Problem with Bluehost Varnish Caching

[Aramaech]

----- Main Issue
I'm wondering if anyone else here uses Bluehos's cloud server plan, and if they have problems with Bluehost's server side Varnish caching system.

My site's been having this ongoing issue where, when the Varnish caching is enabled on my Bluehost account (Bluehost login > performance > caching control), we get what we've not so fondly come to call "the logout bug".  The effect being that the user is automatically logged out on the sites main home page, but is not logged out anywhere else on the site.  Visit some sub-forum, logged in.  Visit the home page, logged out.  Back to the sub-forum, logged in again.  

We were eventually able to narrow it down to a host side caching issue, and disabling the Varnish caching on the Bluehost account works to resolve the bug.  ...that is until Bluehosts cloud servers come under too heavy a load, which causes the Varnish caching to automatically come back on, thus triggering the bug.  

Bluehost's explanation of this thing as that it's unavoidable.  That it's might not even be our site causing it, any site on the cloud going under a heavy load will cause ALL varnish caching on All sites on those servers to kick on.  So I figure, if it's not our site causing it, at least Someone else must have experienced this issue... and maybe, just maybe, someone here knows how to fix it.  Permanently.


Below is a preemptive list of settings that perhaps could be relevant.  

-----  Considerations
! = suspect

• We recently started using Cloudflare free CDN to lessen to server load.  Problem still occurs occasionally tho.
!• AdminCP > Posting > General Tab > Remote Images > Serve images from local server > is set to on (We have a SERIOUSLY image intensive gaming forum.  Perhaps this is causing the heavy server load?)
• AdminCP > Posting > General Tab > Remote Images > Allow Remote Images > is set to on
• AdminCP > Posting > General Tab > Remote Images > Cache Remote Images > is set for 7 days

!• AdminCP > Advanced Configuration > Server Environment Tab > Cache Sidebar, header and footer blocks > is set to 6 minutes.
• AdminCP > Advanced Configuration > Server Environment Tab > Enable Automatic Polling > is set to on
• AdminCP > Advanced Configuration > Server Environment Tab > Enable Template Disk Caching > is set to on

• AdminCP > Advanced Configuration > Data Storage Tab > Data Storage Method > is set to File System
• AdminCP > Advanced Configuration > Data Storage Tab > Caching Method > is set to -No caching-
!• AdminCP > Advanced Configuration > Data Storage Tab > Caching page output for guests > is set to 10 minutes, as of yesterday.  Before that it was set to 6 minutes for a few months. Before that, it was set on 30 seconds.

!• We do have quite a few 3rd party plugins installed, as well as a couple apps, and quite a few extra ckeditor buttons.  The issue was happening with all of them disabled (not the cke editor), but maybe having them all installed is enough?

[Xenboy]

You have way too many variables here to be able to track down the problem successfully (short of pure luck). Did you try installing a test version of IPS in the same account and see if the problem goes away with a plain install with no other themes, plugins or other items installed? If it doesn't go away then chances are good that the issue may be related to the caching. Caching isn't magic, though it can really help to cut down on the load generated by constantly updating dynamic content. The caching can cause unexpected issues all by itself. If the problem finally goes away on the test install of IPS after you turn off caching, then you know that's probably the issue. It may be that your settings aren't allowing IPS to do what it needs to do.

Of course if it does go away on the test install then it is probably your customized IPS installation that is the problem. Unfortunately, the only way to narrow things down is to add one plugin or theme back to your test install at a time until the problem returns and you know the item you added last is contributing to the issue. Disable the setting, plugin or theme and either do without it or find something else to do what you need to do.

Good luck!

[GrandTheftArmA]

Quote

 

 AdminCP > Advanced Configuration > Data Storage Tab > Caching page output for guests > is set to 10 minutes, as of yesterday.  Before that it was set to 6 minutes for a few months. Before that, it was set on 30 seconds.

 

Disable guest caching should solve your issue.