[Building Sakai] Building scalable Sakai tools

[Mark Breuker]

Hi all,

We are experiencing performance issues with Mneme in a worksite that has around 2500 students. When an instructor wants to open the list of submissions per quiz / assignment the page takes around 1 minute to load :( We asked Edia to investigate the issue for us (see analysis attached) and found some parts in the code that can be improved.

We are also seeing similar performance issues in other tools. Assignments also performs very badly. Assignment 2 is a lot better but still takes around 6 seconds to load a similar page with the same amount of users/submissions. I know Alan Berg has also documented slow performance in a number of other tools here: https://confluence.sakaiproject.org/display/WGMOOC/MOOC+Scalabilty

In order to move forward and fix the issue in Mneme (and other tools) I would like to know if there are common design patterns that can (and should) be used when doing thinks like loading a list of all users in a site combined the date they submitted an assignment. Arguably the best way would be to perform a SQL JOIN query (that joins the site member info with the submission info) on the database but that would brake the service oriented design of Sakai.

Bottom line: I'm looking for some input to document design patterns for highly scalable Sakai tools. I've started a page on Confluence here: https://confluence.sakaiproject.org/x/owPzB

Cheers,

Mark

Mark Breuker
Product Owner
Tel.: +31 71 5451 203

Leidse Onderwijsinstellingen bv
Leidsedreef 2
2352 BA Leiderdorp
www.loi.nl

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