is this an error in some of the moodle.org sites? Or in your own server?

If it's in your server I'd suggest you to take a look to disk space (perhaps it's really full). Else, try to repair the log table in your DB, you can do it from phpMyAdmin.

Hope this helps, closing as "not a bug". Ciao

I suspect there is something serious about this. Please refer to http://moodle.org/mod/forum/discuss.php?d=94934 .

This is the improvement that added the "disk full" emails. MDL-11893

I would suggest to limit the number of emails (1/day...) and... also... to add the log record information to the message, in order to see what's causing the error on insert and fix it.

Feel free to comment....

Ciao

P.S.: Anyway Manish, I really think that this issue in the logs cannot cause the quiz problem you comment at all ( http://moodle.org/mod/forum/discuss.php?d=94934 ). 99% they are different things.

My GUESS is that this issue a temporary problem on that server which has now caused permanent errors in the table that need repairing.

Thanks!

Eloy, the problems related to quiz remain and the reason of correlating the two is that there were no issues with quiz earlier and the problems have cropped up later and if you look at my post you would notice some zeroes in the screenshot which I guess are not usual in the table.

we have just send to CVS some changes to logs (MDL-11893) in order to:

• only be notified once per day.
• in the notification get the database statement that caused the problem.

So, if you can update your site in 24 hours... hopefully some error will happen again and then, if you share the problematic statement here... we'll be able to try to fix it. TIA!

About the quiz problem... I really think they are unrelated (at least I cannot imagine any relation until we get the information above, to see if the problems in logs are happening when logging some quiz operations).

Anyway, I'd suggest you to:

• Create one new bug in the tracker (quiz related), giving as much info as possible and pointing to the discussion in moodle.org forums.
• Link the discussion back to the new bug in the tracker.

That way, quiz maintainer (Tim Hunt) will be able to suggest you things / request more information and detect where is the problem.

Thanks a lot! Ciao

Here are the contents of the email I got just now after replacing datalib.php file:

Insert into log table failed at Wednesday 16th of April 2008 07:23:05 AM.
It is possible that your disk is full.

The failed SQL is:

INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1208344985', '2', '13', '61.2.34.159', 'choice', '751', 'view', 'view.php?id=751', '15')

I wonder if it has anything to do with http://tracker.moodle.org/browse/MDL-13812 .

Insert into log table failed at Wednesday 16th of April 2008 11:50:06 AM.
It is possible that your disk is full.

The failed SQL is:

INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1208361006', '2', '1', '172.16.80.254', 'course', '0', 'view', 'view.php?id=1', '1')

and did you received those emails from the same server? Strange, because one of the things implemented is about to receive only ONE notification per day. Uhm...

Anyway, the offending SQL statement looks really perfect (no strange chars, correct numbers...). I've executed here manually and there isn't any problem with it.

So... next step should be about to examine MySQL logs to see if something is being notified there when your logs fail to be inserted.

I really cannot imagine any reason for this failing randomly. Perhaps some buggy MySQL version could be the problem? Or so very-very busy server? Only that and table needing repair/optimise are my ideas.

Ciao

I have not received that email since last 4 days. When I got most of those emails it appeared to be a very busy period for the server. There was an event and a very large number of users were accessing the site.

Now, how a busy server is linked to that message would be interesting to understand.

I would suggest to:

1) Analyse and optimise your database from time to time (it's a heavy operation, so it's recommended to perform it when the server is idle).
2) Test if MySQL concurrent-inserts can give you a benefit (http://dev.mysql.com/doc/refman/5.0/en/concurrent-inserts.html). I've some servers with that variable set to 2 and seems to make a good job, alleviating things under high concurrence. Not 100% guaranteed, but could be a thing to explore.

I'm going to close this because seems to be some problem in your end... feel free to continue commenting here if you need anything else.

Ciao

Insert into log table failed at Tuesday 01st of July 2008 12:45:33 AM.
It is possible that your disk is full.

The failed SQL is:

INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1214887533', '0', '', '67.195.58.180', 'resource', '0', 'view', 'view.php?id=', ' ')

However, some discussion about how to detect/fix the actual problem could be useful in the moodle.org forums

eg http://moodle.org/mod/forum/view.php?id=596

The SQL fails because it is an invalid SQL statement. The course field is set to blank. It should be a numeric value and MySQL is smart enough to know that it is a number even though it has ' ' around it...but since it is blank it mismatches the field type. I don't see how this is anything but a Moodle problem.

