Quizzes Loads Slow - Other functions working fine

Quizzes Loads Slow - Other functions working fine

by Shelly Vaughan -
Number of replies: 5

Redhat Linux 7.6
Apache 2.4.6
PHP 7.1.30
Postgres 9.4.23
Moodle 357.2019-07-18
20 GB RAM
24 Cores CPU

Moodle quizzes (view.php) loading takes about 8-10 seconds, Creating an attempt(attempt.php) takes 8-15 seconds regardless of quiz size or question types.  Quiz questions with small images as part of the question or answers takes an additional 8-10 seconds per image to load. For quizzes with only text questions and a few images, all the text of the questions load - but it takes 8-15 second later to load the images.  The load issues for images when using legacy files is loads within 1-3 seconds. 

We are not experiencing any load/performance issues with any other functions, including functions that have images such as assignments, web pages, forums etc. The issues seem to be related the quiz function.  We recently migrated our system to a new server as outlined above.  Any direction would be appreciated.

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In reply to Shelly Vaughan

Re: Quizzes Loads Slow - Other functions working fine

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers
Firstly, did it work ok on the "old" server?

Can we get some more detail of the architecture. Is this a single machine? Is it a VM? Anything else you can think of. What, if anything, have you done to tune Apache and Postgres? What monitoring have you got (e.g. munin) so that you can see if anything odd is happening during quizzes? Do you have any non-core quiz questions?

On the face of it (from the information given) there's nothing jumping out that would explain this, so it's going to be something you haven't told us?
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In reply to Shelly Vaughan

Re: Quizzes Loads Slow - Other functions working fine

by Alain Raap -
Picture of Particularly helpful Moodlers
Shelly, there is an open Moodle Tracker about a quiz performance issue, don't know if this could point you in a good direction: https://tracker.moodle.org/browse/MDL-66199?jql=project%20%3D%20MDL%20AND%20component%20%3D%20Performance

How did you test the performance, how large is your database (in memory?) and do you use a caching server like Redis or Memcache?
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In reply to Alain Raap

Re: Quizzes Loads Slow - Other functions working fine

by Shelly Vaughan -

Hi Alain,

 

Thanks for following up.  We identified the issue as we had moved servers and the Postgres autovacuum was off.  We now have it configured to run daily.

 

Shelly

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In reply to Shelly Vaughan

Re: Quizzes Loads Slow - Other functions working fine

by Alain Raap -
Picture of Particularly helpful Moodlers
Shelly I’m glad your problem is solved, btw we share (nearly) the same server configuration, feel free to have a chat to exchange experiences. We use MariaDB
for the database.
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In reply to Shelly Vaughan

Re: Quizzes Loads Slow - Other functions working fine

by Mei Ling -

Hi Shelly,

Mind to share what is the issue and how you have solved it? Our university faced the quizzes slow issue as well, but we're clueless now. Appreciate if you can share some tips here.

Thanks!


Average of ratings: Useful (1)