DNS Cache

I've been thinking about the need for speed. Phorum is very fast, but it can be made faster...On every forum post Phorum attempts a DNS lookup (if the installed PHP version supports gethostbyaddr, and dns_lookup is enabled) and if there are a lot of users posting, heavy network traffic, system load &c so you can be left waiting a short while for the post to be processed.

So, what I was thinking would be a good new feature in Phorum 5 would be a DNS cache (either standard built-in). I already have a hacked version of 3.4 doing this, using a table in the database, and it works very well and you certainly notice the difference on high-traffic systems.

Now, I have this as part of the base code, but was wondering what you guys thought? Add-on plugin or standard feature?

I'm not sure if thats really needed.
If you are really having speed-issues because of DNS-Lookups, then you could just disable this feature or (if its your own webserver) add a local dns-server which does caching on its own.

if you still want to add this, then I would prefer it as a plugin though I don't really know how to make a real mod of it. afaik there is only one place to change in post.php to call another function instead of the gethostbyaddr, right?

Yup! A few constants in .../constants.php and a function (phorum_dns_cache) in .../common.php

I must say that this is going a bit too far IMO. If your servers are having DNS issues, that is a problem to be solved by either turning off DNS lookups in Phorum 5 or fixing your server. I just don't see this as a thing that the core Phorum should do.

NOw, as for a module, this is how you do it ;)

Turn off DNS lookups. Write a module that hooks into the "post" hook that does the lookup (with caching) and replaces the value in the message before it is posted.