[brentroose]

A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds. This optimization process with so much fun, and so many people pitched in with their ideas; so I eventually decided I wanted to do something more.

That's why I built a performance challenge for the PHP community

The goal of this challenge is to parse 100 million rows of data with PHP, as efficiently as possible. The challenge will run for about two weeks, and at the end there are some prizes for the best entries (amongst the prize is the very sought-after PhpStorm Elephpant, of which we only have a handful left).

I hope people will have fun with it :)

[Tade0]

Pitch this to whoever is in charge of performance at Wordpress.

A Wordpress instance will happily take over 20 seconds to fully load if you disable cache.

[rectang]

Are you talking about a new, empty WordPress instance running the default theme? Because if so, that doesn't match my anecdotal experience.

If you're talking about a WordPress instance with arbitrary plugins running an arbitrary theme, then sure — but that's an observation about those plugins and themes, not core.

As someone who has to work with WordPress, I have all kinds of issues with it, but "20 seconds to load core with caching disabled" isn't one of them.

[embedding-shape]

Microbenchmarks are very different from optimizing performance in real applications in wide use though, they could do great on this specific benchmark but still have no clue about how to actually make something large like Wordpress to perform OK out of the box.

[tracker1]

Wordpress is something that I cannot believe hasn't been displaced by a service that uses a separate application for editing and delivery.

It seems like something like vercel/cloudflare could host the content-side published as a worker for mostly-static content from a larger application and that would be more beneficial and run better with less risk, for that matter. Having the app editing and auth served from the same location is just begging for the issues WP and plugins have seen.

[monkey_monkey]

That's often a skill issue.

[rkozik1989]

Much like anything else your performance is going to vary a lot based on architecture of implementation. You really shouldn't deploying anything into production without some kind of caching. Whether that's done in the application itself or with memcached/redis or varnish or OPcache.

[The_President]

I’ve long since abandoned WP but this seems like an SQL resource issue as it bogs up against the oom reaper dealing with no swap. WordPress is like a mid level V6 Kia with all the options and a huge aftermarket.

[gib444]

> A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds

That's a huge improvement! How much was low hanging fruit unrelated to the PHP interpreter itself, out of curiosity? (E.g. parallelism, faster SQL queries etc)

[brentroose]

Almost all, actually. I wrote about it here: https://stitcher.io/blog/11-million-rows-in-seconds

A couple of things I did:

- Cursor based pagination - Combining insert statements - Using database transactions to prevent fsync calls - Moving calculations from the database to PHP - Avoiding serialization where possible

[Joel_Mckay]

In general, it is bad practice to touch transaction datasets in php script space. Like all foot-guns it leads to Read-modify-write bugs eventually.

Depending on the SQL engine, there are many PHP Cursor optimizations that save moving around large chunks of data.

Clean cached PHP can be fast for REST transactional data parsing, but it is also often used as a bodge language by amateurs. PHP is not slow by default or meant to run persistently (low memory use is nice), but it still gets a lot of justified criticism.

Erlang and Elixir are much better for clients/host budgets, but less intuitive than PHP =3

[NorwegianDude]

Fun challenge, but running the benchmark on Apple hardware is a weird decision as Apple doesn't even have server hardware. Would make much more sense to run it on a dedicated Linux box as that is more accessible and more realistic.

[contingencies]

Hehe. Optimization ... it's a good way to learn. Earlier in my career I did a lot of PHP. Usually close to bare.

Other than the obvious point that writing an enormous JSON file is a dubious goal in the first place (really), while PHP can be very fast this is probably faster to implement in shell with sed/grep, or ... almost certainly better ... by loading to sqlite then dumping out from there. Your optimization path then likely becomes index specification and processing, and after the initial load potentially query or instance parallelization.

The page confirms sqlite is available.

If the judges whinge and shell_exec() is unavailable as a path, as a more acceptable path that's whinge-tolerant, use PHP's sqlite feature then dump to JSON.

If I wanted to achieve this for some reason in reality, I'd have the file on a memory-backed blockstore before processing, which would yield further gains.

Frankly, this is not much of a programming problem, it's more a system problem, but it's not being specced as such. This shows, in my view, immaturity of conception of the real problem domain (likely IO bound). Right tool for the job.

[ge96]

5 days to 30 seconds? What kind of factor/order of magnitude is that damn

What takes 5 days to run

[hosteur]

Poorly made analytics/datawarehouse stuff.

[slopinthebag]

One query per column per row

[CyberDildonics]

Using a language that is 100x slower than naive native programs to do a "speed challenge" is like spending your entire day speed walking to run errands when you can just learn how to drive a car.

[lofaszvanitt]

Do not update the leaderboard.... at all.

[user3939382]

exec(‘c program that does the parsing’);

Where do I get my prize? ;)

[brentroose]

The FAQ states that solutions like FFI are not allowed because the goal is to solve it with PHP :)

[onion2k]

A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds.

When people say leetcode interviews are pointless I might share a link to this post. If that sort of optimization is possible there is a structures and algorithms problem in the background somewhere.

[nicoburns]

I find that these kind of optimizations are usually more about technical architecture than leetcode. Last time I got speedups this crazy the biggest win was reducing the number of network/database calls. There were also optimisations around reducing allocations and pulling expensive work out of hot loops. But leetcode interview questions don't tend to cover any of that.

They tend to be about the implementation details of specific algorithms and data structures. Whereas the important skill in most real-world scenarios would be to understand the trade-offs between different algorithms and data structures so that you pick an appropriate off-the-shelf implementation to use.

[tuetuopay]

Well leetcode asks you to implement the data structure, not how and when to use which data structure. I don’t need to know how to implement a bloom filter on a whiteboard off the top of my head to know when to use it.

[slopinthebag]

Do you think they achieved that performance optimisation with a networked service because they switched from insertion sort to quicksort?