Le 11/01/2017 à 08:39, Michael Paquier a écrit :
> On Wed, Dec 14, 2016 at 12:19 AM, Robert Haas <robertmh...@gmail.com> wrote:
>> On Mon, Dec 12, 2016 at 4:31 AM, Gilles Darold <gilles.dar...@dalibo.com>
>> wrote:
>>> Applied in last version of the patch v18 as well as removing of an
>>> unused variable.
>> OK, this looks a lot closer to being committable. But:
>>
>> [long review]
>
> Gilles, could you update the patch based on this review from Robert? I
> am marking the patch as "waiting on author" for the time being. I
> looked a bit at the patch but did not notice anything wrong with it,
> but let's see with a fresh version...
Hi,
My bad, I was thinking that Karl has planned an update of the patch in
his last post, sorry for my misunderstanding.
Here is attached v19 of the patch that might fix all comment from
Robert's last review.
Best regards,
--
Gilles Darold
Consultant PostgreSQL
http://dalibo.com - http://dalibo.org
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 30dd54c..dd23932 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -4211,6 +4211,14 @@ SELECT * FROM parent WHERE key = 2400;
<primary>server log</primary>
</indexterm>
+ <para>
+ When logs are written to the file-system their paths, names, and
+ types are recorded in
+ the <xref linkend="storage-pgdata-current-logfiles"> file. This provides
+ a convenient way to find and access log content without establishing a
+ database connection.
+ </para>
+
<sect2 id="runtime-config-logging-where">
<title>Where To Log</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 10e3186..e4723f4 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -15441,6 +15441,19 @@ SELECT * FROM pg_ls_dir('.') WITH ORDINALITY AS t(ls,n);
</row>
<row>
+ <entry><literal><function>pg_current_logfile()</function></literal></entry>
+ <entry><type>text</type></entry>
+ <entry>primary log file name in use by the logging collector</entry>
+ </row>
+
+ <row>
+ <entry><literal><function>pg_current_logfile(<type>text</>)</function></literal></entry>
+ <entry><type>text</type></entry>
+ <entry>log file name, of log in the requested format, in use by the
+ logging collector</entry>
+ </row>
+
+ <row>
<entry><literal><function>pg_my_temp_schema()</function></literal></entry>
<entry><type>oid</type></entry>
<entry>OID of session's temporary schema, or 0 if none</entry>
@@ -15658,6 +15671,39 @@ SET search_path TO <replaceable>schema</> <optional>, <replaceable>schema</>, ..
the time when the postmaster process re-read the configuration files.)
</para>
+ <indexterm>
+ <primary>pg_current_logile</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>Logging</primary>
+ <secondary>pg_current_logfile function</secondary>
+ </indexterm>
+
+ <para>
+ <function>pg_current_logfile</function> returns, as <type>text</type>,
+ the path of either the csv or stderr log file currently in use by the
+ logging collector. This is a path including the
+ <xref linkend="guc-log-directory"> directory and the log file name.
+ Log collection must be active or the return value
+ is <literal>NULL</literal>. When multiple logfiles exist, each in a
+ different format, <function>pg_current_logfile</function> called
+ without arguments returns the path of the file having the first format
+ found in the ordered
+ list: <systemitem>stderr</>, <systemitem>csvlog</>.
+ <literal>NULL</literal> is returned when no log file has any of these
+ formats. To request a specific file format supply,
+ as <type>text</type>, either <systemitem>csvlog</>
+ or <systemitem>stderr</> as the value of the optional parameter. The
+ return value is <literal>NULL</literal> when the log format requested
+ is not a configured <xref linkend="guc-log-destination">.
+
+ <function>pg_current_logfiles</function> reflects the content of the
+ <xref linkend="storage-pgdata-current-logfiles"> file. All caveats
+ regards <filename>current_logfiles</filename> content are applicable
+ to <function>pg_current_logfiles</function>' return value.
