Smarty

[mohrt]

Is this a single server or a cluster? Is the cache on a shared file system? What exactly has changed in your environment aside from PHP? Are you able to run a test with a "downgraded" version of PHP, leaving all other environment conditions the same?

[Moggia]

It's several load balanced single servers, and the error occurs on all of them.
The cache is on a ram disk in test and production, and on a disk on dev.
The only thing that has changed is that our production environment now uses Ubuntu Linux instead of Red Hat Linux. But I have seen the error also on dev, and in development we use OS X.

The error is very hard to reproduce cause it happens so rarely. Actually in production we keep a log of a certain part of our website that uses Smarty cache, and every time the cache is empty we log it. And for some reason the error started do decline in frequency on the 30th of January, and we haven't seen any error in February! Very strange cause we can't think of any changes we have done.

Anyway, just the other day I saw the same error on my own computer in development using OS X and Smarty 3 - so that's why I am not completely confident that the error is gone. But we will deploy our upgraded Site tomorrow - using Smarty 3 - and we will keep logging any empty cache file - so that will be very interesting.

[mohrt]

What do you use for a shared file system? I know I've seen spurious race condition problems with NFS cache before, but nothing that affected the end-user.

[Moggia]

Actually we don't use a shared file system. Instead we have built an cache overlay that broadcasts which file(s) should be cleansed on the local network.

[Moggia]

We are now done with deploying a painful (thousands of templates and lot's of things that didn't work anymore) upgrade to Smarty3!

And what we can see right now the problem with empty cache files are gone!



Thanks everyone for your input.