Would it be possible to add the error message the server returns when the query is executed to the e-mail? This would certainly help narrow down the cause of the problem.

The site load at the time was minimal (two actions in the same minute the log insert failed) so it appears that isn't the issue for us.

INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1221608191', '1239', '177', '84.77.159.214', 'user', '0', 'update', 'view.php?id=1239&course=177', ' ')

Our Moodle is 1.9.2+

I can see two ways to complete the information, adding these:

1) Dump the stack trace to know which script was the original caller of the add_to_log() call. That will help to know the originator of problems like the blank course commented by Matthew above.
2) Try to capture the error from the DB backend. It can show the final cause of the INSERT being rejected.

Ciao

INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1221754135', '781', '1', '62.88.87.237', 'user', '0', 'logout', 'view.php?id=781&course=1', '781')

Disk is certainly not full.
Tables checked and optimized.

lib/datalib.php, function add_to_log()

// MDL-11893, alert $CFG->supportemail if insert into log failed
if (!$result && $CFG->supportemail) {
$site = get_site();
$subject = 'Insert into log failed at your moodle site '.$site->fullname;
$message = "Insert into log table failed at ". date('l dS \of F Y h:i:s A') .".\n It is possible that your disk is full.\n\n";
$message .= "The failed SQL is:\n\n" . $sql;
if ($db->ErrorMsg()) debugging($db->ErrorMsg() .'<br /><br />'. s($sql)); <- This

My site does not has this problem, then I can not check this code.

MyISAM table with dynamic (variable length) rows, the index file for the table (tablename.MYI) stores row locations using 32-bit pointers into the data file (tablename.MYD). That means it can address only 4GB of space.

For a long time 4GB was an entire hard disk and most operating systems had trouble with files larger than 2GB, so when MySQL designed their engine they didnt

think for a while that there will be someone who will use that much of storage or at least reach millions of records in his table :s

from my point of view; the 32-bit pointer is ideal becasue most people are running MySQL on 32-bit hardware (Intel/Linux), hence, the 32-bit pointer is most efficient way to do this on 32-bit hardware.

okay okay.. I know I talked so much.. but how to overcome this problem? and enlarge the limit or 4 GB?

here we go,
we need first to show the table status by executing:

MYSQL>show table status like 'mdl_log' \G
then in the result set you will find Max_data_length: 4294967295 (4 GB).

To change the 4 GB, just execute

MYSQL>alter table mdl_log max_rows = 200000000000 avg_row_length = 50;

now you are done, but notice that the alter statement may take long time.

another note that if you are using 64-bit machine you will not need to execute the alter statement becasue the installation of mysql will increase the max_data_length accordingly.

cheers..

Amr Hourani!

In the 10th February, received:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1234243037', '1', '304', '67.195.37.173', 'slideshow', '7795', 'view', 'view.php?id=7795', '45')

And in 6th February:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1233897328', '1', '1', '67.195.37.119', 'course', '0', 'view', 'view.php?id=1', '1')

I don't know if it is important, but the FrontPage backup keeps returning errors.

• On the 20th of February:

Insert into log table failed at Friday 20th of February 2009 05:26:21 AM.
It is possible that your disk is full.

The failed SQL is:

INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1235107530', '1', '139', '72.30.142.245', 'resource', '0', 'view all', 'index.php?id=139', ' ')

• On the 23rd of February:

Insert into log table failed at Monday 23rd of February 2009 05:22:40 AM.
It is possible that your disk is full.

The failed SQL is:

INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1235366508', '1', '1', '74.6.22.103', 'glossary', '88', 'view entry', 'showentry.php?eid=48', '48')

• Can someone lpease tell me what is wrong. What do I need to do? Is it really a MySQL problem, or Moodle?

INSERT INTO log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1240436633', '1', '1', '189.34.46.213', 'course', '0', 'view', 'view.php?id=1', '1')

We've checked the server's load, cpu and memory usage and everything look normal.
We'll update to 1.9.4+ and comment again.

MySQL server has gone away.

We've moodle working with persistent connections but it didn't help.

At the same time one of the server CPUs hits 100% utilisation. The only way to get out of the situation is to stop the MySql server and then restart it. Apache then sends its error message "INSERT INTO" etc to our admin email address.