+ </para>
+
<indexterm>
<primary>pg_my_temp_schema</primary>
</indexterm>
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 5c52824..3ce2a7e 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -60,6 +60,38 @@ Item
<entry>Subdirectory containing per-database subdirectories</entry>
</row>
+<row id="storage-pgdata-current-logfiles" xreflabel="current_logfiles">
+ <entry>
+ <indexterm>
+ <primary><filename>current_logfiles</filename></primary>
+ </indexterm>
+ <indexterm>
+ <primary>Logging</primary>
+ <secondary><filename>current_logfiles</filename> file</secondary>
+ </indexterm>
+ <filename>current_logfiles</>
+ </entry>
+ <entry>
+ <para>
+ A file recording the log file(s) currently written to by the syslogger
+ and the file's log formats, <systemitem>stderr</>
+ or <systemitem>csvlog</>. Each line of the file is a space separated list of
+ two elements: the log format and the full path to the log file including the
+ value of <xref linkend="guc-log-directory">. The log format must be present
+ in <xref linkend="guc-log-destination"> to be listed in
+ <filename>current_logfiles</filename>.
+ </para>
+
+ <para>
+ The <filename>current_logfiles</filename> file
+ is present only when <xref linkend="guc-logging-collector"> is
+ activated and when at least one of <systemitem>stderr</> or
+ <systemitem>csvlog</> value is present in
+ <xref linkend="guc-log-destination">.
+ </para>
+ </entry>
+</row>
+
<row>
<entry><filename>global</></entry>
<entry>Subdirectory containing cluster-wide tables, such as
diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index 13a0301..ecaeeef 100644
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -146,7 +146,7 @@ static char *logfile_getname(pg_time_t timestamp, const char *suffix);
static void set_next_rotation_time(void);
static void sigHupHandler(SIGNAL_ARGS);
static void sigUsr1Handler(SIGNAL_ARGS);
-
+static void update_metainfo_datafile(void);
/*
* Main entry point for syslogger process
@@ -348,6 +348,13 @@ SysLoggerMain(int argc, char *argv[])
rotation_disabled = false;
rotation_requested = true;
}
+ /*
+ * Force rewriting last log filename when reloading configuration,
+ * even if rotation_requested is false, log_destination may have
+ * been changed and we don't want to wait the next file rotation.
+ */
+ update_metainfo_datafile();
+
}
if (Log_RotationAge > 0 && !rotation_disabled)
@@ -511,10 +518,15 @@ int
SysLogger_Start(void)
{
pid_t sysloggerPid;
- char *filename;
if (!Logging_collector)
+ {
+ /* Logging collector is not enabled. We don't know where messages are
+ * logged. Remove outdated file holding the current log filenames.
+ */
+ unlink(LOG_METAINFO_DATAFILE);
return 0;
+ }
/*
* If first time through, create the pipe which will receive stderr
@@ -570,11 +582,15 @@ SysLogger_Start(void)
* a time-based rotation.
*/
first_syslogger_file_time = time(NULL);
- filename = logfile_getname(first_syslogger_file_time, NULL);
- syslogFile = logfile_open(filename, "a", false);
+ if (last_file_name != NULL)
+ pfree(last_file_name);
+
+ last_file_name = logfile_getname(first_syslogger_file_time, NULL);
+
+ syslogFile = logfile_open(last_file_name, "a", false);
- pfree(filename);
+ update_metainfo_datafile();
#ifdef EXEC_BACKEND
switch ((sysloggerPid = syslogger_forkexec()))
@@ -1098,6 +1114,8 @@ open_csvlogfile(void)
pfree(last_csv_file_name);
last_csv_file_name = filename;
+
+ update_metainfo_datafile();
}
/*
@@ -1268,6 +1286,8 @@ logfile_rotate(bool time_based_rotation, int size_rotation_for)
if (csvfilename)
pfree(csvfilename);
+ update_metainfo_datafile();
+
set_next_rotation_time();
}
@@ -1365,3 +1385,62 @@ sigUsr1Handler(SIGNAL_ARGS)
errno = save_errno;
}
+
+/*
+ * Store the name of the file(s) where the log collector, when enabled, writes
+ * log messages. Useful for finding the name(s) of the current log file(s)
+ * when there is time-based logfile rotation. Filenames are stored in a
+ * temporary file and renamed into the final destination for atomicity.
