Parallel processing/forking in PHP to speed up checking large arrays - php

Question

I have a php script on my website that is designed to give a nice overview of a domain name the user enters. It does this job quite well, however it is very slow. This might have something to do with the fact it's checking an array of 64 possible domain names, and THEN moving on to checking nameservers for A records/MX records/NS records etc.
What i would like to know, is it possible to run multiple threads/child processes of this? So that it will check multiple ellements of the array at once, and generate the output a lost faster?
I've put an example of my code in a pastebin (so to avoid creating a huge and spammy post on here)
http://pastebin.com/Qq9qKtP9
In perl I can do something like this:
$fork = new Parallel::ForkManager($threads);
foreach(Something here){
$fork->start and next;
$fork->finish;
}
And i could make the loop run in as many processes as needed. Is something similar possible in PHP or any other ways you can think of to speed this up? The main issue is, cloudflare has a timeout, and often it will take long enough CF blocks the response happening.
Thanks

Answer 1

* Never Mind Support !! *
You never want to create threads (or additional processes for that matter) in direct response to a web request.
If your frontend is instructed to create 60 threads every time someone clicks on page.php, and 100 people come along and request page.php at once, you will be asking your hardware to create and execute 6000 threads concurrently, to say nothing of the threads used by operating system services and other software. For obvious reasons, this does not, and will never scale.
Rather you want to separate out those parts of the application that require additional threads or processes and communicate with this part of the application via some kind of sane RPC. This means that the backend of the application can utilize concurrency via pthreads or forking, using a fixed number of threads or processes, and spreading work as evenly as possible across all available resources. This allows for an influx of traffic; it allows your application to scale.
I won't write example code, it seems altogether too trivial.

Answer 2

The first thing you want to do is optimze your code to shorten the execution time as much as possible.
For example, instead of making five dns queries:
$NS = dns_get_record($murl, DNS_NS);
$MX = dns_get_record($murl,DNS_MX);
$SRV = dns_get_record($murl,DNS_SRV);
$A = dns_get_record($murl,DNS_A);
$TXT = dns_get_record($murl,DNS_TXT);
You can only call dns_get_record once:
$DATA = dns_get_record($murl, DNS_NS + DNS_MX + DNS_SRV + DNS_A + DNS_TXT);
and parse out the variables from there.
Instead of outright forking processes to handle several parts concurrently, I'd implement a queue that all of the requests would get pushed into. The query processor would be limited as to how many items it could process at once, avoiding the potential DoS if hundreds or thousands of requests hit your site at the same time. Without some sort of limiting mechanism, you'd end up with so many processes that the server might hang.
As for the processor, in addition to the previously mentioned items, you could try pecl/Gearman as your queue processor. I haven't used it, but it appears to do what you're looking for.
Another method to optimize this would be implementing a caching system, that saved the results for, say, a week (or whatever). This would cut down on someone looking up the same site repeatedly in a day (or running a script on your site).

Answer 3

I doubt that it's a good idea to fork with PHP the apache process. But if you really want there is PCNTL (which is not available in the apache module).
You might have more fun with pthread. Nowadays you can even download a PHP which claims to be threadsafe.
And finally you have the possibility to use classic non blocking IO which I would prefer in the case of PHP.