This is happening many times a day - probably 10 times yesterday. We are constantly resetting MYSQL just to keep classes running.

We have updated to the latest release Moodle 1.9.5+ (Build: 20090729)
We are at Mysql community version 5.1.36
We are running PHP 5.2.5 and about to try 5.2.10

Our Mysql runs two installations of moodle (one configured as a staff portal and one for students) - I hope this helps - I will butt out now let the real guru's get on with the job - Thanks to all.

Thanks in advance

Gaurav Parashar

as commented above we cannot really do much here but:

• Test if MySQL concurrent-inserts can give you a benefit (http://dev.mysql.com/doc/refman/5.0/en/concurrent-inserts.html). I've some servers with that variable set to 2 and seems to make a good job, alleviating things under high concurrence. Not 100% guaranteed, but could be a thing to explore.
• Whenever an error happens, report the whole error trace and the sql error, instead of only reporting the insert command, just to see if there is some "wrong" insert somewhere (to fix cases like the one commented by Matthew Davidson above) and what exact type of error is happening in the DB.

But really we cannot do too much else if the insert query is ok (like all cases above but the Matthew one) and the DB is giving errors.

Insert into log table failed at Tuesday 20th of October 2009 02:06:10 PM.
It is possible that your disk is full.

The failed SQL is:

INSERT INTO m_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1256007970', '102531', '3405', '138.77.69.73', 'calendar', '0', 'delete', '', 'Assignment 1 due')

The database seems fine otherwise.

Thanks,
Brad

I think it's the fact that, in the m_log table, all the fields have a 'NOT NULL' constraint, and SQL statements like yours (and some I've seen on our system) try to put the empty string (i.e. '') into one of the fields (like the 'url' field in the SQL statement in your example). Our Moodle administrator contacted me with a similar example, but in our case, the empty string was for the 'action' field.

Perhaps it would be enough to take the 'NOT NULL' constraint off a few of those fields (at least the 'action' and 'url' fields)? Can anyone reading this think of anything in Moodle 1.9.5+ that would break if some of the fields in records in the log table were empty?

Cheers,
Guy.

This bug remains open since ages because of MySQL prone to fail inserting records from time to time and we haven't found any cause in Moodle, but some ideas to avoid that concurrence of workaround it.

So, for the Oracle problem... fixing/testing now... I'll keep you informed. Ciao

Insert into log table failed at Wednesday 04th of November 2009 09:17:10 PM. It is possible that your disk is full.The failed SQL is:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1257391030', '7671', '1', '203.159.103.19', 'user', '0', 'logout', 'view.php?id=7671&course=1', '7671')

Insert into log table failed at Wednesday 28th of October 2009 10:17:01 PM. It is possible that your disk is full.The failed SQL is:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1256786161', '0', '0', '130.126.76.67', 'login','0', 'error', 'index.php', 'mbarton2')

Insert into log table failed at Saturday 24th of October 2009 10:21:39 PM. It is possible that your disk is full.The failed SQL is:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1256440839', '7729', '1013', '130.126.165.185', 'course', '0', 'view', 'view.php?id=1013', '1013')

I've altered the page to email the specific MySQL error. We'll see what happens.

Insert into log table failed at Wednesday 04th of November 2009 09:17:10 PM. It is possible that your disk is full.The failed SQL is:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1257391030', '7671', '1', '203.159.103.19', 'user', '0', 'logout', 'view.php?id=7671&course=1', '7671')

Insert into log table failed at Wednesday 28th of October 2009 10:17:01 PM. It is possible that your disk is full.The failed SQL is:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1256786161', '0', '0', '130.126.76.67', 'login','0', 'error', 'index.php', 'mbarton2')

Insert into log table failed at Saturday 24th of October 2009 10:21:39 PM. It is possible that your disk is full.The failed SQL is:
INSERT INTO mdl_log (time, userid, course, ip, module, cmid, action, url, info)
VALUES ('1256440839', '7729', '1013', '130.126.165.185', 'course', '0', 'view', 'view.php?id=1013', '1013')

I've altered the page to email the specific MySQL error. We'll see what happens.

We've increased our MySQL log level to see if we can get any more details on this error.

if they are "incorrect" insert sqls, then we can fix them. If they are correct sqls, then all we can do is to blame MySQL, or recommend ppl to switch from MyISAM (table locks) to InnoDB (row locks, plus a lot of nice extras like proper isolation, transactions...).

Ciao