Caching & Application Cache in Cluster

Re: Caching & Application Cache in Cluster

by Jeff White -
Number of replies: 4
You cant use Redis 100% for all parts of your "caching" as cache, temp, muc (moodledata/muc),  lock, and more will still use a directory that must be shared.


  1. How to setup Redis for MUC application/session cache. Note that MUC session cache is different from the session cache you set in your config.php. 
    1. Go to cache/admin.php
    2. Click add instance on installed cache stores on the redis row
    3. Add your redis server
    4. Scroll down to Stores used when no mapping is present
    5. Click Edit Mapping
    6. Change application & session to your redis instance.

I would love it too if I could use moodledata for only filedir and some other files. Hopefully we will get there one day. 

Average of ratings: Useful (3)
In reply to Jeff White

Re: Caching & Application Cache in Cluster

by Luis de Vasconcelos -
Thanks Jeff

Note that MUC session cache is different from the session cache you set in your config.php.

Can you explain this further? How many caches are there?

What caches go in Redis and what caches don't go in Redis?

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In reply to Jeff White

Re: Caching & Application Cache in Cluster

by Saad Zaman -

Thanks a lot Jeff for this insight.

Do you have any idea of what parts of moodle rely on these ", temp, muc (moodledata/muc),  lock, " i just want to be sure , what areas of the system will degrade when i move to NFS

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In reply to Saad Zaman

Re: Caching & Application Cache in Cluster

by Jeff White -

Ill refer to Howard's post:  https://moodle.org/mod/forum/discuss.php?d=385374#p1553414

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In reply to Jeff White

Re: Caching & Application Cache in Cluster

by Saad Zaman -
"Some aspects of the cache system are shrouded in mystery"


Lol Looks Like We as a community agree on this :D 

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