ }
}
pfree(buf.data);
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/misc/guc.c,v
retrieving revision 1.211
diff -u -r1.211 guc.c
--- src/backend/utils/misc/guc.c 11 Jun 2004 03:54:54 -0000 1.211
+++ src/backend/utils/misc/guc.c 13 Jun 2004 15:57:42 -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;
@@ -1644,13 +1646,23 @@
{
{"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 | GUC_REPORT
},
&log_destination_string,
"stderr", assign_log_destination, NULL
},
+ {
+ {"log_filename", PGC_POSTMASTER, 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
{
@@ -4779,6 +4791,8 @@
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 13 Jun 2004 15:57:42 -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 1.335
diff -u -r1.335 pg_proc.h
--- src/include/catalog/pg_proc.h 6 Jun 2004 19:07:00 -0000 1.335
+++ src/include/catalog/pg_proc.h 13 Jun 2004 15:57:57 -0000
@@ -3588,6 +3588,16 @@
DATA(insert OID = 2243 ( bit_or
PGNSP PGUID 12 t f f f i 1 1560 "1560" _null_ aggregate_dummy - _null_));
DESCR("bitwise-or bit aggregate");
+DATA(insert OID = 2550( 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 = 2551( 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 = 2552( 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 = 2553( 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
* of a function is dependent *only* on the values of its explicit arguments,
Index: src/include/utils/builtins.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/utils/builtins.h,v
retrieving revision 1.241
diff -u -r1.241 builtins.h
--- src/include/utils/builtins.h 2 Jun 2004 21:29:29 -0000 1.241
+++ src/include/utils/builtins.h 13 Jun 2004 15:58:00 -0000
@@ -356,6 +356,10 @@
extern Datum current_database(PG_FUNCTION_ARGS);
extern Datum pg_terminate_backend(PG_FUNCTION_ARGS);
extern Datum pg_cancel_backend(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);
Index: src/include/utils/elog.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/utils/elog.h,v
retrieving revision 1.68
diff -u -r1.68 elog.h
--- src/include/utils/elog.h 5 Apr 2004 03:02:10 -0000 1.68
+++ src/include/utils/elog.h 13 Jun 2004 15:58:01 -0000
@@ -182,8 +182,11 @@
#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 char *LogFileRotate(void);
+extern char *LogFileName(void);
#endif /* ELOG_H */
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