+ */
+static void
+update_metainfo_datafile()
+{
+ FILE *fh;
+
+ if (!(Log_destination & LOG_DESTINATION_STDERR)
+ && !(Log_destination & LOG_DESTINATION_CSVLOG))
+ {
+ unlink(LOG_METAINFO_DATAFILE);
+ return;
+ }
+
+ if ((fh = logfile_open(LOG_METAINFO_DATAFILE_TMP, "w", true)) == NULL)
+ return;
+
+ if (last_file_name && (Log_destination & LOG_DESTINATION_STDERR))
+ {
+ if (fprintf(fh, "stderr %s\n", last_file_name) < 0)
+ {
+ ereport(LOG,
+ (errcode_for_file_access(),
+ errmsg("could not write stderr log file path \"%s\": %m",
+ LOG_METAINFO_DATAFILE_TMP)));
+ fclose(fh);
+ return;
+ }
+ }
+
+ if (last_csv_file_name && (Log_destination & LOG_DESTINATION_CSVLOG))
+ {
+ if (fprintf(fh, "csvlog %s\n", last_csv_file_name) < 0)
+ {
+ ereport(LOG,
+ (errcode_for_file_access(),
+ errmsg("could not write csvlog log file path \"%s\": %m",
+ LOG_METAINFO_DATAFILE_TMP)));
+ fclose(fh);
+ return;
+ }
+ }
+ fclose(fh);
+
+ if (rename(LOG_METAINFO_DATAFILE_TMP, LOG_METAINFO_DATAFILE) != 0)
+ {
+ ereport(LOG,
+ (errcode_for_file_access(),
+ errmsg("could not rename file \"%s\": %m",
+ LOG_METAINFO_DATAFILE_TMP)));
+ return;
+ }
+}
+
diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index 66d09bc..60ab512 100644
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -892,3 +892,99 @@ parse_ident(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
}
+
+/*
+ * Report current log file used by log collector
+ */
+Datum
+pg_current_logfile(PG_FUNCTION_ARGS)
+{
+ FILE *fd;
+ char lbuffer[MAXPGPATH];
+ char *logfmt;
+ char *log_filepath;
+ char *log_format = lbuffer;
+
+ /* The log format parameter is optional */
+ if (PG_NARGS() == 0 || PG_ARGISNULL(0))
+ logfmt = NULL;
+ else
+ {
+ logfmt = text_to_cstring(PG_GETARG_TEXT_PP(0));
+ if (strcmp(logfmt, "stderr") != 0 && strcmp(logfmt, "csvlog") != 0)
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("log format \"%s\" is not supported", logfmt),
+ errhint("The supported log formats are \"stderr\""
+ " and \"csvlog\".")));
+ PG_RETURN_NULL();
+ }
+ }
+
+ fd = AllocateFile(LOG_METAINFO_DATAFILE, "r");
+ if (fd == NULL)
+ {
+ if (errno != ENOENT)
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not read file \"%s\": %m",
+ LOG_METAINFO_DATAFILE)));
+ PG_RETURN_NULL();
+ }
+
+ /*
+ * Read the file to gather current log filename(s) registered
+ * by the syslogger.
