Hi everyone!
A situation has been discovered in which empty .log files are being created.
--Reproduce:
1) You need to set the following parameters in the "postgresql.conf" file:
log_destination = 'csvlog'
logging_collector = on
log_rotation_age = 1min
log_directory = '/home/user/builds/postgresql/log'
2) After starting the server, two files are being created in the
directory with logs:
-rw------- 1 user user 1,4K oct 10 13:29 postgresql-2024-10-10_132907.csv
-rw------- 1 user user 172 oct 10 13:29 postgresql-2024-10-10_132907.log
3) The .log file is created anyway, regardless of the log_destination
parameter.
The following message is displayed in the .log file (due to the fact
that the log_destination
parameter is set = 'csvlog'):
|
|2024-10-10 13:05:52.539 MSK [1629065] LOG: ending log output to stderr
2024-10-10 13:05:52.539 MSK [1629065] HINT: Future log output will go
to log destination "csvlog".
Next, the stderr stream is redirected to a .csv file.
4) Now, logs are rotated once a minute (due to the set log_rotation_age
parameter). Moreover, all
open log files are rotated, including the .log file that I wrote about
above. New ones are being created
.csv and .log files. Logs themselves are sent to .csv, and nothing else
is output to .log
and it remains empty:
-rw------- 1 user user 1,4K oct 10 13:29 postgresql-2024-10-10_132907.csv
-rw------- 1 user user 172 oct 10 13:29 postgresql-2024-10-10_132907.log
-rw------- 1 user user 1,4K oct 10 13:30 postgresql-2024-10-10_133000.csv
-rw------- 1 user user 0 oct 10 13:30 postgresql-2024-10-10_133000.log
--Fix:
To correct the situation, you can add a check for the "Log_destination"
parameter in the "logfile_rotate()"
function of the "syslogger.c" module. Then only the logs specified in
this parameter will be rotated.Thisis doneinthe proposedpatch.
Best regards,
Arseny Kositsin.
From 3b33349ada0ab50c334a2801a2ba41d4ba3d77e7 Mon Sep 17 00:00:00 2001
From: Arseny Kositsin <arseny.p...@gmail.com>
Date: Mon, 28 Oct 2024 18:08:38 +0300
Subject: [PATCH v1] Fixed creation of an empty .log file
When logs are rotated, if the log_destination = 'csvlog', besides .csv
file, an empty .log file was created. In order to correct this behavior,
an additional check has been added to the log file_rotate() function.
---
src/backend/postmaster/syslogger.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index 7951599fa8..cd29e863ee 100644
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -1374,22 +1374,25 @@ logfile_rotate(bool time_based_rotation, int size_rotation_for)
fntime = time(NULL);
/* file rotation for stderr */
- if (!logfile_rotate_dest(time_based_rotation, size_rotation_for, fntime,
- LOG_DESTINATION_STDERR, &last_sys_file_name,
- &syslogFile))
- return;
+ if ((Log_destination & LOG_DESTINATION_STDERR) != 0)
+ if (!logfile_rotate_dest(time_based_rotation, size_rotation_for, fntime,
+ LOG_DESTINATION_STDERR, &last_sys_file_name,
+ &syslogFile))
+ return;
/* file rotation for csvlog */
- if (!logfile_rotate_dest(time_based_rotation, size_rotation_for, fntime,
- LOG_DESTINATION_CSVLOG, &last_csv_file_name,
- &csvlogFile))
- return;
+ if ((Log_destination & LOG_DESTINATION_CSVLOG) != 0)
+ if (!logfile_rotate_dest(time_based_rotation, size_rotation_for, fntime,
+ LOG_DESTINATION_CSVLOG, &last_csv_file_name,
+ &csvlogFile))
+ return;
/* file rotation for jsonlog */
- if (!logfile_rotate_dest(time_based_rotation, size_rotation_for, fntime,
- LOG_DESTINATION_JSONLOG, &last_json_file_name,
- &jsonlogFile))
- return;
+ if ((Log_destination & LOG_DESTINATION_JSONLOG) != 0)
+ if (!logfile_rotate_dest(time_based_rotation, size_rotation_for, fntime,
+ LOG_DESTINATION_JSONLOG, &last_json_file_name,
+ &jsonlogFile))
+ return;
update_metainfo_datafile();
--
2.34.1
