Guys,
on ipb3 and nginx we had a huge discussion how to cache and tweak sites.
Now we are going to move from 3 to 4 and we have a crazy issues with site performance.
Imaginge that gallery main page is loading 16-20x longer that it was loading on ipb3. Forum main site is loading about 50-100% slower than on ipb3.
We have enabled memcached and php7 optimization and it looks really crazy becase sometimes gallery is generated in 100ms, sometimes is generated in 2s, what is interesting when I test on firebug I see such a load times:
900ms, 80,900,900,900,80,80,900,80,900,80
memcached is set for 60s.
On other board - which is very small i have such times:
500,60,60,60,60,500,60,60,60,60,500.
Which definietly shows me that on first server something is wrong with caching. On second site it looks very good: first time - collect data from db, process and store to memecached, second, third, forth and others: collect data from memcached, next one - regenerate data: collect from db, process, store to cache.
How to handle this topic? Any hints?