CodeChef server

Why was the CodeChef site very down today the judge was also very slow and was taking to much time to judge the solutions also there was problem logging to the site there were too many HTTP error messages.


It took more than 10 mins to judge my code. We were stranded in a state where we couldn’t proceed further waiting for the results. Please improve the performance of the server. It is very frustrating :slight_smile:


Man, Its very frustrating… !! I submitted a solution in the last 2 mins and poor thing it is still running even now!!! God bless codechef …!! Phew!!

I also felt the same. My submission took 10 mins and finally i got TLE and so i had to recode my solution. So I could not proceed with the next problem waiting for 10 mins and the resubmission also took a lot of time. Also I felt the contest could have been extended for 30 mins.

I know that the judging was really slow, But you can’t just blame them.

In contests like Google CodeJam and Hackercup, you don’t get to resubmit as well as you don’t get to know if your solution is right or not.

So probably, it is good if we are accurate from our side.

PS - My team made 4 wrong submissions :stuck_out_tongue:

No point blaming code chef but they banned my IP (i don’t know why??) during the last 10-15 mins and i was unable to submit solution to problem F.

Probably i should have done it faster.

Couldn’t Submit solution to 4th problem !! trying all the time in last 20 min . :frowning:
Surely should have done it quickly but it would had made the difference .

Judging took too much time !
Codechef need more servers to handle huge number of submissions.


account got automatically got logged-out in last few minutes :frowning:


Also there was a big difference between the difficulty level of last two questions and the 4th and 5th question.

Same problem here. Waited too long(10-15 minutes) just to see a runtime error due to a minor mistake, could have been corrected very early if the problems were judged fastly. Couldn’t even submit the problem in the last 20 minutes as we got logged out automatically, and on logging in, the multiple login session problem occured (I even took the screenshot of it showing 5 sessions simultaneously). It would have made a huge difference, codechef should take appropriate measures towards it (if possible).

No matter how accurate you become, each and every minute is important. You cant just resolve the situation by saying that we should’ve solved the problem a bit faster. That’s not how this works. It’s all about when the solution hits you. Its Codechefs fault and they should’ve known better.

A few things we need to make clear.

  1. There was no issue on the CodeChef website till the last 2 minutes of the contest. Apart from occasional 503’s (an error that we throw when we have too many requests coming in from a single IP or overall on the website) and a forced “no submission allowed now, try after a minute” message in between, there wasn’t any issue in browsing the website, opening problems and making submissions. And these can be overcome by just refreshing the page. The site wasn’t slow.
  2. Throughout the contest, the submission queue got much higher than the usual. Due to this everyone got their submission feedback late than the usual. However, this was same for everyone without any exception. This happened for the obvious high number of users and also because of the fact that we had relatively much higher number of easier problems in a short contest for such a large number of users. This is something where we went wrong in estimating the capacity of our judge servers. Our judge infra is not on the cloud for many technical reasons, and hence we could not pull up more instances on demand. We did put in extra servers (as many as were available) in the infra, but the rate of number of submissions was always higher than the rate of the solutions getting judged. We certainly made a mistake here - we must have had more number of judge servers or lesser number of easier problems (something that the problem setting panel wanted to have to encourage all the programmers and to not select teams based on penalties but on the number of problems solved).
  3. In the last 2 mins, for reasons that we are still investigating, the site did become slow and users were logged out. We suspect some issue with the AWS RDS, but we can only know after some investigation. This did cause people to not be able to submit during this very small time period.

I agree that in a contest like this, the result feedback should have been faster, and that even a single minute’s inability to take in submission could potentially become a big loss for a few teams. However, I disagree that any of this made the contest unfair to anyone apart from those who could not submit in those ending 2 minutes. And it hurts to see the exaggerated numbers for the period of time when the site was not functional. We were basking in the success of hosting one of the biggest contest ever on CodeChef without any issue when the last 2 minutes happened. And before anyone complained, it was visible on our monitoring screens that something has gone wrong.

So while, we have always acknowledged our mistakes and appreciated critical feedback, it is very important to keep it factual. When we feel that something is not working on a website, there can be various reasons for the same. Some people who faced slowness, did call in to our helpline numbers or pinged me and the team on FB or social media. We kept answering their queries and figured out that it was either their internet that was slow or the browser was acting up. I am not saying that all your issues would be related to that, but unless we get factual feedback, there is no way we can work on it to improve. If anyone here feels that we have improved from where we used to be, it is only because of your feedback and our keenness to accept our mistakes.

Thank you everyone.


Same with me. Waited too long(10-15 minutes) just to see a TLE due to a minor mistake and also not able to submit in last 2-3 minutes

If there was some problems in the last few minutes of the contest, contest should have been extended by 5-10 minutes because in a contest like this every minute is precious. So overall the contest was less than 3 hours.

Those two minutes of yours at the end wasted a whole year of mine preparing for the contest…I had solution of 5th ready and they logged me out…What should I do now???
Did the number of teams suddenly increased during the contest…You must have had full idea of the quantity of the submissions that will be made??
And Leave alone yesterday,Site many a times show Server is overloaded during normal days …Why???

The waiting time for the result of a submission depended on the length of the submission queue which varied throughout the contest. To assume that each team had to wait for the same amount of time is inaccurate because it is like assuming that all teams submitted solutions at the same time.
Besides, in such a scenario, if you have a Wrong Answer, you have to wait for 10 minutes, then stop thinking about the problem you were working upon and come back to the WA problem. This discontinuity hampers the overall performance. So teams who are in the habit of getting AC after 2 or 3 WAs are doomed.


@anup :diamonds::diamonds: The problem was not just in the last 2 minutes. It was 20 minutes before the contest when we got logged out automatically, and after logging in, we faced the multiple login problem, disconnecting other session was not working. After 10 minutes when it worked, we made one submission in the last 2-3 minutes, and it said something “Not allowed”.Then we opened the submission page and then the language option was not showing any field for 4-5 times.The contest ended after that. Such things should not happen for a contest like ACM ICPC.Even last 2 minutes are crucial in such acontest.

@anup Also we emailed codechef just after the contest regarding this problem and also uploaded the screenshot of multiple login sessions, but no one has replied till now.

@thezodiac1994 Rightly said, it makes huge difference on getting a WA and a AC after such a long judging time.

I just don’t know what people at Codechef office are happy about. Reference:

There servers weren’t ready to take the load of the high submission rate but still they went for the Common Online Test. My team was logged out 9-10 times due to session limit and the submission’s were in Queue for more than 20 minutes. It’s just frustating.