[Performance] Mention cachetool for clearing opcode caches?

[apfelbox]

In the performance article, the section about byte code caches mentions the problem with clearing the APC/OpCache from the CLI.

The article mentions a working, but rather impractical way:

You either need to restart the web server or call the apc_clear_cache() or opcache_reset() functions via the web server (i.e. by having these in a script that you execute over the web).

If you are running PHP via FCGI (like FPM) you can use the cachetool to send the cache clear command directly via the FCGI protocol. That prevents exposing a publicly callable cache-clear script (which might be a DDoS attack vector).

So my question: would be beneficial to mention this tool here as a better solution to this problem?

[xabbuh]

I haven't seen the tool before. Did you use it? If so, what's your experience with it?

[apfelbox]

I have used it and it works reliably and is very easy to use.

It sends request directly via FCGI, so that you can run several PHP commands in the web server PHP pool (instead of the CLI php).

Practically all our dev & production deployment scripts contain now:

FCGI_PORT=9100
cachetool --fcgi="127.0.0.1:$FCGI_PORT" stat:clear
echo "Stat cache cleared."
cachetool --fcgi="127.0.0.1:$FCGI_PORT" opcache:reset
echo "Opcache cleared."
cachetool --fcgi="127.0.0.1:$FCGI_PORT" opcache:status
echo "done."

It is a big step up from putting a publicly reachable PHP script in your app that is called via cURL on deployment.

[xabbuh]

Looks like it could make sense to document this tool. What do the other @symfony/team-symfony-docs members think?

[javiereguiluz]

👍 clearing the OPCache is a must and the current solutions (graceful web server restart or fake page loading calling opcache_reset()) are not entirely satisfying. The mentioned tool looks popular and mature enough to me.

[HeahDude]

Great, let's do this! @apfelbox will you open a PR? Thanks!

[plandolt]

I think beside giving the community the information about this tool and how to clear the opcache nicely we could also spread the information about atomic deployments. @jwage did some nice findings on this with nginx using $realpath_root without the deprecated AppClassLoader (see https://twitter.com/jwage/status/930862249648025600 and https://twitter.com/jwage/status/930992190947504128).

[javiereguiluz]

Fixed by #9107.