1.6 - release notes

This version of Mooshak introduces a considerable amount of new features and fixed a few bugs

New Features

  • Modifications in SafeExec

    One of the major improvements in this version is in SafeExec - the sandbox where programs are executed in Mooshak - resulting from a contribution of Mohit Nanda mohit.nanda@tcs.com. He made this contribution while working for Tata Consultancy Services, a software consultancy firm based out of India. With this performance enhancement Mooshak is able to support more teams per server.

    A paper describing these modifications was published in the "International Conference for Computer Applications 2010 [ICCA '10]" and presented in Pondicherry, India on 26th December, 2010.

  • Web services

    Mooshak was originally designed as a web application for managing contests and later adapted for e-learning. Mooshak now exposes also two of its core functions as RESTful web services:

    Evaluation

    With this service a remote program can invoke a Mooshak server to evaluate a program. It must provide the program itself, an URL to download the programming exercise (or a local problem reference) and a reference to the evaluation capability (basically the contest and programming language configured in the server).

    Repository

    With this service Mooshak can be used as a programming problem repository. Using just an URL a remote program can download programming problems/exercises from a Mooshak installation. Hence, a Mooshak installation can act as a repository for other Mooshak installations acting as an evaluator.

    To activate these features you need to set the service type you want to provide (or both) at the Service field in the contest folder. There is a new contest type Service that activates all the required fields for this type of contest. To set the contest type use the Contest > Type ... command on the contest's folder.

    To grant access to a remote system you must create a "team" with its IP number. Note that the dots in IP numbers must be replaced by underscores. If you try to enter an IP number as team id then Mooshak will automatically replace these characters.

    There is a proto_service contest on the distribution of Mooshak that exemplifies these configurations,

    To test these features just add service.html to the URL of your Mooshak installation. If you Mooshak is accessible at http://localhost/~mooshak/ you will find the service sandbox at

    	http://localhost/~mooshak/service.html
          

  • Support for Mono

    Mono is an open source implementation of Microsoft's .NET Framework based on the ECMA standards for C# and the Common Language Runtime. With Mono it is possible to use Windows languages that traditionally require IDEs available only on that operating system. Support for Mono was introduced in Mooshak following suggestions of Mohit Nanda.

    The major issue is the fact that Mono processes must run on a specific user ID (UID). By default Mooshak uses a range of UIDs to be able to control forks, as these in Linux are controlled per user. Thus, when configuring a language supported by Mono you must enter a specific UID created for that purpose.

  • Bulk reevaluation

    The reevaluation is a feature available since the first versions of Mooshak. In a contest it is sometimes necessary to reevaluate submissions, for instance: if an error is detected in a test case; or if the evaluation process was not completed, due to the excessive load of the server. When used on a regular basis as a pedagogical tool, the occurrence of this kind of problem increase significantly.

    There is now a menu on submission folders named Reeval aggregating bulk reevaluation commands. The first command in this menu reevaluates all submissions in the folder. The other commands provide different criteria to select the submissions that must be reevaluated: by classification, by programming language, or by problem.

  • Improvements in quizzes

    Mooshak has support for quizzes as a complement for automatic evaluation of programs but this feature is being used in courses from other areas, such as mathematics. To support this use were introduced two new features:

    LaTeX import command

    This command imports quizzes in LaTeX format. Imported quizzes must follow a special LaTeX style that is available on the dialog box of the import command.

    MathJax support

    LaTeX expressions in these quizzes will be displayed using MathJax. Mooshak proxies the latest version of MathJax to ensure that quizzes can be used in a controlled setting where students computers can only access the Mooshak server.

  • LaTeX expressions in problem descriptions -

    Although MathJax support was introduced for quizzes, it can also be used in HTML problem descriptions. To use MathJax in HTML files uploaded to Mooshak make sure they contain in the header the following tag:

        <script type="text/javascript" src="../mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
        

    In that HTML file you can include LaTeX math expressions surrounded by \( \) or \[ \ ].