+ */
+ while (fgets(lbuffer, sizeof(lbuffer), fd) != NULL)
+ {
+ /* Check for a read error. */
+ if (ferror(fd))
+ {
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not read file \"%s\": %m",
+ LOG_METAINFO_DATAFILE)));
+ }
+
+ /*
+ * extract log format and log file path from the line
+ * lbuffer == log_format, they share storage
+ */
+ if (log_filepath = strchr(lbuffer, ' '))
+ *log_filepath = '\0';
+ else
+ {
+ /* Unknown format, no space. Return NULL to caller. */
+ lbuffer[0] = '\0';
+ break;
+ }
+ log_filepath++;
+ log_filepath[strcspn(log_filepath, "\n")] = '\0';
+
+ if (logfmt == NULL || strcmp(logfmt, log_format) == 0)
+ {
+ FreeFile(fd);
+ PG_RETURN_TEXT_P(cstring_to_text(log_filepath));
+ }
+ }
+
+ /* Close the current log filename file. */
+ FreeFile(fd);
+
+ PG_RETURN_NULL();
+}
+
+/*
+ * Report current log file used by log collector (1 argument version)
+ *
+ * note: this wrapper is necessary to pass the sanity check in opr_sanity,
+ * which checks that all built-in functions that share the implementing C
+ * function take the same number of arguments
+ */
+Datum
+pg_current_logfile_1arg(PG_FUNCTION_ARGS)
+{
+ return pg_current_logfile(fcinfo);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 37e022d..eb56e8d 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -3183,6 +3183,10 @@ DATA(insert OID = 2621 ( pg_reload_conf PGNSP PGUID 12 1 0 0 0 f f f f t f v s
DESCR("reload configuration files");
DATA(insert OID = 2622 ( pg_rotate_logfile PGNSP PGUID 12 1 0 0 0 f f f f t f v s 0 0 16 "" _null_ _null_ _null_ _null_ _null_ pg_rotate_logfile _null_ _null_ _null_ ));
DESCR("rotate log file");
+DATA(insert OID = 3800 ( pg_current_logfile PGNSP PGUID 12 1 0 0 0 f f f f f f v s 0 0 25 "" _null_ _null_ _null_ _null_ _null_ pg_current_logfile _null_ _null_ _null_ ));
+DESCR("current logging collector file location");
+DATA(insert OID = 3801 ( pg_current_logfile PGNSP PGUID 12 1 0 0 0 f f f f f f v s 1 0 25 "25" _null_ _null_ _null_ _null_ _null_ pg_current_logfile_1arg _null_ _null_ _null_ ));
+DESCR("current logging collector file location");
DATA(insert OID = 2623 ( pg_stat_file PGNSP PGUID 12 1 0 0 0 f f f f t f v s 1 0 2249 "25" "{25,20,1184,1184,1184,1184,16}" "{i,o,o,o,o,o,o}" "{filename,size,access,modification,change,creation,isdir}" _null_ _null_ pg_stat_file_1arg _null_ _null_ _null_ ));
DESCR("get information about file");
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 4c607b2..07c67d7 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -466,5 +466,4 @@ extern bool has_rolreplication(Oid roleid);
/* in access/transam/xlog.c */
extern bool BackupInProgress(void);
extern void CancelBackup(void);
-
#endif /* MISCADMIN_H */
diff --git a/src/include/postmaster/syslogger.h b/src/include/postmaster/syslogger.h
index c187a5f..0a417e2 100644
--- a/src/include/postmaster/syslogger.h
+++ b/src/include/postmaster/syslogger.h
@@ -87,4 +87,15 @@ extern void write_syslogger_file(const char *buffer, int count, int dest);
extern void SysLoggerMain(int argc, char *argv[]) pg_attribute_noreturn();
#endif
+/* in backend/utils/adt/misc.c and backend/postmaster/syslogger.c */
+/*
+ * Name of file holding the paths, names, and types of the files where current
+ * log messages are written, when the log collector is enabled. Useful
+ * outside of Postgres when finding the name of the current log file in the
+ * case of time-based log rotation.
+ */
+#define LOG_METAINFO_DATAFILE "current_logfiles"
+#define LOG_METAINFO_DATAFILE_TMP LOG_METAINFO_DATAFILE ".tmp"
+
+
#endif /* _SYSLOGGER_H */
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index e1bb344..e2532e6 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -522,6 +522,8 @@ extern Datum pg_collation_for(PG_FUNCTION_ARGS);
extern Datum pg_relation_is_updatable(PG_FUNCTION_ARGS);
extern Datum pg_column_is_updatable(PG_FUNCTION_ARGS);
extern Datum parse_ident(PG_FUNCTION_ARGS);
+extern Datum pg_current_logfile(PG_FUNCTION_ARGS);
+extern Datum pg_current_logfile_1arg(PG_FUNCTION_ARGS);
/* oid.c */
extern Datum oidin(PG_FUNCTION_ARGS);
--
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