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mjnaderi / Sharif-Judge

A free and open source online judge system for programming courses
https://github.com/mjnaderi/Sharif-Judge/tree/docs
GNU General Public License v3.0
388 stars 152 forks source link

Queue failed to process if submission take too long to complete? #32

Open truongan opened 9 years ago

truongan commented 9 years ago

Long story short, my assignments has one problems with fairly large test case. The whole problem would take Total Execution Time: 37282 ms to complete. And then the submission status just stuck at PENDING

I ssh into the server and execute php index.php queueprocess run to see the output (after change line 56 in index.php to define('ENVIRONMENT', isset($_SERVER['CI_ENV']) ? $_SERVER['CI_ENV'] : 'development'); of course)

PHP Fatal error: Call to a member function row() on a non-object in /home/judge/web/testjudge.truongan.name.vn/public_html/application/models/Scoreboard_model.php on line 131

The fatal line was: $scoreboard_enabled = $this->db->select('scoreboard')->get_where('assignments', array('id'=>$assignment_id))->row()->scoreboard;

I tried to var_dump($this->db->select('scoreboard')->get_where('assignments', array('id'=>$assignment_id))) and it print out bool(false)

So my best guess is that the database access failed somehow. I was not familiar with CodeIgniter enough to investigate any further. Even The backtrace failed to printout (I don't know why) though I believe it start from applicatiopns/controllers/Queueprocess.php:135 $this->queue_model->save_judge_result_in_db($submission, $type);

Also the source code was in C++, I had sandbox turned off because it increase execution time too much. When I did try to upload a simple "Hello world" program to the problem it execute fast enough for the system to just it as wrong. But the solution for the problem just stuck at PENDING because it took longer to executed.

If you need any more information just let me know.

mjnaderi commented 9 years ago

What database are you using? Add echo $assignment_id; before that line, and see the result.

truongan commented 9 years ago

Hi @mjnaderi Thank you very much for your fast reply. I'm using mysql, echo $assignment_id; print out 2 which was the correct id for my assigments.

And FYI, adding $this->db->reconnect(); to the file applicatiopns/controllers/Queueprocess.php: before line 135 seem to fix the poblem for me. Could you verify it please?

mjnaderi commented 9 years ago

--Updated-- It seems that database connection times out. This is how reconnect is implemented for mysql driver: https://github.com/mjnaderi/Sharif-Judge/blob/Version-1/system/database/drivers/mysql/mysql_driver.php#L168 And this is how reconnect is implemented for mysqli driver: https://github.com/mjnaderi/Sharif-Judge/blob/Version-1/system/database/drivers/mysqli/mysqli_driver.php#L138 Dump the result of mysql_ping($this->db->conn_id) or $this->db->conn_id->ping().

mjnaderi commented 9 years ago

Also check connection timeout in MySql settings, and try increasing timeout using mysqli_options, just before running submitted code.

truongan commented 9 years ago

mysql_ping($this->db->conn_id) failed I guess, it simply printed out NULL and caused a warning message

Severity: WarningMessage: mysql_ping() expects parameter 1 to be resource, object givenFilename: /home/judge/web/testjudge.truongan.name.vn/public_html/application/controllers/Queueprocess.phpLine Number: 135

$this->db->conn_id->ping() dump out

bool(false)

And for the dbdriver info, I'm using mysqli.

linhtlthp commented 9 years ago

Lien he voi minh!

2015-05-09 9:15 GMT+07:00, truongan notifications@github.com:

mysql_ping($this->db->conn_id) failed I guess, it simply printed out NULL and caused a warning message

Severity: WarningMessage: mysql_ping() expects parameter 1 to be resource, object givenFilename: /home/judge/web/testjudge.truongan.name.vn/public_html/application/controllers/Queueprocess.phpLine Number: 135

$this->db->conn_id->ping() dump out

bool(false)

And for the dbdriver info, I'm using mysqli.

Reply to this email directly or view it on GitHub: https://github.com/mjnaderi/Sharif-Judge/issues/32#issuecomment-100411843

linhtlthp commented 9 years ago

Minh da lam Full code va chay oke!

2015-06-10 23:44 GMT+07:00, Linh Pham Van phamvanlinh.group@gmail.com:

Lien he voi minh!

2015-05-09 9:15 GMT+07:00, truongan notifications@github.com:

mysql_ping($this->db->conn_id) failed I guess, it simply printed out NULL and caused a warning message

Severity: WarningMessage: mysql_ping() expects parameter 1 to be resource, object givenFilename: /home/judge/web/testjudge.truongan.name.vn/public_html/application/controllers/Queueprocess.phpLine Number: 135

$this->db->conn_id->ping() dump out

bool(false)

And for the dbdriver info, I'm using mysqli.

Reply to this email directly or view it on GitHub: https://github.com/mjnaderi/Sharif-Judge/issues/32#issuecomment-100411843

truongan commented 9 years ago

Can adding $this->db->reconnect(); to Queueprocess.php:134 be considered a fix to this problem? I think we can mark this as resolved, if you too busy to commit a fix I can send you a ping request