Bug Guest Cache is Longer than Expected

[semprot]

I notice that on latest version 3.4.0, guest cache is longer than expected.
I see it caches item up to 40 minutes.

Here is my setting :

operator : memcache
default cache ttl : 300
guest full page caching ttl : 600
cache data registry : 0
cache who's online : 60

other cache settings : off

Flushing memcached from memcache custom admin script works fine.

 

[Fillip H.]

This is working as intended. For performance reasons, Optimise doesn't scan the full list of keys to look for expired values - that would be extremely inefficient on sites as large as yours.

The only way those expired entries would get flushed would be for the guest that generated the cache entry to come back. They would then hit the cache, see it's expired and request a fresh page.

We do set Memcache's Expire flag as well, so if Memcache doesn't auto-prune expired keys then this is a problem with Memcache, not Optimise.

 

[semprot]

Okay after i observed my forum more as guest, i think the problem is not really as described in my first post.

Here is the problem :
In home page only, the cache seems lives longer, because on home page, on a sub forum, i see last post time is 40 minutes ago.
But when i click that sub forum, and i see list of threads, the cache TTL works fine as expected.

So i think somehow it happens only in my home page.

You can compare cache result of this sub forum

http://www.semprot.com/forums/gambar-cewek-indonesia-igo.326/

between in home, and when navigating that sub forum.

Now i'm experimenting with turning off "Cache Data Registry", whether it will affect the home page cache issue or not.

And it's not my memcached, because i made a simple PHP script to get & set cache with various TTL, and the script works fine.

Update : here i attach 2 images, when i mouse over on the time of the last post

Update 2 : in home, i see last reply in [bd] widget shows correct post with correct TTL. So it seems problem happens only in home, only in normal post information

 

[semprot]

Fillip H. : have you checked this issue?

Thank you

 

[Fillip H.]

I don't have any further information at this time. I think the best course of action is to wait and see if this is a widespread issue, as I don't even know how I would begin looking into this.

If we get more reports in, maybe a pattern will emerge

 

[semprot]

I don't have any further information at this time. I think the best course of action is to wait and see if this is a widespread issue, as I don't even know how I would begin looking into this.

If we get more reports in, maybe a pattern will emerge

I've found the cause.

It is another add on :
Optimized List Queries by Xon | XenForo Community

That add on has additional feature to cache node for guest.

Therefore DB optimise caches the cache result of that add on.

I've disabled "cache node for guest" feature of "Optimized List Queries" add on, everything works now.

This is not a bug

 

[Fillip H.]

Great, thank you for getting back to me