Hi,
in our deployment with Seafile PRO 6.3.13 on Ubuntu 18.04.2 LTS we experienced that the Web UI is slower after adding “memcached” as described in
https://manual.seafile.com/deploy/add_memcached.html
Page loads in about half a second when navigation through the UI instead of instantly (no delay) without this option.
So we removed it.
Can anyone explain what performance should exactly be improved by adding “memcached”?
Would it improve anything else besides Web UI navigation?
There seems to be an ongoing controversy over memcached and how to deploy it on Seafile. Sadly, I think I’ve seen this behavior as well where pages visibly appear to display slower after memcache is deployed.
Can you check your results against what is posted here and see if there are any errors in the logs?
Thanks
I will find some time to test it
In general: what should be the benefit of memcached? Just the Web UI faster or if more, what else?
Because even without, our Web UI of Seafile is lighting fast in response time - just not with memcached 
The manual is not so clear what performance boost to expect.
I have never seen a formal statement from Development but there is this from the Manual:
Seahub caches items (avatars, profiles, etc) on the file system in /tmp/seahub_cache/ by default. You can use memcached instead to improve the performance.
By extension I assume it also includes icons and thumbnails, presumably to speed the redraw of directories with many files.
I have not seen anything that quantifies the alleged improvement.