Clear gettext cache of PHP-Apache Server to apply .mo updates

Question

Although many questions on SO already relate to this, they're A) pretty old and B) I felt that it's better to ask about this here, as it seems to be related to some server-level, and not programming-level, cache.

The problem is that our server, using Apache and PHP, uses gettext with the .po and .mo files, in the native confoguration, that is using bindtextdomain with the folder structure:

translations/
    en_GB/
        LC_MESSAGES/
            mydomain.mo
    fr_FR/
        LC_MESSAGES/
            mydomain.mo

to for example load english and french translations for the mydomain text domain. Loading the translations to the server and using them for the first time with PHP's native gettext(), _(), etc. functions works, all good. The problem is that, when we update our .mo files with new translations, these updates are not applied. Several sources state that the apache server has to be restarted to flush the gettext cache:

• SO
• GNU
• Lingohub

etc.

Is it still true to the current date that gettext caches of a Apache-PHP application can exclusively be flushed by restarting the apache server? Is there no other approach to do this? Consider that we have a managed VPS-hosting, hence no root access & we're not allowed to restart Apache on our server.

I know that you could theoretically implement a logic which adds timestamps of your modifications to the domain name mydomain, but according to this post here, "changing the domain to get rid of the cache problem [...] will create lots of out-of-date cache in memory.", so I'm wondering if that approach is actually viable.

PHP is running as php-cgi on our Apache server. I've also noted now that the LC_MESSAGES folders contain a .nfs.... file which I am seemingly unable to delete (if I delete it, it simply reappears). Could this indicate that my .mo files have been reopened / accessed by some app, not closed, and thus cause some kind of unwanted translation cache?

Answer 1

I've been reading on multiple places that this gettext cache should not be such of a big problem if PHP is not running as an Apache module on your server (and in my example, PHP's running as FastCGI). And indeed, the problem was actually a different one:

• After listing all locales available on my Apache server via locale -a, I've got to see that the names of the available locales all include the encoding in their name. So instead of e.g. en_GB and fr_FR, the locales are en_GB.UTF-8 and fr_FR.UTF-8.
• I thus adapted the folders from being the above-mentioned ones:

translations/
    en_GB/
        LC_MESSAGES/
            mydomain.mo
    fr_FR/
        LC_MESSAGES/
            mydomain.mo

To these:

translations/
    en_GB.UTF-8/
        LC_MESSAGES/
            mydomain.mo
    fr_FR.UTF-8/
        LC_MESSAGES/
            mydomain.mo

Then, everytime I Update the contents of my .mo files, I just login via ssh and run:

killall -9 php-cgi

And the new translations are properly loaded. Note that neither an Apache Restart nor root access is needed to do this. But note that the command:

killall -9 php-cgi

Had no effect before I included the encodings in the locale folder names; so it seems that the locale folder names (and the locales you specify when loading textdomains in PHP) must be in the same form as the locale names on your server, obtained via locale -a.