  • Listings optimizations

    Mooshak generates lots of listings: submissions, rankings, questions. These listings are produced when teams/students submit a problem or ask a questions, but they are also regularly pooled just to update the interface.

    When Mooshak is used in very large contests or classes, with several thousands submissions, large listings become a burden to the server. The creation of a network of servers balances the load of compiling and executing programs, but not the load of generating listings. To cope with this issue the following features were implemented in Mooshak.

    Incremental ranking listings

    In contests with thousands of submissions rankings take too long to compute. Mooshak now supports policies that compute rankings incrementally. In this version there is an incremental variant of the ICPC policy, also used as default policy. Other incremental policies may by added in future versions.

    Listing cache

    Listings take time to compute and produce a considerable amount of I/O. On the other hand, Mooshak has to produce many similar listings since by default they are updated by pooling the server on regular intervals (typically 5 minutes). This new feature reused a similar listing (a request with the same parameters) produced recently (be default, less than 1 minute ago). The cache is not used if the user has made a recent change (less than 1 minute). Thus, if a team submits a problem, or asks a question then a fresh listing is produced.

    To activate this feature you need to set to yes the Incremental flag on the contest folder. This feature is not automatically set since it was reported to occasionally produce inconsistent listings, in situation that were not possible to reproduce. Hence, you should only use this feature in contest with a large number of participants (several hundreds)

    Note: this feature requires tcl version 8.6 or higher and will be automatically disabled on previous versions, even if the flag is set.

  • Searchable questions

    During contests (or classes) teams (or students) ask the same questions repeatedly. To avoid this question listings are now searchable. On the header of these listings there is a field where the users can type query terms to filter questions listing. The questions are sorted by relevance and questions where the search terms occur in the subject are considered more relevant than those where they occur in the text.

  • Problem release schedule

    A start and stop date/time can now assign to each individual problem. If a problem has a start date/time them neither is the problem description shown before that moment, nor are submission to that problem accepted. By the same token, if a problem has top date/time them neither the problem description are shown after that moment, nor submission to that problem are accept.

    These date/time are absolute and should be within the start-stop interval of the contest. However, if the contest is used on virtual mode then these date/times are adjusted to the moment the team/student first logged to that contest.

  • Single simultaneous team session

    In large on-line contests team members tend to open several sessions, thus increasing the server(s) load. To prevent it Mooshak can be configured to disallow multiple simultaneous sessions on team accounts.

    This configuration is available on the data/configs/sessions folder with the Single session field set as no. It affects only teams. Other profiles, such as admin and judge continue to be able to have multiple session, even if this configuration is set.

  • Importing teams data from CSV files

    A new command Data > import ... in the Groups folder enables the import of a Comma-Separated Values (CSV) file with teams data. The file content must have 1 record per line and columns separated by commas, semi-colons or tabs. Separators are automatically detected.

    An optional header line may assign a names to columns. The type of each column is automatically inferred from the headers, if possible.

  • Generate and export passwords in Excel format

    A new command for generating and exporting passwords to an Excel format is now available on Group folders. This feature was a contribution of Arjun R P and Pranav M, both BSc final year students in Amrita University, in India.

  • Arabic translation

    Mooshak interface is now also available in Arabic thanks to Shadi Saleh.

  • Session count broken by profiles

    On the header of the left column in the admin interface, the number of open sessions is displayed broken by profiles. So, now you can check how many teams, or guests are using Mooshak.

Fixed bugs

  • Major security holes (thanks to Pakeo palkeo@gmail.com and to a student of Steven Halim stevenhalim@gmail.com)
  • Tests are now executed by the lexicographic order of their path-names
  • Feedback works with uploaded test files
  • Name clash in variable ($classify) used in dynamic correctors
  • Error in replication when servers use an alias as internal name (thanks to Robert R. Enderlein mooshak@hc2.ch
  • No crontab for username when checking submissions
  • Error in feedback when no test cases where defined
  • Error when exporting problems from contests without dates
  • Undefined variable errors in CenTOS
  • Removed redundant users
  • Safeexec library flag to compile in recent version of Ubuntu